Polk Audio's genesis: the Model Nine :)

mhardy6647

Since "we" got off on a little tangent in another thread ( https://forum.polkaudio.com/discussion/194010/reserve-series-does-the-black-color-have-a-texture-feel-to-it ) about the (somewhat) infamous Polk Model Nine... I am taking the liberty of starting a thread dedicated to Polk's first consumer loudspeaker.

The quasi-legendary story https://forum.polkaudio.com/discussion/comment/264355#Comment_264355 goes that Polk was on the pathway to build Bose 901 clones, but the folks on The Mountain in Framingham (or wherever they were back in the early '70s... Cambridge, perhaps?) suggested that perhaps that wasn't the best possible idea. The nascent Polk Audio had a fistful of CTS 4.5 inch "fullrange drivers" with nowhere to go.

Out of this came the Model Nine -- a tower loudspeaker touted by Polk as crossoverless and meant (it seems) to provide some of that ineffable Bose sound everywhere, with four CTS fullrange drivers in toto (3 on one side, one on the other), a passive radiator to provide a variation on "bass reflex" (Helmholtz resonator) loading, and a piezoelectric CTS tweeter (which requires no additional crosssover -- it's a capacitor, and so it acts as its own crossover).
modelnine by Mark Hardy, on Flickr
(snipped out of a brochure which can be found at https://polksda.com/pdfs/ModelNineManual.pdf

The precise introduction date for the Model Nine appears to be lost in the mists of time (or maybe that's marijuana smoke haze?). Thank heavens for https://worldradiohistory.com/ which gives us some superb, searchable resources to look for arcana like this!

Audio mentions it in March 1974:


The first ad I've managed to find in a national hifi magazine was in the May, 1974 issue of Audio:



Stereophile cops that they've acquired a pair (presumably) to test in their Autumn-Winter 1973 issue! https://worldradiohistory.com/Archive-All-Audio/Stereophile/70s/Stereophile-1973-Autumn-Winter.pdf

don't blink or you'll miss it in that laundry list!

I first encountered the Model Nines at the student pub*, the Rathskellar, at Johns Hopkins (ahem, excuse me, The Johns Hopkins University ) in the summer of 1976. They used a pair of white-finished ones, somewhat incongrously placed in front of the bar under the skylight-ceiling adjacent to the Rat's dance floor. I must've heard them (probably many times) but they didn't make much of an impression on me, other than 1) knowing they were from JHU alum Matt Polk and 2) they were Polk's first speakers. I'd acquire my first Polks a couple of years later, mostly due to the time it took to squirrel away enough money to buy a pair of Monitor Series Model 7As!

_________________
* In those days, the drinking age in MD for beer and wine was eighteen. I was not quite eighteen when I matriculated @ The Hop, but, in those halcyon days, no one really much seemed to care about such trivialities.

mhardy6647

For whatever reason, the results of Stereophile's assessment of the Model Nine didn't appear in print until Summer, 1975.
So, I hear you ask , what did Stereophile think of the Model Nine?
Well... not over much, it seems.
https://worldradiohistory.com/Archive-All-Audio/Stereophile/70s/Stereophile-1975-Summer.pdf



Two interesting things may be noted in that brief and not particularly encouraging 'review': there's a comment (response) from the manufacturer and in those days, apparently, Stereophile was including subjective (i.e., imputed) "response curves" for the speakers they tested!
Here's Polk's response:




As an aside, Stereophile also tested Jim Bongiornio's famous GAS Ampzilla power amp in the same issue. GAS's response immediately follows Polk's, and it is much lengthier! I haven't read it yet, but I suspect it is very entertaining.

And those response curves?
viola umm, I mean... voila.



(note also the comparator loudspeakers in that "graph" -- some faves from then, some still held in no mean regard by the vintage-hifi buffs)




... and here's the "response curve" they imagined they heard, relative to some other speakers they were testing at the time.

Gardenstater

Audio gave it a full review in the May 1975 issue which I posted here:

https://forum.polkaudio.com/discussion/191081/post-your-vintage-polk-speaker-magazine-reviews-here#latest

The reviewer there wasn't particularly enamored with it either lol

BlueBirdMusic

I missed that review in the 70's. Now I am up to date.

Gardenstater

That Stereophile had a lot of chutzpa, to try to put it kindly.

mhardy6647

Iwas gettin' to the Audio review... jeepers, I gotta eat and stuff, you know?

Gardenstater

You can eat when you're dead......err uhh....never mind. Anyways, here's a pretty interesting one and may be a missing link to some of the early Model Seven weirdness and it has the Model 9A as well. But check out the Seven. Two 5-1/2" midwoofers?? 150 and 5,000 Hz crossover points (not 60 and 3,000), 4 Ohms nom. impedance (not 8), 19"H x 12"W x 8-1/2"D (Not 24 x 14 x 9-1/4), 36 lbs (not 35). This might be the version right before they went to the Monitor 7 and they had replaced the piezoelectric tweeter with a dome tweeter (as they did in the Nine making it the 9A), necessitating an actual electronic crossover network. Perhaps one of the 5-1/2" midwoofers was rear facing, as maybe the dome tweeter may have been. It would be nice to get some more info. of this rare bird, like maybe some pics with grille off. High Fidelity 1976 Buying Guide.

mhardy6647

I dunno -- until & unless it's tracked down in the wild, I am thinking that the Model Seven described in '75 (and even '76) was that era's equivalent of vaporware.

I actually spent a ridiculous amount of the past couple of hours looking for a photo of the aforementioned "Rat" @ JHU -- and coming up distressingly blank. I did find 127 JHU yearbooks online... and I ascertained that the Student Union "complex" (such as it was) as I knew it was opened in 1975... but photos of the Rat? Nope.

I then, as a subsequent OCD task, tried to track down senior photos of one Matthew Steele Polk, Jr. (A&S Physics '71) but failed at that, too.

https://jscholarship.library.jhu.edu/bitstream/handle/1774.2/37636/1971_Yearbook.pdf

Gardenstater

I would like to see that yearbook photo lol. And some pics of the Rathskellar with the Model Nines. I really believe the Model Seven was real. It went up in price from $119 ea. in Aug 1975 to $125 ea. in that 1976 High Fidelity listing. They sent questionnaires to the manufacturers and that's how they got the information. Doesn't really seem like vaporware. @CarlJacobson_POLK @SeleniumFalcon @dorokusai could you find out if this was real or not, and about how many were sold? Thanks.

https://worldradiohistory.com/Archive-All-Audio/Archive-High-Fidelity/70s/High-Fidelity-1976-Speaker.pdf

westmassguy

mhardy6647 wrote: »

And those response curves?
viola umm, I mean... voila.



(note also the comparator loudspeakers in that "graph" -- some faves from then, some still held in no mean regard by the vintage-hifi buffs)




... and here's the "response curve" they imagined they heard, relative to some other speakers they were testing at the time.

No wonder I used to line the bird cage with that rag back then.

Gardenstater

@mhardy6647 What is this speaker on the left with the tweeter in the middle? This is from Audio Mar 1976

mhardy6647

It's the MiniMonitor -- but I don't ever recall seeing one thus configured ("MTM", that is -- or MTPR, more accurately, I suppose).



The Koss M80 had the "MTM" layout, if memory serves

Koss M/80.

Gardenstater

I believe it is considerably wider than the Mini Monitor and it has a passive radiator with the flat in the center, in addition to having a completely different configuration. In Oct. 1975 they already had a Monitor 5. When did they come out with the Mini Monitor?

Gardenstater

Here's the mini monitor from Audio Apr 1977. In this picture it looks *much* smaller than the Monitor 7

Gardenstater

The price of $99 ea is more in line with the 5. In Oct 1977 the 5 was $99.95ea and the Mini Monitor was $79.95 ea

audioluvr

Best way to make an obsessive compulsive perfectionist is to use words such as vague and dull to describe his first product.