Tomb of the Unknown Early 90's "Monitor" model

theunknownmonitor

I bought a pair of Polk bookshelf speakers in the early 1990s, as a gift for my parents. There is no model number on them anywhere. They are only labeled as "Monitor" on the back label, and I have no documentation for them. They are acoustic suspension cabinets, with a 5 1/4" woofer (rubber surround and rubber center cap), and a 3/4" tweeter (non-dome and with some kind of dispersion plug). The cabinets measure approximate 14" H x 8" W x 8" D.

For the size and price ($199 in the early 90's), they sound pretty good, even now. Cosmetically, and sound-wise, I'd hate to get rid of them! I'm just trying to gain some insight as to how they fit in amongst the lower-priced line of 90's Polks.

I'm attaching a a photo of the fronts, and the back label/input area. If anyone can identify a specific model number and/or point me to some specifications or ANYTHING, I'd be grateful.

Thanks!

Gardenstater

I've never seen ones that look like yours. I've never seen ones that were not ported in the lower front, first off. I've seen the Peerless tweeter, Audax, and the SL1500. Yours is closest to the Audax I've seen but that was square and yours is round. Your midwoofer is different. I've never seen anything but the usual MW's.

Yours must be later than all the above.

VR3

Reminds me of the s series

mhardy6647

looks like these, FWIW. Just called "Monitor"

https://www.pinterest.com/pin/854487729283911051/
https://reverb.com/item/18250763-polk-audio-monitor-loudspeakers-1990s-black-wall-mount-hardware-attached

It's on page 3 of https://us.v-cdn.net/5021930/uploads/editor/if/m12xmg945hv4.pdf

That oh-so-generic Audax tweeter was everywhere in, what?, the 1990s.

Astrl55

For the sake of accuracy, it should be noted that the production date for the monitor 5 (pg. 9 in pdf linked above) appears to be off by a year.

It reads: Monitor (Model) 5
1979 – 1985 $450

I believe the correct start year is 1978.
(I can back this up with my original dated receipt for a pair)

Gardenstater

There was a Monitor 5 listed in the Audio Oct 1975 Buyer's Guide.

mhardy6647

The 5 definitely doesn't date back to '75, Audio notwithstanding (and FWIW).
It wasn't on the market in '77 when I got really interested in these loudspeakers.

In terms of the 1990s "Monitor" being asked about by the OP...
https://forum.polkaudio.com/discussion/183454/help-identifying-old-speaker-model

Gardenstater

Good info on the "Monitor" Doc Hardy and even if I deserve further rebuke for derailing the thread, here is the vaporware entries in the Audio Oct 1975 Buyers Guide. There was no entry in the 1976 but there was in 1977, so that is kind of weird.

Astrl55

I'll take the hit for de-railing the thread -- mea culpa

mhardy6647

Note that the information on the woofer size for the 9 and 7 are wrong [EDIT: see below] and the tweeter for the 9 was a piezo (the 9A had a dome tweeter). The 5 is implied to have been a two-way sans PR. I think there was a little editorial haziness goin' on in 1975 @ Audio, for whatever reason.

EDIT: In fairness, the 'woofer' specifications apparently reflect the size of the PR -- but it's still, at
best, misleading... I really wouldn't put much stock in Audio's product listing for 1975.
Perhaps @SeleniumFalcon can give, or get someone else to provide, some more info on the history of the "5".
My recollection of the 5 is that it wasn't even on the market yet when I bought my demo 7As, July 21, 1978 (FWIW).

mhardy6647

SIHAB

It's what it says it is, Monitor!

Gardenstater

I've seen some data mistakes for sure. I wouldn't doubt that some of this was given over the telephone and prone to errors. I am VERY impressed however by how much of the data for the Monitor 5 they actually got reasonably correct, and am having a hard time believing that the product wouldn't even exist for a few years lol. Like weight, dimensions, freq. response, sensitivity, and to even list a price wow! They may be hazy but I wouldn't have minded having them advise my father on what stocks to buy in his portfolio. Sorry, just joshin' a little.

mhardy6647

Reminds me of Henry Kloss' early 1990s CambridgeSoundworks Six* -- early versions of which (like the second pair that I had) were made in Newton, MA, none too far from the Mass Pike interchange/Newton exit.




* crossed with the tweeter used in their later (?) CSW Seventeen, come to think of it. The CSW Six used a
very Kloss-esque cone tweeter (to good effect, IMO, and FWIW).

theunknownmonitor

Thanks for all the info, everybody. After comparing the specs with low end stuff on the current market, I'm realizing how good these things still are. My parents didn't have a use for them anymore, after 28 years, but I'm going to keep them and find a room to put them in! :-)

My first exposure to good speakers was sometime in the late 1980s, when my best friend got some Monitor 10B's in middle school. That "ruined" me forever, in the sense that I got more and more picky about stereos. I've mellowed out since college, especially when I realized my hearing was the best it would ever get already. But I still enjoy good, dynamic recordings (increasingly difficult to find nowadays, with the catastrophic loudness wars, ugh!) played back on a decent system.

Friendly reminder: wear hearing protection ALWAYS when around loud machinery and any ther source of loud noise! I started wearing foam plugs everytime I mowed the lawn, beginning in 8th grade, and now I realize how lucky I was to do that.

Thanks everybody!

spaceboy13

Greetings from 2024! Hopefully this thread isn't completely dead yet. I just bought a pair of these at a thrift store for less than 10 bucks.

They have the MW5505 5.25 inch woofer and an SL4000 tweeter. The driver is dated April 14, 1993. Matches the date on the huge wax-covered crossover blob on the inputs. While elated since I knew Polk is a great brand, they sound like @#$# when put on my record player with a little Pyle amp-let. The Sharp speakers I am currently using (6 ohm) sound WAY louder.

I tore them apart today but first measured the impedance across the input terminals: 3.8 ohms for both, which was surprising. out of the enclosure, the woofer was at 3.8 and the little tweeter was OL (infinite - that can't be good). Seems like they should be closer to 6 or 8? The woofer cones seem intact and they are moving; Given the impedance maybe they are blown but hoping some new caps in the crossover (or other suggested mods) will make these sound like new.


Thoughts? Thanks so much!
Pete in Seattle

audioluvr

Spaceboy, Welcome to Club Polk. You get what you pay for. Sometimes you score gold, sometimes you score shi(t). run a signal through the individual components to see if they play. That will eliminate whether you have a woofer/tweeter problem or a crossover problem. Crossovers can always be upgraded.

pitdogg2

Tweeter is dead, shot, kaput

F1nut

You are not measuring the impedance, you are measuring resistance.

spaceboy13

Thanks guys. Yep, I realized my mistake wrt impedance. I think the ~4 ohms on the drivers is probably okay; but I took out the other tweeter and it's like 4 ohms too...so for sure I have one dead tweeter. Both drivers seemed to have stuck coils; I've read a bunch of forums about the 5-1/4's having issues. I man-handled them and they sounded better.... not sure if I want to invest in a whole re-coning kit for them (assuming I can find one)... Yep, win some lose some. I think I'll keep fiddling and let y'all know what I find out at least for a couple more days