Let's see what we can find out about them, Storm. Jack may have a data sheet, or someone will find info online.Originally Posted by Storm
I could also measure them with the crossovers and horns, maybe....
Let's see what we can find out about them, Storm. Jack may have a data sheet, or someone will find info online.
I could also measure them with the crossovers and horns, maybe....
Zilch----I have data sheets on the T-35 As and Bs around somewhere but it's been two moves since I've seen them, I'll dig around. The difference is the magnet, the A has a bigger one than the B and then the T-350 a much bigger one yet. I presume the Wolverine T-35W had the smallest magnet of them all. And then the ST-350 butt-cheek. That's 5 tweeters from one diaphragm. Clever guys in Michigan.
I've used both A&B T-35s and never heard much of a difference, if any. That's just me though, I hesitate to make a strong claim one way or the other.
I am still totally confused as to why these sound so much better.. Being a lover of both EV and Altec, I should be the first to embrace these, but can only see harm with the addition of these tweeters. Adding something like my 2405H's would do wonders as the Altec horns lack UHF's. but these T-35's do little more than bump up frequencies already well presented by the Altec's.. which may be what Storm likes about them, but it may confuse others with similair speakers as to what the real differences should be...
Storm, I am sorry for being so critical of these speakers as I can tell you are enjoying them immensely. The reason why I am so skeptical is that its extremely difficult to improve upon the stock design, and in order to improve upon something as great as your Valencias you can't just swap something in and hope for the best, it needs to be extremely well thought out.. And based on the auction, and the feeble networks created to adapt these EV's into the system, it just doesn't compute why these are so much better. After reading through this thread and examining the T-35's response, if anything, they should sound less neutral, and more inflated in the region where Altec tends to have some issues.
I am anxious to know if indeed this person knew what he was doing with the addition of these tweeters as its always possible that someone stumbled upon something special, whether it was well thought out or not. A lot of great discoveries happen by pure chance, and hopefully this will be one of them
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we've got the 'heavylifters' on it now. Wait for their report. All else is just PM material.Storm, I am sorry for being so critical of these speakers as I can tell you are enjoying them immensely. The reason why I am so skeptical is that its extremely difficult to improve upon the stock design, and in order to improve upon something as great as your Valencias you can't just swap something in and hope for the best, it needs to be extremely well thought out.. And based on the auction, and the feeble networks created to adapt these EV's into the system, it just doesn't compute why these are so much better. After reading through this thread and examining the T-35's response, if anything, they should sound less neutral, and more inflated in the region where Altec tends to have some issues.
I am anxious to know if indeed this person knew what he was doing with the addition of these tweeters as its always possible that someone stumbled upon something special, whether it was well thought out or not
The on axis response is only part of it. The directivity between the two horns will be quite different with the T-35 holding a wider dispersion pattern 5k and up. Off axis you would get a bit more upper treble around the room. May be enough to change the in room balance and brighten things up a bit even though the altec horn looks better in the on axis measurement.I am still totally confused as to why these sound so much better.. Being a lover of both EV and Altec, I should be the first to embrace these, but can only see harm with the addition of these tweeters. Adding something like my 2405H's would do wonders as the Altec horns lack UHF's. but these T-35's do little more than bump up frequencies already well presented by the Altec's.. which may be what Storm likes about them, but it may confuse others with similair speakers as to what the real differences should be...
Rob
I've been wondering what considerations, if any, were given in the completed versions to phase interaction of the new tweets, either from a mounting or an XO POV?
One of Altec's old rules stated 'when a 511/811 horn flange shares a common baffle (plane) with a LF driver (as in the Vals) the HF should be cabinet-wired (at driver terminals) out of phase to correct the acoustic phase misalignment at XO caused by the signifigant voice coil offset. (How many of these used systems are actually properly phased now is a crapshoot, however, phase-flipping while replacing diaphragms happens a lot.)
It may be too late for this to be meaningful to the modded-and-gone example, but if a guy wasn't pinned down to an XO point yet....
As for 1" Altecs, they share the same rolloff as any 1" driver, only varying by diaphragm and Bl differences. Considering the long list of diaphragm part numbers Altec produced in 40+ years dwarfs the short list of drivers they fit, correctly infers the occurrence of wide variances, which may be an excuse for the glaring lack of published data. While there are claimed to be certain "magic" 'frams and definitely were some duds, again, there's no backup for specific claims, and they're all decades old/unpredictable now anyway. Uniformity finally settled in with the long-running current 'frams.
Altec marketing used the prose-du-jour, but NEVER claimed flat response to 20kHz with a 1" driver .
Thank you, Moldy. From what's been posted here already, it's clear that there's no rational "One diaphragm fits all" approach. The Radian diaphragm, for example, may fit all of those many drivers mechanically, but the performance cannot possibly be equivalent to the variety of Altec originals. Maybe it's better than some of them, or most, even, but I'd suspect GPA has a substantially more informed handle on this aspect of refurbing and upgrading Altecs. That seems to be where concerned collectors go to get it "right."
On the other hand, if I were doing a comprehensive upgrade of an Altec system, including redesign of the crossover, or an active approach, I might be looking real hard at trying to incorporate a modern "standardized" diaphragm that worked for my design objectives, irrespective of what Altec originally used. That's not something can be done by "ear," though, in my experience, and certainly not by random substitution.
In this case, I'd suggest "None" is a reasonable assumption. The choice and installation appears to be largely based upon convenience. I doubt there are many other tweeters that would integrate into the available space. I'm reminded of the one in which a cute little sectoral supertweeter is mounted between the vanes of the horn.
I'm trying not to overthink this, though. If it were JBL, and all I wanted to do was add some "sizzle," I'd stick on a 2405 and a 1 uF cap, choose the phase by ear, and be done with it.
However, if what is required is conversion to a true three-way, that calls for a more considered approach. It may be possible to take advantage of a precipitous rolloff, as Source suggests, but there's also the dispersion and phasing elements you and Rob have mentioned to be evaluated. That's all going to require measurements....
http://www.audioheritage.org/vbullet...ad.php?t=14754Glad to know there is a fellow proud Altec owner in Phoenix.
I told you there was a difference in the sound - couldn't you hear it?
-Storm.
One thing I would like to add here. The difference comes from inputing part of the bandwidth that is missing on the 806A driver. This addition comes from reading and taking information in the above post. (link is present below) The driver I added is being used as a UHF driver because of the dramatic fall off the stock Altec driver has. I your case if/what you think is a great improvement, and looking at the 6db network installed on your array I think most of what your hearing is an overlap/spike.
This is what nightbrace is trying to explain here. I think a better driver and a better x-over network design would yield you results that are true to the human ear, and fill in what is missing. When I get mine totally done I want you to come over for a listen OK? Then you can see and understand what we are talking about.
J/S-S1A
http://www.audioheritage.org/vbullet...ad.php?t=14731
maybe he is not going for traditional "Hi-Fi" sound....
My xover has deliberately designed overlap from 802Gs to 075s.... (the bullets come in at @ 7KHz, Altecs roll off naturally)
I like the "sparkle" that the arrangement provides....
to each their own...
Post your crossover details, please....
Its a Richard Long and Associates RLA X2000 electronic crossover....
18db butterworth filters
100Hz & below to subs;
20Hz - 800Hz to 515B;
800Hz - 20KHz to 802G;
7KHz & above to JBL 075
looks like this one...
and a pic of the rear...
is here
def. not you dad's hi-fi
I was just looking more closely at the photos of Storm's new speakers.....
I hope the previous owner did not cut up original foam inserts to add the tweeter.....
Yes, they cut them to fit around the tweeter.
Does not bother me. I will never remove the tweeter anyways.
-Storm.
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