Monitor 10 tweeter replacement or thermal switch?

zschulz2

Hey guys! First post here.

I recently acquired a set of Monitor 10s and from pics I posted on FB and rear labels, I’m told they’re 10B’s.

When I first hooked them up, at higher volume I noticed crackling coming from one of the tweeters. From researching this (esp in this forum) I quickly learned that the RD-0194 replacements were available from Polk and a decent easy upgrade as well.

Polk has them in stock and I’m ready to order, however this morning on my FB post someone suggested it might not be the tweeter at all and is possibly a thermal switch that has gone bad, which I should replace with a resistor. So...

1) I figure I’ll replace the tweeters anyway, but how do I know if the thermal switches need replaced, and
2) is that an easy enough/cheap enough job to do on my own?

I figured the tweeters would be easy enough to do but I’ve never worked on speakers before and these are my first true vintage speakers (these replaced my early 90s Polk S10 floor speakers).

Thanks for any and all help guys! Glad I found this resource.

[Deleted User]

Usually a problem connected with a Polyswitch (think of it as a resettable fuse) is that the tweeter shuts off for a short time rather than producing distortion. Usually distortion coming from a tweeter means something is broken inside the tweeter and it needs replacing. A good way to test this is to exchange the two tweeters, if the distortion follows the tweeter then it's the cause.

pitdogg2

Red tab is positive connect the black wire to it.

Gardenstater

Might be best if you posted some pics here rather than relying on FB.

If there is enough of a lead on the polyswitch above the circuit board to grab onto, you could jumper it with some mini test hook clips like these:




https://www.amazon.com/dp/B0852KRNPP/ref=sspa_dk_detail_1?psc=1&pd_rd_i=B0852KRNPP&pd_rd_w=B286c&pf_rd_p=48d372c1-f7e1-4b8b-9d02-4bd86f5158c5&pd_rd_wg=jEQi3&pf_rd_r=DK4PF48PDNP8Y9417GFR&pd_rd_r=1354d337-517d-4652-81b4-336b1a109a18&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyU0tNMjNJNzdJTlpXJmVuY3J5cHRlZElkPUEwMTg5MDIxMlo4NVhZVzIwNzA4QyZlbmNyeXB0ZWRBZElkPUEwNjc3OTIzM1NFSFMyR05RS1FPOCZ3aWRnZXROYW1lPXNwX2RldGFpbCZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=

zschulz2

If there is enough of a lead on the polyswitch above the circuit board to grab onto, you could jumper it with some mini test hook clips like these:




https://www.amazon.com/dp/B0852KRNPP/ref=sspa_dk_detail_1?psc=1&pd_rd_i=B0852KRNPP&pd_rd_w=B286c&pf_rd_p=48d372c1-f7e1-4b8b-9d02-4bd86f5158c5&pd_rd_wg=jEQi3&pf_rd_r=DK4PF48PDNP8Y9417GFR&pd_rd_r=1354d337-517d-4652-81b4-336b1a109a18&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyU0tNMjNJNzdJTlpXJmVuY3J5cHRlZElkPUEwMTg5MDIxMlo4NVhZVzIwNzA4QyZlbmNyeXB0ZWRBZElkPUEwNjc3OTIzM1NFSFMyR05RS1FPOCZ3aWRnZXROYW1lPXNwX2RldGFpbCZhY3Rpb249Y2xpY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU=[/quote]


Thanks for the feedback!
Like I said I’ve never worked on vintage speakers, or any speakers for that matter, so I don’t know what a poly switch is...lol.

Sorry to be a noob but to do some tests like that I’d need some step-by-step guidance.

Gardenstater wrote: »

Might be best if you posted some pics here rather than relying on FB.

Gardenstater

If you can remove the 4 screws holding the crossover assy onto the back of the speaker in question and take a picture of the circuit board and post it here that would help a lot. Make sure your amplifier is turned off first.

zschulz2

xschop

The Mylar dome flange right next to the upper right magnet screw looks delaminated.

zschulz2

@xschop

Sorry I have no idea what that means. Lol Replace the tweeters and you think I’m good?

Gardenstater

If your tweeters are wired with Faston connectors which are removable from the tweeter terminals it will be easy enough to swap them around as Kenneth suggests, otherwise you will have to desolder and solder. Make sure you keep the polarity the same.....black wire and white wires connected to the same terminals that they are currently connected to. It does seem unlikely that the polyswitch, which is a small gold or yellow colored device on the crossover circuit board, would produce distortion but if it is in some sort of partial failure mode maybe it is possible.

I'm thinking that you may have 10C's but I'm not really sure.

xschop

zschulz2 wrote: »

@xschop

Sorry I have no idea what that means. Lol Replace the tweeters and you think I’m good?

Do what Ken suggested first.

Gardenstater

Be careful if your tweeters are soldered because it is very easy to destroy them in the desoldering process. With Peerless tweeters I know that is such an issue that most people choose to clip the wires at least an inch from the tweeter terminals. I don't know what the situation is with the SL2000 tweeter. If you have a situation where you are in doubt, just do that and crimp on a male faston to the short tweeter wire remaining and a female on the wire coming from the crossover. Then you can swap out tweeters easily in the future.

F1nut

All SL2000 tweeters are connected with fastons.

zschulz2

@Gardenstater
They’re not soldered on. I think I’m gonna order new tweeters regardless, and just see if there’s any issues.

zschulz2

Hey everyone!

My replacement RD-0194s came in today but I had a quick ?

The old ones had one terminal marked with a + connected to a black wire. Other side was white wire with no marking.

The new tweeters have no + mark but one terminal is coated in red color.
Should I treat that as positive and connect the black wire to it?

Thanks!

@F1nut @KennethSwauger

As a side note the old tweeters had a label dated 1986. Would that make them Monitor 10Bs or Cs?

Gardenstater

Red has always been for the + wire (black) on my Peerless tweeters.

Faustin

For MOST older Polk's, positive wire is black.

F1nut

The new tweeters have no + mark but one terminal is coated in red color.
Should I treat that as positive and connect the black wire to it?

Yes

As a side note the old tweeters had a label dated 1986. Would that make them Monitor 10Bs or Cs?

Yes