I haven't seen too much HPM-100 chatter for some time, back when I did mine I used a HPM-900 mid driver and changed the midrange cap value to match the 900, really liked the outcome.
Pioneer HPM-100 successful crossover mod!
- Thread starter mattsd
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Port Entropy
Active Member
I just completed this mod. I went with the Dayton inductor (I do think the smaller size probably made it a little easier) and the Audyn cap for the .15uf. I'm very happy with the results. I'm not sure how this would compare to a recap at stock values, but it sounds good to me. It seems to have gotten rid of the low-mid hump which gives it a more open sound. I'm still dialing it in/tweaking.
But another thing occurred to me: has anyone tried reducing the value of the resistor on the super tweeter? I have tried searching, but haven't found anything. They definitely don't add much as they are, and I think the speaker could benefit from a little more "air".
Would changing the value of that resistor only impact the output of the super tweeter, or would impact the whole circuit or change the speaker's impedance? Could there be a negative side effect? I guess an increased chance of blowing the super tweeter?
But another thing occurred to me: has anyone tried reducing the value of the resistor on the super tweeter? I have tried searching, but haven't found anything. They definitely don't add much as they are, and I think the speaker could benefit from a little more "air".
Would changing the value of that resistor only impact the output of the super tweeter, or would impact the whole circuit or change the speaker's impedance? Could there be a negative side effect? I guess an increased chance of blowing the super tweeter?
Bimmerb5
New Member
I'm in the process of rebuilding the HPM 60 which has the same crossover topology as the HPM 100 with different values of course. As far as I can see from the schematic, the midrange has a high pass filter and not a band pass filter, so it's acting as a tweeter and a midrange. There seem to be too many drivers operating at the same frequencies. I will measure each driver's frequency response and impedance plot. I have the dsp NanoAvr to setup individual crossover so I can listen to what frequencies sound the best in terms of instrument separation, clarity, accuracy, articulate, vocals, and of course each driver doing its proper function. I've already completed the cabinets in cherry wood veneer, stained in early American walnut, so this won't be your father's HPM 60...
. The crossover will be a completely different animal. The signature sound of the drivers won't change, but the quality of the sound will change. The drivers seem to be fashioned off JBL type drivers. JBL revamped the L100, so I think the HPMs are due for a make over (the L100 new are $4000/pair) we'll see how my HPM 60 turns out. I'll post pictures soon.
Port Entropy
Active Member
I ended up adding a choke on the mid myself, after completing the modifications outlined here. I remember reading about this in another thread, but I can't seem to find it. The person in that thread mentioned they were modeling it after another Pioneer crossover - maybe the HPM 900. I'm not sure what value they used.
I just tried out some spare inductors I had lying around. I don't remember the value - I think .4 or .45mh and I am pretty happy with the results. I think a slightly lower value to raise the low pass point a bit might be better, and next time I place an order with Parts Express, I will probably try that out. It looks like the 900 uses a .35mh inductor.
Adding the inductor on the mid definitely seemed to smooth things out and cut out that high mid peak. There seems to be a lot less overlap with the tweeter. I was able to raise the pot on the mid a good amount. Before, I had them below -3. Now, I think they are between 0 to +1. It helps to fill out the mids without adding harshness.
Timothy Flath
Well-Known Member
Anyone have a modern 2019 parts list from mouser on a good decently priced crossover upgrade for my second pair of HPM-100 100/200 speakers. My main pair are my primary listeners in my media room. The second pair have beat up but functional cabinets with drivers in superb condition. Originally bought them as parts speakers but are every day users. I want to try updating the x-overs myself to hear for myself how perfection can maybe improved. Thanx
FWIW the 12" woofer was left to run way too high in frequency. The graphite cone with the aquaplas coating produces a enormous spike at around 2.5k hz. This accounts for the perceived harshness in the midrange. The spike, from what I've read (Lynn Olson et al) is the nature of the drivers made as such. Not just in the HPM series.
They, the graphite aquaplas cones, exhibit visceral bass punch. I'd work with that and then sort out the mid/upper frequency response. Those woofers are really good for what they do well.
They, the graphite aquaplas cones, exhibit visceral bass punch. I'd work with that and then sort out the mid/upper frequency response. Those woofers are really good for what they do well.
Timothy Flath
Well-Known Member
You either love em or hate them. I never tire of listening to them (every day). I am quite obviously in the "love em" camp as per (notice the EQ in the picture):
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Port Entropy
Active Member
So are you looking to modify the crossover values as discussed in this thread, or are you just looking to replace with modern components of the same value? If you think they are "perfection" as they currently play, you may not want to rebuild the crossover, or at least keep the values the same.
Timothy Flath
Well-Known Member
I will try either. Love them as they are but having two sets I can always experiment with my beater man-cave ones to see if they can become even better. So ideally I guess I would be seeking both - happy either way though. Thanks. TMF
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Bimmerb5
New Member
I've been testing and listening to the HPM 60, the newer model. The setup that I use is with the DSP Nanoavr where you can set the crossovers electronically then listen. So far the best integration of woofer and midrange is 1200 hz for the woofer and 1200-4000hz for the midrange and tweeter. The tweeter seems to produce the harshness that most people complain about. I will definitely replace the tweeter with a modern planar tweeter. If the midrange handles above 4000Hz, the you get that "lisp" to female voices. The super tweeter was a novelty back then, and not needed today. A $35 planar tweeter goes beyond 30 Khz and outperforms the paper tweeter and super tweeter. You still retain the 70s flavor, but at a higher quality of sound. Using the DSP NanoAvr gives me the flexibility to examine each driver during testing while changing the crossover points, so you can tailor the sound to your liking. The next step will be to design a proper 3 way crossover with the desired crossover points. I will run a sweep on each driver to get the FRD, and ZMA files. Don't forget this is my take on these speakers and what pleases my ears.
liveoffroad
New Member
i rebuilt some hpm 100 crossovers last year, tried many different configurations (including lowering the crossover point on the woofer) but finally settled on using the hpm 900 mid with a bandpass filter matching the hpm 900 crossover to match. no adjusments to either the woofer or tweeter crossover points other than just replacing caps. I'm extremely pleased with the results, as are anyone who has listened to them. They are extremely clear and not at all fatiguing like they were before
Bimmerb5
New Member
The other odd design feature of the crossover is that the midrange has a high pass filter and not a bandpass, so the midrange is acting as a tweeter. The biggest problem with these speakers is the crossover. Replacing the parts with the same values won't solve the major issue either. The crossover has to be redesigned for the proper frequencies to bring out the best in the drivers.
liveoffroad
New Member
Absolutely true as long as your actually measuring the freq. response of the driver. people making crossover adjustments without doing this is what scares me- i'm sure there are all sorts of unwanted peaks and valleys in the response curve. However, i suspect that part of what makes these vintage speakers so cool is that they DON'T operate the same as today's speakers, and that gives them a vintage sound. I also recognize that argument is a slippery slope leading to "leave them alone" which i don't agree with either. I tried to find a balance of improving on the design without changing too much. the crossover on the hpm 900 is much "better" by design standards specifically on the midrange, so that's what lead me to my decision
flyingfinn
New Member
Has anyone ever tried lowering the xover point of the super tweeter? Being a ribbon tweeter, it can be very detailed. Offhand, I would say around 7khz would be ideal. Then, simply attenuate down the paper tweeter. I guess the big question would be whether or not the super tweeter can handle the 7khz xo point.
hpm-100 has the same transformer as hpm-60 (STV-013)
hpm-60 >>> 0.5uf cap and 6ohm resistor in series.
hpm-100 >>> 0.15uf cap and 10ohms resistor in series.
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xXColdShotXx
Active Member
Hey Mattsd, Would you happen to know an upgrade list for mouser for the crossover upgrade parts? Parts express site doesn't seem to be working lately, I bought 2 sets of hpm-100's 100 watt version from my uncle and wanna do the crossover upgrade. Also what's the easiest way to get deoxit/faderlube into the mid and high pots on the hpm-100's?
xXColdShotXx
Active Member
Does anyone know a good resistor replacement for the hpm-100 crossover for the round tweeter?
pognoot
Well-Known Member
Check out the all new MV Audio crossover for the HPM-100. This is not a mod to the existing crossover, but something brand new in 2020. https://www.mvaudiolabs.com/speakers/untamed-vintage-pioneer-hpm-100/
Copa1934
My ears are bleeding
That's a bloody cool page. Author isn't the best in his grammar or word usage, but the technical aspects are easy enough to follow. I've had a pair of 200w variety for some time now. Picked up cheap due to fire damage (no they weren't on fire, but the home they came from had been). Cosmetically sick. Only the woofers survived. Cabinets, sadly, were sanded down to particle board (or MDF, I guess). Big job ahead, but thankfully still a back burner while I review renovation articles. Thanks for posting this.
pognoot
Well-Known Member
Agree, it's the best write up I've seen yet on the HPM-100. I've ordered the parts for this crossover and I will be building a new crossover board for mine as soon as they arrive.