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Hi. I am new to this forum , so be kind. I am looking to build a 2way system using a JBL woofer and an AMT Heil air motion tweeter. Which woofer would you recommend considering i am looking to crossover no lower than 800 and want to keep the cabinet volume between 3-4 cu ft. I am not very knowledgeable about JBL drivers so i would appreciate advice. I will be driving these with a 15 watt el84 push pull tube amp.
steve.
I'd use an LE14.
Sounds like a good choice to me as well. The Le14 is a large 14" driver with a 4" coil used in L250/L250Ti/L240Ti/L220/L222. You could also go with 12's with 3 " coils like 2214 used in the 4425/L100T/XPL-200 and a 12" 128h-1 used in 120ti/4412 if you have difficulty finding LE-14's. The Le-14 comes in several versions. The Original Alnico A white cones and the H's gray cones which are Ferrite. The A's are on Ebay all the time. The H's are also up but hard to find and expensive lately. You can order LE-14h-3 which is the best of the lot from JBL but they are not inexpensive .Quote:
I'd use an LE14.
Rob:)
The LE14 isn't fantastic at 800Hz and has relatively low sensitivity. I can think of a couple of non JBLs that I would use first. How about the JBL 1200FE?
Widget
I see Rob added to his post. His 2214 suggestion also makes sense to me. I think it would have a bit more bass than the 1200FE but not quite have the control.
Widget
Thanks for the replies.Quote:
Originally Posted by Mr. Widget
Is there somewhere i can see the specs for the various drivers. I don`t know the sensitivity of the le14 or the 2214. You also mentioned other non jbl drivers?
Steve.
OK you have the T/S tables which gives you efficiency in %
Here http://www.lansingheritage.org/html/...s/tech1-3a.htm
You need conversion table
Here http://www.trueaudio.com/downloads/spl_eff.xls
Or you can just look up the systems where the drivers were used. Most systems are based on the woofer sensitivity so it's works out pretty well using the system numbers in Db, just watch the distance on the older systems. There are rated at 15 ft as opposed to 1 meter.
Here http://www.lansingheritage.org/html/...e-speakers.htm
4425 is 91 db on the 2214 and L240Ti is 89 and L250 is 90 for Le-14.
Rob:)
Thanks Rob.Quote:
Originally Posted by Robh3606
I guess i just need to decide between the two. Does anyone have any other suggestions? I`m leaning towards the le14 from opinions i`ve been reading. How is the d123a-1 in comparison? This is a wide range woofer right? Bear with me, i`m learning.
Steve.
That is the L100/4311 woofer. In those applications it was run wide open with no crossover so it rolled off naturally. It uses a curvalinear cone and has a decent X-Max. Personally I like it but I think you can get a smoother more extended low end response in your volume from some of the other woofers. What I would do is take any woofers you are considering and running them in a box program to see what they will do in your chosen volume range. Win Isd is free and can be downloaded here:Quote:
How is the d123a-1 in comparison?
http://www.linearteam.dk/default.aspx?pageid=winisd
The program comes preloaded with many drivers from many manufacturers so it makes things a bit easier than searching for T/S pararmeters and then loading them.
If you know anyone who owns JBL's or any other system that uses the woofers you are interested in go have a listen. You can get a general concensus about how a driver sounds and find it just doesn't work in your application or doesn't sound right to you. It's hard giving subjective opinions for that reason.
As far as any of the woofers listed so far I have used all of them and in general I think it would be hard to go wrong with any of them once they are properly installed in a well built cabinet, tuned, and crossed over in their intended range. They are all a bit different but all perform well.
Rob:)
An LE14 with only 15 watts???Quote:
Originally Posted by Robh3606
Maybe, I know I would need much more power. Personally I wouldn't consider any woofer with less than a 93dB sensitivity and I think I'd prefer a high efficiency number with an added self powered sub.
Widget
Here's a thought.
Go with JBL 12's that still have recone kits available. 123A-3, 2213A/H (not A-1, nor 2212...too expensive to recone), 122A, 128H/-1, 129H.
2213's are plentiful on ebay and they can still be reconed. Couple it with a passive radiator like the AMT-1's have, fill it with lots of damping material to kill the ringing of the PR and tune it to your liking in 2-3 cu ft box. The 2213 (123A-3) has the cloth surround that will be very durable. I think you'd be very satisfied and it would work well with a tube amp.
Hello Widget
I understand your concerns however the woofer efficiency in the systems is posted and an efficiency chart is posted. I hear you on the power, but you don't know how loud, what size the room is, listening habits and so on. The point I was making is they are all good drivers and set-up you won't need subs.
It was a general statement. I wouldn't use less than 100 watts with any of them but that's me.
I have seen people power 87 Db stuff with 2 watt SET'S and be just fine with it. That said how sensitive is the Heil?? That is what is going to determine how sensitive a driver he can use.
Rob:)
- Cyr Marc ( over at the H.E. forum of the A.A. site ) is positively effusive over the combo of the Heil with an Altec 414-8C ( I think that's the preferred impedance ). The 414 has a mid nineties figure for sensitivety . Iconic sells a new version of this speaker .
- Do some site searches in their archives for that name ( he hasn't posted for quite some time ) .
- I don't know the enclosure sizes he and his cohorts prefer for this combo / so you'll need to search out that info . You may need to register at Audio Asylum to research this info.
- I'd somewhat ignore what the TS parameters suggest for an ancient legacy Lansing design / such as this .
- Find out what the guys say actually "works" .
- You may want to ask them if they've ever tested PRs ( passive radiators ) with the 414 . The original ESS/ AMT(s) used those to pretty good effect .
:)
Ok, i`ve picked up a pair of D123s and am thinking a ported box about 4.0cu ft tuned to 38-40hz? I know that these don`t have the bass of the 123a-1s, but are more efficient. Anybody got any experience working with these drivers?
Steve.
I've had some of those. They are nice vintage full range speakers, but don't expect any bass.
I'd like to be a little more encouraging about the D123. It is a more linear driver than the other D's (D131, D130 and D208), and less efficient, which will make it a better match for the Heil tweeter, which is not as efficient as one might think.Quote:
Originally Posted by castlesteve 1
I have put the D123 in a box about the size of the one you suggest, and I think it will work. Mine was crossed over to a tweeter at about 1500, if I recall correctly. You could even use a somewhat higher crossover point than your original idea of 800, which would be better for the Heil and I'm guessing the dispersion patterns would be more in line. I've never finished a system using the Heil, but I've experimented with it.
You will get bass with the D123 in that box, do not fear. What will not be there will be VLF. I doubt that you are shooting for that right now. The D123 has a free air resonance of 35 Hz. I would experiment with different degrees of damping in the box, starting with fairly light (one layer on one of each set of opposing surfaces).
The 6BQ5 makes a very nice little amp, and those fifteen watters have more guts than many people would think. You already know that you are not looking for gut thumping volume.
You have to understand, most JBL people slowly become bass freaks once we discover what true VLF is like. As Widget said, that may be in your future. But for now, I think the project you are contemplating will be quite satisfying.
David
I've done comparisons of the efficiency ratings of some drivers that appear in charts with both old and new methods. It appears that adding 49 dB to the old rating will give the number arrived at by the new method with closer miking. The LE14 is listed at 44 dB in the old charts, so by the new method I would expect 93 dB. It is more efficient than one might think.
David
I've seen JBL rate the LE14A/H at 91db and at 93dB... like so many of their specifications, I have no idea why their numbers would vary.
Widget
I doubt the specs vary as much as the accuracy of the copywriting and proofreading. The online information about the LSR32, for example, stated that the midrange was 2" when in fact it was a 5" midrange with a 2" voice coil. As happens on the internet, this bad information was copied everywhere and probably hurt the sales of the speaker. After all the effort that goes into engineering speaker systems, to have this kind of thing happen is really ridiculous.
David
Take a look in the T/S tablesQuote:
I've seen JBL rate the LE14A/H at 91db and at 93dB
http://www.lansingheritage.org/html/...s/tech1-3a.htm
Then use this with the %
http://www.trueaudio.com/downloads/spl_eff.xls
Looks like rounding???? Not sure on the 93
Rob:)
Thanks for the encouraging replies. I was beginning to think i had made a mistake in buying these woofers. I will experiment with raising the crossover but i have read that the aluminium dustcap on these has a breakup node around 6-7khz which i would like to avoid. I am also looking to pickup apair of Altec 414s which i will A/B with the 123s.
All i have to do now is build the boxes. These will be the biggest yet! I am going to use plywood and laminate the baffle with 1/2" mdf.
Thanks again, Steve.
http://img.villagephotos.com/p/2006-...-system005.jpg
I don't think it's a breakup node, but rather a bump in response based on the dimension of the aluminum dome. I wouldn't use a twelve-inch much over 1000 Hz, anyway, so the 7k mode should not be a problem. The Altec 414 is a very good idea, but I'm a little concerned about efficiency matching. You want your woofer to be the least efficient element you will be linking with a passive crossover. You don't want to be in the situation of having to pad down your woofer to match the tweeter. See if you can find an efficiency rating of the Heil before you buy any more woofers. Have fun.Quote:
Originally Posted by castlesteve 1
David
I've had a pair of AMT-1s in their boxes in the closet for.....awhile......and gathered what info I could when I got them. Can't find the file, but 97dB 1W/1M is what I recall, down to around 700Hz, with a fairly quick rolloff. The power rating surprised me, IIRC, around 125W. Someday, I'll find out for myself.Quote:
Originally Posted by speakerdave
Here's a (semi-useful?) response plot;
http://www.audioasylum.com/forums/MU...ges/78320.html
And for the dedicated patent-reader;
http://patft1.uspto.gov/netacgi/nph-...&RS=PN/4160883
Here is a link for the ess http://www.lautsprechershop.de/hifi/...endchen_en.htm
I just got a pair of the AMT1's from Gordon W and here's my idea.
AMT1 HF 7500+
511 802-8b Mid <500-7500>
jbl 2225 woofer 500hz and below
I would build a 9846 box and run it sealed.
Now I think that would rock.
I could run a pair of Crown VFX-2A's with Altec 9441 HF, Hafler DH-200 on the Mid and 9442 LF.
That would give killer mids and HF with TIGHT LF
I'm not trying to be a party killer, but you should do a frequency response check on your Ess tweeters.
This winter I was visiting a friend with some test equipment in the trunk, and both tweeters was stone dead above 10KHz. Both checked with and without the Ess crossover in the loop.
Attached is the left speaker without the crossover connected.
You mean the curve was the same? Can you post the two curves, with and without the crossover?Quote:
Originally Posted by yggdrasil
David
I'm sorry. Looked around on the computer, but it seems only one set of curves have been saved.
I can remember though, that the only reason for measuring without the crossovers was that I could not believe the curves with crossovers in the loop.
How big is 9846?
Seems inappropriate to run 2225H sealed.
Have we been through this already in another thread?
Hi Steve
I happen to have a pair of free floating Heil AMT's so it was pretty easy to generate a fresh curve. The mike was set at 0.5m, with impulse gating wide open (to see LF limits) and 1/10 octave smoothing (I did not set a reference level). You will need a little compensation to get the top end to be really flat. Otherwise the AMT's do have an interesting sound to them.
Best regards,
Keith
Well, there's two independent results half a world apart in substantial agreement. :thmbsup:
[Love it when that happens.... :yes: ]
My friend is using 123a & AMT1 combination and is preparing text for this project. Visit his web http://www.moxtone.com/Slavooy.htm and contact him for the details.
I am new as well and have already made a two way using the Heil series 1C, upgraded crossover parts on the original AMT crossover (Madisound) and used an Altec 414c mid/woofer due to its quickness. Bass is not strong but the transparency is quite good. Used a modified transmission line similar to a 1/4 wave and minimal distance between the altec and the heil to properly converge the waves at the 800 hz crossover. The Heil as I recall is 97 db/watt/1meter/4 ohm efficient which is a good match for the altec at 96db/8ohm. The old crossover provides matching for output and frequency response on the tweeter anyway so it worked reasonably well. I like my pair very much.
More could be done of course by the experts here but I was pleased with the results of my first project to the point I have no desire for an upgrade after using them for almost a year. :bouncy:
Get yourself a pair of AMT1's. Drop an Altec 414c where the woofer is. Keep the passive. You are on your way. When you have the time/motivation/inspiration go ahead and start experimenting with a woofer as a sub or part of a three way. Or as an intermediate step re-design your two way and crossover using the same drivers. Maybe try a petite onken. Or go with a big t-line.
I personally started from scratch with an Altec/Heil combo using a modified QWTL. It weighed in at about 4.5 cu. ft. total. Bass roll off began at 55 hz and I was never quite satisfied with its reach to the bottom. That said the quality of the bass was quite good, and overall a more remarkable speaker than the KEF 104/2's they replaced, particularly in the transparency department where they are no slouches. Slightly more dynamic as well with crossover upgrades. You will need to keep that crossover to begin with, unless you are going to an active one, as things get complicated using such a high efficiency 4 ohm tweeter matched to an 8 ohm midbass. I almost maxed out the built in attenuation on the heil crossover and found the frequency adjustment helpful as well.
As I said I am now moving on to a two way plus sub or a three way. Just got a pair of JBL 2235H's to experiment with but I will for sure be doing away with the bottom part of the t-line I built for the two ways. I will stick with the 414c's in the midbass for now rather than try to stretch the voice of the JBL's (as a two way option) as the Altec's are such a good match for the quickness and transparency of the Heil's- I know I would lose something if I eliminated them to go straight to the JBL's. I will be going with all new crossovers through ERSE Audio when I decide which way to go; be that two way plus sub or three way. The sub option takes up more floor space but is much easier to tune for room acoustics. Wish me luck. We sure have passion for this hobby don't we? :bouncy:
Hey - keep us informed with how this progresses! Sounds very interesting!Quote:
Originally Posted by cerondipity
And, of course, pictures are ALWAYS welcomed!
Or, if you really want to be fun - you have a listening party for the locals (grin) ...
Interesting sounds are also appreciated!
This was supposed to have been a response to the last post the chain: 2 Way using AMT Heil-Quote:
Originally Posted by cerondipity
I was not trying to reply to my own post! Now the board will not allow me to delete it as it has already been replied to. The point is I think everyone should listen to a Heil/Altec 414 combo or maybe a pair of 123a's as suggested, or whatever, before deciding to jump in with grand plans. Its so simple just to get the complete cabinets and replace the midbass, keep the crossovers and adjust them as required to get a feel for the sound. I started by disconnecting the tweeters on my KEF's and ran the Heils full range on top. Yeah, the cross was off but they sounded great. Perfect for those live performances. Staid up all night listening. Thanks hjames for watching my first speaker project evolve. And thanks to everyone who has been helping with suggestions. This is a great forum.
get a pair of AMT1's. Then go with the previous suggestions which include a 123a out of an L100 or an Altec 414 and replace the existing midbass of the AMT1. This simplifies things immensely. Keep the crossover and adjust as required. Keep the passive radiator. It's a lot easier to start with the existing cabinet and crossover than to start from scratch without benefit of hearing what it will sound like. If you like the sound then start planning...New cabinets, new crossovers, maybe go to a three way or just add a sub?Quote:
Originally Posted by castlesteve 1
Bye buddy.....Quote:
Originally Posted by Zilch
But to the point, 2226h works fine sealed, it's just not maximally extended- subs no longer optional.
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