Saturday, April 10, 2010

PA speakers

I made these speakers for my musician friends, colleagues at work, who formed music group "Coomasie Blues Band". These speakers were made for their rehearsal and small venue concerts. These speakers are made of 18" high power PA woofer per side, four 6" Dayton PA midranges, Radian 485 2" compression tweeter and Selenium supertweeter.
Speakers are very efficient, sound is powerful and authoritative, but not flat. Woofers can not keep up when it comes to the efficiency with the rest, radians are most efficient and have to be tamed by the L-pad. Open baffle midranges give the speakers clean sound, especially for voices, which these speakers are mainly used for. Much better than if voices are handled by 15" PA woofer.

These speakers are powered by Behringer 2500 watts amp and use Behringer Ultracurve equalizer. You can see the eq required to make these speakers flat in the living room. Radians need to be lowered as most efficient, woofers roll of too soon, but that's fine for PA, especially if these are for vocals mostly. One has to be gentle with volume control, as it goes loud very quickly. At one party we tested the speakers a was unbearably loud at 50 watts only, so efficient are the speakers. I once powered the speakers with 2 watts OTL tube amp, that was all needed for normal listening. Ideally one should biamp these speakers.

Update...these speakers were converted into domestic, since the music group no longer performs. Tweeters were too high, so I moved them lower to the ear level, Radian horn was not needed, was removed and sold, and crossover was simplified and optimized using Holm Impulse software. I added external crossover into wooden box. Bi-wiring is possible. Speakers sound exceptional, highly efficient, dynamic, yet balanced and pleasant sounding. They sound good quiet or loud, they do not care, they just play nice music. NIKKO high quality electronics helps too. Some pics...

Friday, April 9, 2010

Big open baffle speakers

Blast from the past or Magnavox revenge...

I had quite a few Magnavox speakers laying around. So I decided to put them all on open baffle. They turned out wonderfully. Amazing clarity. Everybody who visits wants to hear them and everybody is amazed. Such dynamic and crystal clear open sound. Speakers are made of two 15" woofers per side, crossed with 5.5 mH inductor, one 12" midbass crossed with 150 uF bipolar capacitor, one 10" midrange crossed with 40 uF capacitor and a horn tweeter crossed with 2.5 uF capacitor. So the speakers are actually not completely open baffle, since the tweeters are not radiating back. But who cares! I have not measured the efficiency of the speakers, but trust me, must be close to 100 dB/w/m. Speakers are powered with fully restored and upgraded Magnavox, what else, push-pull amplifier 20 watts per side. That is enough to make ears bleed.
I can finally enjoy Carl Orrf's Carmina Burana or Verdi's Requiem in concert like scale I once experienced live.

...and here are some pics from above mentioned fully restored Magnavox amplifier...

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