Polk Series 2 Speakers- Worth Fixing?

hewhorocks

Ok so I scored a pair of cosmetic mint Polk Series 2 monitors at a tag sale. Paid $50 including the stands. Swapped them into my system and they sound terrible. No highs from either speaker. Seems like the tweets are blown.

SL2500 is the model of the tweet.

Are these worth fixing? Price point?

Thanks

AudioGenics

Welcome to Club Polk !

here's a couple of threads that may provide additional information.

http://www.polkaudio.com/forums/showthread.php?t=89925

http://www.polkaudio.com/forums/showthread.php?t=82861

just my opinion but
I think it is worth restoring the Polks .

Rivrrat

What model series 2?

hewhorocks

I dont see a model #

Tag just says series 2.

Rivrrat

How many mid woofers? how big is the passive radiator?

hewhorocks

I've discovered they are M5JR. Doh it was infact on the tag.

Hopefully the pic helps with an assessment....


I had a similar pair in the past but sold them, regretfully.

AudioGenics

excellent and from the picture look in nice shape.

good luck on your search for tweeters
but check the continuity of the tweeter first
and also
upgrade the Crossovers while you are at it
There are threads that discuss it.

might check if there are any fuses that need replacement
or if the Xover needs a polyswitch.

jtgranby

They look to be in great condition and they are definetly worth fixing. SL2500 tweeters are not availble from Polk, but Polk Audio tweeter RD0198-1 is a drop in replacement. Call polk and order a pair cost is right around $100 for 2.

Jim

audiobilly

These look great, I would say fix em up.

The schematic shows that they could have polyswitches (saftyguard on the schematic) in them.

http://www.polkaudio.com/forums/attachment.php?attachmentid=18769&d=1155784674

They could be giving you a problem, and tweets be OK. Polyswitches are in series with the tweeters, and open if their current rating has been exceeded (to protect the tweeters) and will short again after they cool off. I have found that if they have been "opened" a lot, they open or go highly resistive for good. This can effect the sound of the tweeters.

An additional 2 cents worth.

Toolfan66

I would fix and upgrade them if they were mine...

hewhorocks

No fuses I can see. Not on the tweeter nor on the crossover. How would I fix / reset a polyswitch?

Schurkey

hewhorocks wrote: »

How would I fix / reset a polyswitch?

They are "self-resetting". In theory, once they cool down, they automatically reset. In actual use, the contacts burn a little more each time they're tripped; and when they re-set the sound quality is a little worse each time.

How do you fix them? Simple. Get a decent amp that WON'T CLIP at any reasonable SPL level, and BYPASS THE POLYSWITCHES. I suggest using a straight piece of wire, but some folks will suggest a .2--.5 ohm resistor as a bypass; and of course that's up to you.


The unasked question is "Are the polyswitch(s) or the tweeter(s) (or both) the actual problem here?" and we've got no definite answer until you do some more diagnosis.

agfrost

I don't see a polyswitch in the schematic for the 5jr+ Series 2. Feel free to correct me if I'm wrong.

Schematic PDF

Big Dawg

hewhorocks wrote: »

No fuses I can see. Not on the tweeter nor on the crossover. How would I fix / reset a polyswitch?

Welcome to Club Polk. Very nice speakers, absolutely worth fixing.

Call Polk customer service - I think that they may replace the poly-switches for free, or certainly for little cost. Or, you can either bypass them with a piece of wire or a small resistor (again, check with Polk CS for resistor value).

If you end up buying anything from Polk, be sure to mention that you are part of Club Polk - you will get a discount off of their regular prices.

audiobilly

The polyswitch has to be replaced. If indeed there is one on the crossover board. You may not have any in your series of 5Jrs', there were more than one version of these babies. These guys typically look like ceramic capacitors. You will have to determine what schematic is correct for the crossovers that you have, and verify what parts are what. Here is modern version example that Parts Express sells,
http://www.parts-express.com/wizards/searchResults.cfm?SEARCHFILTER=polyswitches&srchDesc=polyswitches

You can use an ohm meter to check continuity of the polyswitch. One can also just remove the polyswitch and use a jumper wire in its' place (good for testing purposes also). The polyswitch does have a very small resistance. Some will argue that if a polyswitch is removed, the equivalent resistance should be installed in place of the polyswitch, else the tweeter will be louder than it was designed to be in that box.

Have you checked the tweeters? What do they measure with an ohm meter?

audiobilly

I agree agfrost, the most modern version of the schematics do not show a polyswitch being used.

agfrost wrote: »

I don't see a polyswitch in the schematic for the 5jr+ Series 2. Feel free to correct me if I'm wrong.

Schematic PDF

Hay Big Dawg, FWIW, I talked to Polk Audio Customer Service just over a month ago, and they did not offer polyswitches.

Parts Express is a good place to start.
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=071-254

Big Dawg wrote: »

Welcome to Club Polk. Very nice speakers, absolutely worth fixing.

Call Polk customer service - I think that they may replace the poly-switches for free, or certainly for little cost. Or, you can either bypass them with a piece of wire or a small resistor (again, check with Polk CS for resistor value).

If you end up buying anything from Polk, be sure to mention that you are part of Club Polk - you will get a discount off of their regular prices.

skrol

The Monitor 5jr Series II speakers were designed around 1989-90. I am fairly certain that Polk was not using polyswitches by this time.
Stan

hewhorocks

I'll take a photo in of the crossover in the morning. Ive never used an Ohm meter before, but I am willing to learn.

My first thinking was, odd both tweets were bad?

I shifted the balance L/R. Both speakers sounded dull and no highs. I confirm sound and air pushing the two lower speakers but the tweets silent.

agfrost

Let me add that I've got the same pair of speakers, and that I think that they're worth springing for new tweeters, should that be the fix. I had to do mine after attempting to fill a reception hall with them, and the RD0-198 replacement tweeters were a definite improvement over the SL-2500s (not that you've been able to listen to them!).

They appear to be in really nice shape and will reward you for bringing them back to life! Welcome to Club Polk and keep us abreast of your progress.

Jay

whgarrett1394

I love my M5jr series II speakers. I hope to someday do a tweeter replacement and xover refurb, but for now they are fine. I had to paint them though. Couldn't deal with that oak veneer stuff. They are satin black now. :biggrin:

skrol

Lasareath wrote: »

What?!, my CRS+'s are from 1989 and they have polyswitches

Well I'll be a monkey's uncle (what does that mean any how), you are right.

George Grand

Have to play devil's advocate.

Any pair of speakers that I have to sink $100 into is going to be a lot more than a pair of Monitor 5 Jr. I think you over paid.

Rivrrat

Thanks George, I was going to say that yesterday, but didn't.

The thing here is, if you end up with 150+ in those speakers, you'll have more into them than you'll ever get out. For 150, you can get a nice pair of M10's.

If I were to fix them up, I'd only be doing it with used tweets (assuming the polyswitchwes aren't bad). You can probably break even by parting them out and selling the drivers.

George Grand

All depend on what the buyer wants to do with them.

I just don't think it is the "steal" or fantastic find that everybody else does.

hewhorocks

Thanks for the honest opinions.

See I do have other speakers. I have a pair of NHT on that system now. Also a nice pair of Mission speakers on deck. Makes one think about additional investment.

But I had fond memories of this speaker sounding awesome. Could be an opportunity to learn how to use an Ohm meter, add knowledge to the group with some pics and a project.... mmmm


pics on the way

skrol

Your speakers don't have a fuse on the back do they? If so, the fuse protects the tweeter and if it is blown, the mid-woof will play but the tweeter will not.

If it is the tweeters, you may be able to find some one selling some SL-2500 cheaper than Polk CS or even scavenge some SL-2500 out of a pair of speakers. I seen some beaters on CL from time to time.

BTW, based on a photo in my collection I see that polyswitches were used in at least some of the Monitor 5 Series 2 speakers.

hewhorocks

I dont see a fuse. Here is a pic though....

skrol

I don't see a polyswitch on top. If there is one it may be underneath if you remove the 4 screws and gently lift the board. If you do, also check for bad solder joints.

Joe08867

Sounds to me like the tweets are blown. I had a pair from the same year with the SL2500. Not fuse, no polyswitch. I had to replace one tweeter due to excessive volume.

The RDO-198 is a drop in replacement for those and sound great.

Not sure if they warrant the cost but I would do it if they were mine.

audiobilly

Looks like no polyswitch, no fuse, and these schematics are your crossovers,
http://www.polkaudio.com/forums/attachment.php?attachmentid=18771&d=1155784674
As agfrost has stated.

It would be worth while to measure the tweeters to insure they are bad before you spent "any" money, I would think. If both tweets are indeed bad, with no circuit protection this seems more likely now.

Also you can save money and buy used SL2500s', if money is an issue.

I have one SL2500 if you are ever interested. Just FYI.

George Grand

Rivrrat wrote: »

. For 150, you can get a nice pair of M10's.

This morning I picked up a pair for $40. They were not loved at all, so if they perform at all (haven't put electricity to them yet), it'll be in someone's garage. No way they'll ever be living room presentable. Damn shame.