4560's

[Tim Williamson]

Hey all,

New here, pretty cool place!

I mostly listen to jazz music, and have toiled at getting a great single/full range driver speaker set up. It is always an on going process.... but I am pretty happy with that.

While the fullrangers are great on Jazz, they do not go to "11" for those occasions I want to pop on Who, Live at Leeds.... King Crimson.... or a Clash album. So, I decided what I really needed (OK, so it is want... no need!) was a pair of theatre speakers to satisfy those urges to play music at a volume satisfactory to true concert reproduction. I did not simply want loud...... heck, that can be achieved with any modern speaker. I wanted theatre sound! Anyway... a couple people I know reccomended Voice of the Theatres (A7).... and a few more suggested, if budget was an isssue (it is) that I could get some killer JBL speakers set up for good price.

I just bought a pair of 4560's for $200 (I'm thinking a pretty good deal(??). It is just the enclosure and drivers. Boxes are a bit scratched, but I can fix that....sonics are what I care about (drivers are supposed to be good.... havn't picked them up yet). Now to the question at hand..... what horns to cover mid/high (and associated crossover)? Some have suggested Altec.... prices for these are all over the map.... and I don't see much JBL horn stuff out there......... my lack of knowledge about these is obvious... and help would greatly be appreciated.

[mikebake]

Is is the JBL box or is it a clone?
What driver is in the box? The JBL 2226 is the best all around choice.

4560's, when used in a full-range manner and not simply as a midwoofer box, came from the factory as a two way and a three way. (http://www.jblpro.com/pub/obsolete/Cabaret_Series1.pdf)
For a two way, use the JBL 2370A horn with a 2426H or equivalent JBL driver, and as a three way you can add the 2405H slot tweeter. The crossover you should use for the two way is a 3110 and for a three way add the 3105. These can be found on ebay, among other sources.
This box is only fully horn loaded above 200hz, so low frequency reproduction is down. You can EQ this a bit to compensate, with acceptable results.

[Tim Williamson]

OK, the ones I bought are the same enclosures as pictured.

I would like to run them two way for simplicities sake.

Guess I should have done my homework.....only down to 100hz? Hmmm.... does is drop like a rock at that point...or roll off smoothly?

Was I correct in hearing that the JBL comression drivers and horns were less expensive than Altecs? Is there huge audible reason for disparity in price?

[mikebake]

I have seen a curve somewhere...........they aren't bad down to about 80, it seems. I have notched down the mid before, negating some of the gain of the box, but for "home audio" purposes, no big deal. The box excels at long throw situations outdoors.

The 2370A is a pretty nice horn, works well for this unit.

Don't know about price and sound comparisons on the drivers; just use the JBL.

[Tim Williamson]

ooops... here is pic of a box........

[mikebake]

I thought you said it had the drivers. No woofers? BTW, while the A7 may garner more acclaim, I have heard it and the 4560 quite a bit and I like the 4560 with proper JBL components better. The Altec woofer is nice, but the JBL box/components have more punch.
Find some 2226's (not hard) for the woofer. Also, does the cabinet have the JBL tag on the back? Post a photo of the rear, if you would. Is that your actual unit, or a stock photo?

[Tim Williamson]

The pic I attached was only something I found on the internet. The ones I bought do have drivers. 2220 drivers I think (does that sound right?). Here was actual description:
">Perkins Bins 1 Pair 15" Clair Bros Box JBL Full Range
>Full Range 15 " JBL Driver"

[mikebake]

Is it this pair?
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7368705577

Those would appear to be Clair Brothers knock-offs. You could easily end up stuffing these boxes with $1000-1500 worth of components to get them satisfactory, and the boxes, while likely sonically okay, appear to be beaters. Maybe you can stop now and go another direction, and save the $.

[mikebake]

Here is the 4560 box loaded with 2345 horn, 2405 tweeter, and E130 woofer. The 2370A is a better horn than the 2345 aluminum dinosaur, but the slot tweeter is still a very nice unit. The 4663 came with a phenolic driver mid. Original JBL 4560 cabinets have the cutout at the top for mounting the horn. This is how the ones I have originally came; now I use them as a two way with the 2370A horn and 2226 woofers.

[Tim Williamson]

Yes, those are them. The boxes are heavily worn.... however, that is of no consequence to me. I have the ability and skill set to refinish them should I want to. If these enclosures are sonically sound, and the drivers work..... why not go on? In the end, if I really like them....I can always replace the 4560 boxes and move any horns purchased to newer set up.

Anyway..... I will stop now and suck up my loses (my ego is not so great as to blindly trudge on regardless...) if these enclosures are no good. It would cost me more than $200 just in wood to build my own.... and I really do not have the time for the labor.

[Tim Williamson]

Cool. Given the road weary condition of the ones I just bought..... I would have no hesitation in cutting open the top and putting in the horn as in that picture. Cool...... that would be quick work with the power tools. This could be really fun eh?!

[mikebake]

There is nothing wrong with a box that works finally sonically and is a beater cosmetically. I have/had lots of them.

You'll have fun.

You might want to recone the woofers, or better yet find some nice 2226's. Make sure you have a big backyard party; these things are built for that!

[Tim Williamson]

....what is the compression driver model that you fitted to the 2370 horn?

[speakerdave]

He's already given you that--the 2425. The 2370 with 2425's sometimes go on ebay for less than $200 per pair, though sometimes more, and this would be the combination to look for. The 2345 horn in the photo was mounted with the Alnico 2470, which is the same driver as the LE85, but with a phenolic diaphragm, as Mike said, instead of the aluminum. The 2470 with the 2345 is a decent combination, but you definitely would want to supplement the high frequencies above 10k Hz. The horns can often be had very cheap, although the drivers more. I would not play the 2345 with a titanium diaphragm; that would probably be unendurable.

Peeling these speakers off and starting over actually may be the best suggestion. Pull the drivers and ebay 'em. If they are Alnico you might get your money back.

SR speakers are not easy to convert to home use, but the 4628 is easier than these guys, and it shows up for sale pretty regularly. I think for in home rock and roll, for someone who likes 2-ways, the 4430 is the best way to go. If you have the stamina, read Mr.Z's Quick and Dirty 4430 thread. He's outlined many ways to get there.

David

[Tim Williamson]

Mike/Dave,

Thanks lots for the input.

My original plan was to use these boxes, and plop the horn on top. If I needed to replace driver in the box.... oh well, so be it. The crossover, all I need to do is find schematic and I'll probably have almost all the parts here to whip it up..........wha-la, rock'n speakers.

I don't look at this as one time deal. That is to say, given my curious nature, I anticipate playing with various drivers and such over time. Right now, just getting something whipped up for pretty cheap was the goal (hoping to come in uder $500).

Oh yeah...... is there schematic anywhere for 3110 crossover?

[speakerdave]

I mostly listen to jazz music, and have toiled at getting a great single/full range driver speaker set up. It is always an on going process.... but I am pretty happy with that.

I'd like to hear more about your adventures with full ranges. I first found this site while looking for information about the JBL LE8T, and still have an interest in it. I prefer the simplicity of full range or near-fullrange with supplement at top or bottom or both, although my experience with JBL has convinced me that multi-way speakers with band-limited drivers and well-done crossovers can really be good. I think some of the best speakers going today follow the idea of putting a broad middle-range frequency band in one driver (Von Zweibach, the JBL LSR 32). Even the JBL 4-way monitors benefit, I think, from the same idea in a more limited way.

But you are right. The drivers (and amps) that make the best compromises for full range do not pound well.

David

[speakerdave]

The crossover, all I need to do is find schematic and I'll probably have almost all the parts here to whip it up..........wha-la, rock'n speakers.Oh yeah...... is there schematic anywhere for 3110 crossover?

Nice, if it were that easy. The schematic is at JBL Pro, with a lot of other good stuff:
http://www.jblproservice.com/pdf/Network%20Schematics/3110%20Network.pdf

But a key part is unobtainable (the tapped coil). Z. and Co may have worked out an equivalent on the Quick and Dirty thread. Happy hunting, there!

David

[johnaec]

Also be aware of the difference between the 3110 and the 3110A, (which I have not been able to find a schematic of, though I may have seen one posted here at some time).

The 3110A adds a 3-way compensation switch to adjust the HF curve for constant-directivity horns.

John

[Tim Williamson]

Dave,


Big thanks for the links. I am sure I can have my brother whip of a crossover to do the right job. I am really looking forward to this project..... though I expect it will take some time (probably a month+ until I pick up the 4650's in PA.... and buying horns/drivers for the mid uppers.
This pair of speakers is going to be learning experience for me. Once I learn what I like, and don't like.... then I will take the plunge into a permanent high end pair.

Per single driver/fullrangers. I first was intrigued with the idea.... so I had my brother whip me up some Voight pipes w/fostex drivers. Even though the drivers were just OK.... and the enclosure an approximation.... and MDF (I hate MDF!)... I heard something......something good...... I knew there had to be more!
Long story short........ my brother (former Madrigal employee.... and knows much more about the technical stuff than I!)and I ended up importing cool high end driver from a company called Lyeco.... it's an 8"er. Have them in some TQWT enclosures at the moment..... they sound pretty great. In the next week or so I will be building some ONKEN type ported enclosures. By next spring I think my back yard will look like the shores of Easter Island!
Most stuff (jazz wise), sounds really, really great. AC/DC does not. and of course there is the shortage of LOUD! So here I am..... not only hangin' with fullrange geeks......... now to theatre freaks! Does everyone see this as as much fun as me?!

Anyone going to the Vacuum Tube Valley DIY sponsored event in April in NJ? Anyone here near Buffalo, NY?

[speakerdave]

I heard something......something good......
That's it.

[mikebake]

Dave,


Big thanks for the links. I am sure I can have my brother whip of a crossover to do the right job.
Not the preferred stock solution, but in that case you might also have some success cloning an SR4725 crossover............

[Akira]

The 4560 was the main stay of the P.A. industry in the 70's and was used in every club and hall north of the boarder. One of the most magnificent concerts I ever saw was ELP 'Brain Salad Surgery' true quad tour, which knocked out four huge banks of seats to accomodate a pure JBL system using 4560's as mid bass only. This is their intended use, with a recommended active crossover point into a phenolic driver at 1200Hz.

I used to own a P.A. composed of 4563's with double slots. This box absolutely kicks ass--no and's, if's or but's. It has the best reproduction of rock guitar I have heard from any cab. Notice I said reproduction. That means sticking a 57 (mic) right up to the edge of 12" Marshall and reproducing it with a much larger, softer and fuller sound than the original. You would not get a good sound by just plugging your guitar straight into it. This box has a 180Hz whack and projects well; again it's intended use. The physical impact you feel off it, is jab in the face, not a slug in the stomach. The jab in the face is the pop you feel as the drummer hit's the low end of the snare drum; the slug in the gut is the wrenching hit you feel from the kick drum. This cabinet requires a sub.

The down fall of this box is that it was intended to be used in a 4way application. All of it's wonderful qualities rely on it's ability to interface at a low crossover point into a phenolic driver--the closest a compression horn ever got to a paper cone speaker. For example, this box has excellent vocal reproduction, but needs that phenolic to help translate the low end of the box to come through smoothly.

I am not sure how it would sound in a house???

[jkc]

The 4560 box was originally intended for a 2220 operating from about 100 Hz up.

People then decided that they wanted more base so stuck other drivers in it but this always results in reduced output below 1Khz, and a not so flat response.

A driver with high X Max will hit the back of the speaker mounting baffle



Try setting it up with a 2220 rolling of to horn of choice at somewhere around 1Khz

Use a couple of 18” for subs

Try some HF like slots and away you go.



This sounds like the new stereo I am building for the garage.



You will find the 2220 is much overlooked driver but an articulate one.

With its efficiency of 101 dB when horn loaded you end up with very efficient speaker at 107 dB 1watt @1 meter and reasonably flat frequency response from 150 Hz to 1Khz.

[jkc]

Here is some more thoughts on these 4560 boxes at home.



If you go back in time to when these boxes were designed one thing that was lacking was big power amps.

The only way to get lots of noise was to have a high efficiency speaker and horn load it.

The big disadvantage of this is you end up with a big box that is heavy and difficult to move around.

As big amps became more common and cheaper this kind of box fell from grace as even in a fixed installation they take up a lot of real estate and you can do the whole thing with a smaller lighter box.

On of the reasons Neodymium magnets became popular is the extra cost is recouped in freight bills due to the lighter weight.



Any high efficiency driver and horn by nature of its design is going to have a limited bandwidth, this is just the physics of the whole thing.

One thing you do get is a light weight cone and the good transient response that comes from this, and is the reason horn loaded systems have their following.

For a High Fi at home you do not want a 2226 is it has a heavy cone that goes dark around 600Hz and you will lose the open spaciousness and transient response that horns are capable of when driven with a light weight driver.

A 2226 is also not designed to be horn loaded.

The other option for a 2220 is a 2227 that the 2220 evolved into but JBL only made these drivers for a short time as they were so expensive and didn’t sell well.

Avoid phenolic diaphragms at home, they are heavy and have limited bandwidth to 4Khz

Phenolic was designed for extreme high output as metal diaphragms explode if driven to the levels Phenolic is capable of.

When it comes to compression drivers 2” drivers sound better, mainly because there is less compression in the chambers.

I.e. when you compress the air in the throat the compression is not linear so the bigger the throat the less non linerality.



If you want good stereo imaging it is important that the off axis response be smooth and this should be a guide to the dispersion pattern of the horn you chose and the crossover point where the pattern is the same.



I would stick with the 2220 that came with the cabinet at 200watts it will give you 130 dB at 1 meter and at sane levels will require minuscule amounts of power.

If you want the bottom end to keep up you need to look at some 2242’s or 2241’s

My own project uses Radian 2218’s on the bottom but I was just using all the odds and sods I have lying about.

As for horns I have a selection to choose from but my own project is low on the list, but you should be able to achieve time alignment with the drivers.



As for crossovers if you have any intention of cranking it up use active filters with 24 dB slopes.

You don’t need big amps but you do need quiet amps as noise can be a problem.



Hope this helps you on your way. They sound cool and are worth the effort.

[mikebake]

For a High Fi at home you do not want a 2226 is it has a heavy cone that goes dark around 600Hz and you will lose the open spaciousness and transient response that horns are capable of when driven with a light weight driver.

A 2226 is also not designed to be horn loaded.



I agree with most of what else you said, but heavier cone = bad horn driver has been debunked. I also do not see/here where the 2226 goes "darK". Could you explain? Additionally, the 2225 literature states that the driver was made for horn loaded and DR enclosures, and the 2226 is a "direct drop in".

[jkc]

A 2225 and a 2226 are 2 different drivers.

The 2226 has a heavier cone.

The 2226 loses detail higher up due to this.

I was specifically referring to using the drivers at home for a Hi Fi as opposed to a PA application where we do not care so much but it holds true in a PA as well.

The 2226 is capable of better low frequency output than a 2225.



JBL recommend the 2220 for horn loading but not the 2225 or 2226.

If you run the numbers you will see this is the case.

I realise that people load 4560 with these drivers for more base but I was trying to point out that it is at the expense of a more wobbly frequency response and reduced articulation. Acceptable in PA use.



These 4560’s were originally designed to be used with 2220’s



An attachment from JBL

[jkc]

Sorry the attachment was to big
Here is the link to JBL litriture on 4560,s

http://www.jblpro.com/pub/obsolete/Low_Frequency_Enclosures2.pdf

[mikebake]

JBL recommend the 2220 for horn loading but not the 2225 or 2226.



Yes, I agree, later heavier cone drivers were said to have lost resolution in comparison to the earlier lower power models.

With respect to JBL not recommending the 2225 for horn loading, what would "specifically designed for both horn loaded and vented box enclosures" mean exactly then?

http://www.jblpro.com/pub/obsolete/2225hj.pdf

[grumpy]

Interesting thread. I tried a pair of 4560's ($25/cab ... -really- beat)
in a large living room... first w/ E145's, then 2226's (what I had handy)
and a 500Hz crossover to 2350/2446's. Much preferred the 2226's.
Your mileage may vary.

Also tried 1.2KHz and Everest, then butt-cheek horns on top (bi-radial
compensation and 2405's all along, coming in ~8KHz). Would have been
interesting to try a pair of 2220's to see if they integrated better.

In all, it seems that 1) I need measuring tools more than I need more
speakers (living room got -way- out of hand), 2) 4560's did some cool
things, but gawd, those boxes are huge and still need EQ and subs
(didn't have xover to do SUB1500's at the time... too many projects).

OK, so this wasn't exactly "technical" info. Moderator can feel empowered
to delete w/o hurting my feelings. :D

-grumpy

[johnaec]

The other option for a 2220 is a 2227 that the 2220 evolved into but JBL only made these drivers for a short time as they were so expensive and didn’t sell well.JBL does still have it listed among current components at their website: http://www.jblpro.com/pages/components/svg.htm#2227H

'Website out of date?

John

[jkc]

Last time I asked about 2227's I was told they were no longer available but I noted they were available as spare parts. I must have a go at ordering them they are supposedly a very nice driver.

Just sit back and wait a year for them to turn up.

[mikebake]

For a bit further clarification, I would agree that the 2220 is better in that box for it's intended use, but in the posters setting, the 2226 provides better bass. He wasn't intending to come up with subs. In any event, it is a PA box, so every other application is going to have issues. I do still enjoy my two, and have never wanted to get rid of them.

[Tim Williamson]

Mike and all,


This has been really great info! Mike is correct, at the moment I am not going to do the sub woofer thing. Just want to get the pair of speakers mated to horns and sounding good.... then the real insanity (tweeking!) will begin!!

[mikebake]

Member subwoof is in, I believe, the Finger Lakes region and is a good possible source for future upgrades to these. You can contact him thru private messaging from the members list. He knows 4560's. Let us know how it goes and what you come up with.

[Akira]

Avoid phenolic diaphragms at home, they are heavy and have limited bandwidth to 4Khz

Phenolic was designed for extreme high output as metal diaphragms explode if driven to the levels Phenolic is capable of.


I agree with all of your assessments of this box, except your views on the phenolic. The 2470 driver has excellent response up to 9K and is a perfect match for the 2405 slot, except I used two per box to lessen the load. The 2470 phenolic has a smooth paper quality to it, and it is an excellent match up to the 2220. With these drivers used in combination, the vocals form a seamless match at 50' and on. As my only experience with this box is in live SR, I am not sure if that would translate into a small room.

I am aware that Phenolics display the properties you alluded to. (not the 2470) The more famous 2" 2482 was the most powerful driver of it's time and had a wicked response in that 2K to 4K range. By wicked I mean not pleasant, especially when mated with those huge steel radials. We used to call them ear slicers. But, when used with the large slant plate lenses, their paper quality comes through and they almost sound like a speaker.

Sorry to digress, but I'm a phenolic fan.

[Tim Williamson]

Hey All,

Cool discussion, more than I could have hoped for.... this forum is definatly a keeper!

For the moment, I think the plans will be what Mike (I think?) suggested earlier. Use 2425/2370 to tie together the package.... and play from there. The crossover we will tackle...that should not be too painful.

Does anyone else out there actually have these enclosures in hi-fi setting?

The cool thing about the size of this sort of enclosure is that I might be able to get away with it in the house if I screen some Andy Warhol art on the sides!...mwah, ha, ha, ha!

[Tom Loizeaux]

I discovered I had phenolic diaphragms in my 4320s and 4333s some time ago. Both of these use the 2420 drivers and cross to 2405s around 8K (3106 crossovers). I've never felt they were shy in the upper mids! When I compared them to my 4343s (which have aluminum diaphragms), they might have lacked a little of the openess that the 4343s had, but I would call them very comparable in terms of actual use. I have heard that the phenolics will handle more power.

Tom

[duaneage]

Every club I ventured in while in Korea during the 80s had 4550 JBLs. Performance was always top notch. I can tell you for sure that JBL sold more speakers to GIs because of the name blazed on the side of those boxes. Those speakers took HOURS of abuse 7 days a week and never failed.

[Tim Williamson]

Hey all,


With any luck (weather.... I live next to Buffalo, NY ...and it is winter time!)... I will meet a friend of mine and pick up 4560s (yes, the driver in them is 2220).

I found a good deal on a pair of Altec 511B horns (about $100). Just compression drivers and crossover left. Compression driver will probably end up being P.Audio as it fits the bill (and most importantly, fits the wallet [vrs the TAD 2001]). Hoping to have crossover party around New Years (I know... party animal that I am...... GEEK!) and them fired up early mid January. Anyway... that is all superfluous information...just thought I would give an update.

Now to the real question at hand. I have looked around for specs on the 2220 driver, but as of yet, not found them. The reason for this (aside from just my idle curiousity) question is..... my 300B amps should be enough to drive these contraptions?! Or am I adding yet another adventure and getting push pull amp built?

[speakerdave]

The 2220 meets the SET efficiency standards. Here is a spec sheet:

http://www.lansingheritage.org/html/jbl/specs/pro-comp/2220.htm

David

Edit: That efficiency standard (at 30 ft) can be made to correspond roughly to 1 watt at 1 meter by adding 49 dB.

[Tim Williamson]

Thanks Dave,

I did cursory search, but obviously didn't look in the right places.

OK, well..... keep you all updated on how this frankenstinian project goes!

[speakerdave]

The library is not searchable because most of the files are not text files, but jpg's and pdf's. You just need to spend some time over there to learn your way around.

David

[mikebake]

Speak of the devil;

http://www.arduman.com/aa/Resimler/roscoe/syst.jpgSpeak of the devil...................in a home setting.

[Tim Williamson]

.....correction.... the drivers in the 4560s are 2220 in 2225 baskets. Hmmmm, is there spec sheet for this???

Mike..... cool pic!.....

[sa660]

I used this beast for a year or 2.
The setup was 4560+2226 and LE85 with 2309 (I think).
I also tried JBL E145 2220 and Westrex 2080A
I was given the loan of a sub 18" JBL 4645. This really did complete the audible range.

As a 2 way i recommend to complete with 2370 and 2425?
You may be luck and complete with 2397 and adaptor 2327 and 2425.

Regards,

[jbl_man_uk]

I Have tried mine with a variety of drivers,2225,2226,2220,and finally put the E130`s back in.Now finished them off with the 2405 slot radiators mounted in the mouth,as per factory model.

[jbl4ever]

I Have tried mine with a variety of drivers,2225,2226,2220,and finally put the E130`s back in.Now finished them off with the 2405 slot radiators mounted in the mouth,as per factory model.Same here, but with the 2205,2225,2226, or K145 you should put a 3/8 of a inch spacer on the mounting gasket. If not, at higher power inputs the
cone will hit the horn throat. A must if you try to EQ the 6db rise at 200hz due
to the horn coupling:D

[mikebake]

Same here, but with the 2205,2225,2226, or K145 you should put a 3/8 of a inch spacer on the mounting gasket. If not, at higher power inputs the
cone will hit the horn throat. A must if you try to EQ the 6db rise at 200hz due
to the horn coupling:D
I've run 2225 and 2226 in them for several years now and never had that problem......still sounds like a good idea, though

[jbl_man_uk]

The 2226 has a very long cone travel,(1.5 ins)so i can see in therory that if u drive it hard enough it will hit the front horn flares,so the spacer makes sense,as the front mouting gasket isnt very thick.(Never had that problem with the older Altec drivers, 421 8a etc,as Altec allways used a very fat front gasket) .i intend to use my 4560s above 150 hz,crossed actively,with the bass going into Martin Audio 215 bass horns.(not sure if u guys in the US have Martin Audio over there?)

[johnaec]

The 2226 has a very long cone travel,(1.5 ins)Are you sure about that?? The Xmax is only .30"! And I just went and checked one of mine, and there's no way in a million years that you could move the cone in or out 3/4" - I don't think it would even go 3/8" one-way.

The Sub1500 is a different story - 1.5" total travel, (in and out), is about right for those...

John

[jbl_man_uk]

Yep,i made a mistake.its actually 1.6 inches...quote from the spec sheet....max cone excursion (peak to peak) is 40mm (1.6 inches).

http://www.jblpro.com/pages/pub/components/2226.pdf

[johnaec]

....max cone excursion (peak to peak) is 40mm (1.6 inches).Wow, you're right! I was looking at the T/S parameters on the same spec sheet, and actually tried physically moving mine, (safely!). It still seems almost impossible to me that they could move that far!

John

[jbl_man_uk]

Yes I agree John,it does seem to be an amazing amount of cone travel, It might be OK on a factory fresh test unit,but i dont think i would like to try it on one of mine!.ian. London UK.

[mikebake]

Wow, you're right! I was looking at the T/S parameters on the same spec sheet, and actually tried physically moving mine, (safely!). It still seems almost impossible to me that they could move that far!

John
I cranked four of them in sub duty in the big JBL quad 15 box (something like 26 cu ft) in a HUGE auditorium and their excursion that night was unreal; actually sucked the DJ's banner hung in front of them into the vent hole.

[spkrman57]

I think the linear excursion is much less than that.

Ron

[johnaec]

I think the linear excursion is much less than that.

RonA good indication for linear excursion is that Xmax is .30" - I imagine linear might be a little under that.

John

[JBL Dog]

I thought you said it had the drivers. No woofers? BTW, while the A7 may garner more acclaim, I have heard it and the 4560 quite a bit and I like the 4560 with proper JBL components better. The Altec woofer is nice, but the JBL box/components have more punch.
Find some 2226's (not hard) for the woofer. Also, does the cabinet have the JBL tag on the back? Post a photo of the rear, if you would. Is that your actual unit, or a stock photo?

100% agree. The JBL 4560 blows away similar configured Altec cabs. I have a set of 4560 clones that sound incredible.

:p

[bigredplane]

The 2226 has a very long cone travel,(1.5 ins)so i can see in therory that if u drive it hard enough it will hit the front horn flares,so the spacer makes sense,as the front mouting gasket isnt very thick.(Never had that problem with the older Altec drivers, 421 8a etc,as Altec allways used a very fat front gasket) .i intend to use my 4560s above 150 hz,crossed actively,with the bass going into Martin Audio 215 bass horns.(not sure if u guys in the US have Martin Audio over there?)

This is true. I have a pair of JBL 4560bka's with 2226's in them and I had to space the woofer back because it was hitting the cabinet. You can hear it when it happens plane as day.

[mikebake]

This is true. I have a pair of JBL 4560bka's with 2226's in them and I had to space the woofer back because it was hitting the cabinet. You can hear it when it happens plane as day.

Hmmm, I've run 2226's in them for years, loudly, and never had this happen. I am not EQing any bass, though. Other than that, never seen it, even when running them with lotsa juice.

[sa660]

The 2226 has a very powerful magnet, and a very strong Electromagnetic force. If you are using very powerful amps with high dampening factor the excursion will be very well control and you will get very loud noise and very low excursion. If you are using a cheaper amplifier the energy from the mechanical bouncing of the suspension can be added to the forward motion of the cone and cause extra excursion that can hit the 4560 cabinets.:banghead:

[mikebake]

Well there you go! I'm using some QSC PLX's on them, which are generally loafing but do have some balls to them. They've been great amps.