HPM-100 exploded view

[Copa1934]

If you plan to find a trashed orphan to test it out on, go ahead! Otherwise, you're just ruining a collectible pair of speakers. You won't gain much from it, as I think the home series has a lot more going against it than just the mirror imagining. They are rock and roll speakers, not ultra-high end monitors.

For all the talk of why pioneer didn't do this from the factory, it's obvious. Just the added cost in trying to ship and track two separate items that need to stay together is reason enough. Pairing up speakers from a single pile of exact duplicates is so much less labor intensive. Even just the cost of printing new shipping boxes for the different left and right sides...

Totally agree, well pretty much anyway. Finding a spare, empty, cabinet certainly is a preferred approach to tearing up a working system.

Manufacturing costs, cabinet labeling, packaging, distribution, training sales people. And that probably isn't everything. Definitely would be some added costs.

 

[Copa1934]

Honestly I’m truly shocked I was able to get them apart in one piece, so to speak. I bought these at a Yard Sale many years ago, they had been in a house fire. Three of the drivers were destroyed and not usable. The cabinets were swollen and literally coming apart at the seams. The game plan is to get all the dimensions and fabricate new cabinets, but mine will be mirror image. Something of note the front panel is substantially thicker than the sides and appears to be a different compressed board, almost appears to be MDF. The rest are clearly particleboard that have wood laminate on both sides. This will be an interesting journey.

 

[dcgibby]

Just curious why you're going to so much trouble when there are about a million HPM-100's out there (albeit overpriced).

 

[needforspeed]

No wonder they weigh a ton

 

[painttoad]

Just curious why you're going to so much trouble when there are about a million HPM-100's out there (albeit overpriced).

why do any of us do what we do with stereo gear? it's a hobby for many of us.

 

[malden]

since you're making new enclosures, I'd econowave them eliminating the mid, tweet, super tweet and crappy crossover network

mount the woofers up high in the box and put the horn on top

that would be a bad-ass system

something like this...




or this...

 

[OldGman]

Econowave would be an entirely different speaker than the HPM-100.
Perhaps he likes the their sound signature ?
Maybe he has crossover improvements in mind ?
Perhaps the classic look has an unwavering appeal ?

Personally I'd rebuilt them into a taller floor stander, slightly deeper, definitely mirror imaged....but that's just me.
Definitely keep the classic look of veneer.

Hope you get those up and running without too many issues. Pics...yes pics please as you go along the project !!!

 

[homebrew]

New cabinets, mirror imaged. Good idea. I'd recommend 13-ply Baltic birch plywood. The birch can even be stained or veneered. If you decide to stain the birch, use a pre-stain conditioner, otherwise the birch will be blotchy looking.

 

[Copa1934]

Enjoying the dialog. Many people like myself do enjoy these speakers. There are those of us who have often wondered how much a difference it would make to mirror them. Many discussions have taken place on why Pioneer didn't mirror them from the start. Some understand the economics of it, but then there is the distribution side of it, would retailers bother making sure they were properly matched up. I've seen only a couple posts were people did make mirror image of these speakers. I have DSS-9 speakers, that are mirror image. I found placement much easier with mirror image and the sound doesn't change as dramatically moving left/right of the sweet spot. This is an inherent issue with speakers that are not mirror image. Also had S-910/710 speakers, they too were easier to position due to being mirrored. I've seen the latter sold that were not mirrored and can't imagine what that was like. I've also compared the HPM with the DSS-9 and the S-910/710. The DSS hands down are better, for many reasons, but what surprised me was I like the 910 better than the HPM's. Part of it was the imaging issue, which was easier to accomplish with the mirror image speakers. The depth and breadth tended to be better as well.

Yes I will upgrade the crossovers. I'm hoping to reuse the front baffle because of it's heavy construction. I will have to make slide mods to the "mirror" one due to the Midrange and Super tweeter. The tweeter and woofer openings will remain unchanged.

Thank you for the comments and thoughts.

 

[Copa1934]

New cabinets, mirror imaged. Good idea. I'd recommend 13-ply Baltic birch plywood. The birch can even be stained or veneered. If you decide to stain the birch, use a pre-stain conditioner, otherwise the birch will be blotchy looking.

Already have the Baltic birch, and it is 13 ply. ;-)

 

[painttoad]

I'm hoping to reuse the front baffle because of it's heavy construction

just use them as templates and make new baffles.

I will have to make slide mods to the "mirror" one due to the Midrange and Super tweeter. The tweeter and woofer openings will remain unchanged.

how's that? from what i've seen, the woofer opening would be the only thing consistent.

if i were going to make the effort to build new cabinets, i wouldn't halfass it. all drivers would be flush mounted

 

[malden]

Econowave would be an entirely different speaker than the HPM-100.

yes, it would be entirely different

Perhaps he likes the their sound signature ?

any changes to the enclosures or crossovers will certainly change the "sound signature"

Maybe he has crossover improvements in mind ?

that would change the "sound signature"

Perhaps the classic look has an unwavering appeal ?

yes, and to most, the "look" is more important than the "sound signature"

Personally I'd rebuilt them into a taller floor stander, slightly deeper, definitely mirror imaged....but that's just me.

if taller and deeper, would they be narrower to maintain the original cubic feet of the enclosure? Even if internal volume is the same, changing the enclosure proportions will certainly change the "sound signature"

 

[Copa1934]

just use them as templates and make new baffles.

Yeah, looks like that's the only option. Removing the grill peg "receiver" has become impossible. Trying to remove them damaged the baffle, not completely, but did cause separation. As Luck would have it (good), the "recovered" Birch ply I have, from a retired speaker project of a friend, had a baffle that had two sheets glued together to make just over 1-1/4" thickness, so I'll be able to use that. I can have it run thru a sander or planner to bring to the correct thickness. The only issue is if I stick to the factory outside dimensions, the volume will be slightly larger due to the original being 0.84" thick vs. the 0.75" thick ply. I found it interesting that the sides and back are regular particle board, while the baffle clearly is MDF.

 

[painttoad]

The only issue is if I stick to the factory outside dimensions, the volume will be slightly larger due to the original being 0.84" thick vs. the 0.75" thick ply

i'd try build it to interior dimensions myself

or build it to factory height and width and make it not as deep

or build it totally to factory exterior spec and glue wood fillers inside to take up the excess volume

 

[Copa1934]

or build it totally to factory exterior spec and glue wood fillers inside to take up the excess volume

I thought about additional bracing, so that could reduce the volume. Appreciate the positive contributions. TY

 

[needforspeed]

Enjoying the dialog. Many people like myself do enjoy these speakers. There are those of us who have often wondered how much a difference it would make to mirror them. Many discussions have taken place on why Pioneer didn't mirror them from the start. Some understand the economics of it, but then there is the distribution side of it, would retailers bother making sure they were properly matched up. I've seen only a couple posts were people did make mirror image of these speakers. I have DSS-9 speakers, that are mirror image. I found placement much easier with mirror image and the sound doesn't change as dramatically moving left/right of the sweet spot. This is an inherent issue with speakers that are not mirror image. Also had S-910/710 speakers, they too were easier to position due to being mirrored. I've seen the latter sold that were not mirrored and can't imagine what that was like. I've also compared the HPM with the DSS-9 and the S-910/710. The DSS hands down are better, for many reasons, but what surprised me was I like the 910 better than the HPM's. Part of it was the imaging issue, which was easier to accomplish with the mirror image speakers. The depth and breadth tended to be better as well.

Yes I will upgrade the crossovers. I'm hoping to reuse the front baffle because of it's heavy construction. I will have to make slide mods to the "mirror" one due to the Midrange and Super tweeter. The tweeter and woofer openings will remain unchanged.

Thank you for the comments and thoughts.

I did this crossover but it moved the crossover away from the woofers into the mid range. If you look at the factory crossover you’ll be scratching your head lol. I did the kit back then but now looking like you can just buy it

Pioneer HPM-100 Upgrade Crossovers Available - MV Audio Labs

Finally and after many requests - fully assembled and ready to use Pioneer HPM-100 Upgrade Crossovers are now available for purchase.

www.mvaudiolabs.com

 

[OldGman]

I was referring to my personal taste as far as cabinet size.
Not sure if a larger cab would improve the bass by taking it off the floor 6-7 inches, (floor bounce), giving it more internal space to help with backwaves( perhaps muddiness). Never heard a pair but many speakers of that era have been deemed the cabs were/are too small for several reasons? Obviously the port would have to be re-tuned.
Narrower baffles helps with imaging so I've read.
I like the look of taller towers. If I had the components that is what my game plan would be. To myself why rebuild if your just going to throw them on stands to "improve" their sound.
Crossovers (by all means a real novice myself).....why mess with them at all ?
I don't know..... ask all the JBL, Klipsch and others why they mess with them.
By no means am I calling out these folks for anything they do to improve their speakers.
I would at some point like to try a 2way myself. Currently messing with inexpensive OB speakers.
Everything is subjective when it comes to sound preferences. I don't know the OP, his taste in music his listening space etc.
His dime, his time to enjoy the journey.

Just my 2 cents

 

[Lavane]

New cabinets, mirror imaged. Good idea. I'd recommend 13-ply Baltic birch plywood. The birch can even be stained or veneered. If you decide to stain the birch, use a pre-stain conditioner, otherwise the birch will be blotchy looking.

I use wood conditioner on any wood I'm going to stain. It just makes for a much more uniform job. Birch and pine especially.

 

[dcgibby]

why do any of us do what we do with stereo gear? it's a hobby for many of us.

Absolutely true and props for taking on the project. My HPM-100s are modified to the point they really aren't any more. Cabinets are original and that's about it.

 

[homebrew]

I use wood conditioner on any wood I'm going to stain. It just makes for a much more uniform job. Birch and pine especially.

Pine and birch are the main culprits. Harder woods like Oak and walnut behave a little differently. Pre-stain conditioner can't hurt, but it's usually not necessary with those woods. As far as stain goes, I've had the best luck with gel stains, regardless of the wood species.