Polk Monitor 4 - Peerless?

whitemtntn

Hi-- I just picked these up. I'm trying to determine, are these the Monitor 4 with the Peerless tweeters?
I was under the impression that the 4's with Peerless had the logo on the baffle rather than the grill? But these look like the Peerless tweeters..
Thanks!

whitemtntn

mhardy6647

Those are just early ones -- I remember them looking like that when they first came out ('79? '80? Somewhere around then).

Yes, those are Peerless.

FWIW, I quite like the original Monitor 4; perhaps you will, too!

dromunds

I also really quite like those little Peerless gems

whitemtntn

I'm pretty excited to find these.
Back in the 80's I bought new the 4's with the triforce tweeters at a stereo store called Rabsons in Binghamton, NY. I always loved those speakers. I left them to an ex-girlfriend after a bad break-up, always kind of regretted that.... This should give me some closure.

dromunds

"I WANT MY F'ING RECORDS BACK!"

whitemtntn

Yep those too. A truly great collection.
And my nice Technics record player, Yamaha receiver & CD player. I left it all.
Somehow it made sense to me at the time. A couple years later I said ugh why'd I do that...

dromunds

Hey man, I have a buddy who left a S.A.E. preamp and S.A.E. 2400 amp (IIRC), the one WITH METERS. One of the nicest looking vintage amps I can remember. And a Nakamichi 700 cassette player. Look that one up. He still can't believe he did it. At least you're getting some closure.

mhardy6647

I knew that things were gettin' serious when the woman who would ultimately become Mrs. H (then Miss P.) and I merged our record collections.

We had identically two duplicates in our collections (which was probably 300 records in toto at the time).

Linda Ronstadt, Simple Dreams
Crosby, Stills, Nash & Young, So Far

whitemtntn

So I received these Monitor 4's in the mail. Set them up and I have to say, I'm pretty disappointed. They sound kinda tinny and thin. They're small speakers so you can't expect too much bass of course. But I remember my old 4's (with the triforce tweeters) as having a fuller sound. Buying speakers on ebay without listening is a calculated risk...

mhardy6647

Perhaps shifted magnets on the woofers?
They certainly shouldn't sound tinny and thin.

Oh, I guess my other thought is that perhaps the connector polarity of one speaker is reversed relative to the other. Perhaps the + and - terminals on one are labeled "wrong" relative to the other -- I'm speculating here. Easy to test; reverse the + and - connections of one of the two speakers and see if the bass changes.

It is -- straightforward -- to determine the correct polarity of the speakers (specifically, of the woofers) with a battery

westmassguy

mhardy6647 wrote: »

Perhaps shifted magnets on the woofers?
They certainly shouldn't sound tinny and thin.

Oh, I guess my other thought is that perhaps the connector polarity of one speaker is reversed relative to the other. Perhaps the + and - terminals on one are labeled "wrong" relative to the other -- I'm speculating here. Easy to test; reverse the + and - connections of one of the two speakers and see if the bass changes.

It is -- straightforward -- to determine the correct polarity of the speakers (specifically, of the woofers) with a battery

This^^^^^
Check to see if the woofers are "frozen".

dromunds

Peerless Monitor 4’s should not sound tinny and thin. They are an excellent little speaker with a very impressive full sound. Shouldn’t be that hard to track down the problem.

RandyCroissant

When I bought my Monitor 7bs now my Sons, someone before had switched the terminal nuts changing the polarity and they had one blown fuse. Fixed those and they sound great.

whitemtntn

I tried swapping black and red on one for the polarity test. I also gently pushed in the woofer, didn't hear any scratching noise or anything and it seemed to move freely.
I opened one up... everything looks in order. Magnet doesn't look like it's moved.
The treble is pretty clear and sweet, there's definitely sound coming from the woofer, there's just very little bottom coming from the speaker. Maybe that's just its nature, I dunno, first time I've ever heard these.

boston1450

Is that MW correct. Or should it be a 6502 ?

Faustin

boston1450 wrote: »

Is that MW correct. Or should it be a 6502 ?

I had a pair of the early 4's several years ago that had the Peerless and yes, the 6500 mid woofers. IIRC the crossover was identical to an early Monitor 10. Re capped the c/o and took out the crumbling black egg crate foam and added some polyfill. For a bookie they sounded very, very good. After they were completed with new cherry veneer......I gave them away to my daughter's (at that time) boyftiend as a college graduation gift. Sigh

whitemtntn

I wish I had an extra woofer to swap out and test it

whitemtntn

do you know-- is that woofer 4 ohm or 8?

aprazer402

https://forum.polkaudio.com/discussion/comment/1982480#Comment_1982480

Specs on the MW6500 from the above post:

Driver: MW 6500 Driver's model #.

Brand: Polk Driver's brand name.
Fs: 31.0000 Hz (Free air resonance)
Vas: 2.6486 ft^3 (Compliance volume)
Qts: 0.2190 Total Q
Qms: 1.3000 Mechanical Q
Qes: 0.2640 Electrical Q
Sd: 0.0130 M^2 (Piston area)
Xmax: 3.1800 mm (Cone excursion, linear)
Revc: 6.5000 ohms (DC resistance)
Znom: 8.0000 ohms (Nominal impedance)
Pmax: 35.0000 watts maximum rated power

Faustin

^^^^^^^. 8 ohm. Could be several things. From the looks of the pictures there seems to be some corrosion?? Crossover could have a bad cap or resistor?? Some of the fuse blocks get corroded as well. They probably need a complete disassembly, clean up and c/o rebuilt.

whitemtntn

Correct me if I'm wrong but there's just one cap- 5.8uf 50 volt ?

whitemtntn

I was reading that on some documentation but actually I see 3 caps - 34 uf, 12 uf and a third one I can't tell.. Is that right?
And looks like 2 resistors? In case I decide to work this, if anyone can confirm the values for all these items, much appreciated.

Faustin

I could not find a schematic for my early Monitor 4 speakers. The crossovers were the same as the early Monitor 10's. 2) 12 uf caps and 1) 34 uf cap. 1) 2.5 ohm resistor and 1) 2.7. Since the new caps were tighter tolerances than the old ones, I used a 33uf cap in place of the 34. And due to the fact the new caps were so much bigger, I mounted the resistors on the bottom of the board. That said, you are best advised to see what the values of the components are on your c/o's, as people here have found many strange variations of components used on their c/o's. Seems at times Polk used wharever was in stock during a production run. I may have some pictures of the ones I refurbished several years ago.

StantonZ

I've got a pair of these hanging from the ceiling (Atmos setup) in my family/video/audio room. While I rebuilt the XO's on my other (10B) speakers, I have never touched my 4's...and they are going on 40 years old!

whitemtntn

So - on a hunch I bought a Dayton Audio DC160-8 6-1/2" woofer. For $25 I figured I'd try swapping it in for troubleshooting. And sure enough, suddenly the speaker came back to life and the bass was back. Sounds pretty nice. I think the problem is that the 6500 woofers in these are frozen/shot. I'll have to really give it a good listen to decide if these Daytons are worth putting in or if I should try hunting down 6502's or 6503's? I have no desire to fiddle with the magnets on the old woofers. Seems a risk to buy these used on ebay..
What do you think?

dromunds

I thought one of the guys on the forum rebuilt Polk woofers in an exchange situation? Maybe I’m thinking of something else, others can chime in. Otherwise, somebody here may have what you need. I’m confused, if they call for MW6500,, why are you looking for 6502/6503? Does anybody know whether 6501 would be acceptable? I have a pair of those laying around if so. Again, somebody with more knowledge than me can chime in

westmassguy

The original Monitor 4s and 5s (possibly early 7s too) had MW6500s. That's the only driver that should go back in. Search eBay for salvaged woofers. The 6502 was used in later revisions, and will not sound the same. the 6502 is also 4 ohms nominal, so the crossover point will shift.

whitemtntn

From what I understand the 6500 is pretty fragile? Seems it will be difficult to find 2 good ones as old as all the used ones are?

FestYboy

Send them to me, if it's magnet shift, I can keep them alive. Worst case, I'm out shipping cost and a few minutes of time.

dromunds

Awesome gesture