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Some people are having success with the Tymphany DFM-2535R00-08 1" driver

http://www.parts-express.com/peerless-by-tymphany-dfm-2535r00-08-1-compression-horn-driver-2-4-bolt-8-ohm--264-1420

http://www.diyaudio.com/forums/multi-way/293297-recommendations-really-good-cd-replace-b-c-de250-8.html

Presumably $34 each is cheap enough.

ray

I've never heard a compression driver with a titanium diaphragm that I couldn't immediately tell had a titanium diaphragm... They have a distinct sound that I don't care for...

Roscoe

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I can explain it to you, but I can’t understand it for you.

There are some good inexpensive drivers...I had mylar B&C one inchers that were really nice. I think they were $70 new.

But Cogito has ALTEC 802s, which are hard to beat.

The problem is horns. There must be some decent 500 hz horns out there.

Most of the modern stuff is constant directivity design, requiring EQ, but basic CD compensation is the same 6dB rise from 6k as suggested for the Altecs above.

Note that it is Roscoe saying the 511s suck, not Cogito, who actually seems to like them.

I had this very same discussion yesterday with a guy from Audio Karma who wrote me for Altec advice. he has Valencias and likes the 811s but he is looking for 32s. Sent me a link to the JE Labs blog. [ ]

I told him he is lucky that he likes the horns and ignore the naysayers, but if I were looking to improve on the stock config, that is where I would look.

Take my impressions with a grain of salt for I did not compare 511s with other horns. Hopefully over the next few months I will get to hear a few horns at the member's homes.... starting with Roscoe's home middle of this month.

What about 805s?

805 is a large format horn for 288 and similar 1.4" drivers.

Really, one's impressions are one's impressions. Some like what they have just fine and the next guy wants to poke out his eardrums with a pointy stick when they hear the same thing. There are really no rules.

The complications only begin when you start comparing!!

Built the attenuator for the horn and zobel network for the woofer from post #3 in this thread for one channel and compared the two channels. The difference in mid-range is significant. With the attenuator mid-range is richer. Without the attenuator, the mid-range is thinner and it has a slight echo. I did not notice this echo without doing the a/b comparison.

Excellent work!

Without the EQ, the 802/511 probably has a peak at 2-3k that can give you a haircut. Shelving that whole region down can help a lot.

The typical 511 response can be seen on this blog, although the driver under test or the measurement protocol seems to have a serious problem.

http://redspade-audio.blogspot.com/2013 ... sured.html

A broad 5 dB bump in the ear's most sensitive region could make the driver sound thin, eh?

The next step in sophistication is to shelve that region to make it flatter, then apply the 6dB cut below 6kc... but enjoy what you have for a while.

Thx.

The freq response of VOTTs done redspade may not represent any Altec products in real life. They tested a PA driver in a hirez system without a crossover.

I will measure the altecs with and without the attenuator network. We can discuss how to fix the cow horns.

Should be an interesting exercise.

Yeah, that is the only graph I could find on short notice, but the sub 8k region looks about right,.

Altec 288s have the same broad peak, addressed in the so called "Hiraga crossover" which adds a series LR in parallel to the standard EQ scheme. See attached schemo.

Anyway, something to consider but if you are happy with what you have, hang out there for a while and learn what it is.