Pioneer HPM-100 Recapping Walkthrough

xoaphexox

Supernatural Anesthetist
Tonight I recapped my third pair of Pioneer HPM-100's, so I decided to take photos along the way in hopes that it might help someone who has never attempted a recap before, either on these particular speakers or others.

My first step was to purchase parts. For this, I chose Partsexpress. My cart was as follows:

2x 005-10 Mills 10 Ohm 12W Non-Inductive Resistor $3.50
2x 027-419 Dayton DMPC-4.3 4.3uF 250V Polypropylene Capacitor $1.86
2x 027-220 Dayton PMPC-3.0 3.0uF 250V Precision Audio Capacitor $2.79
2x 027-462 Jantzen 0.15uF 1200V Z-Superior Capacitor $7.68

My goal was to replace all three capacitors as well as the resistor for each crossover. I have chosen Solen brand capacitors in the past and find them to be brighter than the Dayton counterpart. They are basically the same price, and since the HPM-100 to my ears is a pretty forward speaker, I went with the Daytons as to not exacerbate the issue.

Here is the speaker prior to doing anything:
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Here we see the back of the speaker. Behind this rear panel is the crossover.

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Here are the parts that arrived. Note parts shown are for both crossovers:
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You will need a phillips head screwdriver to remove the six screws that hold the back panel/crossover to the unit. This part comes off easily.
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To fully remove the crossover, I found it easiest to remove the super tweeter from the front. It is attached with four phillips head screws. This will allow you to take the yellow (+) and white (-) wires off the back of the supertweeter. They are the socket-kind and do not require unsoldering. At this point I was able to reach through the speaker from the back and remove both wires from the woofer (blue and white) so that I would not have to mess with unscrewing and removing the woofer. There was plenty of room for my arm. A penlight will help here if you arent in a bright enough room to see the color of the wires as they attach to the woofer posts.
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Now that you have the crossover in hand, there are four more screws that hold the crossover board to the black plastic holder, and you can unscrew the speaker posts themselves to allow the crossover to come off completely.
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At this point you can use wire clippers, scissors, or needlenose pliers to remove the old caps and resistor. I choose to clip off the old parts and then use desoldering braid to suck up the solder on the pads. The clipped leads that remain just fall out.
7.jpg


Now put the new parts in where you took the old parts out and solder them in well!
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It is a pretty straightforward task. Now sit back and enjoy!!
:music::music:

Rob
 
Excellent post Rob. This will save me alot of time on a project that I've been putting off. Thanks!:thmbsp:
 
Thanks for a really great post. I have two pairs that could probably use a re-cap.

Did you also up-grade the binding posts or leave them stock? I found the old ones to be a bit finicky and was thinking that the time to re-do them would be when the crossover was out of the box.
 
Did you also up-grade the binding posts or leave them stock?

I have not upgraded the binding posts. I agree that they could be a PITA in most situations, but I happen to use speaker wire that is terminated at the end with 'pegs' that fit nicely in the spring posts.

If I was using banana plugs or bare wire I would certainly entertain the idea of new posts.

If you decide to go for it, post some pics :thmbsp:
 
Man yeah !!

:thmbsp: :thmbsp: That's two thumbs up for a great post . You have a pair of minty HPMs there , if they sound as good as they look you are in :music: .
Thank you for the great pics too.

rebel
 
The 0.15 uF caps are a bit pricey. I see there's no others in that value for less, though.

How about 027-406 0.47 uF plus 027-402 0.22 uF in series for 0.1499 uF at $1.61 the pair instead, maybe?
 
The 0.15 uF caps are a bit pricey. I see there's no others in that value, though.

How about 027-406 0.47 uF plus 027-402 0.22 uF in series for 0.1499 uF at $1.61 the pair instead, maybe?

I just use whichever brand of caps my budget allows. This time, I wanted to try the Jantzen Z-Caps. The last pair of HPM-100's I recapped, I used Auricaps. I like the convenience of using one cap.

The Auricaps were from PartsExpress:
027-652 AURICAP 0.15uF-400V CAPACITOR
 
xoaphexox; Thanks to you I recapped my hpms last winter. I used your parts list and it really helped out the tired old hpm crossover. That's a nice write up you did. Only thing I did different is to use a solder sucker and put the new cap wires in the same hole as the old ones were. Got to remember I'm a soldering newbie and wasn't sure of my skills.
 
Great write up. Thank you.

Can you give us your impressions regarding the positive/negative effects this recap had on the sound? Before and after effects?
 
Great write up. Thank you.

Can you give us your impressions regarding the positive/negative effects this recap had on the sound? Before and after effects?

Let's see my impression is that it seems to have less listener fatigue. Bass is less boomy and the highs aren't quite so irritating. I also swapped out the mids and highs before the recap so mine aren't hpm's in the purist sense. That also helped tame some of the boom and sizzle and now I find them quite pleasant to listen to. For the little time and expense involved I found it well worth the effort.
 
Let's see my impression is that it seems to have less listener fatigue. Bass is less boomy and the highs aren't quite so irritating. I also swapped out the mids and highs before the recap so mine aren't hpm's in the purist sense. That also helped tame some of the boom and sizzle and now I find them quite pleasant to listen to. For the little time and expense involved I found it well worth the effort.

Can anybody else add to this comment? Does it make a big difference to recap the crossovers? My HPM's are still a straightforward pleasure to listen to. I wouldn't want to mess with a good thing...

motorstereo, the photos of your mids and highs look virtually identical to the OEM drivers. How or what exactly did you swap out?

Very interesting topic!
 
Rushfan; Those aren't my pics unfortunatly. I swapped out my mids (because one was bad) with mids from a boston a150. They're a direct replacement and I like the sound better than the stock. I've tried a few replacement tweets. I had a dome tweet from vifa which worked quite well; better than stock for sure but the one I like the best is a rat shack planer tweet. I think these are great platforms to work from and make your own frankenspeakers. I haven't tried swapping out the woofer and really don't feel there's a need to as it's one area I believe that's best left alone. With these few mods it makes the hpms sound more "refined". They're still great party speakers but it's nice to have them have their own character. Would I do this to my klh 12's? Ain't no way!
 
Unfortunately I have been too busy with other projects to really give the pair in this thread a critical listen.

It is difficult for me to put in words the changes that I notice from recapped speakers. I can sum them up by saying that they are enjoyable, and I prefer the sound to the way they sounded before the recap. Perhaps its mental, I will never know.

Sonic changes aside, I am relieved knowing that the electrolytic cap is gone and the resistor is replaced so I do not have to worry about anything failing.

Maybe if one of AK's resident geniuses (Zilch, ahem) spies this thread they could chime in with technical benefits from recapping.

My project for today is to recap a pair of JBL 4311. I am a little intimidated by the removing of the metal strip from the front to get to the screws. I would post a walkthrough for the JBL recap, but it has already been done, and quite well, in another thread in this forum. It will be the one I refer to while performing this recap.

Other than that I might take a few moments to adjust a recently recapped AU-919 to spec.

Love the weekends!
 
My project for today is to recap a pair of JBL 4311. I am a little intimidated by the removing of the metal strip from the front to get to the screws.
I did a pair. Putty knife, held flat to the cabinet and worked in slowly across the top and then gently down to break the adhesive. Do NOT pull or rock the knife towards you to work the plates off until you have broken the adhesive or you'll run the risk of bending them and/or cracking the paint, as they're rather thin aluminum. When reattaching, a thin coat of good ol' Weldwood Contact Cement applied to both plates and cabinets and allowed to tack before joining worked best for me.

Caps: You'll need a 3uF and 8uF per cabinet (I used two 4uF tied together for the 8.) I also added 0.001uF bypass caps to the Dayton replacements for the heck of it.

Gonzomeep's suggestion to re-spray the fronts (and rears) in flat black followed by DEFT Clear Wood Finish (Satin) made them look factory fresh. :thmbsp:
 

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Foilcals?

Heatgun or hair dryer and utility knife blade.

Patience.

[Just the blade, not the knife.... :yes: ]
 
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