Dennis Murphy Pioneer SP-BS22-LR DIY Modifications
- Thread starter MCM_Fan
- Start date
MCM_Fan
AK Subscriber
Me, too!!!
Dennis was extremely generous in sharing his schematic and design notes with me. And, when I showed him photos of my implementation, he urged me to post a DIY in the online forums - which is even more generous.
I know it's only been a few days since I posted this, but I am really looking forward to feedback from others who complete the mod. These Pioneer SP-BS22-LR speakers are wildly popular here, especially with the recent sale prices.
The goal of sharing these modifications is to make these improvements available to the widest possible audience. Dennis has always been an enthusiastic supporter of the DIY community. This is just his latest contribution. I urge anyone who has these speakers, and the skills and tools to complete these modifications, to give it a try.
Based on my experience, you won't be disappointed with the results. I love my modded speakers and listen to them every morning and every evening Combined with good electronics and excellent source material, I continue to be amazed at how good these little, inexpensive speakers sound.
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Awesome write-up... Thanks for all of your effort.
I grabbed a pair of the BS22's for $60 during Amazon's last sale... with plans to do this upgrade. Unfortunately, work has been super busy and I haven't even ordered parts yet... and I will be out of town for 3 weeks soon, so I'm not sure when I will get to upgrading these.
I am thinking that instead of using the RatShack PCB, I am going to build a new board with all point-to-point connections. I'm thinking I may just buy the 1.5mH inductor (steel laminate) rather than reusing the stock inductor and adding the 0.5mH air core in series.
Did Dennis specify the Audyn caps for any specific reason? The Dayton metalized poly caps are slightly cheaper, so thinking of using those.
I grabbed a pair of the BS22's for $60 during Amazon's last sale... with plans to do this upgrade. Unfortunately, work has been super busy and I haven't even ordered parts yet... and I will be out of town for 3 weeks soon, so I'm not sure when I will get to upgrading these.
I am thinking that instead of using the RatShack PCB, I am going to build a new board with all point-to-point connections. I'm thinking I may just buy the 1.5mH inductor (steel laminate) rather than reusing the stock inductor and adding the 0.5mH air core in series.
Did Dennis specify the Audyn caps for any specific reason? The Dayton metalized poly caps are slightly cheaper, so thinking of using those.
MCM_Fan
AK Subscriber
These are all viable options and I urge you to try them. This DIY is just one possible implementation of Dennis' crossover design.
The Radio Shack perf board was meant to make this mod available to those who don't have PCB layout kills, or don't want to spend the time and money on getting PCBs fabbed.
Reusing the original 1.0uH inductor was just one way to keep the cost to minimum. A 1.5uH inductor certainly makes sense if you're laying out your own PCB.
Dennis only mentioned that he used the Audyn caps. He didn't give a specific reason. Since he has modded many pairs of these speakers, I went with his recommendation. The Daytons are certainly another option, as are Solens, Sonicaps, etc. Again, this DIY is just one possible implementation of Dennis' design. I encourage you to experiment with other options, and if you do, please come back and share your findings.
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Hi There,
I just completed these mods last night and am now listening to the BS-22s with a nexus 7 tablet as a source playing FLAC files, a YJ Audio three tube pre--6z4 rectifier with upgraded military 5670 tubes in lieu of 2 6n3s, and a modified tpa3116 Danzz-designed YJ black/blue amp (coilcraft inductors, Wima MKP10 input caps, Ceramic bootstrap caps, etc.)
I really liked these speakers before the mods, got them from Amazon with the59$ sale, plus I had a $50 gift card from X-Mas so with shipping I had a grand total of $13.50 into the Pioneers.
Prior to these, I was using a set of Dayton B652s for my near field listening on my desk that also had a new crossover in them courtesy of Dennis Murphy (and his design there really made those better.)
But, while they may lack a little bass compared to the b-652s (with their 6.5" woofers) the Pioneers in stock form were certainly better than the Daytons.
So, I was very excited when Dennis Murphy announced he had a mod for the Pioneers and I was even more excited when he emailed me the specs and BOM and schematics.
Then, I found this thread and thanks to MCM Fan, I had a complete and easy to follow set of instructions for the work.
So, I ordered up the parts and busted out the iron and got to work.
Unfortunately, when I completed the mods I could not get the speakers to work. My 3116 went into protection mode every time I turned the volume up. I thought perhaps it was an amp issue and a big coincidence so I hooked the modded speakers up to my Sansui B2101 in my HT set up and fired them up there. No protection, but the speakers sounded tinny and soft and I realized that the woofers were not putting out any sound--or barely any sound.
So, it seems I failed.
I double checked the instructions, double checked the connections, couldn't get them to work.
Tested all the drivers, they all worked without the crossover (and again, the tweeters were fine) so I guess I screwed up the boards or something with all the desoldering, resoldering, ungluing, etc.
To fix the issues, I decided to ditch the original pcb altogether and just run that part of the crossover circuitry point-to-point.
Laid out the circuit on some board, twisted the ends together, glued them down, soldered it, reconnected my new board piggybacked to the radio shack perf board (connected with the same lead from the added woofer inductor on that board), re-assembled, fired them up on the Sansui B2101 and, SUCCESS!
From what I can tell, I must have messed up the original PCB when I made the mods. But, it seemed weird to me that BOTH speakers would have the same fault when the circuits were separate. I think I may have damaged the pad where the added inductor makes the connection from the radio shack board to the original pcb and thus had the short.
When you connect the two boards you have to solder the inductor to the original pcb pad and screw them together with the spacer to the terminal cup. I solder it then tightened it up to the terminals and when I did that I think the torque ripped that pad off both of the original pcbs. Not totally sure but I think that is what happened.
I think that if you don't have a high level of DIY skill like MCM Fan and others on this board it may just be easier to remove all the parts from the original crossover board and point to point them yourself. Maybe buy 4 of the radio shack boards and just use that to set it up, or use perf board, foam core, whatever you have laying around. Would cost a few more bucks, but at least then you are sure everything is good with the connections and pads and such.
Or, maybe I just needed to take my time and be a little more careful. It's hard to get all that old glue off the original crossover board, remove the parts, get it clean, etc. MCM Fan's diy guide is so sano, so clean, and mine looked like crap by the time I was done hacking away at it.
Other than that, the only other issue I had with the instructions was in the foam measurements. I am 99% sure I measured the pieces exactly for the sides--6.5 x 4.5 and mine were too short and I had to add two @.5" x 4.5" pieces to fill the space all the way along the bottom of the cabinet.
The rest of it worked like a dream.
--EXCEPT for the fact that when I opened my Vifa tweeters from PE to install them I found that one of them had a completely pressed-in dome! Luckily I remembered reading about the toilet paper and mouth suction trick on line and was able to suck out the dimples and such and restore it to "new" form. I didn't want to wait for a replacement from PE. Not sure what happened there, the driver was wrapped and packed perfectly when I opened it.
But I digress.
Once I fired up the modded BS-22s they performed as advertised. Much better high end, way more integrated sound, better soundstage, etc. All those details are there and more. the little breathing noises, the quiet hi-hat hits. I had noticed before that when it was loud and the bass high, it sounded a bit strained, some break up or something. I think the installed foam handles that nicely. I keep going back and forth on whether I want a sub under the desk but I just don't see the point. I have Kraftwerk "Kardiogram" on right now from Tour de France and the bass is great. Tight, focused, can feel it in my chest.
In short, they are as greatly improved by the Dennis Murphy crossover as my B-652s had been, but because the B2-22s in stock form were already better, the mods really took them up another level.
Cash out of my pocket is now like $95 for these, which is about what the mods to the b652s along with the original speakers cost.
So, for the same money, there's no real comparison.
These things are great.
As always, thanks to everyone for sharing your skills and expertise. Thanks MCM fan for all the work on the guide, and thanks to Dennis Murphy for being so nice and always sharing the schematics and specs for these tweaks.
And, if you don't have time or inclination to mod these things yourself, I would just by a set from Dennis Murphy. He's basically giving them away. Totally worth it for what he is charging.
I just completed these mods last night and am now listening to the BS-22s with a nexus 7 tablet as a source playing FLAC files, a YJ Audio three tube pre--6z4 rectifier with upgraded military 5670 tubes in lieu of 2 6n3s, and a modified tpa3116 Danzz-designed YJ black/blue amp (coilcraft inductors, Wima MKP10 input caps, Ceramic bootstrap caps, etc.)
I really liked these speakers before the mods, got them from Amazon with the59$ sale, plus I had a $50 gift card from X-Mas so with shipping I had a grand total of $13.50 into the Pioneers.
Prior to these, I was using a set of Dayton B652s for my near field listening on my desk that also had a new crossover in them courtesy of Dennis Murphy (and his design there really made those better.)
But, while they may lack a little bass compared to the b-652s (with their 6.5" woofers) the Pioneers in stock form were certainly better than the Daytons.
So, I was very excited when Dennis Murphy announced he had a mod for the Pioneers and I was even more excited when he emailed me the specs and BOM and schematics.
Then, I found this thread and thanks to MCM Fan, I had a complete and easy to follow set of instructions for the work.
So, I ordered up the parts and busted out the iron and got to work.
Unfortunately, when I completed the mods I could not get the speakers to work. My 3116 went into protection mode every time I turned the volume up. I thought perhaps it was an amp issue and a big coincidence so I hooked the modded speakers up to my Sansui B2101 in my HT set up and fired them up there. No protection, but the speakers sounded tinny and soft and I realized that the woofers were not putting out any sound--or barely any sound.
So, it seems I failed.
I double checked the instructions, double checked the connections, couldn't get them to work.
Tested all the drivers, they all worked without the crossover (and again, the tweeters were fine) so I guess I screwed up the boards or something with all the desoldering, resoldering, ungluing, etc.
To fix the issues, I decided to ditch the original pcb altogether and just run that part of the crossover circuitry point-to-point.
Laid out the circuit on some board, twisted the ends together, glued them down, soldered it, reconnected my new board piggybacked to the radio shack perf board (connected with the same lead from the added woofer inductor on that board), re-assembled, fired them up on the Sansui B2101 and, SUCCESS!
From what I can tell, I must have messed up the original PCB when I made the mods. But, it seemed weird to me that BOTH speakers would have the same fault when the circuits were separate. I think I may have damaged the pad where the added inductor makes the connection from the radio shack board to the original pcb and thus had the short.
When you connect the two boards you have to solder the inductor to the original pcb pad and screw them together with the spacer to the terminal cup. I solder it then tightened it up to the terminals and when I did that I think the torque ripped that pad off both of the original pcbs. Not totally sure but I think that is what happened.
I think that if you don't have a high level of DIY skill like MCM Fan and others on this board it may just be easier to remove all the parts from the original crossover board and point to point them yourself. Maybe buy 4 of the radio shack boards and just use that to set it up, or use perf board, foam core, whatever you have laying around. Would cost a few more bucks, but at least then you are sure everything is good with the connections and pads and such.
Or, maybe I just needed to take my time and be a little more careful. It's hard to get all that old glue off the original crossover board, remove the parts, get it clean, etc. MCM Fan's diy guide is so sano, so clean, and mine looked like crap by the time I was done hacking away at it.
Other than that, the only other issue I had with the instructions was in the foam measurements. I am 99% sure I measured the pieces exactly for the sides--6.5 x 4.5 and mine were too short and I had to add two @.5" x 4.5" pieces to fill the space all the way along the bottom of the cabinet.
The rest of it worked like a dream.
--EXCEPT for the fact that when I opened my Vifa tweeters from PE to install them I found that one of them had a completely pressed-in dome! Luckily I remembered reading about the toilet paper and mouth suction trick on line and was able to suck out the dimples and such and restore it to "new" form. I didn't want to wait for a replacement from PE. Not sure what happened there, the driver was wrapped and packed perfectly when I opened it.
But I digress.
Once I fired up the modded BS-22s they performed as advertised. Much better high end, way more integrated sound, better soundstage, etc. All those details are there and more. the little breathing noises, the quiet hi-hat hits. I had noticed before that when it was loud and the bass high, it sounded a bit strained, some break up or something. I think the installed foam handles that nicely. I keep going back and forth on whether I want a sub under the desk but I just don't see the point. I have Kraftwerk "Kardiogram" on right now from Tour de France and the bass is great. Tight, focused, can feel it in my chest.
In short, they are as greatly improved by the Dennis Murphy crossover as my B-652s had been, but because the B2-22s in stock form were already better, the mods really took them up another level.
Cash out of my pocket is now like $95 for these, which is about what the mods to the b652s along with the original speakers cost.
So, for the same money, there's no real comparison.
These things are great.
As always, thanks to everyone for sharing your skills and expertise. Thanks MCM fan for all the work on the guide, and thanks to Dennis Murphy for being so nice and always sharing the schematics and specs for these tweaks.
And, if you don't have time or inclination to mod these things yourself, I would just by a set from Dennis Murphy. He's basically giving them away. Totally worth it for what he is charging.
MCM_Fan
AK Subscriber
steveeboy,
Glad to hear you got them working in the end and are enjoying your modified speakers. They really do sound great, don't they?
Hmm... this one is a bit of a head scratcher. When you soldered the inductor lead wire to the original PCB, did you have the 1/8" nylon spacers between the two boards? When I do this, I place all four spacers and mounting screws between the two board and hold them tightly together when I solder the leads. That works for me (at least it has 4 out of 4 times, so far). Perhaps it would be even better to temporarily use a machine screw and nut to hold the spacer in place and the boards tightly together when soldering this lead.
Still, that's a big pad in the middle of a large plane on the original PCB. Doesn't seem like it would be easy to damage unless the gap between the two boards changes significantly between soldering the leads and mounting the bards on the terminal cup. Did you inspect the original PCB after assembly to see if you could detect any damage visually? If you still have the original PCBs, please take a close up shot of that area of the PCB so we can see if any damage is visible.
If this is damaging the original PCBs, maybe I need to re-write that section of the DIY to suggest screwing the boards, with the 1/8" nylon spacer between, tightly together using temporary machine screws and nuts, before soldering that lead to the original PCB.
Is there any chance this was caused by something else? Maybe something shorting between the two boards. Was there anything protruding more than 1/8" from the back of the Radio Shack perf board that could have been shorting to something on the original PCB? Did you take any photos of the back side of the perf board, or the perf board and original PCB sandwiched together? Given that both crossovers showed the same type of failure, that seems a little unlikely. Oh well, at least you get points for consistency. Whatever it was that happened, it caused both crossovers to fail identically.
MCM_Fan
AK Subscriber
Not quite sure I understand this (again, photos would be helpful). Since I was doing the mods to four speakers, I made templates for each piece. I'll double check my template measurements tonight and confirm that the side pieces are 6.5" x 4.5".
Did you cut the bottom piece of the foam first and make it fit snug all the way around? If so, I'm not understanding where this 1/2" gap is that needs to be filled along the bottom of the cabinet. I cut the bottom pieces to fit snugly and install them first. I then install the side pieces such that they rest on top of the bottom piece. Even if your top pieces are a little short, I don't understand where the gap is you're referring to. If the side pieces are too short, wouldn't the gap be between the top of the foam and the original batting that gets moved to the top half of the cabinet interior, bnot along the bottom of the cabinet as you described?
MCM_Fan
AK Subscriber
Yep, I did that one, too and those Polk RTi28s are now happily making music at my girlfriend's place. Since I picked them up at Goodwill for $24.99, those modified Polks were also a great deal.
Sorry MCM Fan, I wasn't clear.
The foam gap was front to back, not top to bottom.
So, I made template for bottom piece, fit perfectly. made template for back piece below crossover, fit perfectly.
I am 99% sure I measured properly for side pieces--6.5 x 4.5, but those left a gap of @.5" to back of cab and I had to cut two pieces that were .5 x 4.5 tall to fill the gap. I put the side pieces flush to the front baffle.
Again, I may have screwed up the length measure, but I don't think I did.
The top to bottom was fine and the batting fit right from the top of the foam to the bottom of the port tube.
As far as the circuit boards go, I had difficulty drilling the holes in the radio shack perf board so that the screws would go straight into the crossover board and terminal cup. They were crooked. When I tightened those it twisted a bit, bent the perfboard, and cracked one corner--on both assemblies.
When I checked one of the crossover boards on disassembly, I found a lifted pad. I did not check the other board in a similar fashion since I assumed that was the issue.
Could also be a problem with glue removal, since I had no goof off and I was using a razor blade to scrape up the glue and that may have messed up a pad or trace.
Again, I don't think the issue is your instructions or the mod, just my sloppy soldering skills and ham-fisted diy efforts.
And, I violated a cardinal rule, I started work on this project late and refused to go to bed and tried to finish up the project at like 2am.
Once I had the light of day to think and carefully troubleshoot, I could fix the problem.
All I think is needed is a caution to be careful with the torque and such when you screw things back down. Be careful of that inductor lead once it is soldered into place since any front to back motion could lift the pad.
And, you have the hole guides referenced to the radio shack board coordinates, but maybe just lay it on top of original crossover and mark holes for the drill? Or tell people to use a drill press and be very careful with the holes? It's tough to get them exactly on the 15.5 and such with a hand drill, it moves a bit and then your holes don't fit the original crossover and terminal cup exactly.
Just my $0.02.
Again, once I got the woofer circuit issue fixed all worked as expected, and man, these things sound even better now. great on the desktop for near field. so much detail, no fatigue, you start hearing things in the mix and you think it's in the room, or hallway, and you turn down the music because you think someone is in the house or something!
And, they sounded great powered by my big Sansui b2101 amp in the HT set up. Not too efficient, I had to push the amp up a bit higher power-wise to get a similar sound level to my main HT speakers, but they took it fine.
Too bad the word is the tower models --fs52s-- don't have the same magic?
Thanks again for all your work on the guide. It really made the job easier and more manageable.
The foam gap was front to back, not top to bottom.
So, I made template for bottom piece, fit perfectly. made template for back piece below crossover, fit perfectly.
I am 99% sure I measured properly for side pieces--6.5 x 4.5, but those left a gap of @.5" to back of cab and I had to cut two pieces that were .5 x 4.5 tall to fill the gap. I put the side pieces flush to the front baffle.
Again, I may have screwed up the length measure, but I don't think I did.
The top to bottom was fine and the batting fit right from the top of the foam to the bottom of the port tube.
As far as the circuit boards go, I had difficulty drilling the holes in the radio shack perf board so that the screws would go straight into the crossover board and terminal cup. They were crooked. When I tightened those it twisted a bit, bent the perfboard, and cracked one corner--on both assemblies.
When I checked one of the crossover boards on disassembly, I found a lifted pad. I did not check the other board in a similar fashion since I assumed that was the issue.
Could also be a problem with glue removal, since I had no goof off and I was using a razor blade to scrape up the glue and that may have messed up a pad or trace.
Again, I don't think the issue is your instructions or the mod, just my sloppy soldering skills and ham-fisted diy efforts.
And, I violated a cardinal rule, I started work on this project late and refused to go to bed and tried to finish up the project at like 2am.
Once I had the light of day to think and carefully troubleshoot, I could fix the problem.
All I think is needed is a caution to be careful with the torque and such when you screw things back down. Be careful of that inductor lead once it is soldered into place since any front to back motion could lift the pad.
And, you have the hole guides referenced to the radio shack board coordinates, but maybe just lay it on top of original crossover and mark holes for the drill? Or tell people to use a drill press and be very careful with the holes? It's tough to get them exactly on the 15.5 and such with a hand drill, it moves a bit and then your holes don't fit the original crossover and terminal cup exactly.
Just my $0.02.
Again, once I got the woofer circuit issue fixed all worked as expected, and man, these things sound even better now. great on the desktop for near field. so much detail, no fatigue, you start hearing things in the mix and you think it's in the room, or hallway, and you turn down the music because you think someone is in the house or something!
And, they sounded great powered by my big Sansui b2101 amp in the HT set up. Not too efficient, I had to push the amp up a bit higher power-wise to get a similar sound level to my main HT speakers, but they took it fine.
Too bad the word is the tower models --fs52s-- don't have the same magic?
Thanks again for all your work on the guide. It really made the job easier and more manageable.
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MCM_Fan
AK Subscriber
I measured my template and the side pieces are indeed 7" x 4 1/2". I have no idea how that error crept in, but I have updated the original post with the correct dimensions for the side pieces of the Sonic Barrier acoustic foam.
Sorry for the inconvenience this caused, but thanks for catching it.
I used a drill press for drilling all the holes in the Radio Shack perf boards. So, getting them drilled precisely wasn't a problem for me, but I can see how it would be for someone trying to drill them with a hand drill. Maybe a light tap with a center punch at the desired locations, prior to drilling, would keep the drill bit from wondering. Just be careful as the fiberglass is not nearly as hard as sheet metal. So, a very light tap on the center punch would be all that's required.
Yes, I also notice there was some small amount of flexing of the terminal cup mounting posts when installing the new crossover boards. Because these mounting posts are plastic, they are very flexible. When installing the modified crossovers, I just used by and to squeeze the mounting posts together a little to allow the screws to align and thread right in.
I just used my thumbnail to remove the most of the glue from the original PCB. It appears to be some type of rubber based cement and if you can get your thumbnail under it to get it started, it peels off the board with very little left behind. This is very easy on the PCB (not so much on the thumbnail) and doesn't risk damaging the PCB, like a knife or razor blade would. After the glue was all removed, I used some Goo-Gone to clean things up to make the PCBs look nice in the photos, but it really wasn't necessary for functional reasons.
And, this is what it's all about. I'm glad you were able to figure things out and are now enjoying your modified speakers. I listen to mine every day and continue to be impressed by the sound quality produced these very affordable speakers.
alright, good that I was not crazy on my measurements of the foam!
7" by 4.5"
my ham-fisted diy skills are responsible for the other issues I am sure...
Currently listening to them and they just sound:
Thank you so much again for taking the time and effort to post the guide to these mods.
Makes it a lot easier for those of use with the desire but not so much skill...
Now, where is the guide for the fs-52 towers?
:thmbsp:
7" by 4.5"
my ham-fisted diy skills are responsible for the other issues I am sure...
Currently listening to them and they just sound:
Thank you so much again for taking the time and effort to post the guide to these mods.
Makes it a lot easier for those of use with the desire but not so much skill...
Now, where is the guide for the fs-52 towers?
:thmbsp:
Ed in Tx
Super Member
Wondering the same. Crossovers are different so same mods would not apply.
Has anyone traced out the 52 crossover and come up with a schematic?
I really like my FS52 towers, so much so I put the 22's back in their box.
Nope, the driver is different and I'm sure the cross over would be as well.
The 21s seem to have different problems too.
MacNoob
dazed and confused
saw that one recently - 3.9uf cap in series.
MacNoob
dazed and confused
Working on my crossovers right now - wow, that's some superglue they used to fasten the components to the board!
edit - 2 hours later... one crossover almost built. My ty wraps are too big. This is a lot more work than it looks...
One down! Works great and sounds much better. Did an A-B with my son and he picked out the modded one right away. Much clearer high end and less mud on the mids. Pleased!
Both done. I had to fight with my wife to get them back. I swapped a pair of A70 Series II into the family room to get my BS22s back to my computer...
edit - 2 hours later... one crossover almost built. My ty wraps are too big. This is a lot more work than it looks...
One down! Works great and sounds much better. Did an A-B with my son and he picked out the modded one right away. Much clearer high end and less mud on the mids. Pleased!
Both done. I had to fight with my wife to get them back. I swapped a pair of A70 Series II into the family room to get my BS22s back to my computer...
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fredcohiba
Super Member
Great post - but how do they sound compared to X brands?