Replacement drivers for mini monitors?

bassinmax

I spent some time this weekend scanning this site looking for replacement drivers for my mini monitors, the foam has fallen off the mid-ranges. Some of my findings suggested the the MW4500 was a replacement but the part number on one of the drivers and another reference suggests that MW4000 would be the correct replacement.

After peeling off the Polk sticker, stamped on the driver was D 0401-2, 41504, & 2858027 - model number, serial number, and Rola manufacturing info respectfully I presume. On another thread, there was a list of replacement drivers MWxxxx along with the model number; the M4000 was BD 0401-B, suspiciously similar to D0401-2, leading me to believe that MW4000 is the correct replacement for speaker's production. These were purchased in 1979-80 time frame.

It appear that MW4000 are no longer in production
http://www.polkaudio.com/forums/showthread.php?118471-Current-Production-Drivers-Vintage-Support

What drivers are recommended as replacements?

Thanks,
Tony

I was surprise to find the broad interest in the Vintage Polk equipment. For those interested, I worked a little for Audio Krafters in College Park while in college during 1979-80. I started with Polk Monitor 7s but sold my first system to upgrade taking advantage of Salesman's accommodation. I ended up with Spendor speakers, Tandberg receiver, Bang & Olufsen turntable (I suppose no need to explain this to those frequenting this site), a Nakamichi cassette deck and the Polk mini monitors. The Nakamichi eat tapes and died years ago, still using the Spendors, the Tandberg has been relegated to the garage as a radio, and the B&O while still working is sort of useless as my album collection warped during the great flood of '07 in my basement - the sump pump failed while I was away on vacation.

One of the Spendors had faded from sunlight coming through the window. I moved the speakers to my FL house and gave them a good oiling with lemon oil. Since I just happen to have some dark oil for covering scratches, my Mom gave this to me when she downsized, it was vintage oil probably 45 years old and hazmat my today's standards, I remember it from way back when I was a kid, it brought back a lot of the color.

Nightfall

Yep, no need to replace the entire driver if it just needs to be refoamed, unless I am missing something here?

westmassguy

If the original drivers are 8 ohm nominal, the Bose 901 Series I driver will work. It's the same cone and basket frame as the Polks. It will not have the anti resonance coating on the cone, but will have treated cloth surrounds, which will not rot. Any re-foamer worth his salt, will be able to re-foam them with new polyether surrounds.

bassinmax

Thanks for the replies. I am handy but I have reached a milestone in life finally realizing that while yes, I can do something, I now know it will be more involved, take longer, cost more, and won't quite work out as envisioned.

If there are no drop in speakers, then I'll try the re-foaming since I have not done that before.

I was looking at the Bose 901 replacement drivers from Parts Express and Simply Speaker and those are for Gen II-V and have three hole mounts and not four. I think I saw Gen I this weekend but now can not find it.

I did find a Polk MW4000 on ebay and it is way different. However, here's one that looks very similar but unfortunately they do not provide mounting hole spec. Given the price, I may just buy two and make adjustments so that they fit.
http://www.parts-express.com/grs-4fr-8-full-range-4-1-2-speaker-pioneer-type-a11ec80-02f-8-ohm--292-434#lblProductDetails

Tony

Nightfall

There are tons of videos on YouTube on how to refoam a speaker. Watching a few of them may make it feel much less daunting to you. Here's one.

https://www.youtube.com/watch?v=jwcfP5pKeek

westmassguy

bassinmax wrote: »

Thanks for the replies. I am handy but I have reached a milestone in life finally realizing that while yes, I can do something, I now know it will be more involved, take longer, cost more, and won't quite work out as envisioned.

If there are no drop in speakers, then I'll try the re-foaming since I have not done that before.

I was looking at the Bose 901 replacement drivers from Parts Express and Simply Speaker and those are for Gen II-V and have three hole mounts and not four. I think I saw Gen I this weekend but now can not find it.

I did find a Polk MW4000 on ebay and it is way different. However, here's one that looks very similar but unfortunately they do not provide mounting hole spec. Given the price, I may just buy two and make adjustments so that they fit.
http://www.parts-express.com/grs-4fr-8-full-range-4-1-2-speaker-pioneer-type-a11ec80-02f-8-ohm--292-434#lblProductDetails

Tony

This is what I was referring to, not PE Replacements : http://www.ebay.com/itm/Two-2-Vintage-Original-Bose-901-Series-I-Replacement-Woofers-Cloth-Surround-/310991816461?pt=Vintage_Electronics_R2&hash=item48688e870d