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Pioneer HPM-100 Recapping Walkthrough

I was just amazed that with a slight change in the value could make such a difference in sonics, I am enjoying music now from the speakers after I have adjusted the pots to my liking. :music::music::music:
 
I just picked up some beat up HPM-100s for $50 and while re-reading this old thread in preparation for the crossover recap I noticed something in this photo I'm not sure of.

There looks to be some sort of material / padding underneath the two Theta bypass caps that are mounted on the back of the board on the left.

Is this something I need to know about before I just solder / hot melt glue them on as usual.

Thanks!

Zilch said:
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I assume it's so they don't rattle against the PCB at high volumes. You may want to stick some adhesive tape or stuffing (that won't move) there too just to be safe.
 
Great Thread!

Im new here and just read most of this thread, thanks to the OP and all the people who posted!

I'm doing the recap and resistor as outlined in post 1, all the parts are still easy to come by. Im also going to upgrade the speaker binding posts while Im at it. I bought these speakers new in the late 70's. There are the HPM 100 (50-100) as I recall, they were $300. each way back then. I like em.

My question:

I want to make sure all speakers are working. After I finish the crossovers can I test each speaker in the cab by unplugging the other 3 and listening for a short time to each speaker individually without damaging the amp or crossovers? Is there anything else I need to check out while Im here?

Thanks for any info. :thmbsp:

Rob
 
I wouldn't unplug speakers. I typically test by getting my head in front of the speaker, then I wave my hand over each driver I'm testing. If it's working, you'll hear a difference as you hand passes in front of the driver. The supertweeter might be harder to hear unless the test cd you pick has a lot of high end.
 
Like Dr. Mordo says, it's pretty easy to hear each driver just by putting your ear up to it. Super tweeter not so much.
 
redjr said:
Like Dr. Mordo says, it's pretty easy to hear each driver just by putting your ear up to it. Super tweeter not so much.
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You can't hear the super tweet unless it is running all by itself. Disconnect the other drivers and you'll hear it.
 
xoaphexox said:
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:
1.jpg


Here we see the back of the speaker. Behind this rear panel is the crossover.

2.jpg


Here are the parts that arrived. Note parts shown are for both crossovers:
3.jpg


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.
4.jpg


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.
5.jpg


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.
6.jpg


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!
8.jpg


It is a pretty straightforward task. Now sit back and enjoy!!
:music::music:

Rob
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This process was a little unclear to me, as a completely non-technical person. After the leads are clipped, and small leads are left, can the new capacitors be soldered to the older remaining portions of leads? I am contemplating recapping a pair of Design Acoustic PS-10As and a pair of KLH 6s. Whichever I do firs will be my first recap. I have not looked inside either of them to see what the cross-overs are like, or how to access them.
If anyone has a suggestion as to which to do first, I would appreciate any suggestion or any other advice.
 
iramegdal said:
This process was a little unclear to me, as a completely non-technical person. After the leads are clipped, and small leads are left, can the new capacitors be soldered to the older remaining portions of leads? I am contemplating recapping a pair of Design Acoustic PS-10As and a pair of KLH 6s. Whichever I do firs will be my first recap. I have not looked inside either of them to see what the cross-overs are like, or how to access them.
If anyone has a suggestion as to which to do first, I would appreciate any suggestion or any other advice.
Click to expand...

You want to unsolder the old capacitor leads that are left in the circuit board if you clip the old capacitors out. Ideally before inserting the new capacitors you want to be able to see through the holes in the circuit board where the old capacitors were soldered.

Leaving the old clipped leads soldered to the board and soldering the new capacitors on to those leads is undesirable.

Hope that helps!
 
Thank you.

xoaphexox said:
You want to unsolder the old capacitor leads that are left in the circuit board if you clip the old capacitors out. Ideally before inserting the new capacitors you want to be able to see through the holes in the circuit board where the old capacitors were soldered.

Leaving the old clipped leads soldered to the board and soldering the new capacitors on to those leads is undesirable.

Hope that helps!
Click to expand...

Thank you. Would there be a worry about damage to the board?
 
Polarity?

Does it matter which way I put the new caps and resister in? In other words, is there a positive and negative side to the caps? Polarity?
Thanks.
 
joehalo said:
Does it matter which way I put the new caps and resister in? In other words, is there a positive and negative side to the caps? Polarity?
Thanks.
Click to expand...

No, it doesn't really matter. These are bipolar capacitors meaning they can go in any which way.
 
One little thing that does a lot to clear up the sound, at least as much as the recapping, is to bypass the cheap pot's. Replace them with fixed resistors. -1 on the pot = 2,2 ohm in serial and 10 in parallell. It gives you -4 dB, which was right in my case, with HPM-150's.
For even smoother sound, use the midrange from HPM-900/1100, but not its tweeter.

Edit: Slightly different x-over., pic from 150.
 

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Not good!

Well just finished the recap and have been listening to them for about an hour. The results are not good. The highs are much more harsh. Bass is tighter but the highs are just killing my ears. I must have done something wrong but I have no idea what! I cannot get them to sound good no matter what I set the pots to. At high volume the tweeters are distorting also. :tears:
 
Did you keep the old caps? You could try putting the tweeter caps back in to see if that fixes it - double check your solder joints and cap values? I'm sorry to hear it..
 
well, that is troubling. After having mine recapped, it was a serious improvement over those harsh highs I had before.

Double check everything. Something isn't right.
 
I just recapped my hpm-100 (100w version), and I want to make sure that I plugged woofer correctly since, they were connected differently.

As per service manual the blue wire should be plug on +, on the woofer there's a little red dot beside a connector, is this connector the + ??
 
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