Yes get rid of the symbiotiks it gets much,much better.
Yes, ribbons are popular for adding top end 'air' to horns since they're both highly damped, but I imagine your A7s will still be considerably more efficient once EQ'd in-room, so I imagine you'll wind up eating up all this ribbon's nominal power handling/low distortion output in boost EQ to keep pace if you don't use multiples.Originally Posted by edharbur
GM
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.
Was my experience with 808-8A's (symbiotik) in a three way.
The planars mentioned are characterized as good dispersion (though I saw no specs), but if higher efficiency is necessary, you might consider these other (inexpensive) options:
http://profesional.beyma.com/pdf/CP09E.pdf
(spec'd at: 90?x60? dispersion, Aluminum)
PE had them on sale at one point, real cheap.
Looks like perhaps they cut ties with Beyma though (?), perhaps is why they had a sale.
...or selenium slots:
http://www.parts-express.com/pdf/264-360.pdf
(spec'd at: 120?x40? dispersion, Phenolic)
If anywhere near PHL, you're welcome to borrow mine to try out.
I have a couple pair of the older aluminum bodied versions, ST-320, i really like them. In fact, here's all 4 in the "project" room....or selenium slots:
http://www.parts-express.com/pdf/264-360.pdf
(spec'd at: 120?x40? dispersion, Phenolic)
Not all vegetables make good leaders.
Thanks again for the good answers and quick responses. It does me good that a consensus on the ST-320s seems to be developing here - it makes decisions much easier for a complete novice like me.
How did you guys hook them up? In parallel, I assume. Is there a cross over of some kind?
Gearfreak - thanks for your generous offer, but I'm in Ct. Cheaper just to buy a pair, try 'em out, and throw 'em out if hate them, than to drive to Philly.
Bowtie - are those tan horns cored polyester resin fiberglass or fiberglass covered metal or...? If they're 'glass, how "dead" are they? As uneducated as I am about sound and electrons, I am educated about composites. I can knock out a pair of these pretty easily. Worth the effort?
Thanks,
Ed
I just went here. I've concluded that I'm Sargent Shultz. I know nothing, nothing!!
Last of the World's Great Human Beings, well maybe one of the last? OK, just an ordinary slacker then.
I really don't know my glass very well, but i'd guess they're just basic polyester resin fiberglass. I snagged them for 5 bucks on ebay many years ago when you could still ship stuff for reasonable fees. I know pretty much nothing about them besides the obvious. 1 inch throat, with only 2 bolt holes on the flange, likely a 500hz horn. They have a beautiful white(enamel?) finish on the inside and both sides of the driver flange. I'll drop a good pic of one here tomorrow in the daylight. I've used them a few times when just tossing together something to listen to during a project or repair in the basement. I've been very happy with Renkus SSD1800's on them, never tried an Altec driver. I wouldn't call them "dead" but what little "ring" you can get by banging on them is well below 500hz.Bowtie - are those tan horns cored polyester resin fiberglass or fiberglass covered metal or...? If they're 'glass, how "dead" are they? As uneducated as I am about sound and electrons, I am educated about composites. I can knock out a pair of these pretty easily. Worth the effort?
Not all vegetables make good leaders.
Ed, I just reworked my A7s with 806A driver and 811B horns,, I found after removing the old 800E network completely and just running a cap on the horn feed it really came alive again,, if fact more so than the high end Def Tecs sitting next to them,, still no bass though and will never expect much but my SVS sub does the 50hz and below quite good,,
my Marantz receiver (SR9600) will attenuate the horns "if needed" in lieu of the old L pad that was in the N-800E,,
Derry
Edharbur, here are a couple of other thoughts to throw in the mix. Your compression drivers, like most, have a "mass corner" of around 3kHz., and the power response (total power out) vs. frequency continues to roll off at 6dB per octave above this frequency. Many horns including the 511 beam highs somewhat on axis, which brings the top end back up quite a bit If you're listening right on axis. In your shop you are probably hearing something closer to the power response, so that in addition to the poorer highs of the Symbiotics are stealing your cymbals.
A big, live room such as your shop will often recycle midrange energy like crazy. Too much mids sounds exactly like not enough highs (and lows).
I haven't had good luck integrating ribbon tweeters with compression horn systems. While they often sound quite wonderful in direct radiator systems, their dynamics don't keep up with the horns and of course their sensitivity is usually much lower. The big Heil AMT does better dynamically, but will probably still need a level boost.
Back when I fiddled with two way Altec systems endlessly, I would usually put a small value bypass cap in the h.f. section of the crossover to bring up the top end. Your compression drivers are probably padded 6 to 10dB even in an A7 system, and AFAIK the stock crossover pads down the driver that much over its entire range. By letting the highs sneak around the pad, they suddenly come up that same 6 to 10dB and the cymbals are back. Experiment with cap value and perhaps even a bit of padding in that section to achieve the best overall sound and/or measured response. The aluminum diaphragms will help a lot also.
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