HPM-100 exploded view

[malden]

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.

agreed that pre-stain is not necessary on oak but when the boards or veneer are plain-sawn, the grain of new-growth oak can be a bit wild due to the sped-up grow time resulting in wider growth rings. Pre-stain will reduce the contrast

I found this out when replicating some oak door and window casing in my living room. The original 100 year old oak had a tight and even grain while the new lumber had more open and wild grain. Pre-stain helped to tame it

gel-stain may have worked as well to tame the wild grain

had I known this ahead of time, I could have used quarter-sawn or rift-sawn instead of plain-sawn

 

[Copa1934]

Cleaned one of the plates. Clearly the heat from the house fire pitted the plate. Cleaning didn’t remove the lettering, it was already like that before I cleaned it, in case anyone was wondering. The smoke damage is pretty difficult to remove.

 

[Copa1934]

I found this plate interesting. This was removed from the inside, and I cleaned all the debris only to discover this appears to be a plate that was from another speaker in Pioneers line. If you look closely, you can see there’s a little recess for what was likely a badge and then you can see that the holes are countersunk. Basically looks like reused inventory.

 

[Copa1934]

Somehow I made posts to the HPM mirror image thread, which are really only relevant here. Cleaned one of the plates. Clearly the heat from the house fire pitted the plate. Cleaning didn’t remove the lettering, it was already like that before I cleaned it, in case anyone was wondering. The smoke damage is pretty difficult to remove.

 

[Copa1934]

I found this plate interesting. This was removed from the inside, and I cleaned all the debris only to discover this appears to be a plate that was from another speaker in Pioneers line. If you look closely, you can see there’s a little recess for what was likely a badge and then you can see that the holes are countersunk. Basically looks like reused inventory.

 

[kwayde]

Can someone remove my last two entries and this one afterwards. The posts are not relevant to this thread. TY

In the bottom left of your posts there is a report link. Click it then ask the mods to remove the posts.

 

[Copa1934]

Interesting project. Thinking through it, I am wondering how you reattach the baffle once it is "cut out" and flipped

I have a similar thread going, but in response to your statement, I discovered the baffle is not glued in, not in the traditional sense. It's held in place much like a door panel, like with cupboard doors. There is hot glue along the lower edges (not the entire seam), odd really, and I'm assuming Locanti wasn't worried about totally "sealed" since it's a ported cabinet. The trick was chipping away the dry and brittle hot glue, then using a 5lb mallet, with a wood block, from the inside to jar the sides loose. However, removing the mid enclosure and the port tube were a challenge, to say the least. And worse, removing the threaded inserts damaged the baffle (so I left the other baffle alone). Basically the one baffle might be salvageable, though I'm not too optimistic. To do so, however, also means filling recesses for the port tube, the mid enclosure and the Lpad plastic mount plate. Then duplicating these recesses on the other side, thus creating a mirror image of the baffle.

 

[hjames]

AK rules request you keep common content in a Single Thread. Posts with similar content moved to this existing thread.

 

[Torin Krell]

Perhaps these interior views of the Pioneer HPM 100 and crossover mod by GR will help someone here:

 

[Copa1934]

Perhaps these interior views of the Pioneer HPM 100 and crossover mod by GR

I've seen this video before. Really cool, and painful (LOL). Definitely taking this into consideration, however, I plan to unload these as I love my DSS-9 speakers. So buying crossovers is not too likely. I'll check other posts to see what others have come up with for "improvemets", which I know they need. I'm seriously considering recessing the drvers, which is easy enough for me to accomplish. Thank you!

 

[OldGman]

Love the look of those dealer only Lucite speakers.....or so I've read.

Copa1934.
Perhaps I missed it along this thread but I was under the impression that these were "keepers" for you.
I understand the challenge and satisfaction of building a pair but personally going through all that effort just to sell them afterwards? I just can't get there.....those would be keepers after all that work.
Lol
As mentioned about the challenge of improving I absolutely get.
Mirror imaged, recessed drivers, as you mentioned....heck for that matter radius the heck out of that baffle, put the controls in the rear, open cell foam around the tweeter and mid, ( front reflections/diffraction ),brace internaly, make the mids enclosure bigger/deeper, ductseal the basket legs on the drivers(ringing) evil pink layered stuffing on at least 3 walls obviously not in the path of the port.
This is why I had mentioned turning them into a tower ( think JBL 110T). Get the woofer off the floor, add back lost airspace from the bracing and larger mid enclosure.
Crossovers....I'm NO help there, not even suggestions.
Then again they wouldn't resemble that classic look now would they?

Yes......."thinking out loud" AND speaking out of turn.
Ha.

All the best on your project.

 

[Copa1934]

Perhaps I missed it along this thread but I was under the impression that these were "keepers" for you.

Not sure where that came from. I've owned several pairs of HPM-100 (100w and 200w), HPM-60 and 40. But none have ever been keepers. All were "serviced" and resold, to very happy buyers. I don't profit much, mostly do it to keep them out of the landfill. I've read of people doing the mirror image and liking the improvement. I'm figuring on Mirror Imaging and flush mount drivers, upgraded crossovers, in order to get the best possible performance from these speakers without deviating too far from the original design. However, I have many HPM spare drivers, and a tower might just be a cool project. Got the humor in your post.

 

[OldGman]

Copa1934
Kudos to you for retro-modding 50 yr old speakers alive for others to experience and enjoy.
Also keeping them out of the landfill..........PLUS 1
Maybe down the road I'll get to these CS-88a components I have in the closet into some cabinets of sorts.
(Just the drivers/electronics)

 

[Copa1934]

Spoke with Danny Richie from GR research. Good, informative conversation. Seems we have much in common, especially muscle cars. LOL. I'll be going forward with the changes, thanks in part to his feedback. Up in the air over the GR research crossovers, too much for my budget, at the moment.