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Paradigm PDR-10 subwoofer repair

Philbo King

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A week or two ago we were visiting friends and I saw a subwoofer sitting out by their drive in the snow. I asked about it and was told it made awful noises. I "adopted" it and brought it home, and found out the foam surround was falling apart.

I found this kit on amazon
and ordered one.

I did the repair yesterday and used the sub last night to watch some bass-heavy movies (King Kong vs. Godzilla anyone?)

Anyway, it came out very nicely. It's my first attemot at a speaker repair.

The hardest part was cleaning the old glue and schmutz off the outside edge of the speaker frame, which took about 3 hours. Then a series of glue-ups:
- Glue new foam surround to speaker cone, dry 1 hour
- Glue new foam to speaker frame, dry 1 hour
- Glue the gasket, wherever it delaminated during removal, dry 1 hour.
- I used RTV instead of the provided glue to seal the gasket on the speaker atop the new foam, since it looks like these foam surrounds are a primary failure point for these speakers. Hopefully RTV will be easier to separate than the 'airplane glue' provided with the repair kit.

It's worth trying if you use reasonable care and have a bit of patience.

The PDR-10 sub performance surprised me. For a ported 8" sub it goes pretty low. It rolls off by 10 dB at 28 Hz. It won't handle Earth shattering dB levels (it sounds like the cone breaks up if you push it too hard. Can't expect too much from an 8" cone and a 100W amp.) but complements a living room surround system pretty well.
 

teched58

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Apr 14, 2020
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A week or two ago we were visiting friends and I saw a subwoofer sitting out by their drive in the snow. I asked about it and was told it made awful noises. I "adopted" it and brought it home, and found out the foam surround was falling apart.

I found this kit on amazon
and ordered one.

I did the repair yesterday and used the sub last night to watch some bass-heavy movies (King Kong vs. Godzilla anyone?)

Anyway, it came out very nicely. It's my first attemot at a speaker repair.

The hardest part was cleaning the old glue and schmutz off the outside edge of the speaker frame, which took about 3 hours. Then a series of glue-ups:
- Glue new foam surround to speaker cone, dry 1 hour
- Glue new foam to speaker frame, dry 1 hour
- Glue the gasket, wherever it delaminated during removal, dry 1 hour.
- I used RTV instead of the provided glue to seal the gasket on the speaker atop the new foam, since it looks like these foam surrounds are a primary failure point for these speakers. Hopefully RTV will be easier to separate than the 'airplane glue' provided with the repair kit.

It's worth trying if you use reasonable care and have a bit of patience.

The PDR-10 sub performance surprised me. For a ported 8" sub it goes pretty low. It rolls off by 10 dB at 28 Hz. It won't handle Earth shattering dB levels (it sounds like the cone breaks up if you push it too hard. Can't expect too much from an 8" cone and a 100W amp.) but complements a living room surround system pretty well.

FYI, the foam didn't "fail" per se. Foam breaks down over time due to exposure to UV (ultraviolet) radiation (light). Yes, even though the foam is in the dark.
This is a well-known phenomenon. Foam rot was rampant in speakers from the '80s and '90s.

Many speakers today use rubber surrounds (i.e., a rubber ring) instead of foam. It lasts much longer than foam but isn't as flexible, which is a problem vis a vis speaker cone excursion. For this reason, thinner rubber surrounds are now what's most commonly used (my Elac Debut 2.0 B6.2's and also a cheap Klipsch bookshelf both have rubber surrounds). They reputedly last 10 - 15 years, whereas foam lasts about five.

Last point I would make is do not infer from the above that you should go out and find rubber surrounds. The really cheap rubber surrounds you can find on ebay are from China and are NOT like the thinner ones that "real" speaker manufacturers use.
 
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Philbo King

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Thanks for your input. I'm glad they've switched to more durable materials.
 
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Philbo King

Addicted to Fun and Learning
Joined
May 30, 2022
Messages
669
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871
16796783269936346878466686413823.jpg

Here's a photo of the unit
 
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Philbo King

Addicted to Fun and Learning
Joined
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I fired up the calculator to figure out, in a musical sense, how much the subwoofer adds on to the low end. My normal (full range, quad surround) speakers go down to 40 Hz. The new sub goes down to about 28 Hz. The result: 6 musical semitones. Going downward from 40 Hz: E D# C B Bb A G#

Doesn't seem like much, but it has a surprisingly big impact on the sound.
 
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