Pioneer HPM-100 successful crossover mod!

Listening to Imported pressings of Bossa Nova / Latin Jazz records from the 1960's in stereo is simply amazing with the HPM-100's. Detailed is an understatement !
 
I'm going to try this

I agree that listening for more than 30 min at reasonable volume (80-90dB) is rough, it would be nice to tame the mids and still have that nice tight bass.

I've done a few diy projects that have easily taken the place of the HPMs as the SQ is much better, it would be cool get them out and make them more listenable.
 
I have the hpm 200w version and tried them with many different power sources. The best sound these speakers ever produced was with a little tuned pioneer sa-7500. Super detailed without a spec of harshness and had me listening to symphonic music just to hear very high quality detail. Way better than the untuned sa-8500. Then I hooked them to a kenwood model 11gx and they sounded ok. Then a couple of bigger sansui g's and the same. Tuned Pioneer spec 1 with spec 4 and they get super detailed. My point is how important the source is to get the most out of the hpms. The stock hpms will give super detail without one iota of harshness/fatigue hooked to a clean/tuned source.
 
O.k., I've been listening to a variety of music after making this mod on my HPMs: jazz, jazz fusion, classical, blues, male and female vocalists, live performances, a little bit of rock (my tastes have changed a bit since I bought these new in 1977). I had never been satisfied with the sound of my HPMs before, but I now have the speakers that I always wanted. The harshness is gone, the bass seems stronger, the tweeters and supertweeters still make cymbals sing. Individual instruments and sounds are more distinguishable. There is more definition, soundstage, presence-- dimension to the sound.
I used a Sansui 7070 receiver to power my HPMs from new until the last couple of years when I hooked them up to a Marantz 2230 receiver. I liked the sound with the Marantz better, though they were still way too harsh to make my ears happy. I don't know if it is the changing of the crossover points or the installation of sonically better caps than Pioneer originally put in them or a combination of the two that makes the difference. Now they are simply delightful to listen to. Thank you Mattsd for sharing your information with us.
 
Man, it's been awhile since I posted in this thread! I'm glad to hear that the mod worked for you! :thmbsp:

I have had my modded HPM's going as my main speakers ever since I posted this thread, using them with my own gear and to test many, many different receivers and amps I've been repairing or restoring for guys on here and elsewhere (STA-2100D, SX-1280, AU-717, AU-20000 and many more) and I have not found any reason to go back, they have sounded so much better. :music:
 
Man, it's been awhile since I posted in this thread! I'm glad to hear that the mod worked for you! :thmbsp:

I have had my modded HPM's going as my main speakers ever since I posted this thread, using them with my own gear and to test many, many different receivers and amps I've been repairing or restoring for guys on here and elsewhere (STA-2100D, SX-1280, AU-717, AU-20000 and many more) and I have not found any reason to go back, they have sounded so much better. :music:

Matt,

I'll have my x-overs off to you this week too! Can't wait for new and improved sounds!
 
I picked up a pair a HPM100 a couple of months ago. Aside from the veneer on the top of one speaker delaminating (watered plant on top?) everything else looked good. These were in storage for several years.

I applied new veneer to the cabinets (Walnut, Tung Oil finish) and picked up additional crossovers and sent then to Matt.

The original crossovers were the 100W max version while the other crossovers are the 200W version.

I installed Matt's reworked crossovers this weekend. The HPM100 are a better balanced speaker now, even the bass response has improved.

I can recommend Matt's rework. Pick up an additional pair on eBay and send them to him. A worthwhile experiment. And the crossovers take all of 10 minutes to swap out.

The photo of the crossovers shows the original on the left and Matt's rework on the right. Nice work!

The HPM100 with new veneer are pictured here: http://www.audiokarma.org/forums/showpost.php?p=6276679&postcount=43
 

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I'm working on a pair of 200 watt HPM-100's and came across this thread, looks like an easy mod. Maybe I'll go for it and see if I like the results. :scratch2:
 
I'm working on a pair of 200 watt HPM-100's and came across this thread, looks like an easy mod. Maybe I'll go for it and see if I like the results. :scratch2:
Do post your thoughts after you've completed and auditioned. I haven't a clue where I'm going to find the time for all these projects. Ugh!
 
I ordered parts for this today. I have a pair of completely recapped HPM-100 crossovers sitting here collecting dust, since I haven't ever put theming second pair. I'm going to try the mod on these and then swap them in and out of my "main pair" and see what happens.
 
I ordered parts for this today. I have a pair of completely recapped HPM-100 crossovers sitting here collecting dust, since I haven't ever put theming second pair. I'm going to try the mod on these and then swap them in and out of my "main pair" and see what happens.

Cool. I tried this mod and didn't care for it so I switched it back. It's very subtle; the loudness switch on my receiver has a greater overall impact on the tonality than this mod did.

I still think the HPM-100 with a DBX 31 band graphic EQ is about as good as I will ever get from these 35 year old speakers. I'll be interested in your results.
 
Yeah if I don't like it I will just put back the current crossovers (which are also fully recapped but at the original crossover points).
 
I also tried this mod and like it, even though I cannot say that I could hear night and day difference. Attached are a few photos of the completed mod - the white stuff is RTV-162 (there's one photo before I applied it), also the new binding posts.

P.S.: my speakers are the newer "200W" version. I was afraid to screw up so got a pair of older 100W crossovers from ebay for the mod. I read some threads saying that the polarity of the two versions of crossovers were somehow different. Well, FWIW they look the same to me. The wire colors match, the hieroglyphs (?) marking the wires match - everything looks the same. And connecting them in the exact same way as the newer crossovers sounds fine to me.
 

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I just dropped off two amps for Matt to restore in February. Now my interest in this mod is piqued.

I cannot listen to my HPM's more than a half hour without ears ringing, tho my tinnitus is pretty bad some nights. I will say that both my pair and my friend Vegaman9's pair both benefited from a recap (dayton caps I think?) Harshness went way down.
 
I just dropped off two amps for Matt to restore in February. Now my interest in this mod is piqued.

I cannot listen to my HPM's more than a half hour without ears ringing, tho my tinnitus is pretty bad some nights. I will say that both my pair and my friend Vegaman9's pair both benefited from a recap (dayton caps I think?) Harshness went way down.
I believe I mentioned earlier in this post that re-cap helped a lot for mine. This thread has me interested. I actually have two sets of spare networks. I can always mod one set, test, then decide for myself.
 
I recently did this mod. It, IMO, is better than recapped original, but some music still rings your ears, just not as badly.
 
I'll grab some off that auction site and have Matt do 'em up, or maybe try it myself, I've done more than a few crossovers. If Matt says it improves them, I gotta believe it does.
 
Recently bought HPM-100s and did my research on AK and everywhere else on mods.

Matt's mod seemed most interesting, since my ears hate bright music.

So I plunged and did recap and Matt's mod.

Now it sounds really really good. Except the bass is a bit muddy. Specially trying to reproduce the TABLA on Indian fusion music.
ANY HELP ON BASS ???

But I listen to mainly rock and these speakers rock.

Parts used
Obillgato 10uF oil caps (partsconnexion)
Dayton 3.0uF Audio grade cap (Parts express)
Janzen 0.15 Gold Z cap (Parts express)
ERSE 14 guage wire 0.9mH coil (Parts express)

My system
Carver CD player SD-A360
Melody A23 Integrated (tube)
HPM-100 (replaces my Dali IKON-6...they move to Home theater)

Thanks guys
 
I like the HPM-100 but I think a lot of people would describe the bass as a bit muddy, loose, or flabby. It's quite weighty and full, but hardly the last word in tightness. Are you saying the mod made the bass muddier than it was before the mod?
 
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