Polk 7A's... are they worth fixing?

peelerboy

Hi everyone! First post ever here. I just came across some Polk Audio 7A's I've had sitting in my basement for quite a while and am not sure what do to with them. I only stopped using them because of the area I had for speakers in my family room was really limited and I went with some bookshelf types instead.

I hooked the 7A's up yesterday only to learn that it sounds as though one of them has a bad mid range speaker. Is this a difficult operation to repair?...or not worth the trouble? The speaker that was still functioning properly sounds fantastic, while the one with the mid range issue has a slightly scratchy sound. :frown:

Any suggestions?...advice?

Thanks in advance!
Dale

peelerboy

Oh, and here's a couple pix...

scottyboy76

Those are some clean looking speakers.

Im certainly not the expert around here, but im sure they are going to chime in.

so the fuses and surrounds are okay on the bad speaker, if so, i would take the bad speaker off, see if the connector is loose or bad, you know rule out the easy stuff.

Gently push in and out on the speaker, sometimes they can begin to scrape, keep track of which is the top side of speaker, sometimes, if you are lucky, on older speakers, its possible they can start sagging down and scrape, sometimes, turning them so top is bottom can help.

usually that is with larger, heavier woofers, and these arent really known for that, but it costs nothing to try.

good luck, and im sure others with more experience will chime in.

peelerboy

Interesting stuff, Scott! Thanks! Actually, I did very gently push on that mid speaker that sounds like it's having issues and you can definitely hear a bit of scraping coming from it. Is it purely gravity that creates this condition?... or is it something else? Because like you said, this really isn't a very large speaker. Guessing 6" or 7" diameter?

fbm211

well worth fixing.
You can get replacements direct from polk and mention your a member here and get a discount and free shipping.
Or you may be able to find a good used driver on ebay or right here.Make a post in the wanted section.Im not sure of the mid model number but someone else will chime in.
If you go with a new replacement from polk you should replace both mids.

Outfitter03

I won a single Monitor 10A on fleebay locally in October as I was looking to have a spare passive for the ones that I recently purchased. The pictures in the posting were fairly poor and I was surprised when I went to pick it up. The drivers and binding posts looked like yours.

I am relatively new to this Vintage Polk thing and I thought the Monitor 10s not 10A's looked like this. Anyway the drivers are very different on the back also, at least the ones I have are a stamped steel, not cast as in my Monitor 10As. There is not a Polk paper faceplate either, just a stamped number in red ink X,1261. In smaller red ink is 2751. The speaker itself did not have a serial number sticker. The driver has the same felt ring or whatever material it is on the outside. Maybe someone on here knows more about these drivers.

I have two of these drivers. They are in fair to good condition. The speaker wires were soldered to the posts when I removed them so I just clipped them off. I don't know if it was standard practice to solder on connectors or something one of the many previous owners did. These do not have speaker gaskets as they were mortited in place. I have not considered selling these, but tomorrow I could take a picture or two and we could see if these drivers match up to yours.

Oh, the other thing was that I removed an entire leaf sized trash bag full of sheet Polyfill out of this one speaker.:eek: Someone must have liked the stuffed sound.

TroyD

Well worth fixing.

I have a pair that I would NEVER part with.

BDT

peelerboy

Thanks for all the great feedback, guys. I would like to have run a wanted ad for the needed mids, but I don't think my newbe status will allow posting in the classifieds section yet. :frown:

I'd like to get more info on what fbm211 was saying about getting replacement parts directly from Polk. That's gotta' be the best way to go in terms of correct parts, but then again my fiddling with these speakers is something of a passing whimsy and budget to invest is a little on the light side. :rolleyes:

Just as Outfitter had mentioned, my 7A's are also chock full of that polyfill stuff. And not only was the mid gooed into place with what looks like plumber's putty, but the connections are soldered on as well. I know this is all factory original because we bought these speakers brand new decades ago and this is the first they've ever been opened.

Speaking of which, here's a couple pix I just snapped-



The numbers on the magnet weren't entirely clear, but what I could make out was a black ink stamping of "6KU ..." and then directly beneath it "557 732"
Then obviously in red marker it said "23" and either "M" or "W".

Any thoughts as to how to properly identify what I need here?

Outfitter03

Here are three pictures of the drivers that I have. You can see that the speaker connectors are different and Polk was using black and white hookup wire. Otherwise they look very similar.
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Part numbers labels are different though.

comfortablycurt

Definitely worth fixing. I've got a pair of 7A's myself(though mine are later production examples than yours), and I'll never part with them. Truly an excellent sounding pair of speakers.

The only real way to fix them would be to replace the faulty driver. Your best bet would be to track down an original, rather than getting a newer production replacement. The new ones are very similar to the originals, but there's still a slight difference in tonality.

gdb

Are you at all handy at tinkering with "stuff"? If so, you might get that driver operating again if you re-center the magnet. After that's done, I'd suggest putting JB Weld on the other one to prevent shifting magnet syndrome on it as well. Link Below:

http://www.polkaudio.com/forums/showthread.php?t=79649&highlight=magnet

peelerboy

gdb wrote: »

Are you at all handy at tinkering with "stuff"? If so, you might get that driver operating again if you re-center the magnet. After that's done, I'd suggest putting JB Weld on the other one to prevent shifting magnet syndrome on it as well. Link Below:

http://www.polkaudio.com/forums/showthread.php?t=79649&highlight=magnet

Thanks, gdb! I'm definitely pretty handy and do love to tinker with stuff. I'll keep you guys posted if I manage to successfully re-center the magnet! :cool:

gdb

You go boy !!!:biggrin:

nadams

These look like very early 7a's... I've never seen a set with soldered wires. And could the "plumbers putty" be the Mortite that Matt Polk supposedly tinkered with vs the foam gaskets?

peelerboy

Update: Bad news... I somehow managed to prior off the magnet's backing plate with the magnet! :eek: :frown: I'm really losing motivation on this project fast and not sure where to turn next. I was originally going to repair the one bad mid driver and give them back to my brother as a surprise, but now completely need another driver as this one is messed up. D'oh!

Any suggestions? Or, anyone want a great pair of 7A's for dirt cheap just needing one driver? :redface:

Tour2ma

TroyD wrote: »

Well worth fixing.

I have a pair that I would NEVER part with.

BDT

How many autographs are on them now?

peelerboy,
What he said... and please get the exact, original MW replacement. Troy's 7A's may be historical, but all 7A's are a piece of audio history.

I don't think WTB posts are restricted. 100 post requirement is for the sell side.

geppy1

Those are early 6500 drivers. They pop up on ebay and here once in awhile I would find them before i would get the one fits all replacements. they do not sound the same.

peelerboy

Tour2ma wrote: »

How many autographs are on them now?

peelerboy,
What he said... and please get the exact, original MW replacement. Troy's 7A's may be historical, but all 7A's are a piece of audio history.

I don't think WTB posts are restricted. 100 post requirement is for the sell side.

Thanks for the heads up. I think I read that somewhere regarding the classifieds...that I wouldn't be able to post in there until I had a hundred posts or somesuch. But to post a WTB ad may be different? That'd be cool. :cool:

geppy1 wrote: »

Those are early 6500 drivers. They pop up on ebay and here once in awhile I would find them before i would get the one fits all replacements. they do not sound the same.

You guys have me gaining hope & superior attitude again. geppy- are you confident of your assessment of what drivers I need? Because I really don't know enough about them to be able to identify one from another. If I were to go hunting here, eBay or elsewhere...what sort of part number or name should I use in my searching to make sure I get the right one?

Thanks for your help and encouragment, guys!

geppy1

Yes i am. That is a very early one. 1977 to 1978 The next year or so they had a label on the back then in 1981 they were all balck and did not have the grey stuff anymore.

ben62670

Don't toss the old driver. I have one in GA that needs the paper ring. Bad news is that I will not be there till April.

geppy1

Would I lie to you Look what we have here. Notice this pair had one of each. The one on the right is slightly newer.
http://cgi.ebay.com/Polk-Audio-Monitor-7-series-Speakers-Woofers-parts-/130481207259?pt=Speakers_Subwoofers&hash=item1e614937db

geppy1

I mean the black one is slightly newer

peelerboy

ben62670 wrote: »

Don't toss the old driver. I have one in GA that needs the paper ring. Bad news is that I will not be there till April.

Hey Ben... you're totally welcome to this one. If you can't swing by the Dirty-D (Detroit) to pick it up, I'd only ask that you cover shipping costs and this one is yours. :cool:

geppy1 wrote: »

Would I lie to you Look what we have here. Notice this pair had one of each. The one on the right is slightly newer.
http://cgi.ebay.com/Polk-Audio-Monitor-7-series-Speakers-Woofers-parts-/130481207259?pt=Speakers_Subwoofers&hash=item1e614937db

Thanks for the heads up, geppy! Is it okay to just replace the one that's bad?...and would either of these fit properly for my 7A's specs and application?

ben62670

All I would need is just the paper ring. I am not going to use it, but I would like to be able to help a Polkie out in the future. The older ones are getting harder to find.

peelerboy

ben62670 wrote: »

All I would need is just the paper ring. I am not going to use it, but I would like to be able to help a Polkie out in the future. The older ones are getting harder to find.

you'd have to tell me in explicit detail how to properly remove it. I already did a number on the magnet mounting plate, so I'd hate to mess the ring up. :eek: I'm a newb! :redface:

peelerboy

Well guys... I really really appreciate all the help and advice you've provided, but I'm wimping out and throwing in the proverbial towel.

I've decided to part ways with these speakers and would like to ask how much you think the pair is worth with one of them having a messed up driver. I just don't have the time to fool with them any longer and need the space.

Any thoughts as to their value or how to best advertise/sell them?

Thanks again,
Dale

Conradicles

Well I have these now! Small world huh?

Anyway I pulled the crossovers and they have:

12uf cap
33uf cap
2.7 res
4.7 res

These must be some really early model 7A's.
Sweetness.

peelerboy

Conradicles wrote: »

Well I have these now! Small world huh?

Anyway I pulled the crossovers and they have:

12uf cap
33uf cap
2.7 res
4.7 res

These must be some really early model 7A's.
Sweetness.

Very cool. So, did you buy these from Travis?

Conradicles

Sure did. I'll take good care of them

TNHNDYMAN

They were nice Peelerboy and I enjoyed them this summer but wanted to put some $ towards either a preamp or upgrading the crossovers in my other pair of 7's. You gave me a good deal on them and I tried to be fair w/ Eric. He scored a pair of stands the same day and I hope he enjoys them and does the crossover upgrade. I did my part driving them to Asheville so they could stay in the family :biggrin:

Conradicles

Here are the crossovers before the modification:
(Note these are very early models, maybe around 1978 and they used a bit different values than newer versions)