Best DIY combination? also posted in Tech questions...

[colterphoto1]

There was something not quite as outrageous as the Royal Device that was published in an Audio or Stereo Review many years back. The photo showed an array of tweeters in front of three straight firing horns with rooms full of woofers charging them. This was an early surround system as there were 'room- mounted' woofers firing into horns that exit near the sides/rear of the room also. If anyone remembers this, the owner was also a musican like the RD guy and had a drum kit set up in front of the center speaker.

[Islander]

I seem to remember seeing a system like that in a magazine in the early seventies. The wall behind the speakers had three sort of proscenium arches and the system was said to cost $100,000, really high-end at that time.

[DrWho]

Mike, I have those woofers. The 15" ones, they are crazy good:)

That link on the ribbon compression drivers has me thinking. I got 8 Hi-Vi research ribbons left, would you like a pair to play with? You can have a pair, just pay the shipping. These are pretty big, and they sound sweet, just not real efficient, maybe 90 db 1W1M. I was going to do a line array at one time then I lost interest.

I then acquired all the parts to do a Dynaudio Evidence/Consequence. I still got all the stuff for that too. Just no cabinets, I went in the attic to get the 8 woofer's to start the project about a week ago and the surrounds had deteriorated.

So I got 8 brand new Dynaudio 21W 54's, that never had power on them, ruined...........I hate foam surrounds.

I dont know how they are getting the ribbon tweeters to take so much power, they are pretty fragile, and I have smoked a bunch of them. maybe you can figure it out? You want a set?

Hey Mike, I'm definitely down with experimenting with anything you wanna send my way. [Y] How do you want to work out the details?

As far as the power-handling of the SA8535, I have no clue....I wonder if that's with their special "AIR" system and the aluminum baffle. A 107dB driver is gonna be about 10% efficient, which means it will need to dissipate over 200W of heat. A 13ohm impedance is also gonna require over 160V to drive it to full power (which is equivalent to amplifier that can drive 3kW into 8ohms). I simply can't fathom dumping that into a tweeter....that's a ton of energy...but then so is 135dB [] (at 5% THD)

If there specs are even halfway true, then that's gotta be one awesome sounding driver....and it even costs less than the very expensive TAD drivers (about $800USD).

[MikeMilliken]

Mike,

Just send me a PM with your address and I'll get them right out. I want to send them via US Postal Service because thats easiest for me. I'll pay the freight, you have been very helpful and kind.

[DrWho]

PM Sent

So I did a little more research on that ribbon...turns
out Stage Accompany has some other pre-built products they sell, which
also include that ribbon tweeter. Check out the specs in this PDF:

http://www.stageaccompany.com/en/support/download/docs/Techdoc-DS24-SSB36-preliminary.pdf

They're
showing 60W RMS into the same tweeter and 1000W peak...that seems way
more reasonable. 60W into a 107dB driver is a little over 124dB
continuous, which also lines up with their spec. The 98dB sensitivity
for the whole box in that PDF is probably limited by the woofer, which
also lines up with T/S and the size of that box. That also means that
it's able to wick away 6W of heat, which is way more reasonable (still
a lot, but doable). I'm kinda curious what their extra heat dissipating devices will do as its quite clear that ribbon is capable of a lot more excursion than the power can drive it to.

Btw, it should be noted that almost all speaker power specs are
really calculated from a measured voltage and the known driver
impedance. However, speakers are very reactive loads and a friend was
reminding me that the actual power delivered to the driver will be
less...quite less in some cases.

[djk]

http://scrounge.org/speak/burwen/index.html

Anyone that wants to build a pair, I have the JBL 2350 mid horns, 2329 throat adaptors, 2440 compression drivers, and some of those Cerwin Vega tweeters (made by Hepner and later sold to Klipsch).

[DrWho]

http://scrounge.org/speak/burwen/index.html

Anyone that wants to build a pair, I have the JBL 2350 mid horns, 2329 throat adaptors, 2440 compression drivers, and some of those Cerwin Vega tweeters (made by Hepner and later sold to Klipsch).

So is he running a Bessel array on all those tweeters, or are they all acoustically in parallel? That's gotta be one dynamic system.

[colterphoto1]

http://scrounge.org/speak/burwen/index.html

Anyone that wants to build a pair, I have the JBL 2350 mid horns, 2329 throat adaptors, 2440 compression drivers, and some of those Cerwin Vega tweeters (made by Hepner and later sold to Klipsch).

YES that's the one, good research! 1976 I was graduating high school and had stereo posters all over my bedroom wall.

[Islander]

That's the picture I was thinking of as well. It was thought to be totally extreme at the time.