The following is what I have concerning the DIY mod for the Pioneer C22 center. It's been heavily edited so apologies if any part is incorrect or misleading.
I found a thread at Audiocircle on these speakers in which two Dennis Murphy mods are discussed. The lessor known one is to install the same vifa/peerless tweeter, but with just a 3.9 uf cap on the positive side of the tweeter at the crossover.
I did this with the center(c22) and also installed some one inch sonic barrier, Parts Express sells all of this stuff.
Anyway, with the tweeter, cap and sonic barrier, the center performance is markedly better. Previously the cabinet vibrations affected clarity and the dialogue at times. Also the stock tweeter can be a little inexact with some music I’ve noticed.
Could the center channel mod be as simple as adding the Vifa tweeter and a 3.9uF cap?
Dennis Murphy:
OK--I finally got (almost) enough information to model this, and although I'm not sure about the value of the tweeter parallel coil, as long as it's not higher than about .5 mH, you should be able to get acceptable results by removing and throwing away the old tweet, splicing in a 2 ohm resistor and a 3.9 uF cap to the wire leading to the positive terminal of the tweeter, and then attaching the end of that wire and the negative wire to the appropriate terminals of the new Vifa tweeter. The order of the resistor and cap doesn't matter, just so they're connected n line with each other. The highs won't be perfectly flat--they'll trend down about 4 dB before rising again, but the response should be good enough for the superior Vifa tweeter to improve the clarity of vocals. If you hate it, it's easy enough to undo unless you really did throw away the old tweeter.
Dennis Murphy:
Thanks Lary. Just so there isn't any confusion, the mod you implemented in the field is kind of a stop-gap version for people who already have the stock Pioneers. The modded version I sell has much more extensive revisions to the crossover, plus added sound treatment for the cabinet. I know Danny at GR research sells some good stuff--just for my own edification, which subs are you recommending and how much do they cost? thanks
20th February 2020, | |
paulster
diyAudio Member
Join Date: Oct 2011 | Now that Dennis has (sadly) had to get out of the speaker business, does anybody have the details for the SP-C22 center channel mod, or a lead on where to purchase a modified one?
I modified my SP-BS22-LR set some time ago and have been waiting to see when Dennis would make the center available again, but that's not going to happen now.
I'd really like to get a center voiced the same as the modified fronts. |
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The crossover mods move the woofer crossover point down 20% (larger L2-L1 combo), move the tweeter crossover point down 10% (larger L3), goes to 3rd order which not only sharpens the tweeter rolloff but also brings the woofer and tweeter phases close together around the crossover point, and finally brings the tweeter down a bit after 10 KHz. Woofer/tweeter sensitivity balance is unchanged.
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