Ultimate Open Baffle Gallery

:rolleyes: I think that DieterK would like to know the brand of the bass drivers used in your aforementioned dipole loudspeaker.
2 Eminence Alpha 15A for bass, 2 PRV Alto Series 8MR400A Midbass drivers and a Selenium D220Ti compression drivers in Dayton Audio 12" round Waveguides, per channel.The baffle is made from 2 panels of 3/4" MDF glued together and measures 75"H x 23"W x 1-1/2"D. I am using a miniDSP OpenDRC-DA8 and an Integra Research DTA-9.4 multichannel Power amplifier. Crossover points are 300Hz and 3000Hz at 48db/octave slope. At the moment I am using only the xover, PEQ in advanced mode(biquads) and delay features of the miniDSP, and measurements made using the UMIK-1 and REW software , but looking forward to refine using FIR via rePhase.
 
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Earliest of the Ultimate ?

From 1936 :D

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You can google "patent 2160112" and read:

"deploying amplifying tubes and a band by-pass filter whereby only frequencies of low value, for instance from about 20 to 300 cycles, are supplied to the speakers 8. Similarly, the device I2 consists of suitable amplifying and filtering equipment whereby only high frequencies. for instance frequencies above 300 cycles, are supplied through conductors I1 and I8 to speaker Ill."
 
I assumed the boxes were the cross overs and the amplifier was not shown......

We're talking 1939 here. There is no hifi. Bandwidth is maybe 100 to 10khz
If the amps are the same, the woofer just stops working after it's f max and the tweeters are pretty silent undef their f min.
I've made ob's like this. Works fine. A capacitor and a self in front of each amp would also solve all problems.
 
You can google "patent 2160112" and read:

"deploying amplifying tubes and a band by-pass filter whereby only frequencies of low value, for instance from about 20 to 300 cycles, are supplied to the speakers 8. Similarly, the device I2 consists of suitable amplifying and filtering equipment whereby only high frequencies. for instance frequencies above 300 cycles, are supplied through conductors I1 and I8 to speaker Ill."

Soooo......each box is an amplifier/filter?
 
We're talking 1939 here. There is no hifi. Bandwidth is maybe 100 to 10khz
If the amps are the same, the woofer just stops working after it's f max and the tweeters are pretty silent undef their f min.
I've made ob's like this. Works fine. A capacitor and a self in front of each amp would also solve all problems.

But why would you need 2 amplifiers for a mono signal if they
just stop working after f max and under f min ?
 
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I did not post mine here before as they have been waiting forever for a XOver.
http://www.diyaudio.com/forums/multi-way/266524-you-active-multi-way-5.html#post4158184

well I finally got around taking the measurements and finished the work in Jeff B's PCD, which has an active filter section too. Integrating Visaton B200 as the mid with heavily overlapped drivers both at the bottom and on the top was a challenge. In the end it was only possible due to the other two drivers being so well behaved.

Well the end result is just a fantastic sound :D. I currently run them as 3-way only and fully active with F5 +ACA +ACA amps. I may be trying adding the tweeter (even though I feel no need for it) and also getting some passive XOs up on top to turn it into a bi-amped version over time.

but right now I am just enjoying the music.
 

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Latest reshuffling of drivers. Still using the old MCM 21" woofers (2 per panel) and new to open baffle use, the PS220-8. The opening for the woofers is 5.5" wide, giving approx 1/3rd sd opening. The fullrange is slightly blocked, but still sounds nice. No measurements, just enjoying listening.:)
 

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We did an OB set as highschool project. The girl in the pics , has to finish them at home.
Just a basic XO ; series with Zeta = 1,6 , and an L-pad on the Fostex FE206e.
They are "made to personal taste".
She loves them :)

I did about 20 different OB sets last year.
People , that hear mine , want something simular but least expensive.
This girl had that wish also , so we made it cheap and warm / engaging sounding.

Was a reel fun project :)
Everybody happy :)
 

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I've enjoyed the Eminence Beta12LTA with these H-frame Alphas for several years but now the Betas have been replaced by Zenith Alnico's.

I pulled the twelve inch 49CZ's from an old 1958 Zenith console and they're some of the finest sounding wide band drivers I've heard.

For the time being the flat baffle Lowthers are playing second fiddle to the Zeniths.

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