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Speaker Surround Repair - Sony APM-33 - square drivers


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#1 Sub Sonic

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Posted 20 November 2012 - 05:55 PM

Hi all,

I was wondering if anyone has had experience with replacing surrounds on the square bass drivers of a pair of Sony APM-33 loudspeakers? They are around 6-8" across the flat sides from memory.

I spotted a pair for sale and was thinking about buying them and repairing them if possible. I have read on the internet how to manufacture new ones out of chamois, but would appreciate any other suggestions.

Comments on the speakers' sound (or similar model) also welcome!

Thanks!

SS

Attached File  Sony APM-33.jpg   153.04KB   12 downloads
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#2 Gregegg

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Posted 14 December 2012 - 01:17 PM

Hi Sub Sonic, I have a pair that also need the square surrounds. I did a bit of research a few years back and came to two possible routes. (1) Accurately draw a dimensioned drawing and go to china foam surround manufacturer and have it made or (2) make a mould up in aluminium or perhaps MDF and the press 3-4 mm foam sheet ( the really light weight stuff) sandwich it the mould and heat treat in the kitchen oven. The latter seemed to me the best course and cheapest but due to lack of time (and many other audio projects) I have not done either. Anyway, let us know if you find a better solution than chamois. I didn't like the chamios solution because I thought the chamios would be hydroscopic and vary too much with the weather, I'm in Brisbane Qld, good luck
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#3 Sam Z

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Posted 14 December 2012 - 03:51 PM

There's someone in Russia selling remanufactured foam surrounds for these for about 50 bucks plus postage. His auctions aren't listed as worldwide but he'll post internationally.

http://www.ebay.com....1#ht_500wt_1413

People have had good results with the chamois method, it's a lot of work though.

The advent of 3D printing, especially in materials like rubber and foam, is starting to make our lives easier with this kind of thing.

Edited by sam_z, 14 December 2012 - 03:52 PM.


#4 Sub Sonic

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Posted 14 December 2012 - 08:45 PM

Thanks for the suggestions. I ended up getting the speakers for $20 :-)

I'm still wondering whether to just replace the bass drivers with others while still keeping the cabinets original...I have a few different 6" drivers to play with. Decisions decisions...

Regards,

SS
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#5 Sam Z

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Posted 14 December 2012 - 08:58 PM

Oh you gotta keep them original, the woofers are the best part of APMs. They'll sound worse if you put some other driver in and they'll have lost their whole appeal.

But if you decide to get rid of the bass drivers don't throw them out! Send them to me, I'll put them aside for spares as I have a pair of them too.

Personally, I'd order the surrounds from the Russian and re-do them. If he asks alot for postage maybe I could buy a pair too and we could split the cost.

#6 VanArn

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Posted 19 December 2012 - 12:02 PM

Speakerbits in Port Melbourne have a square roll surround replacement kit which suits a 6.5" speaker.Their Part No. is 0605K.