High SPL Design Ideas

[theriam]

Greetings!

I'm a long time JBL fan and I'm in the process of designing a new system for a 50' x 30' room in our barn where we hold several large parties per year.

I currently have (2) 2446H drivers and am planning to order (2) 2242H 18" drivers shortly. I also have two JBL 5235 electronic crossovers and several amplifier choices (multiple Crown MA600, PS-400 and Ashly FTX-2001 units) available to build a tri-amplified system.

Space is not a problem and the ceiling is open to the roof structure - about 24' high. The horns and mid bass drivers will likely be suspended on a back wall with the subs on the floor.

Here are my questions:

Which 12" or 15" JBL driver (possibly 2 per cabinet) would be my best choice for optimal mid range and mid bass performance and efficency to complement the 2446H?

Which horn should I look for to mount the 2446H and at what crossover frequency and slope?

I'm thinking about building sub cabinets similar to the 4645C. Is this the optimal bass reflex cabinet design for the 2242H for the deepest, flatest response? Where would you cross it over to match the above?

I will likely buy used, late model parts to complete this system.

Sorry for the long post... I'm really looking forward to this project and would appreciate some advice and ideas from the forum.

Thanks in advance for the help!:)

Mike

[louped garouv]

how many folks generally gather for these events?

and is the entire space used as the main listening area,
or is the space used in fragments?

bar area, seating, dining, "dance floor", etc?

[pos]

Drew Daniels' system would fit your needs:
http://www.audioheritage.org/html/perspectives/drews-clues/system.htm
http://www.audioheritage.org/vbulletin/showthread.php?31749-Drew-Clues-system&p=320498

[Lee in Montreal]

Theriam, are you open to suggestions? I am asking because using a pair of 2242 as sub-only means you will be missing 80Hz-to-500Hz.

Also, what will be the purpose of that system? If you mention SPL, I suppose it is for house parties... :D

Here's what I would do (I suspect you will be building your own enclosures and are handy).

Low bass ----- 2242-based Bertha subwoofer with Levan extensions (you need to build them)
Bass ----- 2225/2226-based 4520 scoops (used scoops are dirt cheap)
Low mid ----- 2225/2226-based 4560 (used enclosures are dirt cheap)
Mid ----- 2246 on 2350 long throw horns (very cheap too)
High ----- 2405 Ultra high frequencies

[louped garouv]

"berthas" are dual 18s per cabinet, correct?

[Lee in Montreal]

"berthas" are dual 18s per cabinet, correct?

Correct. And a modular design. The horn itself is an add-on. So moving them around is not that hard ;-)

53037
53038
53039

Bertha and Waldorf.
53040

If making a big Bertha is not a possiblity, then I would built two Waldorfs with four 2242

Also Theriam, if you don't already have purchased your 2242, may I suggest you purchase good used 2240s instead as they go lower by at least 5Hz and are dirt cheap. You can buy them for around $250 a pair on original JBL cones. Expect $500 for four drivers, which is less tha one single 2242... Build scoops with them and feel the thump. In each enclosure, one drivers can do 25Hz to 120Hz while the other does 25Hz to 50Hz. For really high SPL, then build four Waldorf/4520 (with eight 2240).

[Eaulive]

If making a big Bertha is not a possiblity, then I would built two Waldorfs with four 2242
The Waldorf is a dual 18??? :blink:

[Lee in Montreal]

The Waldorf is a dual 18??? :blink:

Obviously not, but they can be adapted to the better 18" 2240 just like the 4520 was also adapted for 18" 2240. 15" driver are great, but an 18" is better.

[louped garouv]

Obviously not, but they can be adapted to the better 18" 2240 just like the 4520 was also adapted for 18" 2240. 15" driver are great, but an 18" is better.

and the waldorf is based on the Jensen Imperial, right?

[Lee in Montreal]

and the waldorf is based on the Jensen Imperial, right?

Correct. With a bigger rear chamber and about the same horn length. But much, much simpler path, which avoids a lot of nulls. The Jensen/Waldorf were a great design.

[Lee in Montreal]

and the waldorf is based on the Jensen Imperial, right?

http://www.myspace.com/soundmanshorty/photos/albums/sbs-collaberation-w-sting-intl-aug-30-08/2305250

53045

[reVintage]

Correct. With a bigger rear chamber and about the same horn length. But much, much simpler path, which avoids a lot of nulls. The Jensen/Waldorf were a great design.

Hey Lee,

Would you mind helping us with the drawing/plan? Or is this the original:

http://www.audioheritage.org/vbulletin/showthread.php?31407-Richard-Long-s-Waldorf-restoration&p=316853&viewfull=1#post316853

A little confused if it is, as the chamber looks smaller than Imperials.

[Lee in Montreal]

Hey Lee,

Would you mind helping us with the drawing/plan? Or is this the original:

http://www.audioheritage.org/vbulletin/showthread.php?31407-Richard-Long-s-Waldorf-restoration&p=316853&viewfull=1#post316853

A little confused if it is, as the chamber looks smaller than Imperials.

Here's the original design.
http://www.dcaudiodiy.com/jensen_imperial/page_11.jpg

I woud be very interested in developping that project. The drawing you linked is an old version. Since then I have slightly modified the upper right corner to a rounder shape to avoid any reflection. I guess it will take a few modelizations until the optimal shape is found. Or an original Waldorf to take measures from... :D

Differences could be throat and back chamber volume.

[reVintage]

Hi again Lee,

Thanks! I know the original Imperial very well and have the plans, never heard of the Jensen/Waldorf though. Same, same?

[theriam]

how many folks generally gather for these events?

and is the entire space used as the main listening area,
or is the space used in fragments?

bar area, seating, dining, "dance floor", etc?

We usually see between 100 to 200 people, depending on the event.

Yes, the entire space would be the listening area and is wide open. The dance floor starts out as a 30 'x 30' area but takes over the entire floor late into the night!:bouncy:

[Lee in Montreal]

Hi again Lee,

Thanks! I know the original Imperial very well and have the plans, never heard of the Jensen/Waldorf though. Same, same?

The Waldorf, designed by Richard Long, was contemporary to the 4520, but a very different beast and intended for the dancefloor, while the Jensen Imperial was designed for the lounge. The Waldorf was inspired by the Jensen and is supposed to have a rounder bass than the 4520, most likely because of the bigger rear chamber. The simpler horn path also leads to less reflections and nulls, which will probably affect efficiency and linearity. The 4520 was 4ft tall while the Waldorf had an extra foot (30cm). And for the sake of improving the lower spectrum, nothing can keep a builder from making it 6ft tall. ;)

The 4520 design can easily be modified to reach 27Hz in horn length, but not in horn mouth.

But getting back to the original subject of this thead, I suggest the OP to look at horns if high SPL is the goal. It will require to build many, many 4645 to get the impact of a scoop. :D

[theriam]

Correct. And a modular design. The horn itself is an add-on. So moving them around is not that hard ;-)

53037
53038
53039

Bertha and Waldorf.
53040

If making a big Bertha is not a possiblity, then I would built two Waldorfs with four 2242

Also Theriam, if you don't already have purchased your 2242, may I suggest you purchase good used 2240s instead as they go lower by at least 5Hz and are dirt cheap. You can buy them for around $250 a pair on original JBL cones. Expect $500 for four drivers, which is less tha one single 2242... Build scoops with them and feel the thump. In each enclosure, one drivers can do 25Hz to 120Hz while the other does 25Hz to 50Hz. For really high SPL, then build four Waldorf/4520 (with eight 2240).

I like where we are going! I've always wanted to build a bass horn! Do we have access to good plans for the Bertha? Does anyone on the forum happen to have test data for both designs, Waldorf and Bertha, with JBL drivers?

[Lee in Montreal]

I like where we are going! I've always wanted to build a bass horn! Do we have access to good plans for the Bertha? Does anyone on the forum happen to have test data for both designs, Waldorf and Bertha, with JBL drivers?

Bertha and Waldorf would be the ultimate party mix. They were designed 35 years ago and many clubs still use the same design. and you won't need 1000 watts amp.

Here's the plan for the EAW, similar to the Bertha. You must add the Levan horn extension to reach low. I can't imagine the sound if placed in corners of the room. :D

And some good read.
http://forum.speakerplans.com/paradise-garage-sound-systemcirca-late-70s_topic53115_page1.html

53052

[reVintage]

So, now only plans for the Waldorfs are missing....

[theriam]

Bertha and Waldorf would be the ultimate party mix. They were designed 35 years ago and many clubs still use the same design. and you won't need 1000 watts amp.

Here's the plan for the EAW, similar to the Bertha. You must add the Levan horn extension to reach low. I can't imagine the sound if placed in corners of the room. :D

And some good read.
http://forum.speakerplans.com/paradise-garage-sound-systemcirca-late-70s_topic53115_page1.html

53052

Thanks! Great background info. How would you compare the low end performance of the JBL ASH 6118 design to the Bertha with extensions?

My only hesitation with some of the bass horns systems I've heard (neither of these designs) is they seem to be less than linear ("boomy" or "peaky") in response making them fatiguing to listen to. Their efficiency and output are absolutely without compare but my ears are fairly critical and I don't want to ignore my Audiophile tendencies. :)

[Lee in Montreal]

So, now only plans for the Waldorfs are missing....

Modified for 18" 2240 drivers, right? :D

Are you handy when it comes to make sims? if so, we could explore rear chamber size and throat area...

[Lee in Montreal]

Thanks! Great background info. How would you compare the low end performance of the JBL ASH 6118 design to the Bertha with extensions?

Hmm... Maybe you could build both styles and report? :D

The advantage of the Bertha is the much bigger mouth, which is needed for low frequencies. But both work according to the same principle.

[1audiohack]

Thanks! Great background info. My only hesitation with some of the bass horns systems I've heard (neither of these designs) is they seem to be less than linear ("boomy" or "peaky") in response making them fatiguing to listen to. Their efficiency and output are absolutely without compare but my ears are fairly critical and I don't want to ignore my Audiophile tendencies. :)

That's what EQ is for. You will need an active crossover with delay anyway.

If you build bass horns, and I would, the money saved buying less drivers will be spent on wood and time. Just take it from one with experience, they cannot be built too rigid. If you want even a proven design to sound good loud, they have to be very stiff everywhere, really really solid.

Where in the barn is the sound system going to be placed? Will you post a picture of the inside of your barn? If you hang the mid/high pack on the long wall consider the JBL 2360 or the 2365 horns if you are hanging on the short wall. You can angle them down pointed on axis at the back of the barn and still fill but not kill the people up close, with some EQ they sound great and if you look around you can often get them for little more than shipping

Dang this project just sounds like fun!

[mikebake]

Here ya go. Bet it works pretty well. 53057

[Lee in Montreal]

Rog Mogale has developped 25Hz scoop. if the barn has 25ft ceilings, then those tall cabinets are not a problem... :eek:

Actually even some Waldorf or 4520 can do 25Hz if they are 8ft tall.

53058

[theriam]

That's what EQ is for. You will need an active crossover with delay anyway.

If you build bass horns, and I would, the money saved buying less drivers will be spent on wood and time. Just take it from one with experience, they cannot be built too rigid. If you want even a proven design to sound good loud, they have to be very stiff everywhere, really really solid.

Where in the barn is the sound system going to be placed? Will you post a picture of the inside of your barn? If you hang the mid/high pack on the long wall consider the JBL 2360 or the 2365 horns if you are hanging on the short wall. You can angle them down pointed on axis at the back of the barn and still fill but not kill the people up close, with some EQ they sound great and if you look around you can often get them for little more than shipping

Dang this project just sounds like fun!

It will be fun! It's been a while since I've taken on a speaker project and it will be great to share the results with our friends!

Attached are a couple of pictures of the open barn space. The speakers will be installed on the short side with the mid/high packs on wall in the same general area as the old speakers in the pictures. The subs can sit on the floor to the left and under the staircase.

[Lee in Montreal]

Wow, great space. Looking at how big it is, I would even suggest eight 4520s, in quatuors. :D

Here's one side of the barn.

4520
4560
2350
2360

53071

[1audiohack]

That looks like a party space all right! It will take some real subs to fill it. What speakers are hanging in the pictures? Do they come close to playing loud enough? I'm just trying to get an idea of how loud is loud.

By the way Lee, that looks like a damn good start!

All the best,
Barry.

[reVintage]

Are you handy when it comes to make sims? if so, we could explore rear chamber size and throat area...

I have an acceptable knowledge in using HR and can also interpret the results. Input needed is:

Driver
At
Am
L
T if Hypex
Backchamber volume
Placement

[mikebake]

I would resist the temptation towards the bigger/more solution for this space. It appears it will be a fairly highly reverberant space, and over-scaling the system will just add problems. I'm not so concerned about the subs; a couple of 2242's would be fine in there and give you all you'd need if set up/powered right. One mid, one horn, one tweet per side should be plenty. Large format horns which can can work in large venues may pose problems in there. It might be illuminating for you to hear a modest modern system in there done right, as a reference for what is possible. The nice thing about permanent installations is you can use the old school/heavy/large stuff and not really care, if it's out of the way.

[mikebake]

Another thought that would be cool in there would be a distributed type system, sort of like some club areas use, where you have mutliple smaller cabs covering areas well without needing two mains to generate higher SPL to get the room excited.

[1audiohack]

I too would keep the number of drivers as minimal as possible. Mounted up on that wall a pair of 60 degree horns to keep as much of the energy off the walls as possible will be a good thing.

I have a similar setup in a larger shop. The system is not ideal, it is one JBL 2365/2441, a 100Hz midbass horn with a 2206 in it on top of two 34Hz bass horns. This did not provide sufficient nor a good homogenous bass field on the floor so I added four 40Hz folded bass horns in one corner, it sounds pretty good and is intelligible in a very reverberant space, but it will not achieve dance floor sound pressure levels with the sound quality I would like.

[theriam]

That looks like a party space all right! It will take some real subs to fill it. What speakers are hanging in the pictures? Do they come close to playing loud enough? I'm just trying to get an idea of how loud is loud.

By the way Lee, that looks like a damn good start!

All the best,
Barry.

The speakers on the wall are used primarily for background music and will be removed. When we have a party, we usually hire a DJ or a band. The new system could eliminate that expense.

The drivers in the cabinets pictures are some low end MCM catalog drivers I slapped together in some old boxes. 12" poly woofers with 1" compression drivers behind the horns. There is also a 12" Pyle dual voice coil sub (not pictured) that fires towards the rear wall. The wall speakers are powered by a Crown MA600 in stereo mode and the sub is powered by another Crown MA600 bridged mono crossed over at 100hz. They sound fairly balanced but they don't compare in efficiency and output to an older speaker project I have loaded with 12" JBL131 and JBL 2404H drivers. I also have a pair of 15" Altec 515B's that don't have a home at the moment.

Surprisingly, the room does not have any terrible resonance or reverberation issues.

Thanks again for the feedback!

Mike

[Lee in Montreal]

I have an acceptable knowledge in using HR and can also interpret the results. Input needed is:

Driver
At
Am
L
T if Hypex
Backchamber volume
Placement

PM sent

[Eaulive]

I can feel the thump already :dj-party: :bouncy::D

[pos]

Interesting info on bertha/levan horns:
http://www.wavemusic.com/community/showthread.php?t=2893

[Lee in Montreal]

And how that "barn" can be set-up :D

http://www.systemsbyshorty.com/sbsstereo1.swf

[theriam]

Guys,I just scored a deal on two brand new in a box SR-4719X dual 18" subs that I could not turn down! The original owner bought these new about 8 years for a home theater project and never used them. I can't wait to fire them up! Attached is a quick picture.Now that I have a basic direction, what are your thoughts on the best matching top cabinets for these? I'm leaning towards the SR-4732X or 4733X. Does the Forum have any experience with ethier of these units? In a tri-amplified configuration, how would you power them using Crown Macro Tech series amps (models?). I also picked up a like-new dbx RackDrive PA unit with RTA mic to EQ and tweak the system.Thanks in advance for the input! Happy New Year! Mike

[more10]

Nice subs! Now you only need 5 kW to make the barn shake :-)

I would choose SR-4732X or SR4722X because of the 12" which I believe sounds better than a 15" in the mids.

[more10]

You can build 4 tapped horns with the elements from the subs, and put a horn in each corner of the barn. I have used one tapped horn with a 2226 in a small barn. One 15" is enough :-)

[theriam]

Guys,

I wanted to update the group on my project. Attached are pictures of the complete system at this stage. The tops are SR-4731X and the subs are SR-4719X. We just held our annual Memorial Day party with 100+ people and the comments from the crowd were great! You know you had the place rockin when the police stop by to tell you to turn it down! :bouncy:

Powering the system are two Crown MA 2400 bridged mono on the subs (about 2,000 watts/channel), one MA 2400 on the mids and on MA 1200 on the horns. I have the dbx PA+ proving the crossover and equalization.

Personally, I was very impressed with the clarity, balance and output of the 4731's. They sound fantastic and were a great recommendation! Thanks!

However, I was hoping for more out of the 4719's. Everyone seemed to like the way they "hit" but I found them a bit lacking in punch and their response drops off quickly below 40hz requiring heavy equalization. I also noticed that their response in my room seemed somewhat directional - odd for a sub. The best bass extention was with the cabinets front firing, side by side (mutal coupling?) and seemed to be more pronounced standing less than 15ft way or more than 50 ft away. I have had other subs in that room that performed better in a rear firing configuration that seemed more uniform in response and coverage.

Any ideas to try or am I expecting too much from the 4719s? This has me thinking how much better the Bertha's would be in comparison.

Thanks,

Mike

[JuniorJBL]

Try moving the left one into the corner and face it towards the other sub.

[dezmond]

Nice system, are you still set up like this ? I would stack the subs .

[Ed Kreamer]

Mike,

Congratulations in obtaining your system. I'm not familiar with the 4719 so I don't know how much very low bass it can produce, but in viewing the photos of your barn, it appears that the walls are not reinforced metal siding. This could be a significant part of your problem. If the walls are flexing out of phase it it will destroy the bass. I have personally witnessed this problem in my wife's church. In the organ loft the pedals are very powerful, but in the nave they can hardly be heard. Several consultants have pointed out that because of the particular construction methods, the walls flex killing the pedals. I wouldn't be surprised that this may be part of your problem.

Anyway, good luck and have fun.

Ed