My A7-500s. A journey

[gearfreak]

How did the piezo's sound? ...

Wow, 8!
The piezos I have are an array of 4, mounted in a little nacelle off of some Dukane's.
The nacelle will fit behind the grille cloth/in the port if I want it to (stacked 828's).

Probably better than one might think, but I know I didn't have the XO point for the piezo's sorted. There was more overlap than called for.
I then became sidetracked a/b'ing the vintage piezos with modern ones.
Then I got some more horns.
Then... ...well, we all know how this goes. :-)

I'll return to playing with the tweeters after I've figured out more of what I've concocted w/these XEQ-808's + padding.
I am sure the whole shootin' match could be streamlined a bit.

[Panomaniac]

Analog Addict (Alan) has an array of little horns on top of his multicells. They may be Foster or similar. It works really well.

Gearfreak: Thanks for the tweeter list. I actually have a pair of those little Beyma buyouts. They're pretty useless. But they were cheap!

My main trouble with the 288 is a deep notch at 8444Hz. 2nd Harmonic distortion peaks wildly there, too. If it weren't for that, I'd be super happy. Wavelength of 8444Hz? 4cm. Depth from driver flange to tangerine plug? 8cm. Hmmmm...... Could it be the bug screen? I took it out (and put in a rubber washer that was missing) and thought that would do it. No such luck. ;( In fact it's worse, if anything. Like the bug screen might have dampened the resonance. A 290 driver on the same horn does not have the notch, tho it's hard to tell because it's so far down at 8.4K. An old Radian driver has some of the notch and distortion, but not as much or as sharp. It also does not have the top end of the 288. Sure wish I could figure out what it is and kill it.

[VolvoHeretic]

I then became sidetracked a/b'ing the vintage piezos with modern ones.

How did the a/b'ing sound? My piezos were bought from Radio Shack in the '70s and didn't have a manufacturer or wiring instructions and according to this thread, should only be Motorola's.

However, I use a heavy does of EQ and boost the highs and lows extremely and had the upper horns padded down to about 75%.

Using piezo tweeters wisely: a "how to" - AudioKarma.org Home Audio Stereo Discussion Forums

[gearfreak]

How did the a/b'ing sound?

eh, I didn't get quite so far as to develop and opinion before becoming side-tracked.
The newer ones either had better sensitivity/output (if that would be the correct term), or went higher in a noticeable register.
Maybe that makes the vintage ones 'smoother' or maybe it makes them 'broken' ;-).

Analog Addict (Alan) has an array of little horns on top of his multicells. They may be Foster or similar. It works really well.
Gearfreak: Thanks for the tweeter list. I actually have a pair of those little Beyma buyouts. They're pretty useless. But they were cheap!

You are welcome for the additions to your list. That's funny about the CP09's. Maybe if I look at mine and they are less than ideal, we can send them along to VH to play with. ;-)

I've liked the fostex (via Zenith Allegro 3000's iirc), and in fact that may have been used as well in some TOA PA cabs (MIJ) - which I also liked.
So they might be a sleeper for this application, if avail in quantity as such. I have no other particular experience with them though.

[gearfreak]

... My main trouble with the 288 is a deep notch at 8444Hz. 2nd Harmonic distortion peaks wildly there, too. ... Sure wish I could figure out what it is and kill it.

So it's not the tweeter overlap, seen in the prev. FR graphs?

Maybe try a different horn? (assuming, same peak with both 288's of course).

[Panomaniac]

It's a deep notch, maybe 20dB. I think it's the driver since 2 other drivers on the same horn don't have the notch, or not as bad. Both 288s do. I have someone helping me make it go away. Will try a different horn if I can.
The notch is narrow, about 1/7th octave, but I don't like it. I've tried to blend the tweeters over it, but no real luck. Too bad because with the proper HP shelf on the 288 + 1005 it can be flat to 15KHz. No need for a tweeter.

[Steve Mac]

No need for a tweeter.

I've got a ribbon tweeter at 10kHz with a 511e+288h.
The high end no longer "beams". So much more enjoyable and sounds effortless. JMHO...

[Altec Best]

I've got a ribbon tweeter at 10kHz with a 511e+288h.
The high end no longer "beams". So much more enjoyable and sounds effortless. JMHO...

I also like the 511E/288 ! Effortless is how they perform ! With very little power needed as well.

[Panomaniac]

Yes, the tweeter can help spread the love. I don't think the multicells are as directional at the top end as the 511 and 811 horns. Perhaps I should measure that. A tweeter will probably sneak into the system anyway, but I'd like to hear what the 288 can do without it.

[Steve Mac]

Yes, the tweeter can help spread the love. I don't think the multicells are as directional at the top end as the 511 and 811 horns. Perhaps I should measure that. A tweeter will probably sneak into the system anyway, but I'd like to hear what the 288 can do without it.

Well I cannot disagree with this. I believe I spent more time worrying about the mid bass and mid range and balance with the sub. But I might suggest not working on trying to eke out high end performance because I failed to be happy no matter how much I tried. Actually it interfered constantly with the mid range balance and I never came close to the beauty of the maggies I owned. So once I just got the mids and mid bass right...just add something up high. THEN I found the system was more tweakable and the mids were just so much easier to play with...then it was more fun than frustration. Well...as long as the crossover point was around 10k. Much below that and it gets difficult...not impossible...just more factors. But in a way it makes sense because you want the fewest components to keep the sound as coherent as possible...and above 10k it's more or less sensed as air and sparkle. JMHO...