PDA

View Full Version : JBL 4520 speaker replacement.



Tube Radio
12-10-2016, 07:41 PM
The local skating rink I go to has four JBL 4520 cabinets used as subs.

One caused a woofer to self destruct by someone pushing frequencies under 30Hz through the cabinet at high levels and the horn unloaded causing the speaker to go into over excursion thusfore destroying itself.

I removed the blown driver and it is a Peavey Black Widow.

Pretty sure that is not a proper speaker for that cabinet.

What currently available driver would be a good choice for those cabinets?

The drivers are wired in parallel for a 4 ohm load, but I'm thinking a 16 ohm driver would be better as I would have an 8 ohm impedance per cabinet which will put less load on the amplifier.

robertg
12-11-2016, 06:31 AM
http://www.jblpro.com/pub/obsolete/Low_Frequency_Enclosures2.pdf

This will tell you, unless there is something newer that will work. I see lots of E140, 2220, and 2225 drivers for sale. The E145 is rare.

Tube Radio
12-11-2016, 08:18 AM
Ideally I would want a currently made driver if possible.

The cabinet with the black widows in it did actually sound ok, but not great. Seems like the bass under 40 Hz is not there much at all.

At another skating rink that has cabinets like these they had a pair of drivers in one cabinet that had concert on the dust caps. Now those sounded good and even had good bass under 40Hz.

If I cannot find a currently produced driver for these speakers I wonder if there's a car audio sub that will work?

Lee in Montreal
12-11-2016, 08:25 AM
The local skating rink I go to has four JBL 4520 cabinets used as subs.

That would be a first mistake ;-) The 4520 is NOT a sub. It is a bass cabinet. ;-)

The ideal woofer has a low Qts. The original 2205 had something like 0.2 and good old 2225 have 0.28

I suggest not to go with 2226 which is clearly a bass reflex driver (and it would require major eq to cut 100+ Hz)

Or sell the cabs and get bass reflex cabs with modern drivers requiring gobs of power to feed. ;-)

Tube Radio
12-11-2016, 09:15 AM
When the place was originally built they were most likely used as bass cabs, but I just call them subs because they are used like a sub would be.

In that case most currently produced pro audio subs should be considered bass cabs given most only go down to 40Hz :D

Ruediger
12-11-2016, 11:18 AM
<snip>

I suggest not to go with 2226 which is clearly a bass reflex driver (and it would require major eq to cut 100+ Hz)

</snip>

The 2226 is very similar to the 2225. The params fs, Vas, Qt are that similar that each of them can be used as a plugin replacement for the other.

Ruediger

Lee in Montreal
12-11-2016, 01:40 PM
The 2226 is very similar to the 2225. The params fs, Vas, Qt are that similar that each of them can be used as a plugin replacement for the other.

Ruediger

I currently have half a dozen units of each and find they don't sound alike at all. While I consider the 2225 a bass driver, the 2226 is more a mid bass driver with hyper "enthusiastic" midrange requiring a lot of eq to give any decent bass. Looks like there's more to a woofer than just T/S specs.

But hey, the OP is free to experiment. He may well try a set of 2226 woofers,but he still wont get 30Hz sub bass from that driver and that cabinet.

Lee

Tube Radio
12-11-2016, 03:09 PM
In the past I have seen some drivers listed as being designed for horn loaded cabinets and scoops so maybe one of those drivers will work?

I'll look up some tonight and post them here.

The crossovers used have a high pass filter of 25Hz. Will that be enough to protect the speakers from the low frequencies this cabinet cannot handle.

Tube Radio
12-12-2016, 09:15 AM
I looked online and found a thread on here from 2013 where a member used these woofers in the 4520 bass cabs he built

http://www.parts-express.com/dayton-audio-pa380-8-15-pro-woofer--295-034


Would that be a good choice?

More than likely I will power them with this amp as it has built in crossover and other processing things.

http://www.parts-express.com/yamaha-px3-power-amplifier-2-x-500w-at-4-ohms--247-6156#!

Lee in Montreal
12-12-2016, 09:40 AM
Fs is 31Hz and Qts is .27
And they are dirt cheap.

Why not try them? :)

But remember that by design those 30Hz cabinets have a 60Hz fundamental (where peak is).

Original 2205 woofers had Fs30Hz and Qts .20

4520 response

http://oi52.tinypic.com/29x6ly1.jpg

If you want some serious 25/30Hz sub bass cabs, you should perhaps look into building some Bertha horn loaded cabs w/ Levan horns. These will make you spill your guts on the dance floor. ;-)

http://a4.l3-images.myspacecdn.com/images01/24/dd88f6f52faa71570e995abfe1401241/l.jpg

Please, show us pictures of your 4520s... I had a set in my basement and loved them. But the restroom furnitures and cosmetics didn't agree on the floor above. ;-)

Tube Radio
12-12-2016, 10:03 AM
Very nice speaker stack there. :yes:



I will have to take some pictures next time I go to the skating rink.

The cabinets are in good shape. Just some wear and tear on the front bottom since these sit right at the edge of the skate floor.

I do plan on trying those drivers though. Will get two and see how they sound in one cabinet before buying more.


These will be paired with one BFI Bullfrog front horn loaded cabinet per bass cabinet which has a 15" driver and a slot port firing out the front and will be used from 120 Hz up to either 800Hz or if they will go to 1.7KHz that will be better as it will cut down on the cost of the driver needed to replace the compression drivers in the Yamaha 6115H horns.

The 4520 speakers will be used from 120Hz down to their lowest frequency. The amp does have settings for a high pass so I can easily set the high pass to whatever value works best with these cabinets to keep the woofers from reproducing any frequencies that will cause the horn to unload and damage the driver.

So basically I would need to set the EQ to reduce some of the 60Hz signal? Didn't read the manual completely, but I think that Yamaha amp may have an EQ in it. If so that will make setting it very easy.

Lee in Montreal
12-12-2016, 11:14 AM
You will have to boost 60Hz down to 30Hz. You can probably cut at 25/28Hz w/ a 48db/octave filter. The bass that people will hear is around 80Hz. Easy target. The bass people will feel is under 50Hz. That takes power and many cabs.

How many 4520 do you run in that skating ring? And how much bass do you expect? What type of music do you play?

Is that the Olympia ? If so, you may need many 4520s ;-) 8 maybe. or if you're enthusiastic about getting some great thumping bass, perhaps you could build some Berthas and load them with 18" 2242 drivers. A pair of these is all you need for such a large room... and you could keep on using whatever number of 4520 you already have.

On the picture below, I iinda see a pair of 4520s placed one of top of another. Maybe I am wrong. If you want to play lower, you should put the mouth of the cabs together. So, side by side to add mouth area. Four pairs of 4520s would be great. ;-)

http://www.olympiaskate.org/uploads/1/0/1/8/10188737/4719707.JPG

Tube Radio
12-12-2016, 12:32 PM
That isn't the one, but is in the city where I live.

They also use four JBL 4520 cabinets and they used Peavey SP-1 speakers at one point, but replaced three of the 8 with other newer Peavey speakers. Not sure how they were originally set up but back in the 80's when all 8 Peavey SP1 speakers and all four JBL 4520 bass cabs were working the sounded nice and had decent bass.

Their system is in need of work as well, but I contacted the owner a couple years ago and she wasn't interested.


The one I'm working on the sound system at can be seen here starting at 9:05 in the video https://www.youtube.com/watch?v=cbfF9ezn2mU Unfortunately they don't have any good pictures of the floor.

There are four 4520 cabinets.

Music they play is whatever is popular at the moment so mostly rap and hip hop.

I know I will not get bass down to 20Hz which is ok. Saturday when I got one of the bass cabinets working the bass from just two cabinets sounded ok, but I need to get the other two working. One measures infinite ohms on the wiring exiting the cabinet so either a wire on each speaker is disconnected or the drivers are open. The other cabinet as I mentioned in the first post caused a driver to self destruct. Suspect the other cabinets do not ave the proper drivers in them either.

The type of bass I'm looking for is more quality versus loud.

At the other skating rink one of their 4520 cabinets had two speakers in it that had CONCERT on the dust caps and it sounded pretty good in the lower bass, althoug I'm sure it didn't go down to 20Hz.

Whoever helps with their system replaced those with different drivers, although I don't know what brand and model.

I do know one cabinet may have the original or proper drivers in it and it sounds fairly good and was very natural sounding and better quality wise than most subs I've heard. Even though it doesn't go down to 20Hz what is there sounds so good. Sort of makes you forget the bass that is missing.

That I believe is the bass I'm aiming for.

Tube Radio
12-14-2016, 10:11 AM
I've got one more question.

Given these cabinets will be used for bass only, what is the optimum crossover frequency I should use between these and what I'm using for midbass-midrange?

I saw it mentioned where 120Hz was a good crossover point, but I forget the reasoning for that. Think it may have had something to do with the front and back waves cancelling each other out or something similar.

Also given the resonance is at 60Hz my thought is to decrease the output at 60Hz then do any necessary EQ of the lower frequencies to get as good sounding bass as possible while still being able to go loud enough without causing damage to the drivers or amp.

The amp itself is rated at 500 watts per channel into 4 ohms. Given I will be using two 8 ohm 500 watt drivers wired in parallel in each 4520 cabinet will one channel of the 500 watt amp be enough or does that mean I need an amp of 1,000 watts?

The Yamaha amp series I'm going with has the eq, crossover, delay, filters, limiter and front panel lock built in.

That will make it easy to

1. eq the cabinets
2. Provide proper crossover point between the bass cab and midrange/tweeter cab
3. Adjust the delay to time align the bass cab with the midrange/tweeter cab
4. Set a high pass filter for the 4520s so frequencies below where the horn unloads will not reach the drivers
5. Limiter will help keep the speakers from being overdriven.
6. Lock the front panel controls using a code so only authorized people can change any settings.

It also has a USB port so its settings can be saved to a thumb drive.

That way I can set up one bass cab and midrange/tweeter cab then transfer the settings to the other three amps.

Lee in Montreal
12-14-2016, 11:22 AM
Don't lower the 60Hz fundamental, raise 30-60Hz instead.

On the 4530, phase cancellation is 120Hz which is 3 times the horn lower freq. The 4530 has exceptional kick bass, but not much lower bass.
On the 4520, which is a 30Hz horn, the lower bass is much better but not much kick bass, and I suspect that phase cancellation happens at 90Hz. That's when the wave from the horn fights against the wave from the woofer. The best way to be certain is to use a calibrated microphone and REW - Room EQ Wizard (it's free).

BTW Whatever comes out of the cabinet'S mouth is 180 out of phase with the woofer.

http://www.roomeqwizard.com/

Tube Radio
12-14-2016, 01:16 PM
Oh ok. Do I need to set the crossover at 90Hz or will a higher crossover point work?

Also am I limited to 500 watts or is the wattage limit 1,000 watts since I will have two 8 ohm 500 watt drivers in parallel?

Now if the cabinet has any resonance at higher power levels how would I fix it?

I figure that once all the speakers are fixed I won't need to run as much wattage to the speakers.

Looking at the frequency response graph http://www.jblpro.com/pub/obsolete/Low_Frequency_Enclosures2.pdf it looks like there's a slight dip of around 3db around 150Hz.

Best thing for me to do is fix one cabinet then feed an audio generator through the amp and have a listen to frequencies 150Hz and below just to see what I'm dealing with.

That way I can hear any frequencies where there are issues and figure out the best way to work around those issues to get the best possible sound I can out of the bass cabs.

Lee in Montreal
12-14-2016, 02:09 PM
Hey buddy

If you are used to bass reflex cabinets, you have probably already realized that a lot of energy is wasted in absorption and that not much is actually output. Hence requiring big amps. Horns are way more efficient. All the energy sent to the driver is actually output. You will not need big amps to get good thumping. It is surprising to have loud music while the cone is barely moving. So, whatever amp you have picked will be good. Just make sure they never clip. Clipping = DC
Your crossover frequency will be determined with what will play on top of the 4520s.

Place your cabinets side by side to connect their mouth.

Tube Radio
12-14-2016, 02:38 PM
yes I'm used to bass reflex cabinets. Have two 1 cu ft ones with a 12" each in them in my home system and it takes lots of watts to keep up with the rest of the system.

Never had a proper horn loaded bass cab, but I have heard the ones at the skating rink you posted a picture of and one of the ones that was working properly did indeed sound very good to me.

So a 500 watt amp on each of four JBL 4520 cabinets loaded with the drivers I listed will go more than plenty loud enough for the skating rink?

What you said about it being surprising to have loud music with the cones barely moving really hits home as it brings to mind how if a low frequency at high wattage is played into the speaker below the frequency the horn unloads at the cone goes from barely moving to suddenly moving a lot and can indeed self destruct in short order.

Also if the cabinets should happen to vibrate should I put some bracing on the outside rear of the cabinets?

With the Yamaha amp I'm using I can set the limiting to where the system cannot go any louder than a certain point which will be good as that will protect the whole system from over powering and keep the system from being damaged by DJs who love to jack up the bass knob on the mixer.

In the case of the self destructing woofer I think the problem was the amp is way over powered for the speakers used which in normal cases is fine, but in the case of anyone and everyone having their hands on the mixer and the system being in disrepair one thing led to another and a woofer destructed itself.

Lee in Montreal
12-14-2016, 02:53 PM
If you run a digital crossover (which I suggest you do for better sound shaping and time alignment), you can set limiters.

On the amps, you can also probably set a 28/30Hz high pass filter to protect the drivers.

And set a new rules for your DJs... If they blow a woofer, they pay for it... ;-)

Tube Radio
12-14-2016, 03:25 PM
The Yamaha amps I'm going to recommend to the rink owner have built in DSP which will serve for the eq, crossover limiter and high pass filter for the woofers.

That way they don't have to buy separate equipment with knobs for people to dick around with.

No one will be able to dick around with the Yamaha amps as the whole front panel can be locked out with a code and the only ones who will know that code are me and the guy they have help with the sound system. Also with the settings stored on a thumb drive it will be easy to set it back to where it should be if someone should somehow figure out how to change things.

My plan is to volunteer time on Saturdays to show people how to run the sound system properly.

Concerning blowing speakers with the limiters and high pass it will be extremely hard to do, but I'm sure someone will find a way to do it anyways :banghead:

I'll mention to the owner that any equipment that breaks due to abuse should be paid for by whoever operated the mixer at the time it happened.

Lee in Montreal
12-14-2016, 04:24 PM
BTW if you have those on top, they shall be great. You can then probably crossover at 90Hz and get the kick bass out of the Bullfrog.

Then what's on top of those? ;-)

http://media.liveauctiongroup.net/i/13488/13727913_2.jpg?v=8CF4795F85BE340

http://media.liveauctiongroup.net/i/13488/13727913_1.jpg?v=8CF4795F85BE340

Tube Radio
12-14-2016, 05:43 PM
That's the speakers which will be on top of the 4520s.

On top of those will be a single Yamaha 6115H horn with Eminence PSD2002S-8 drivers with 1" to 1.4" adapters.

The speaker stack is like this

Yamaha horn
Bullfrog
4520

Sadly the two Yamaha horns I opened were minus the original drivers and I found one in a storage closet minus the diaphragm.

So the crossover between the Bullfrog and Yamaha horns will need to be 1.6KHz which is easily taken care of by this http://www.parts-express.com/eminence-pxb2-1k6-2-way-speaker-crossover-board-1600-hz--290-634

I'm tempted to use the higher power Yamaha amp for both woofers in the 4520 and use the smaller Yamaha amp and have it three way active, but I don't think the rink owners can afford that plus that's just more to get miss adjusted and there will be no tweeter protection, whereas that Eminence crossover has tweeter protection.

What I will do when I get it all together is play the system as loud as it should ever go then set the limiters on each amp to prevent it from going over that loudness level.

I can see why the rink chose those components. They are very efficient and don't require a lot of watts. One amp was most likely an original one and it was a Yamaha only rated at 85 WPC, but it had went out and was not used. Goes to show that efficient speakers don't need much power to go loud.

Will definitely experiment with the crossover point between the 4520 and Bullfrog.

Sadly there isn't much info at all online about those particular Bullfrog speakers.

Now I did find a complete minus the driver Bullfrog cabinet in a storage closet. Now if I could find the other three Bullfrog cabinets and the other four Yamaha horns I could recreate their whole original sound system only better due to the new Yamaha amps. I wouldn't even need any more amps as I can just parallel two of the Yamaha Bullfrog cabinets on each amp channel.

Also I think that Yamaha amp has a setting to adjust impedance. Not sure what that's for unless it is to let the processing circuitry know what impedance the amp has to drive so it can optimize the amp section to the load impedance.

Now the Bullfrog cabinets do have drivers in them, but I don't know what they are yet. If the drivers are not good the one 4520 had two Peavey Black Widow woofers in it (one self destructed) and I suspect there may be more of them. If I find four Black Widows in proper working condition would those be good for the Bullfrog cabinets? If so that would save them $319 in costs.

The only thing that concerns me about using the Dayton Audio drivers in the Bullfrog cabinets is the frequency response graph towards the 1.6KHz crossover point where the off axis response starts to be different than the on axis response. Suppose the front loaded horn might take care some of the issues provided the horn can load the driver at that high of a frequency as the Bullfrog cabinets were most likely originally crossed over at 800Hz based on the Yamaha compression driver's listed frequency response.

I am thinking of mounting the amps on top of the Yamaha horns so that they are easily accessible and in the air conditioned part of the rink, but I don't know if I should.

Crossing over the Bullfrogs at 90Hz may be better because I may not need to eq below 60Hz as strongly.

Lee in Montreal
12-14-2016, 07:09 PM
Well, the 15" drivers in the Bullfrogs might hardly reach 1.6KHz. Even a clean 1Khz might be a challenge. It seems your Yamaha horns are quite incomplete. Compressors without diaphragms are literally worthless. May I suggest another combination on a budget.

Two stations.

Each station comprises two 4520 scoops side by side. Two bullfrogs (great for snare drum snap), one on top of the other. Maybe even only one single Bullfrog per station. And a JBL 2360 horn on top with 2" throat compressor. That shall be a simple 3-way system. And I suggest a digital crossover.

One big amp feeds two 4520 on 4 Ohms (one amp per 4520 is better but more costly). One medium size amp used assymetrically : one channel feeds the Bullfrog. The other channel feeds the 2360 horn. Both amps located by the stations.

The 2360 horns are usually cheap to get as they are huge and can hardly be shipped. They are basically cinema hardware that often gets crushed. The 2360 is designed for 500Hz and up. Pretty good until 12Khz. In your case, it could run from 800Hz.

http://img.photobucket.com/albums/v668/Lee_Vuong/JBL%20parts%20factory/NiceStack.jpg

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=52814&d=1315626311


Here's an eBay ad for some JBL 2360 horns. Usually, you get to pay half that price. Also, 2445 compressors with original diaphragms are usually quite cheap at $200.00usd a pair.

http://www.ebay.com/itm/JBL-LARGE-31-Speaker-Horn-Mounting-Hardware-Loudspeaker-2360-2506A-60962-VTG-/351919241493?hash=item51f0057915:g:Nd0AAOSwXeJYEq5 n

http://i.ebayimg.com/images/g/Nd0AAOSwXeJYEq5n/s-l1600.jpg

Tube Radio
12-14-2016, 07:56 PM
I like that, but the problem is cost and space.

The next time I go there which may be after Christmas I may see if I can test one of the Bullfrog cabinets and see how high in frequency it will go.

If it will do 1.6KHz and sound good that will be good, but if not I will need a good 1.4" compression driver.

Would this driver work?

http://www.parts-express.com/eminence-psd-3014-8-14-titanium-compression-driver-8-ohm-4-bolt--290-566

Maybe eventually as they get more money I can add this Yamaha amp to each speaker stack which will get me the digital crossover I need. It would be used for the 4520 cabinets.

http://www.parts-express.com/yamaha-px5-power-amplifier-2-x-800w-at-4-ohms--247-6157

Lee in Montreal
12-14-2016, 08:34 PM
If you've noticed, this is a Lansing forum. We can hardly recommend a crappy eminence or Yamaha driver over a much better JBL 2240-41-45-50-51 compressor...

BTW The Eminence's claim of 800-20KHz is perhaps far fetched too... :eek:

Tube Radio
12-15-2016, 02:04 AM
Will have to look up those drivers

EDIT:

Just looked up those drivers.

Those are low frequency drivers at least that's what I saw when looking them up.


Everything is all set. Talked to the owner's daughter today and her dad doesn't quite have the money right now to put into the sound system.

short_circutz2
12-17-2016, 09:49 AM
If you've noticed, this is a Lansing forum. We can hardly recommend a crappy eminence or Yamaha driver over a much better JBL 2240-41-45-50-51 /snip/

Considering Eminence is one of, if not the largest, oem manufacturer of speakers, they are a good alternative for a temporary solution if you are looking to properly restore the equipment with JBL or Altec components once the $$ is available. It's not that their components are "crappy"...it's an option Ive had to use in 9ne club here I've worked with for the last 25 years. I had to replace 6 15" speakers in some Martin 115 bins that were i itially loaded with JBL 2225. I wasn't about to get the owner to shell out for 6x 2226 speakers, and reloaded them with Eminence units suitable for horn loading, which performed well.

Cerainly not up to what I would accept from JBL. But the alternative at the time was having 6 empty bins that couldn't be used.

I understand the whole "not gonna recommend" because it's not JBL, but unfortunately, some of us arent made of $$ and have to look to alternatives. I'd love to have a full SRX800 series of foh stacks and stage monitors...but alas. Will have to make do with homebrew monitors loaded with E140 and eminence horns/drivers and non standard double 18 cabs that hopefully will work with the 2242 speakers I just scored on a few weeks ago.

Tube Radio
12-17-2016, 11:13 AM
Agreed.

If it were for myself I'd get JBL drivers as I wouldn't abuse them.

Given this is for a skating rink I hesitate to use the JBL drivers as I'm sure the system will be used and abused.

Lee in Montreal
12-17-2016, 12:32 PM
Considering Eminence is one of, if not the largest, oem manufacturer of speakers, they are a good alternative for a temporary solution if you are looking to properly restore the equipment with JBL or Altec components once the $$ is available. It's not that their components are "crappy"...it's an option Ive had to use in 9ne club here I've worked with for the last 25 years. I had to replace 6 15" speakers in some Martin 115 bins that were i itially loaded with JBL 2225. I wasn't about to get the owner to shell out for 6x 2226 speakers, and reloaded them with Eminence units suitable for horn loading, which performed well.

Cerainly not up to what I would accept from JBL. But the alternative at the time was having 6 empty bins that couldn't be used.

I understand the whole "not gonna recommend" because it's not JBL, but unfortunately, some of us arent made of $$ and have to look to alternatives. I'd love to have a full SRX800 series of foh stacks and stage monitors...but alas. Will have to make do with homebrew monitors loaded with E140 and eminence horns/drivers and non standard double 18 cabs that hopefully will work with the 2242 speakers I just scored on a few weeks ago.

Crappy : What do you think of a company that claims 800-20khz from his driver when basically only TAD and their very pricey units can achieve this performance, or a JBL driver with expensive Berylium diaphragm. Reminds me of Radio Shack.

Alternatives were given to buy used JBL drivers at equal (or lower) price. Per exemple JBL 2445 with their original Titanium diaphragms often sell locally for $200.00cad a pair (that's $150.00usd for TWO). Why would I pay more (each) for some Eminence drivers? i was not bashing him for using Eminence or any other brand. Just not recommending it after I showed there are better solutions.

Lee

Tube Radio
12-17-2016, 03:19 PM
Given how big Eminence is especially with the OEM market I doubt they would claim their driver can do something it cannot do.


Also if these were mine I would use JBL, but I cannot see risking JBL drivers in a situation where they can and probably will be abused.

Sure the Yamaha amp I'm going to use has limiters, but with the passive crossover I'd be limiting the power to the bullfrog cabinets and unless the max power level the Bullfrogs need to fill the place with sound is less than the max power level the compression drivers can take, they can still be damaged.

Now when the owner gets enough cash if there are four JBL drivers available I might look into getting them, but they will need to fit a 1.4" throat and play up to 16KHz.

It's more about making the system as robust as I can while still sounding good.



It's gonna be nice to have all this high quality sound with the 15" drivers barely moving :D

Tube Radio
12-31-2016, 10:21 PM
Posting about this has really made me want a couple of these for my own stereo and makes my 12" subs seem quite inadequate, but I don't have the space.

Lee in Montreal
01-01-2017, 05:48 AM
Let us know how you are progressing with the rink's sound system.

Tube Radio
01-01-2017, 07:28 AM
Unfortunately I cannot do anything until they get the money to put in the sound system.I do agree on using two amps per speaker versus a single amp and passive crossover.

Tube Radio
02-21-2017, 04:06 AM
Time for a much needed update.

Had some bad news that the rink was closing for good after this past Sunday night session which it did do.

The good news is that in talking to someone associated with the rink they have someone lined up to possibly buy the rink and I told the person I'd offer to help the new owner in any way I can so it is still possible for the sound system to be realized.

Going to present the new owner with two options.

1. Two amps per speaker stack no passive crossover for $5,380.32
2. One amp per speaker stack with a passive crossover for $3,780.32

Tube Radio
02-22-2017, 05:30 AM
What I might do is this. Get one woofer and one horn driver and try the 800Hz passive crossover just to see how it sounds. If it is good enough then I may go with that option in order to save the new owner some money as there's a lot he/she will need to do to the rink and that will cost a lot of money.

That said later on the system can be upgraded with separate amplifiers for the Yamaha horns when the owner has the money.

Another thought is this.

Use one amp per speaker for the 4520 and Bullfrog then use one amp per pair of speakers to drive the Yamaha horns. That way only 6 amps are needed versus 8.

Also if the drivers in the Bullfrogs are good I may not replace them, but I will see if the drivers have a number I can look up to find the maximum power they can handle. That way I'll know if I still need to replace them. I know that most likely the system will never run over 100 watts of output, but at the same time the system needs to be fairly idiot proof.

I will talk to the new owner and perhaps work out some sort of guidelines for using the PA such as only allowing people who know what they are doing to operate the PA and having it to where if something breaks and it is determined to be from abuse, whoever was supposed to be operating the PA at that time would pay for the necessary repairs. I would also suggest to the owner that he/she put it in writing and make each employee and guest DJ sign a copy.

Tube Radio
02-26-2017, 07:29 AM
A further update. :(

Found out the building had went into foreclosure and that the owner took all the sound system stuff claiming it was his.

Don't know the legality of what he did given he isn't the original owner and didn't buy the stuff with his own money, but if the potential new owner can't get it all back I'll have to start over from scratch on building the system.

My temptation is to have some 4520 cabinets built with modified plans that extend their low end down lower than the stock cabinets.

Then perhaps have some JBL midbass horns built and find some 811B horns unless another horn would be better.

Is that a good idea or would something else be better?

What I don't know is if the owner took the empty Bullfrog cabinet. If not it could be possible to have a good speaker box builder duplicate it.

Lee in Montreal
02-26-2017, 07:47 AM
Build a set of Berthas with Levan horns. They house two 18" each. Load them with JBL 2442 woofers. They are the best bass horns on earth. Make a little internet search. ;-)

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=53040

https://s-media-cache-ak0.pinimg.com/736x/e6/35/1b/e6351b78f70174817dcc325e86f07136.jpg




http://www.dancetech.com/aa_dt_new/pa/plans/EAW_BH882.jpg

Buy four 4530, not two 4520. The single 4530 has a much better kick than the 4520. Those are dirt cheap on the used market and not worth wasting time building.

Tube Radio
02-26-2017, 08:27 AM
That would work, but space is limited so I'd have to stick close to what was there or smaller.

Now of course if I can find some 4520 cabinets used that would be good.

Now concerning the bullfrogs if a similar Jbl horn loaded midbass cabinet is readily available used I might go that route.

Lee in Montreal
02-26-2017, 08:44 AM
If you want to reach (slightly) deeper with those 4520s, you will need to increase the perimeter of the 4520s mouth. That is done by placing them side by side. So, you'll need two cabinets per side.

If you build them, then nothing can keep you from adapting them for 18" drivers. Get some JBL 2240 with Fs30, they are usually quite cheap.

Lee in Montreal
02-26-2017, 02:17 PM
How to build 18" a superscooper. Have a CNC shop groove the side panels for you. You make 8 of them, grouped by 4 units for deep 30Hz bass.

4' tall x 2' wide x 2' 6" deep

https://www.youtube.com/watch?v=pYy-iitwY6I

Grouped 4 x 4
https://www.youtube.com/watch?v=UyMCbrECAow


http://the-key.enix.org/~krystal/hornplans.free.fr/wpimages/wpbee8bf10.jpg

http://the-key.enix.org/~krystal/hornplans.free.fr/wpimages/wpa8ed5f6e.jpg

http://the-key.enix.org/~krystal/hornplans.free.fr/wpimages/wpeaf2270b.jpg

http://the-key.enix.org/~krystal/hornplans.free.fr/wpimages/wp126ee95a.jpg

Tube Radio
02-26-2017, 02:50 PM
Very nice.

Will have to keep in touch with my contact and see if they get the sound system back and if not I'll present them with the option to build the cabinets or go some other direction.


If the sound system cannot be recovered and I do not have a Bullfrog cabinet to duplicate would building or finding some JBL 4550A speakers be ok for frequencies from 90-800Hz? If I have to build them would the same drivers I planned on using for the 4520 work for these?

Perhaps then for the treble horns some 511B horns with a good quality driver.

Tube Radio
03-01-2017, 05:57 AM
The new owner is just going to buy everything new so I'm going to present him with this idea:

Buying 4520 cabinets or building the ones you showed the plans for here.
Buying Altec 816 cabinets or building them from plans or if the empty Bullfrog cabinet is still there having someone duplicate it.
Buying 811B horns and some BMS 4550 compression drivers.

I could of course do a search for the Yamaha horns and buy them and the eminence drivers or perhaps find some other vintage horn that can load down to 800Hz and fit the BMS driver.

It may be easier if I were to use a super tweeter like some of the Altec three way cabinets used with the horn loaded woofer or perhaps find four of those cabinets with all the drivers.


I still am thinking of the 811B and Eminence PSD-2002-8 driver as I know that driver on that horn is flat from 1.2-16KHz, but I know the horn loaded midbass cabinets will not go up to 1.2KHz and as such that driver cannot be used.

That said if I do go with the 811B horns I will need to have them painted unless I can find four black ones.

I'm going to try and make a good case to the owner as to why new speakers aren't the best way to go far as ultimate sound quality is concerned.

1audiohack
03-01-2017, 06:20 AM
The new owner is just going to buy everything new....

I'm going to try and make a good case to the owner as to why new speakers aren't the best way to go far as ultimate sound quality is concerned.

This is very budget dependent.

Much has been learned in the 40+ years since all the enclosures talked about here were made and used. It seems for a time things got worse and the big old stuff really did sound better but those days are now past. There are point source boxes with well defined pattern control that will absolutely smoke the big old black stacks of yesteryear. I have lots of the old stuff and some of the new stuff and the old stuff almost never comes off the mezzanine anymore.

I have not been able to see in the pictures any details about where in the room and how the system is deployed. Do you have any pics with the lights on?

Is there a budget yet?

Barry. (Who is not an audio equipment sales person). :)

Tube Radio
03-01-2017, 07:18 AM
No budget yet.

Here's a video showing the speaker locations https://www.youtube.com/watch?v=8cNCbA3srl4

Also as seen in the video there are some speakers in the wall and hanging from the ceiling. Should I put speakers back in those locations or will one in each corner be enough?

The rink is the typical oval shaped skate floor and one speaker stack is in each corner.

I've thought about new speakers, but the older horn loaded speakers were so efficient and don't require much wattage to go loud.

I'd prefer to stay away from new speakers as the older speakers do sound so good.

If you have ever heard a JBL 4520 cabinet with the right drivers installed producing bass at extremely high levels with the cones barely moving you'll understand why I prefer to go vintage.

RMC
03-01-2017, 08:34 PM
With all due respect to my fellow members, I've seen some questionable technical stuff going by here...

I know a thing or two about these cabinets because many years ago I knew people who earned a living making those in their shop, as well as 4530, 4550, 4560 plus others and selling them to sound contractors. I've also been around these cabinets for as long as I can remember in clubs or other places, as well as having a lot of technical info in my library on them. By the way, I've read sometime ago (can't remember where) that JBL had supposedly sold the patent for these enclosures to Ampex ???

4520/4530 type of cabinets are rear loaded folded horns (13 ft. and 7 ft. respectively) basically designed for short-throw applications (e.g. clubs, discos). 4550/4560 type of cabinets are ported front loaded horns basically designed for long-throw applications (e.g. stadiums, outdoor concerts). None have deep bass.

"Mixing and matching" these two types of cabinets in the same stack in random ways, as seen on some pictures in this thread, doesn't make sense acoustically speaking, though different stacks for each type, at different locations (apart), could make sense to reach different audiences (close-by and further away people).

JBL's low-frequency enclosures document (see attached) is pretty clear on intended purpose of these cabinets plus on the go or no go issues related to bass frequencies, very interesting and will dissipate misconceptions about them. THEY ARE NOT SUBWOOFERS, contrary to popular belief, they are not designed to go deep (30-40HZ), but rather for efficiency and "punch" amplifying some part of low-frequencies giving impact to the beat in dance music. People routinely try to extract high level deeper bass from it than what it's really capable of. Proof in the Xmax of the most suitable JBL drivers: most limited at 5mm or less, far from subwoofer range. Therefore, to avoid busting other drivers and distortion a steep high-pass filter in the 40-50HZ is a must. EQ should then be applied as required with the 63HZ slider (no less). Better be safe than sorry...

George Augspurger (a former technical director at JBL) wrote about these speakers as far back as in 1962 (see attached) with construction plan and dimensions on page 3).

The widely used setup with with these short-throw cabinets in the 70's and 80's was with 2205 woofers which I have original (obsolete) replaced by the 2225 (obsolete) now replaced by the 2226... not the same T/S parameters but the nearest JBL has in the catalogue... Moreover, a number of guys did load these short-throw cabinets successfully with the higher efficiency/sensitivity K-140/E-140 musical instrument bass driver since the parameters of the 2205 and K-140/E-140 were pretty close. Be aware the latter has a more rising mid response for bass guitar sound harmonics, hence a 100 db sensitivity rating compared to 97 db for 2205 but has a flatter response. These drivers were made for smaller volumes (e.g. inside 4520/4530).

The rest of the usual setup was JBL's 2440 horn driver/2390 folded-plate or more often 2395 slant-plate acoustical lens, again for short-throw applications, and 2405 tweeters.

JBL's Acoustic lens family document along with their intended purpose is also attached here (see)

Again, mixing randomly long-throw radial horns with acoustical lens in very close proximity as seen in some pictures here is begging for trouble since it isn't acoustically wise... (see attached document by Augspurger also from 1962 ! , about acoustical lens and how they work). A LOT of people don't really know how these project sounds. Some pictures here in this thread show lens way up there on top of a tall stack of cabinets/drivers, a configuration more common for long-throw devices, probably thinking the slant-plates project sound downwards, which is not the case, thereby creating a sound coverage problem). Extremely clever horns made to increase horizontal dispersion !

As a general simple rule-of-thumb, for long-throw you want more directivity, while for short-throw you want more dispersion of sounds. Cinema sound/home theater sound is somewhat of an exception to this for reasons related to the perceived location of sound (like dialogue). John Eargle(RIP) from JBL wrote a short but interesting article on this. Klipsch's home theater speakers, with Tractrix horn, illustrate that point.

Finally, I'm not surprised the Peavey driver died since it may not have been suitable for this application, in addition to the fact that most people beat the hell out of these boxes. Before choosing, one must find something with comparable T/S parameters/specs, as I have done above re 2205/K-140/E-140. You should try to have two of the same driver in a 4520 cabinet for enhanced performance. Here in point form some notes on that: used 2205 same specs if original(?) but probably reconed to 2225, same specs?; used 2225 probably reconed, same specs?; new 2226 expensive, same specs?; used K-140 probably reconed (to E-140?), closest specs; used E-140 probably reconed, closest specs; used K-145/E 145 probably reconed, specs not far off. Most probable JBL candidate? E-140 i guess, for availability, if in good shape and $ ok.

I hope this helps you in getting a good old 4520 back in shape for a long time. I liked them. Regards,

Richard SORRY, GOTTA GO I'LL POST THE ATTACHMENTS TOMORROW.

Tube Radio
03-02-2017, 02:48 AM
I'll talk to the owner when he is ready to do the sound system and see if he wants to go with the 4520 or the version posted here that uses a single 18" driver.

I suppose some are using the 4520 as bass and the long throw cabinets as midbass perhaps.

Its nice that people have taken a design and improved on it. Shows that it was a good basic design to begin with.

I do agree the 4520 isn't a subwoofer.

I like how it sounds though. Brings sort of a realism to what bass it does produce and the bass sounds so natural and effortless probably due to less distortion and such because the speaker cones barely move while producing loud bass levels.

The other local rink has four and they sound ok.

One of theirs at one point was loaded with two drivers labeled concert on the dust caps. Probbaly car audio subs. That one would go deep far as bass response was concerned, but it didn't necessarily sound as natural as the other cabinets.

So here's what I'm thinking.

1. 4 of the 4520 or 8 of the 18" version for the bass
2. 4 bullfrog or Altec 816 cabinets or 8 of the same for 90-800Hz
3. Horns for the treble 800-16KHz
4. New Yamaha amps with built in DSP.
5. Either a passive crossover on the midbass and treble horns or double the amps and the built in active crossovers.

EDIT:

Now if I build the 18" version of the 4520 what frequency should the speaker be crossed over at?

Also what driver should I use since the PD-1850 is not available in the USA?

Lee in Montreal
03-02-2017, 09:24 AM
Your challenge will be with your choice of horn/driver for 800Hz-16Khz
I suggest you look at the JBL 2360. It will do that. Easily.

BTW Contrary to what was pretended in the post before yours, the 4520 doesn't have a 13ft horn. Who ever wrote that never had or worked with these cabs. They are 8ft vs 7ft for the 4530. Which is why they shift the pass band slightly lower. Gaining a bit of bottom end, loosing a lot of kick. ;-) 8ft horn is 35Hz cut-off and peak at 88Hz (frequency of the "round" bassline) with phase reversion at 105Hz. While 7ft is 40Hz w/ peak at 100Hz The frequency of the kick) and phase reversion at 120Hz

BTW Here's what I had in my basement. Therefore talking from experience and recognizing what these cabs are, and what they are not. ;-)

http://img.photobucket.com/albums/v668/Lee_Vuong/JBL%20parts%20factory/DSCN0929.jpg

http://img.photobucket.com/albums/v668/Lee_Vuong/JBL%20parts%20factory/DSCN0925.jpg

Which is why I suggested that if you want really deep bass from a bass horn, you will have to go BIG and build some Berthas as they reach an easy 25Hz with the long Levan extension. You need to experiment by yourself before starting to give advises to that investor. So, go out and listen to as many systems as you can... And remember that what as great for 1984' music might not fit in 2017 ;-)

RMC
03-02-2017, 10:30 AM
Sorry, I have not been able to post the attachements, I have tried many ways as indicated on the site but it just won't work... If you have an e-mail address I can forward them directly to you for posting if you wish.

As for Lee's comment about the length of the 4520 folded horn, he should read what the designer/manufacturer of that horn says: JBL, Professionnal Series, Low frequency Enclosures, dated May 1980, page 2 where it specifically states " Model 4520 dual driver horn, thirteen-foot folded horn ..." Yep ! At the same time having a look at the frequency responses provide by JBL for 4520 showing it is already down -5db at about 42-3HZ, -10db at 37-8HZ and -15db at 32HZ ... JBL also warns about excessive cone excursion and possible damage, suggesting power input be restricted at very low frequencies. Is Lee pretending to be more knowledgeable or smarter than JBL Engineering ?

Richard

Tube Radio
03-02-2017, 10:57 AM
Lee, my plan is to go with the 18" scoop you posted the plans to and do two per speaker stack as you suggested. That would get me to 30Hz and I can set the high pass crossover of the Yamaha amp at that frequency. I will need a suitable driver for that cabinet though as the one recommended on the plans isn't available in the USA.

For the 800-16KHz frequency range in a thread I started about the 811B horn (fairly easy to get for not much money on ebay) someone mentioned the BMS 4550 as a suitable driver.

I have indeed heard some 4520 cabinets at the other local skating rink and they sounded good far as bass goes. They did not reproduce the extreme low bass though, but still sounded great.

Figure 30Hz with two of those super scoopers per stack is plenty low enough for a skating rink.

I've been to many different skating rinks and what always sounded best to me were the ones with the older systems.

The current rink I'm designing the system for I went to about 5 years ago when everything worked and I thought the 4520s sounded so good.

In a way I think the quality of the bass somewhat makes up for what isn't being reproduced due to the 4520s not going low enough.



EDIT:

Ebay is my friend.

Found four 811B horns and four 4560 cabinets. Without drivers of course.

Forwarded the info to the new owner to see if he wants to buy them.

If so the horns and midbass will be taken care of.

All that will be left is to build the super scoopers.

RMC
03-02-2017, 04:36 PM
From the latest pictures provided by Lee of his former 4520 cabinets, the black glue job on the dust caps is a sign that something went wrong... Dust caps were probably cut open for some reason. Are these 2205 reconed to 2225 ? Or 2225-6 repaired ? Or rotten foam or other debris removed from the gap? If 2225-6 drivers or 2205 reconed to 2225 then one must realize the parameters of the 2225-6 are different from the original intended driver for 4520 the 2205. The 2225 at 5 mm Xmax has a little more cone excursion which may explain why he could hit them harder (not much deeper) in the bass range (the 2226 has even more Xmax at 7.6 mm). The following example illustrates some evident differences in the following sequence (2205/2225/2226): Fs 30/40/40HZ; Qts .21/.28/.31; Vas 297 l/170 l/175 l. As can be seen the 2205 had a much lower Fs (free air resonance) and much larger Vas (suspension compliance equivalent volume). This is why I suggested a possible E-140 for replacement driver in addition to market availability...

With regards to the stacking issue "... my plan is to go with the 18" scoop... and do two per speaker stack ... That would get me to 30 HZ... Figure 30HZ with two of those super scoopers per stack..." The cruel reality is that if one cabinet doesn't go down to 30HZ then two won't go either, regardless of whishes. Speaker engineer Drew Daniels of JBL has explained that a long time ago in Modern recording Magazine. Moreover, the additionnal document, from John Eargle and Mark Gander both world-renowned engineers from JBL, I transfered to you (Tube radio) today was also for that purpose. Look at pages 5 and 6 in PDF numbers or pages 416-7 from the original Journal of the Audio Engineeering Society, more specifically Fig. 9 on page 416 and the "Mutual coupling" section on page 417 to realize that what you plan to get (deeper bass) by stacking two of the same cabinet doesn't exist. Same frequency respose but higher output, that's it, no further bass extention from mutual coupling or stacking. Sad but true... Sound is a science.

As for the 4560 enclosure your best bet is probably again the E-140 driver (but see JBL low-frequency enclosure document). Regards,

Richard

Lee in Montreal
03-02-2017, 05:05 PM
Dear RMC

I have absolutely no clue where you are going. Have you ever owned or measured a 4520, or are you just one of these internet experts? 8ft is what the horn is. :confused:

If you can get 12ft out of this horn, we have a new genius.

http://bilder.hifi-forum.de/medium/72163/jbl-4520-original-front-schnitt-600-pixel_77208.jpg

As for the dust caps missing or repaired from the 15" woofers, again, I have no clue what you're talking about. They are still there, and the coils never bottom out. :eek:

And BTW I really don't see what you're doing in this conversation. Do you have any background related to the topic that you wish to share with us?

BTW Junior member should learn how to behave... ;-)

1audiohack
03-02-2017, 07:42 PM
No budget yet.

If you have ever heard a JBL 4520 cabinet with the right drivers installed producing bass at extremely high levels with the cones barely moving you'll understand why I prefer to go vintage.

I have and I agree, they can sound good. I am a high efficiency guy too.

I am guessing it would be out of the budget but you could swing a single Danley J1-94 in a corner and never have to work on anything again. But what's the fun in that right? ;)

All the best,
Barry.

Tube Radio
03-02-2017, 08:47 PM
RMC, the cabinets would be side by side not stacked.

1audiohack
03-02-2017, 09:32 PM
Hi Tube Radio;

I want to clarify that I am not trying to talk you into, or out of anything.

I just know that there is some smashingly good sounding new stuff out there, that's all

Hope your fun continues.

Barry.

Tube Radio
03-03-2017, 03:39 AM
Agreed there are good new things out there, but to get as good as the vintage stuff would it cost more?

RMC
03-03-2017, 03:02 PM
Hi Justin,

Unfortunately for you, mutual coupling of identical bass cabinets means "closely spaced driving units", so no matter if it's on top, under or side by side... However, you will gain in output, though not in deeper bass.

I'm glad to have contributed relevant and valid info to help you make an informed decision, this is what this site is all about, regardless of whom/where it comes from. It's great to have many point of views and various sources of info before committing to such an important project. No one (including me) has exclusivity of knowledge or expertise. I hope the numerous documents I sent you will be helpful.

Finally, that my colleague "senior member" misbehaves himself by loosing his cool and politeness over other contrary contributions tells a lot, it's a very old trick used when painted in the corner or not having a valid argument to debate or undo well established facts: you attack the messenger... Doesn't bother me.

By the way, the length of the 4520 horn as stated by JBL does make sense if you really think about it, however one has to know how to calculate it too !

Regards,

Richard

Lee in Montreal
03-03-2017, 04:38 PM
Hi Justin,

Unfortunately for you, mutual coupling of identical bass cabinets means "closely spaced driving units", so no matter if it's on top, under or side by side... However, you will gain in output, though not in deeper bass.

I'm glad to have contributed relevant and valid info to help you make an informed decision, this is what this site is all about, regardless of whom/where it comes from. It's great to have many point of views and various sources of info before committing to such an important project. No one (including me) has exclusivity of knowledge or expertise. I hope the numerous documents I sent you will be helpful.

Finally, that my colleague "senior member" misbehaves himself by loosing his cool and politeness over other contrary contributions tells a lot, it's a very old trick used when painted in the corner or not having a valid argument to debate or undo well established facts: you attack the messenger... Doesn't bother me.

By the way, the length of the 4520 horn as stated by JBL does make sense if you really think about it, however one has to know how to calculate it too !

Regards,

Richard

Well. Where to start...

Placing 4520s side by side, or stacked on top of each other, as long as their mouth are together does use the coupling effect that raises the overall output, but it will also increase the output of the lowest frequency the horn can play. It is one of the rules from the Keele papers where the circumference of the mouth needs to equal half the wave length of the lowest frequency the horn can play. With its 8ft horn that allows 35Hz as the lowest frequency, the mouth's perimeter needs to be (344m / 35) /2 = 4,9m... Otherwise that 35Hz will be weak. 4,9 meter is far from what the mouth is with its 33" width (0.84m) and 28" height (0.7m) = 3 meters. Far from 4,9 meter... But put two 4520s together and the combined perimeter becomes 4.76 meters which is pretty close from half the 35Hz wave length and will get you that stronger 35Hz. This is exactly why bass horns are positioned in groups. To increase their combined mouth perimeter. Not just for coupling.

As for the 12ft horn of the 4520, if we agree that the 4530's horn is 7ft, then compare the drawings of a 4520 with the ones of the 4530, and let's try to find that 5 extra feet of horn. ;-) It is common knowledge among 4520 afficonados that JBL published a typo that time. ;-)

4530 - 7ft / 40Hz horn -

http://hornplans.free.fr/wpimages/wp991f9cd6_41.jpg

4520 - Where are the 5 extra ft compared to a 4530 ? ;-) If it were indeed a 12 ft horn, then the 4520 would be a 28Hz horn. Which it is obviously not.

http://bilder.hifi-forum.de/medium/72163/jbl-4520-original-front-schnitt-600-pixel_77208.jpg

Tube Radio, if you can make four groups of two 4520s in your rink, you can have fun. Put them in the corners to get some extra loading and they can sound great. You can find some well built 4520s for cheap these days. But perhaps you should have them built better than originally. Thicker outer panels and more bracing.

1audiohack
03-03-2017, 05:21 PM
Agreed there are good new things out there, but to get as good as the vintage stuff would it cost more?

For sure. Big vintage stuff can be had for pocket change.

I have not been in a roller rink in ages but don't remember any of them sounding too good. Loud is easy, multiple sound sources and lots of reflective surfaces act to degrade the sound quality.

For what it's worth, a single Danley J3-94, a 90 x 40 degree fully horn loaded box costs about $23,000. USD and you would need a sub for that one. It's been too long since I priced a J1-94 but they are more.

The only reason I brought it up was that just one of these will, eq'd to run with no sub in an enclosed space like yours would play way louder than any remotely sane person would ever tolerate and as such not be in danger of being damaged, and sound spectacular doing it.

I have one system comprized of RCA 9462 bass horns with Community M80 mid bass horns and Community RH60's that sound stunningly good. But, they are seven feet wide and 11 feet tall, and one J1 will best them in any metric, except cost. :)

I hope you get to play there again.

All the best,
Barry.

Tube Radio
03-06-2017, 07:11 AM
Lee, would it be better to pair two super scoopers versus two 4520s?

Sure I could probably buy some 4520s, but shipping would be expensive.

With the 4520s though I already know what driver will work, but for the super scoopers I have no clue what driver works unless I can import the drivers listed in the plans.

What I need to do is look at all the components I have selected and see how tall the speakers will be. If they are taller than a normal person it may be that I have to suspend the 811B horns from the ceiling or mount them to the cabinets at a downward angle.

1audiohack, many don't sound good, although I was in one in Atlanta GA a few years back that used older three way speakers that had an aperiodic chamber for the midrange (electro voice I think) and it blew me away with how good it sounded.

What I wonder is this.

If instead of building two super scoopers I have one built twice as wide and have both 18"s in the same cabinet would it be any better?

LOL wow the 4560s are 7" deeper than the super scoopers and 12" taller.

Looks like the speaker stacks will be fairly tall minus the 811B horns.

Length 30" 2 1/2'
Width 60" 5'
Height 84" 7'

Going to be some impressive speaker stacks.

That's provided I go with the super scoopers and the owner did buy the 4560s.

If he didn't buy those then I'll see if that one bullfrog cabinet is still there and have four of those made.

With the DSP built into the Yamaha amp I am using I should be able to make these speakers sound good.

I can set the high pass to the frequency at which the horn starts to unload at which will keep the driver from self destructing itself.

I noticed on the plans for the super scooper it lists a cutoff of 38Hz which is only 4 Hz lower than the 4520. That said what is the real benefit to the super scoopers?

Also the speakers don't necessarily have to all be stacked on each other.

I could stack the super scoopers with their mouths together then on the right or left put the 4560 and 811B on top of it and I could make a place under the 4560 for the amp to be mounted in as I'd need to raise the 4560 up some off the floor so it can be at ear level for the average height person.

Three of the corners won't be a problem to arrange the speakers like that. The fourth corner would require altering a wall which shouldn't be that hard to do.

Lee in Montreal
03-06-2017, 07:42 AM
Hi buddy

You already know what the 4520 sounds like. That's a first step. It will sound even better once you start shaping the sound with a digital crossover. But hey, you already understand some of the limitations.

Now to the 18" Superscoopers. You will never how they sound from simply reading articles on the internet. You need to step in and build a set. Then only you will understand what they do. Or don't do. Sure you can load them with brand new and expensive drivers, but you can also experiment with some JBL 2240 w/ Fs =0 and Qt=0.23 or equivalent.

Only by experimenting will you know what works best. Or go to exterior events, see what is used for sound reinforcement. Compare. Is that the sound you like? Also, considering that you will most like play CDs and newer music where there's a lot of content below 60Hz, I'd make sure that the bass cabinets you use will give you plenty of "meat" in that range. And BTW, I would still consider building and installing Berthas for deep basses. Check on the net if there's a club using them in your state. Then go travel.

BTW Have fun reading this.

http://www.whathifi.com/features/inside-story-ministry-sound-sound-system

https://pbs.twimg.com/media/BOaPJSgCMAIeB--.jpg

And that was the original Ministry of Sound stack that was sold off a while ago and restored by an enthusiast in England.

http://scientitian.com/images/originalMOSstack.jpg

Tube Radio
03-06-2017, 09:39 AM
You're right I do already know what the 4520 sounds like and it's a sound I personally like.

Would be easy at some point to add one of the other types of bass enclosures that go lower than the 4520 should that be needed which can be crossed over at 42Hz using one of those Yamaha amps.

I'm debating on whether the 4560 was a good choice for the midbass cabinets due to its size.

In a way I'd like to stick with the Bullfrog cabinets or just have some Altec 816A built from the plans. That way I can still put speakers back in the wall on one side and hanging from the ceiling on the other side to have them in their original configuration.

When they originally stopped using the Bullfrogs and Yamaha horns and just had the EV cabinets on the 4520s I noticed more of an echo that wasn't present when speakers were in all 8 locations.

From looking at some of the remains of the original system I don't think there was any sort of crossover used originally that I could see unless the owner had installed a capacitor in the Yamaha horns which I didn't see any evidence of and that may explain why two Yamaha horns were missing their drivers as they probably blew from seeing a full range signal for too many years.

Those Yamaha amps will make setting up the system so much easier as the built in DSP does the crossover, EQ, delays ETC...

Now concerning the 811B and midbass cabinets I'm going to try one passive 12 db/octave crossover on one midbass and horn just to see how it sounds and if the midbass and horns are balanced with each other. If they are not I will go with another Yamaha amp for the midbass and horns.

That said if I do two 4520 cabinets side by side or stacked per corner I would need two amplifiers anyways.

Far as mounting the 811B horns I will most likely have cabinets built so I can set them on top of the midbass cabinets, although if I have some 816A cabinets built I could have the builder build in a space for the 811B horns to mount right in the cabinet unless there's already plans out there for an 816A and 811B two way cabinet.

Here's the speaker placement options I can go with

http://i863.photobucket.com/albums/ab196/jmcinvale/Olympia%20Macon/Speaker%20stack%20plan%201.png (http://s863.photobucket.com/user/jmcinvale/media/Olympia%20Macon/Speaker%20stack%20plan%201.png.html)



http://i863.photobucket.com/albums/ab196/jmcinvale/Olympia%20Macon/Speaker%20stack%20plans%202.png (http://s863.photobucket.com/user/jmcinvale/media/Olympia%20Macon/Speaker%20stack%20plans%202.png.html)

http://i863.photobucket.com/albums/ab196/jmcinvale/Olympia%20Macon/Speaker%20stack%20plans%203_1.png (http://s863.photobucket.com/user/jmcinvale/media/Olympia%20Macon/Speaker%20stack%20plans%203_1.png.html)

I could just get the stuff and do it like one of those huge Jamaican sound systems with stacks upon stacks of speakers :D



EDIT:

Is there any good plans for the 4520?

Lee in Montreal
03-07-2017, 07:53 AM
4520 plans are all over the internet.

But before you go this direction, have some reading :
http://www.diyaudio.com/forums/subwoofers/231894-difference-between-super-scoop-folded-horn-subwoofers.html

Startec's 18" Super bass horn seems a better choice for modern music. Tons more of lower bass. Plans are available and free. 3 meters/10ft horn = 28Hz horn in group
http://forum.speakerplans.com/super-bass-horn-v-02-by-startec-quad-acousticsf_topic20503.html

Plenty of better bass horns than 4520 to be built.

A simple google with "bass horn" as search topic will give tons of interesting reading. Front loaded vs rear loaded horns. Compare response graphs. ;-)

http://users.skynet.be/fa567915/IMG_8823.JPG

18" Super bass Horn (simulated) response

http://forum.speakerplans.com/uploads/6359/amano_-black_vs_SBH_grey_with_lf18x451.png

JBL 4520 - Lots of 80Hz bass (great for bass driven reggae). But not much below... ;-)

http://oi52.tinypic.com/29x6ly1.jpg

So. Don't commit to the 4520s before you tested better horns... ;-) Build one. Measure it. Then compare. Your ears and chest will tell you right away which horn works best.

Tube Radio
03-07-2017, 10:30 AM
I looked on the internet and saw a lot of 4520 plans but they to me didn't seem complete enough, but I'm not a cabinet builder so maybe they are indeed complete enough.

I'm thinking perhaps the 4520 used for the subs then perhaps later on adding some bass horns for under 42Hz.

RMC
03-07-2017, 02:16 PM
Hi Barry (1audiohack),
I'm glad you brought-up some critical acoustic notions in this thread on March 3, on which I will expand a bit. I couldn't agree more with you with regards to skating rinks not sounding too good, that loud is easy, the fact there is some smashingly good sounding new stuff out there and that many reflective surfaces degrade sound quality. One of those skating rink existed for some time (now closed) about 20 min. from where I live. The sound was just horrible for the same reasons you mentioned. The bigger the better or the more the merryer isn't necessarily true in acoustics... Though, generally speaking, some materials like wood are more noble than cement/concrete in acoustics, except to confine low frequency noises.

"Loud is easy". Yes it is, however one has to realize at some point that by making customers or patrons a little more deaf each time, these persons won't need your services and gear anymore... Lots of big loud gear may make the DJ feel/look powerful, smart or in command, can sound impressive to teenagers, but it can also be detrimental to sound quality because of bad room acoustics, plus in the long run it's slowly killing the business. There's often many persons outside the room discussing, an indicator of too loud ?

There is no valid point in blasting people away, or the glasses off the tables. Overkill and overspending on equipment doesn't make a business profitable, the main reason why they float or fail. A skating rink is basically a business, similar to many others where logical choices must be made according to a business case and budget, including sound, but in a more challenging acoustical environment in this particular case.

"Reflective surfaces". Acoustics can be "destructive". Simple repeated hand claps in many parts of a large room are a good basic indicator of that room's reverb time. Skating rinks don't favour acoustics by design, and acoustics handicap skating rinks sound. The golden rule: to stay away from trouble. In such situations it implies to minimize interactions between room and sound, otherwise you may fail, first by not trying to be the loudest guy on the block (aggravating a bad situation), and second, by avoiding tall stacks of speakers projecting high spl sounds above people and straight out to the back or side walls for example. Yes, a good crowd of people has absorption (less if many are in the corridor !), well padded seats and some carpeting also do, reducing sound reflections bouncing around, but less reduction at lower frequencies, which often leads to a huge "boom box" effect, if the bass is let loose (too amplified/not properly controlled), a muddy peaky sound not pleasant to hear... It's incredible the number of places I went to over the last 40 years (clubs, bars, discos, marriages, parties, shows, gatherings, etc.) where the sound was simply bad. Lots of dollars waisted on piles of equipment, without little consideration to simple acoustic ways to improve. BTW some of the best sounding are simple: four mid-sized JBL Studio Monitors hanging around the dance floor, aimed at the crowd, at an acceptable SPL. Another similar one used Bose 802 with "sub" at right locations...

"Good sounding new stuff". When a remake of a room's acoustics is out of bound ($), then the only logical alternative is CONTROL of sound, by adapting/being clever on choice of equipment. This is the type of situation where professionnal acoustical consultants or sound contractors would typically specify, much more often than not, relatively small two-way dispersed directional speakers aimed directly at the audience along with some form of short throw bass cabinets in a bi-amp system, instead of the big boxes stacking solutions. It makes sense acoustically in this type of environment. The best way I know to achieve sound quality here is directivity, placement and short throw to minimize creating/amplifying reflections on every boundary. This means speakers relatively close-by projecting directly on the listeners to avoid additionnal acoustical problems, including hanging boxes if need be. To name names, E-V, JBL, EAW, Renkus Heinz, Peavey Architectural Acoustics, Clair Brothers Audio, etc. have all been increasingly going in that direction for some time by making a wide variety of new speakers better adapted to different challenging situations. One-size fits all, like in the good old days, seems pretty much gone now.

The new name of the game in this on-going trend to somewhat smaller boxes is: control/ portability/ expandability/ flexibility (various configurations, creating arrays).

As they say, it's business, only business... Since success isn't measured by DB SPL, might as well make it sound good, not primarely loud. I like the big stuff too 4520/4560/4550 when the situation requires it.

Richard

JeffW
03-07-2017, 02:34 PM
I have one system comprized of RCA 9462 bass horns with Community M80 mid bass horns and Community RH60's that sound stunningly good. But, they are seven feet wide and 11 feet tall, and one J1 will best them in any metric, except cost. :)



To wit:

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=63611&stc=1&d=1416279247

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=63612&stc=1&d=1416279413

About the most fun I've had in years, stereo-wise.

Tube Radio
03-07-2017, 03:16 PM
With smaller speakers comes less efficiency requiring more drive power, but with horns the drive power is much less.

Also I do know how the rink sounded when the whole original system worked properly and at least to me it did sound very good until they replaced the speakers on the 4520s with Electrovoice speakers and stopped using the ones hanging from the ceiling and mounted in the wall.

Once they did that I could hear an echo at the middle of the rink and it did not sound good. Plus the speakers had to be turned up much louder and the sound right by the speakers was way too loud.

If the horns like I am planning on using are set up right they will sound very good.

I don't really want to go the smaller less efficient and to compensate throw gobs of power at the speakers solution as I DJ at a rink like that and the sound isn't all that good with the subs requiring a lot of power.

Just because a system is overbuilt does not mean it has to be played at maximum volume.

Like the ministry of sound sound system that was mentioned earlier. Their current system is 25,000 watts per speaker stack, yet they never use nowhere near that much power.

Why so powerful? Because an amplifier used at or near maximum power all the time won't sound as good or last as long as an amplifier of twice the power used at half its maximum output power.

RMC
03-07-2017, 04:30 PM
Famous horn speaker designer Paul Klipsch once said "what the world needs is a good 5 watt amplifier", with regards to is well-known La Scala and Klipschorn speakers (104-107 DB sensitivity)...

Richard

BMWCCA
03-07-2017, 06:01 PM
Famous horn speaker designer Paul Klipsch once said "what the world needs is a good 5 watt amplifier"...He also cried "Bullshit" a lot, but I'll refrain from that here!

1audiohack
03-07-2017, 07:03 PM
Famous horn speaker designer Paul Klipsch once said "what the world needs is a good 5 watt amplifier", with regards to is well-known La Scala and Klipschorn speakers (104-107 DB sensitivity)...

Richard

I have to push the "Bull Shit" button on Paul, no amp can fix a La Scala haha!

Killing people with SPL is no doubt bad practice and I do not condone it. I do like the get up and go of a well tuned large format speaker system, as you may have guessed.

The shop in the picture Jeff posted is a 200 by 68 foot concrete box. The solution to acceptable sound inside is keeping the sound off the walls and on the floor as you have said, and a single stack source up high makes that a lot easier. The HF is a 60X40 horn ≈20 feet above the floor. Looking through the horn, the top line points ≈10-12" above the floor line ≈185 feet away. This naturally shades the output so the closer one gets to standing underneath the horn, the output is reduced in proportion. There is right about 2dB SPL from the front of the shop to the rear, the sound is surprisingly very well balanced. You have to be within 20' of the far wall to pickup any backslap and you really have to listen for it.

There are two 55 HP CNC lathes near the center of the floor and the noise on the floor changes throughout the day. To deal with this and other DSP chores there is an old BBS 8810 that employs ambient noise compensation. There is a $50. Behringer mic hanging about 100' from the speaker stack. With this set up properly the sound system level stays where one can hear it anywhere any time.

I am not trying to run away with your thread TR. Just wanted to share a working solution to another acoustically challenging environment.



I agree Jeff, we need to do that again!

My best All!
Barry.

Lee in Montreal
03-08-2017, 07:23 AM
Why so powerful? Because an amplifier used at or near maximum power all the time won't sound as good or last as long as an amplifier of twice the power used at half its maximum output power.

Indeed.
Older people, especially DJs, will remember fried voice coils because of too small amps being used, clipping all the time and outputting DC. Wondering if 5W amps would have worked better... ;-)

Probably what "DC" meant in the Crown DC150 ;-)

JeffW
03-08-2017, 07:59 AM
The stacks I posted above were running a touch over 5 watts

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=63624&d=1416332967

You could feel the music from here when they were opened up a bit

http://www.audioheritage.org/vbulletin/attachment.php?attachmentid=63640&d=1416337154

Lee in Montreal
03-08-2017, 11:25 AM
The stacks I posted above were running a touch over 5 watts



You could feel the music from here when they were opened up a bit



How much db did you have at, say, 40Hz ? What about peaks? Would that be enough to impress drum'n'bass or EDM dancers in a club? ;-)

Lee

PS are these 5W amps in the picture? if more, why then? ;-)

Tube Radio
03-08-2017, 12:48 PM
1audiohack, that's ok. Every bit of advice helps.

Wondering if I should use some sort of DSP box such as a Mini DSP before the amplifiers that can work with a room measurement mic in order to optimize the whole system to the room? I could then just use the built in DSP of the amps for the crossover and limiting with the Mini DSP doing the rest.

Think the plan will be this.

4 or 8 4520 cabinets for the bass to 90Hz or whatever is the best crossover point for them.
4 4560 cabinets for the midbass to 800Hz or 8 Altec 816A cabinets for the midbass to 800Hz (depending on if the owner already bought those 4560 cabinets.
4 or 8 Altec 811B horns with BMS 4550 compression drivers.
8 Yamaha PX3 or PX5 amplifiers (depending on just how much headroom is needed)
Maybe Some sort of DSP box that can work with a room measurement mic and software.
A DJ style mixer

Lee, those berthas look awesome. How low in frequency do they go? If low enough is it possible to just add one to one end of the rink crossed over at 42Hz.

If I do add one that may come later as needed.

The idea is for this to be the best sound system out of any rink in the local area and with the advice I've gotten here and my knowledge of how to set up sound systems and what sounds good I believe that I can achieve that goal.

Far as using 8 midbass and horn speakers I can just parallel two each per amp channel unless it is best for each speaker to have its own amp channel.

Setup will be easy as I'll be able to set one amp up then transfer the settings to the other amps.

If the audio cabling is still there I think each of the four original amps were fed in parallel.

Will that be ok? Also is there any DJ style mixers that output a mono signal or will I need a box to take care of that?

I do see a problem using only one 4520 per speaker stack. That is I'll need 6 amps if I run the 811B horns on an amp channel.

Using two 4520 per speaker stack will eliminate that issue, but I'll then need 8 amps.

Now if I use the PX5 amps I'll have 500 WPC 8 ohms and would need two per speaker stack for sure.

Thinking the PX5 would be better anyways as the woofers I'm going to use with the 4520 cabinets are rated at 500 watts and with the PX3 running them in 4 ohms I have 500 watts max and the amps will be running near maximum unless I'll never need anywhere near 500 watts at sane listening levels given the efficiency of those cabinets.

BMWCCA
03-08-2017, 05:09 PM
Probably what "DC" meant in the Crown DC150 ;-)Not familiar with a DC150 Crown.

D150, yes. DC300, yes. Just not DC150. I've run an original D150 (the one without any front panel) for over 40-years without issue. The only blown tweeter I've ever had is an 075 when I didn't know any better and was pushing my 030s with a Kenwood receiver. JBL repaired it under their "lifetime" warranty terms but alerted me to check for a "high-frequency oscillation" from my amp. I just sold the Kenwood instead, and that original 075 is still working today. So is the Crown.
:dont-know:

Lee in Montreal
03-08-2017, 05:18 PM
Not familiar with a DC150 Crown.

D150, yes. DC300, yes. Just not DC150. I've run an original D150 (the one without any front panel) for over 40-years without issue. The only blown tweeter I've ever had is an 075 when I didn't know any better and was pushing my 030s with a Kenwood receiver. JBL repaired it under their "lifetime" warranty terms but alerted me to check for a "high-frequency oscillation" from my amp. I just sold the Kenwood instead, and that original 075 is still working today. So is the Crown.
:dont-know:

Hey buddy.

You are correct... D150 and DC300. My bad. It was a very long time. ;-)

Tube Radio
03-09-2017, 04:31 AM
While putting the parts list together I saw where the Yamaha PX5 amp has a power boost mode that is similar to what other amps call bridging.

Figure that if I use four 4520 cabinets I can set the amps in power boost which will give up to 1400 watts at 4 ohms, although with the two drivers in a cabinet in parallel the maximum I can feed the drivers will be 1000 watts. That should give plenty of headroom.

I can then maybe use Yamaha PX3 amps for the midbass and treble drivers.

Concerning the 4520 cabinets should I just run the wiring out of the cabinets or is it ok to install a terminal plate with a speakon jack on it?

What concerns me about that is power handling.

Would the jacks be good enough or will a direct wire of the drivers to the amp be best long term?

Lee in Montreal
03-11-2017, 03:26 PM
Here is Eaulive's (a member here) set-up from 4 years ago. Pretty simple and it sounded good. The midrange horn was home made and sported a 10" driver.

https://farm4.static.flickr.com/3612/5842988435_74c15b88d0_b.jpg

@Tube Radio. You mentioned wanting to use mini-DSPs... Why simply not get a regular digital crossover such a DBX Venue 360. It will do time alignment, auto-eq, bass synth and boost

Tube Radio
03-11-2017, 09:09 PM
That's a very nice setup

Can the DBX work with a measurement mic?

As it turns out I may be having some 4520 cabinets built for the rink I currently dj at as they use four yorkville subs on one side and they aren't necessarily good sounding or efficient.

Driving them with a pair of qsc rmx2450 in bridged mode and the bass near the dj booth is severely lacking.

Lee in Montreal
03-12-2017, 08:59 AM
That's a very nice setup

Can the DBX work with a measurement mic?

As it turns out I may be having some 4520 cabinets built for the rink I currently dj at as they use four yorkville subs on one side and they aren't necessarily good sounding or efficient.

Driving them with a pair of qsc rmx2450 in bridged mode and the bass near the dj booth is severely lacking.

The DBX Venue 360, as well as the Behringer DCX 2496, both work with a calibrated mic. I have a Behringer, it is fine though, but just because I couldn't afford the DBX ;-)

Great that you can have some 4520s built. Also, remember that the cabs were originally designed for the 2205 drivers which had Fs30Hz and a low QTs. Have a you found a modern replacement yet?

Tube Radio
03-12-2017, 10:04 AM
Awesome. I'll add the dbx to the list of equipment to buy.

I found a replacement for the drivers that a fellow forum member used. Its a Dayton audio 15" woofer for $75 each. The link was posted somewhere early in this thread. I can find the link and post it again later today.

So basically I can set the amps up to where it sounds ok in the center of the rink then use the dbx with mic to optimise it?

EDIT:

Here's the drivers I intend to use.

http://www.parts-express.com/dayton-audio-pa380-8-15-pro-woofer--295-034

RMC
03-13-2017, 07:58 PM
Hi Justin,

I had a quick look at the woofer you found on Parts-Express web site: Dayton Audio PA- 380-8

First, you should check on Dayton's own web site to validate driver data given by Parts Express to be sure those are the real parameters, sometimes there are errors on commercial sites. Below I used as is on P-E. If indeed the parameters are the same, you may still have some "problems" with regards to parameters proximity with the 2205 driver Lee correctly identified as being the real match for 4520.

You shouldn't base your driver choice mostly on the close resonance frequency in free air (Fs) between JBL's 2205 (most appropriate driver) and the Dayton Audio driver. There's a lot more than Fs to consider, but lets stick to just a few basic ones to facilitate your search, and not chase ghosts. As of most recent, JBL recommended two drivers for the 4520/4530, the 2205H and the E-140. Plus many guys did use with good (not ideal) results the E-145 for its longer cone travel (Xmax: 7.1 mm), specially those who really wanted to beat the hell out of this box at lower frequencies... The following numbers will help you see the type of numbers to look for and those to try to avoid. Vas: volume of air having same acoustic compliance as driver suspension.

Some basic parameters of the 2205H were: Fs 30HZ , Qts .21 , Vas 297.3 liters
Some basic parameters of the E-140 were: Fs 32HZ , Qts .17 , Vas 297.3 liters
Some basic parameters of the E-145 were: Fs 35HZ , Qts .25 , Vas 274.7 liters (little high on Qts)

Even with this partial data you can see why the 2205 and E-140 were recommended, and why some did want to use the E-145 (not ideal but lets say acceptably close). Under, you'll see what's not close enough (but in the case of the 2225 remember it's about the nearest left in the JBL catalog approx. 1985-2005, now replaced by 2226 which is even further away on Qts at .31).

Some basic parameters of the 2225 were: Fs 40HZ , Qts .28 , Vas 170 liters
Some basic parameters of the Dayton are: Fs 31.6HZ , Qts .27 , Vas 175.2 liters (6.19 cu. ft. to metric )

Other than Fs, the Dayton driver is far off on Qts and Vas compared to 2205. In fact, two of its three parameters are close to those of the 2225. I do know many persons did use 2225 in 4520/4530 as "second best" for reasons of availability (see above), but as a knowledgeable member said in another thread it is not really suited for this purpose (45 series). I know it was rather used extensively in JBL's 46 series.

Some other data for Dayton looked ok, like sensitivity, Xmax (unless you plan a really rough LF ride for it).

Most probably you'll have to make compromises, and that's ok if you give more weight to the important data. I wouldn't lose sleep, in this case, on an Fs of 30 VS 32 VS 35HZ. But I would be more concerned with the other two parameters of the Dayton.

it may be difficult to find an exact clone, i know, the 2205 was a bit lonely in its category, and the other compatible one (the E-140) were both discontinued a long time ago. if i were you i'd try to find another more suitable candidate if you want to have the kind of sound and performance you're expecting from the 4520. it's not a question of good or bad drivers but simply suitability for intended purpose. The 4520/4530 rear chamber (behind the drivers) has a very small volume and pretty low Qts tends to be good for that.

To make it easier on you, I suggest you search first by diameter, Fs, Qts, Vas and then when you have a few good prospects in sight, look at the other driver parameters of interest, and decide. Regards,

Richard

Tube Radio
03-13-2017, 08:54 PM
Fellow forum member NickH used them in his and they worked very well for him.

So at only $75 a pop I'm inclined to try them once I get the cabinets built.

Lee in Montreal
03-14-2017, 08:19 AM
Redundancy - Here was my comment early in the thread. Post #4. ;-)


That would be a first mistake ;-) The 4520 is NOT a sub. It is a bass cabinet. ;-)

The ideal woofer has a low Qts. The original 2205 had something like 0.2 and good old 2225 have 0.28

I suggest not to go with 2226 which is clearly a bass reflex driver (and it would require major eq to cut 100+ Hz)

Or sell the cabs and get bass reflex cabs with modern drivers requiring gobs of power to feed. ;-)

Tube Radio
03-14-2017, 01:26 PM
Oh ok so that's why the Dayton Audio woofer worked so good in the forum member's cabinets.

Eaulive
03-16-2017, 06:42 AM
[QUOTE=Lee in Montreal;403592]Here is Eaulive's (a member here) set-up from 4 years ago. Pretty simple and it sounded good. The midrange horn was home made and sported a 10" driver.

Hey that's me :-D

And it's a 12" B&C 12PE32 as a midbass driver ;-)

JeffW
03-16-2017, 07:36 AM
Hey that's me :-D



Nice to see you around!

Tube Radio
03-16-2017, 12:10 PM
[QUOTE=Lee in Montreal;403592]Here is Eaulive's (a member here) set-up from 4 years ago. Pretty simple and it sounded good. The midrange horn was home made and sported a 10" driver.

Hey that's me :-D

And it's a 12" B&C 12PE32 as a midbass driver ;-)

Awesome system you have there.

Tube Radio
03-24-2017, 07:12 AM
An update. They are still waiting on the bank to lower the price some as what they expect to get out of it is way more than what rinks are currently selling for around the local area.