Well done Dave, Thanks!
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Well done Dave, Thanks!
Not unlike the ~equivalent throat portion of a 511/811. ;)Quote:
Originally Posted by speakerdave
BTW, funny about the aluminum ring, I had to fabricate one for my speakers as the larger horn would hit the newer style cones without it. ?? worked fine. I measure 1-1/2? id in the throat of my 604C egg crate horns and that is the same dimension as the exit on the 604B pole piece. Is the throat of your horn larger than that? Looks like the mounting holes are in a different position than they are in my horns. Mine are vertical but yours look to be 10 or 15 degrees off of horizontal
Martyh45 - have you thought about getting some of the GPA H-III horns from Bill at GPA? Maybe they would do what you want to do without casting the UREIs?
Hi, my understanding is that they will not fit the older 604's. I should say though that I have not talked to Bill since he was still in the design stage for those horns so they may. Strange as it might seem, I really don't need new horns. It's more about figuring out how to draw and copy the old horn. maybe tweek it a little. I like doing that type of thing.Quote:
Originally Posted by gortnipper
Yes, . . . or, I was thinking some foundation sill foam might be worked into shape.Quote:
Originally Posted by martyh45
Not really like that. It's not a radial horn. Photos two and three were meant to show that as you go from one side to the other there is some up and down, some belly, crowning in the middle.Quote:
Originally Posted by bfish
One could certainly monkey with the clones and make holes and foam edges to one's heart's content. The main point for me was to make a horn a little bigger than stock because as I understand it the UREI 811 crossover point is a little lower (or the UREI horn addresses the unloading of the stock horn--I can't remember which). I was interested in trying the 604-8G's with the 811 UREI time-aligned crossover, and believed that the UREI horn was necessary. However, it seems to me that all that would be necessary would be to fashion edge extensions of sill foam for the stock horn. Having never heard the UREI's I might be missing something obvious to those who have, of course. I like the effects of the coaxial very much. I listened to 604-8G's for years, and have recently been experimenting with Tannoy/Manley/Mastering Lab 10's. The imaging of those is fantastic. However, I have found for the time being that a really good bass reflex/horn two-way with a 650-700 crossover is nearly the equal of it for imaging, and is superior in other ways as well. For up-close listening without low bass, or with a subwoofer, the Manley Lab 10's are magic. In the mid field, I actually prefer the LSR32 from JBL, however, a clearly superior speaker in many ways. The stock Tannoy SGM10b's, which I also have, are nothing close to the Manley/Mastering Lab version.
I have not done a direct comparison with the 604's and my big two-ways, since I don't have cabinets for the 604's right now. The two-ways are a WHW configuration, and I believe this adds to the coherence. Most of my listening is done on large JBL 4-ways. I find most other speakers have audibly greater intermodulation distortion. The imaging is not as good, though. Fortunately, most of the time, imaging for me is a psycho-acoustic phenomenon that has little to do with enjoying recorded music, which many times does not support it. I do believe, though, it is a meaningful measure of some aspects of speaker performance, and when one is experimenting at the boundary of in-room realism, the coherence of coaxial design helps achieve the emotional palpability of really great listening. So, I keep them around. What I would really like to hear is a coaxial with a one-inch TAD compression driver mounted on the back of an Altec 414 with a 604 horn. I think that would work pretty well.
So I think I've answered my original question.
It appears that Urei did make graft-on horns, and that would be what mine has.
They list it as the '800H' as seen:
http://studioelectronics.biz/ureipdf/824.pdf (yes use this one)
and with lesser info and quality:
http://www.jblproservice.com/pdf/Vin...s/UREI-811.pdf
Quoting the former doc (sic) :
Urei 800H Custom H.F. Horn
Designed to retrofit 604E and 6048G compression drivers.
Mouth opening 6.50" x 3.25", length 5.0"
(Approx. 0.9" longer than standard sectorial horn)
Additionally, some discussion of the slots, foam padding etc occurred and I don't know what was revealed. Here in this copy of their 'A' series ad, they outline reasoning behind such accoutrement, point by point. (thanks to the host of the ad).
http://www.in2guitar.com/stereo/ureiad39p.jpg
Gearfreak,
That's some nice sleuthing that you've done there ! :)
Do you have any test equipment to measure ( & confirm ) the smoothing effect that this Urei horn has ( or should have ) on your 604Es ?
- Here's a pic that shows the fairly ragged response of the "E", as published by Altec in 1971 . Some of it's upper mid is arguably smoother than the "G" ( as posted by Urei ) .
- You can see I've made a collage using some of the info that you provided ( also, I resized & rescaled things for ease of making a few direct comparisons ) .
- I find it interesting that the 604E & 604Gs undulations are quite different ( though, still pretty wild ) .
http://www.hostboard.com/forums/hbmc.../2009/10/1.png
- For comparisons sake, here's the GPA 604-8H-III compared to the older 604E . Scales ( vertical "db" & horizontal "FR" ) have been matched .
http://www.hostboard.com/forums/hbmc.../2009/10/2.png
>< cheers :)