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In Reply to: RE: No I read it. You talk in conceptual terms allot IMO. Be great to know specifics too posted by 2chJunkie on February 22, 2015 at 07:36:08
Sorry I can't give you all the details on my latest systems, thinking of a commercial venture so I hope you understand. I do want to help you because you have all the decent stuff I was playing with years ago and you are really close to making something world class great with most of what you already have.
I know where you are, in the "its all good" phase. I actually do appreciate some lost cost gear and use it on the tv, computer to hide horrible source material but lets have some separation here, your bad boy Edgar system should not be lumped in to the same category as the cheap stuff and lower end gear at least it won't after I help you tweak it.
1.First thing, Bruce told me many many years ago is that tractrix horns beam badly at 20x the flare rate so 650 cutoff x20=13000 hz.
The horn on your TAD 2001 is much too large for good dispersion
and probably has a bit of a tunnel effect for the highs. I would recommend around a 2000hz or higher cut off wood tractrix horn for your TAD2001. Round wood horn is preferred but if you are pressed for time and money Parts Express has a metal elliptical tracrix STH100 by fatial pro for around $31 each that sound pretty good for 5000k and up. I cross them at 5-6k or above on a buddies system with 2440's on mids.(I know, metal horn=cow bell), mount them to wood and use a little bit of clay and they won't attract any cows. (don't go crazy with clay just a handful) Also use with wide part of ellipse going vertical towards ceiling for best imaging.
2.Do what you have to by selling some of your unused gear for money to get some beryllium truextent diaphragms for your 2441's. Will blend better with your 2001's even if you have some decent sounding diaphragms's in your 2441's now. I have heard the Truextent diaphragms in the Classic Loudspeaker's room many times. First time the dynamics were so real they actually scared me. I was not facing the speakers and a trumpet solo came on, I thought someone was playing a joke with a real trumpet behind me!!! Fun stuff.
3. Time align your drivers voice coils, especially on the highs.
4. Now the mid bass and bass is what separates good horns from great horns. An Ev force on j horn, hmm guessing Bruces "show" horn. That is a "not bad" set up but I think you will be very happy if you spend a little time changing things in this area. My favorite mid bass and bass horn driver was also what Bruce used before field coil, the JBL 2220 15", and yes in alnico of course. You will end up with a straight horn in the 80-120 to 500hz area eventually but in the mean time find some nearly free Peavey Fh-1's, stick some JBL 2220's in there and make every LaScala owner so very jealous. I think this set up will out do the Force/j combo.
A 2220 with a heavy aftermarket cone and lower fs actually worked better using it on a 35hz-100 bass horn. (Might be the only time ever I liked an aftermarket cone over a factory JBL.) The original factory coned 2220 is just really nice driver for midbass and lower mids, no make that a fantastic driver.(aw shucks, I don't want to drive the cost of these up but what the heck) The factory coned 2220 has a mass roll off of around 400hz in a horn and does up to about 900hz as a direct radiator comfortably without beaming. Be careful with some of the other JBL 15's in a bass horn that look similar to the 2220, they have a little less x-max. The 2220 was actually one of the few driver made as a bass horn driver.
Follow Ups:
I completely understand your point of view. And I wish you well on your possible business venture. You sound seasoned enough to make a real go at it.
Just to clarify. The J horn midbass horn is made by Ed Gindin. He and Bruce know each other very well and respect one another. It uses a 12" driver. Im not sure if fitting it with a 15" is ok or advisable. Maybe he will chime in on all this if he knows of this thread.
You mention the JBL 2220A. I mentioned my JBL A130. At my novice glace they look real similar. Are they close enough where they would be acceptable? Have a pair with original (maybe vintage recone, have to look) cones. Be great to put them to use if possible.
Any advice on active crossovers or even passive? I loosely recall what Bruce was up to with passive ones. I really do like active with its versatility. And what it allows an amp to work within. Infact I was just reading up on actives over on heritage. My ashlys are not held in the highest regard by many in the know. I already knew this. I know most audiophiles like Marchand and Bryston. Yeah its nice when good gear is under the $1K mark. Again my $ situation is different these days. Cant spend like a fool anymore in my 20s pre kid days LOL...
Again I really appreciate your thoughts and advice. I love to learn from folks who know far more than me. Not a though bar to achieve ;)
Gotta run now too....
TTYL
I have not messed with 130's in quite a while and after I discovered 2220's I retired all my 130's to guitar amps or to vintage hifi collectors if they were rare original coned models. Don't flame
me if I am wrong but I think most of the 130's have slightly less xmax than the 2220's.
Keep your 130's until you get some original paper surround edge 2220's and compare. They are so close but they are not the same, Lansing Heritage forum can explain all the little details between the two drivers. Metal dust cap on the 130's is not really used in hifi anymore, I am not even going to make a comment on the the metal versus paper caps sound, please listen, I think you will have a preference right away.
Paper surround versions of either speaker have MUCH greater detail if you are going the stretch up to 400-500hz.
If your 130's or 2220's are original paper edge drivers you probably don't want to go below 80-90 hz in a bass horn and 120hz as a direct radiator unless you don't care about wearing them out pretty fast and the cost of recone with a real JBL kit is pretty high.
I don't think any 15's would work well in your 12" j horn, different back chamber requirements plus they may not even physically fit? throat is probably too small also.
I understand what you mean about a high efficiency JBL 12" in the horn not being as impressive as it should. D120, etc. seems like it should be better than it is but 2220 blows the it away for hi fi or even pa use.
Ahhh here I go again driving up the cost of 2220's, my favorite all around
15" driver by JBL.
The 2220 works in these applications fantastic: 35-120hz in a bass horn and on a straight 80 or 100hz up to 400 flat as a mid bass horn driver. 120-900hz flat in a tiny cab as a direct radiator.
Yeah I know the K-horn guys are going to say "my K-horns" go from 35-400
on the bass and I would say that huge time delay and lack of upper bass lower mid harmonics is too big an issue for me but hey obviously doesn't bother some as much as myself. K-horns rock for parties just as they are though!
It's the JBL D130 with aluminum cone that should be avoided except for guitar or lofi. I avoid it for guitar too.
I wrote 130's off for hi fi way back in the 1990's when I discovered 2220's, that darn metal dustcap on 130's. I heard some guys put felt on them for hi fi but these are collectable speakers and you could hurt the value doing stuff like that.
Now I have to correct you though and this time I checked. The 130 is indeed a quite different speaker than the 2220. type in jbl thiele/small parameters on a search engine and pull up the specs of both. FS, QTS, Xmax, etc. in fact almost all the specs are really different between the two drivers and not just a small percentage, these are vastly different drivers.
I think I also remember the 130 had a thinner top plate or something like that, everything on 130's was done to get max efficiency out of it and damn the flat response!!!
I guess when I left the 130's for dead 20 years ago I forgot how different
they were from the 2220.
It is all coming back now, the JBL D120 I think was more similar to the 130
and again completely different from the 2220 type purpose. JBL made 120's to "get loud" It has been so long that I have cared for either 120 or 130 on hifi, the details were getting really foggy.
Now again I will say understand why you chose the EV Force over the JBL 12's you probably tried in your bass horn.
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