Dennis Murphy Pioneer SP-BS22-LR DIY Modifications

After going thru this thread does anyone know if there is a Dennis Murphy mod for the center channel or is it just for the bookshelfs? I was thinking about getting the center channel but don't want it to not match up.
 
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After going thru this thread does anyone know if there is a Dennis Murphy mod for the center channel or is it just for the bookshelfs? I was thinking about getting the center channel but don't want it to not match up.

Not that I know of. I'm a 2 channel stereo guy, for the most part. I don't even own any dedicated center channel speakers. So, I have no idea what the Pioneer SP-C22 crossover even looks like. I believe Dennis sold a few of the SP-C22 speakers that he modified himself, but I don't believe he ever shared the schematic for those modifications.

So, it looks like you have a few options:

Contact Dennis directly through his company Philaharmic Audio and ask him if he has any modified SP-C22 center channel speakers he will sell you.

If not, ask him of he'd be willing to share the details of his mod (which would be INCREDIBLY generous of him, yet again).

Or, just get a second pair of SP-BS-22-LR speakers, modify them, keep one as your center channel and sell/trade the other one to another HT enthusiast who has modified, or is considering modifying, his pair of SP-BS22-LR speakers.
 
Im still interested as well, hoping to use two modded center channels as L & R, that's the primary reason I haven't parted with my center speaker yet.
 
Thank you MCM fan for the reply. I am currently using my un-modded Pioneers for stereo listening only but was thinking about going to the 5.1 route down the route only if the center channel mod is available. I could go with 3 modded BS22's but center channel placement would be kind of awkward. I will try to reach out to Dennis and report back if anything comes of it. I might just mod these and just go with a separate home theater system too ;).
 
I'm not an expert in crossover design. I know which end of a soldering iron is which, but I leave the design to the pros like Dennis Murphy.

That said, I would think you'd want to stick with 20 AWG for the inductor to keep the DC resistance the same. Changing from 20 AWG to 18AWG would reduce the DC resistance, but I don't know if it would have a significant impact on the crossover frequency

One thing I do know is that reusing the stock inductor paired with the 0.5mH air core inductor (Parts Express PN 255-036) will save you a couple bucks per speaker. The 0.5mH inductors are less expensive than 1.5mH to begin with, plus by using two of the 0.5mH inductors per crossover (one in the woofer circuit and one in the tweeter circuit), you qualify for a quantity discount from Parts Express. It's not a big deal, but it helps keep the costs down a little.

Of course, you'll save more by hard wiring your crossovers instead of using the perf board approach. So, it's all relative.

Thanks MCM for the reply. Like I said, I went ahead and ordered the parts and will wire the inductors in a series. Now all I need to do is finish one project for my wife, which keeps getting delayed, and then I am on to the speakers .... hopefully before the end of the month. Looking forward to it.

And again ..... thanks for the wonderful write up and photos. And thanks to DM for being so generous. I may yet give his MBOW1's or CAOW1's a shot one day.
 
I only have about an hour of listening time with these speakers but I can say they are pretty remarkable as is. They replaced Madisound Kanspea P1000E with Fostex FF105WK drivers. Those are very bright sounding even with many hours on them (they're about a year old). I'll spend a few months listening to the BS22's and then decide if the mod makes sense for my ears. Thanks for posting the mod!
 
@MCM_Fan I got overzealous and started unsoldering the wrong part and hogged up the ring that it gets soldered into. Is there a way for me to jumper it ?? Thanks
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Just adding my thanks to MCM_fan and Dennis Murphy for this. I'm listening to my modded BS-22s now. I had picked them up as part of a used, complete 5.1 pioneer system for cheap as the surrounds. They're replacing my ancient and tired Boston a60 in the living room, with the a60s filling the role of surrounds.
 
@MCM_Fan what's your opinion on trying this mod on a pair of BS41s or BS21s? The BS41 has a larger 5.25" woofer and a lower crossover frequency of 2.5kHz vs 3kHz on the BS22s.
 
@MCM_Fan what's your opinion on trying this mod on a pair of BS41s or BS21s? The BS41 has a larger 5.25" woofer and a lower crossover frequency of 2.5kHz vs 3kHz on the BS22s.

I have no idea how it would sound. This particular crossover mod is specifically tuned to the BS22 drivers and cabinet. It will not be optimized for other drivers or cabinet sizes.
 
Too bad no local Fry stores anymore. I have a,stock pair. I would have picked up second to try mod
 
Hi Im new to the forum I joined because Im doing the mod on my speakers, I know it says for exper DIY and I dont think Im expert but I think I can pull it off, the Instructions are very detail but Im new to making a circuit board, Ive been reading and watching videos on how to read schematics, how to solder on pc boards and read the instructions 7 times now, the only thing Im missing is the picture of the back of the new pc board, and the back of the tow joint together, Does any body hase this pictures tha they dont minde sharing? Much apricieted.
 
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