Sanity check on compression drivers for 811B horns

Tjj226

Member
2012-12-02 2:49 am
Hello everyone.

First and foremost I want to say that I have no clue what I am doing, so if I say something stupid, please be patient :p

I recently acquired some 811b horns and I am looking for a decent driver to pair with them. I have done some research on different drivers that would work well with them but most of the recommend drivers seem to be out of production (BMS 4550) or very expensive (faital pro).

I found these PVR drivers that are cheap, but they seem to be far from ideal https://www.parts-express.com/pedocs/specs/294-2833--prv-audio-d290py-b-specifications.pdf

Do you guys think the PVR drivers are worth a shot? Or are there better drivers out there that you guys can recommend for 200 a pair.
 
Greets!

Ideally one needs an Altec or similar driver that has the Altec's built in small conical horn where all its > ~ 4 - 16 kHz BW is generated, otherwise assume you'll be disappointed with any other driver attached to any of the Altec 1" throat horns unless a super tweeter horn is used.

Not familiar with any drivers other than Altecs of which the 802-8G, 902A, 909A series and Great Plains Audio [GPA] 1" are best, hence pricey, especially if needing parts or rebuilding at GPA now that in this past year their prices have doubled :(.

GM
 

Tjj226

Member
2012-12-02 2:49 am
Greets!

Ideally one needs an Altec or similar driver that has the Altec's built in small conical horn where all its > ~ 4 - 16 kHz BW is generated, otherwise assume you'll be disappointed with any other driver attached to any of the Altec 1" throat horns unless a super tweeter horn is used.

Not familiar with any drivers other than Altecs of which the 802-8G, 902A, 909A series and Great Plains Audio [GPA] 1" are best, hence pricey, especially if needing parts or rebuilding at GPA now that in this past year their prices have doubled :(.

GM

Thanks for the reply. I had no idea the Altec drivers had built in conical horns. Do you have any information on this internal horn?

I have access to a pretty nice CNC mill and I just so happen to have some aluminum stock lying around.

If I knew the geometry of the altec driver, I could theoretically make an adapter.
 

Tjj226

Member
2012-12-02 2:49 am
I've used the Altec drives with the 811s, of course. But I've heard the Selenium drivers on them and they were very good, much smoother than I expected. That's where I'd start.

Thank you for your response. Do you know which selenium driver it was? There are 3 of them on parts express. They are cheap enough where I will probably buy a pair just to have for experimentation. :D

You're welcome!

This blows up and accurate enough to scale with 1" exit: http://www.lansingheritage.org/images/altec/specs/components/802d-804a/page1.jpg

GM

I see. Very interesting. I will see what I can come up with.
 

Tjj226

Member
2012-12-02 2:49 am
Thank you to everyone who has responded. I have a couple last questions before I pull the trigger.

Im looking at these selenium drivers https://www.parts-express.com/pedocs/specs/264-270-d220ti-spec-sheet.pdf

Here is where I start to display my lack of understanding. It lists a minimum frequency crossover of 1500hz at a given power rating. The woofer I want to use in conjunction with the horns is the jensen F12N field coil woofer which has a sensitivity of about 100db per watt.

Since I will need to pad the horn down to match the woofer, is it possible to get away with crossing the horn over at 1K?
 
Since I will need to pad the horn down to match the woofer, is it possible to get away with crossing the horn over at 1K?

You're welcome!

Yes, at the expense of a lower peak power handling capability. Power is reduced by 4x/octave, so if you limit it to ~6 W/active, ~12 W/passive you should be fine since there's only a little more than a half octave drop [0.585].

FWIW, this driver is a better fit to an 811, both physical mounting and a lower Fs since you're wanting to use a lower XO point plus a little cheaper ;): Peerless by Tymphany DFM-2535R00-08 1" Compression Horn Driver 2/4-Bolt 8 Ohm

This one is rated 30 W, so ~8 W.

GM
 
I used Selenium the 205 driver with an adapter on an 811. I am more concerned with the horn than the driver for hi-fi use. Be sure to damp the lips with duct seal or equivalent to help deaden the ringing.

Yeah, for sure the sectoral horns need some tweaking and for me duct seal or similar isn't near enough for me.

So you're saying otherwise the combo performs fine? I mean my experience WRT screw on/sectoral or multicell has only been in PA apps [just a horn] and PWK calling them 'squawkers' is most apt, so have never considered it an option for HIFI regardless of driver quality.

GM
 

pelanj

Member
Paid Member
2008-07-17 8:47 am
Hořovice
I have a pair of D210Ti, which are D220Ti predecessors. I have used them for years and they are still in use in these boxes - Eminence Beta 12 CX + Selenium D210Ti MLTL (huge)

Used down to 1.2 kHz 3rd order for HiFi and also as a small PA for vocals in a loud metal band small rehearsal room driven at 125 W amp per speaker - the amp was mostly at the edge of clipping the vocal peaks / without a compressor. They survived a few years this torture and still in perfect shape. I will try to dig out some measurements of the D210Ti on a 15 cm "kugelwellenhorn" with an adapter.

They also sell the OMF version, which is a bolt on. This is the measurement on an aluminum CD horn: https://www.prodance.cz/protokoly/Selenium_D220Ti_OMF+A7570.pdf
Megaton A7570 zvukovod | Reproduktory - Zvukovody - Zvukovody 1" | PRODANCE
 

Tjj226

Member
2012-12-02 2:49 am
You're welcome!

Yes, at the expense of a lower peak power handling capability. Power is reduced by 4x/octave, so if you limit it to ~6 W/active, ~12 W/passive you should be fine since there's only a little more than a half octave drop [0.585].

FWIW, this driver is a better fit to an 811, both physical mounting and a lower Fs since you're wanting to use a lower XO point plus a little cheaper ;): Peerless by Tymphany DFM-2535R00-08 1" Compression Horn Driver 2/4-Bolt 8 Ohm

This one is rated 30 W, so ~8 W.

GM

Crap. I already got the seleniums. I will probably return them and get the peerless drivers since those just look ideal in more ways than 1.

And I can't ever see driving the speakers with more than a couple watts. I don't enjoy listening to my music very loud (105db+) which is part of the reason I like horns so much. They just do an absolutely fantastic job of playing music at moderate and low volume.