Another Unity Horn

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Tom Danley said:
I can measure up to 20 feet high, 2 or 3 meters is no problem.
My turntable has clicks at 2.5, 5 and 10 degrees, would 5 degrees be better instead?
Do you want from 0 to 90 degrees, half or full circle?
Hey, I’m not saying they will be as nice as yours but I am curious how they would look on your visual’s and willing to take the data. I will do this after the trade show next week.

Best,
Tom

Hey Tom, Earl ... any update on these measurements?
 
winslow said:
Can't help you there...I've tried the last couple of years to get a hold of Assistance Audio with no luck. The other BMS guys like Martinelli Sound have stopped selling BMS too.

The BMS from US Speaker is about $120 each, whereas I can get the Selenium for less than $70 each from Parts Express (have a buddy with a wholesale account there). $100 savings is a big deal to me. Especially considering that if something happened, I could get the Selenium fixed.

Just for laughs, I checked into the JBL compression drivers which are made by BMS. Looks like they're not widely available, and they cost 50% more :(

http://cgi.ebay.com/1-JBL-2407H-1inch-High-Frequency-Driver-NEW_W0QQitemZ110218642411QQcmdZViewItem

Here's some more info on JBL's compression drivers which appear to be made or licensed by BMS:

http://www.audioheritage.org/vbulletin/showthread.php?t=6368&page=7
 
I called up Assistance Audio and Jack answered.

SCORE!

Based on the conversation I had, there won't be any problem getting the BMS compression drivers. That was my main concern, that I'd waste a year of my life cranking out a new design only to have the compression drivers dry up.

I took a look at the B&C that Winslow likes, but the BMS is superior IMHO. It's also smaller, which is a HUGE plus in this application. The smaller it is, the further back I can put it on the dash.

As for the waveguides, I have them sitting here, but I'm spending the next couple of weekends cranking out some subs for my Summas:

http://www.diyaudio.com/forums/showthread.php?threadid=114340&goto=newpost
 
I wonder how high it will go?

It's compelling to "own a piece of history."

But I gotta think the Yorkville U15 would have superior performance. The Unity on Ebay has no woofers, just midranges. And I believe a conical horn should perform better than a square horn.

In fact the only reason I'm going with a triangular waveguide for *this* project is because that shape blends with the windshield and dash better than any other.

Bear in mind this is pure conjecture; I've never seen or heard either.
 
Hey guys, ever since I bought the Summas I basically lost interest in DIY. So all my projects are sitting on the shelf collecting dust.

I highly recommend buying a pair; with speakers like this there's really no reason to waste time or money on the quest for "the ultimate speaker."

Also, I got a job where I work from home now, so car stereo is a bit pointless now :(

I probably drive about 90 minutes a week now - I used to drive twice that much every day.
 
Patrick Bateman said:
Hey guys, ever since I bought the Summas I basically lost interest in DIY. So all my projects are sitting on the shelf collecting dust.

I highly recommend buying a pair; with speakers like this there's really no reason to waste time or money on the quest for "the ultimate speaker."

If I were recommending something in that size range, I'd concur. I'm happy with what I have, but if I were starting now, that's what I'd get (or, in my case, make). I haven't heard the Summas, but I have - sort of. My system is based on Nick Mckinney's original DIY Unity's. I've followed Dr. Geddes work the last couple of years, and even bought some foam for my horns from him - probably the first Diy'er to do so. My speakers are actively crossed over with a DEQX and an analog active crossover to the sub portion, so they are active 4 way.

If I take polar measurements of the horn and mid bass, I get something that looks very much like those on the Gedlee site. In the Unity set up, the compression driver is crossed to the mids at about 1.2kHz and the horn to the mid bass at about 350 Hz. I've experimented with leaving out the Unity Mids and crossing the compression driver directly to the 15" mid bass at about 1.3 kHz (closest match of the polar responses) The difference between the Unity configuration and the pseudo Summa is fairly subtle. The full Unity system places the image level a little higher (which I like), but little else changes. The Unity system is very good, but unless you are going for very high SPL, I would say that the added complexity isn't cost effective. The Unity can be done passively too, and the crossover might be a little easier to perfect than for the Summa, but not by much.

The Unity can make do with a mid bass that doesn't reach up into the mid range, but the drivers I have excel there anyway. Cheaper and easier to select a better mid bass than to use the Unity Mids.

Sheldon

edit: My current system is pretty much as described here: http://www.diyaudio.com/forums/showthread.php?s=&threadid=69906&highlight=

I've added the foam (which is very worthwhile). I've also reduced the depth of the enclosure behind the 15'' driver by about 40%. Next, and probably final thing, is to put a significant radius at least on the edges of the horn and maybe the upper half of the cabinet. This will have to be added as an extension. It will take some work to make something that looks nice.
 
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