MST

[Guest speedracer]

Hi Guys, so what's the opinion of this model ?

[dynaco_dan]

Hi there;

A lot of looky loos but no one has dared to comment yet.

There was at least two versions of this cute little baby sized LST.

There was the orginal 4 tweeter model which was re-designed to a 3 tweeter system.

One of the outer tweeters was deleted.

There was some problem with the output, or dispersion, I believe.

There has been a few partial write-ups about one or both versions.

They did not have the success of the more common speakers.

I have never heard either version and I would like to hear the differences.

I would think that the 4 tweeter units would have the better dispersion at least.

Hard to think of a too bright AR speaker.

There would have been at least better power handling with the 4th tweeter installed.

[Guest speedracer]

so the early ones had 4 tweeters, later or re-designed had 3.

[Steve F]

From a Sept 2002 post of mine:

"The MST was introduced in March 1975 along with the 11 and 10Pi as part of AR's new ADD (Advanced Development Division). The cabinet was shaped like a smaller version of the LST, with three radiating cabinet panels--one forward facing, and two angled away to the left and right of the front panel.

It used an 8" woofer and three 1 1/4" cone tweeters (similar to the tweeter in the AR-6 and -7), not the 3/4" dome. The speakers were mirror-imaged, with two of the tweeters side by side above the woofer on the front panel, and the third tweeter on the side panel. One side panel was blank. AR's instructions were to orient the speakers with the tweeters on the inner panels for a more tighly-focused stereo image, and to place the speakers with the tweeters facing out for a more diffuse, spacious effect.

The forward-facing tweeters crossed over from the woofer at 1600Hz; the outer tweeter handled frequencies above 5000Hz.

There apparently were some response irregularities in early-production MST's due to measurement inconsistencies between AR's different testing facillities, but this was straightened out in due course.

It was actually quite a nice sounding speaker, but the relatively high price ($159 ea. in 1976) for a speaker with a 3dB down point no better than an AR-6 and the difficult-to-place LST-type cabinet limited its commercial success.

Victor Campos, who was involved with the MST's design, said on "Shop Talk" (a Boston-area hi-fi radio talk show in the '70's) that the the MST's woofer design optimized all the theoretical magnetic and mechanical parameters for an 8" woofer in that sized enclosure. He said of the MST, "It could put out bass like nobody's business for an 8" woofer."

Add'l comments of mine from 2006:

The MST/1 was always a mirror-imaged speaker in the US market. AR's 1976 literature (available in the Library) even described the different audible effect of placing the tweeter panel angled inward or outward.

I agree, however, that it was somewhat inconsistent that the 5, 3a, 11, 10Pi and LST-2 were not mirror-imaged, and all of those speakers had market lives that overlapped the MST/1.

10-07:

The 4-tweeter version was never a US model. US MST's were 3-tweeter'ed units.

Steve F.

[dynaco_dan]

What a coincidence, same name as the ebay seller!

Are you the ebay seller?

[Guest speedracer]

yes sir !

[dynaco_dan]

I deleted my comments.

[Guest mikeg]

What type of 8 inch speaker was used in the MST/1 ?

Was it the same as the AR4 ?