M&K S-150THX Speaker Review

[Sam Ash]

It would be nice to see a review of the current version of the s150 and the s300

 

[Postlan]

Excellent for the age and an unconventional speaker design.

 

[m8o]

Nice use of way back machine! :^D I have 3 of these I will never part with. 2 matching subs (a requirement to use one w/ these, that M&K pioneered or was at the forefront at least early on way before this series) and 2 tripole surrounds too.

The latter should not have had the THX designation as it could not handle the power of the THX spec, and are blown. The subs however, minus a switch problem with one of them, are exceptional. An anecdote I'll share is I once had two techs working on workout equipment in my basement; I had my M&K system on. One of the techs played bass. He was listening critically to the bassline and kept commenting on how inlove he was with the bass as it was the best he had heard; the sound was what he was always going for but could not achieve. I explained the push-pull arrangement of the dual 12" made for extremely low distortion. I didn't go on to say I suspect his bass amp plus driver was giving him dozens if not hundreds of times higher distortion.

It was sobering to learn of the original company's decision to throw in the towel in response to the crimal activity of the chinese cloners, and those that supported it thru the sales channels. Countless companies have suffered similarly but M&K's story stood out to me.

 

[m8o]

I remember reading something too about only 1 tweet running the higher stuff.

1.3khz is a rough crossover point for those tweets I imagine, but running 2 (or more) lessens the load.

The top and bottom tweeters are in series, thus each gets half power. That pair is in parallel to the center, which gets full power.

 

[MoreWatts]

It was sobering to learn of the original company's decision to throw in the towel in response to the crimal activity of the chinese cloners, and those that supported it thru the sales channels. Countless companies have suffered similarly but M&K's story stood out to me.

The demise of original M&K, and the recent bankruptcy-related sale of Audio Research, shows what a tight margin small, specialized manufacturing often operates with. I visited M&K facilities in Culver City in the 1980s, and later in Northridge, California. It was just one warehouse-size building, and not a really large one, in an industrial park. It made me realize why they always had supply issues -- they weren't that big!

M&K essentially botched a manufacturing move to China, Audio Research was sucked dry by a corporate raider, and then jettisoned. Neither of these relatively small companies could recover when something upset the apple cart.

I am impressed that the new M&K uses designs that appear exactly the same as the old stuff. They still advertise that they are used in many studios, and thrive in the European (and maybe Asian?) home theater market. Venerated Perlisten uses the push-pull design in their subwoofers.

Ken Kreisel deserves more mention when important and innovative speaker designers are discussed. Carbon copies of his designs from 30 years ago are well respected today.

 

[slk23]

Our main music/home theater system includes M&K 750 THX speakers, which are basically a smaller version of the 150s. I love the way they sound. And ours are floor standers in birch or some other light wood so they look nice too.

 

[hyfynut]

In my understanding of the definition, it is: "A waveguide is a structure that guides waves, such as sound (acoustic waveguide), light (optical waveguide), radio waves (radio-frequency waveguide) or other electromagnetic waves, with minimal loss of energy by restricting the transmission of energy to one direction."
Source: https://en.wikipedia.org/wiki/Waveguide

So, per that definition, I would say the foam would cause a loss of energy as it's absorbing high frequencies as apposed to simply modifying them like a horn or other hard non acoustically porous device no?

 

[respice finem]

So, per that definition, I would say the foam would cause a loss of energy as it's absorbing high frequencies as apposed to simply modifying them like a horn or other hard non acoustically porous device no?

Yes, it won't reflect like hard surfaces do. The question is, definition-wise, where "minimal" energy loss ends (in this case it would be a "miniature" absorber). Whatever we like to call them, they seem to do their job, in a simple and cost effective way.

 

[B-Flow]

I have a trio of unique, one-of-a-kind M&Ks. These started life as regular S150s in the short lived cherry veneer cabinets. Being in the business at the time, and having gotten to know Ken and Chuck, they agreed to do for me a very special thing, what amounted to a "field upgrade", turning them into the pro MPS2510 (which were never made with the veneer cabinets). Specifically, they sent replacement tweeters (upgrading them all to the better TL ones), replacement foam appliques (slightly different sized pieces) with some VERY PRECISE instructions as to where to position them, and of course the crossover was swapped out. The latter being the real key: Unlike the consumer S150, the MPS2510 had two switches. The first changes the vertical directivity from THX spec (very narrow), to Wide (or "not so narrow"). The latter being to address the abnormally close distance one might find themselves at a mixing console where its not hard to be outside of the sweet spot vertically (at home theater distances somewhat less of an issue). Still, I've always used them in the wide setting as I do enjoy slouching in my la-z-boy during a movie and yea, I can hear the attenuated treble if I do so in the narrow setting. IIRC this switch was added to very late model S150s prior to the company closing. The other switch, only ever found on the pro crossover, was even more interesting, though esoteric: A single/stacked selection. In the stacked setting, the top/bottom tweeters no longer get the different signal (which is what gives the trio their vertical directivity). Instead the three get an identical signal, turning them into a line array. This was so that 2 or more MPS2510s could be stacked on top of each other (creating a 6+ tweeter line array of sorts) for when an application called for even more output (which is crazy when these things are already capable of a prodigious, clean, uncompressed output).

These have been the pride and joy of my reference theater for almost 20 years now and I have no inclination or interest in replacing them. With the corresponding MX-125 sub (also one-of-a kind having been built custom with MX-350 drivers) with the crossoever they were designed for, they are quite simply the perfect speaker in my estimation. I only wish I had gotten a set of Ken's tri-pole surrounds before he shut down the company.

 

[617]

I have a trio of unique, one-of-a-kind M&Ks. These started life as regular S150s in the short lived cherry veneer cabinets. Being in the business at the time, and having gotten to know Ken and Chuck, they agreed to do for me a very special thing, what amounted to a "field upgrade", turning them into the pro MPS2510 (which were never made with the veneer cabinets). Specifically, they sent replacement tweeters (upgrading them all to the better TL ones), replacement foam appliques (slightly different sized pieces) with some VERY PRECISE instructions as to where to position them, and of course the crossover was swapped out. The latter being the real key: Unlike the consumer S150, the MPS2510 had two switches. The first changes the vertical directivity from THX spec (very narrow), to Wide (or "not so narrow"). The latter being to address the abnormally close distance one might find themselves at a mixing console where its not hard to be outside of the sweet spot vertically (at home theater distances somewhat less of an issue). Still, I've always used them in the wide setting as I do enjoy slouching in my la-z-boy during a movie and yea, I can hear the attenuated treble if I do so in the narrow setting. IIRC this switch was added to very late model S150s prior to the company closing. The other switch, only ever found on the pro crossover, was even more interesting, though esoteric: A single/stacked selection. In the stacked setting, the top/bottom tweeters no longer get the different signal (which is what gives the trio their vertical directivity). Instead the three get an identical signal, turning them into a line array. This was so that 2 or more MPS2510s could be stacked on top of each other (creating a 6+ tweeter line array of sorts) for when an application called for even more output (which is crazy when these things are already capable of a prodigious, clean, uncompressed output).

These have been the pride and joy of my reference theater for almost 20 years now and I have no inclination or interest in replacing them. With the corresponding MX-125 sub (also one-of-a kind having been built custom with MX-350 drivers) with the crossoever they were designed for, they are quite simply the perfect speaker in my estimation. I only wish I had gotten a set of Ken's tri-pole surrounds before he shut down the company.


View attachment 308535

Very cool. An irreplacable piece of speaker history. The M+K guys were really clever.

 

[Maginness]

<snip> I only wish I had gotten a set of Ken's tri-pole surrounds before he shut down the company.

I still have the tri-poles and my S-150THX fronts, so glad I've kept them all these years.

 

[m8o]

I only wish I had gotten a set of Ken's tri-pole surrounds before he shut down the company.

Thanks for sharing. A great read.

Just a comment about the tripoles. They are very fragile and may not have survived all the years for your in a similar fashion to me.

 

[norman bates]

I'd surprised I haven't seen more on push-pull subwoofers here given their cleaner distortion measurements......

KEN KREISEL DXD-12012 Dual 12" Push-Pull Subwoofer - HomeTheaterHifi.com

Ken Kreisel of M&K sold his company years ago, and it continues to thrive. Now he is back, selling subwoofers and speakers mainly to the pro market, under the company name KEN KREISEL.

hometheaterhifi.com

granted, like many others, sub/subs in too small a box (vs 4th) with mucho boosting, then subsonic roll-off.............

 

[javajaws]

I actually still use a set of these in my home theater (with 2x tripole surrounds!). Been rocking them since I bought them back in the 90's. They've been used with the full gamut of video technology over the years: 32" CRTs, plasma TVs, projectors, laserdisk, etc. I can for sure say I've gotten my money's worth out of them and that they have stood the test of time. I've run mine the last few years with a large Rythmik sub. Use them for movies only - for audio I listen in a different room with F208s. For movies I've found their sound great - but admittedly when you listen to something for so long it becomes how you expect things to sound.

Sad to think that I should probably think about finding replacements soon (like in another 5 years lol). What's funny is that within a month of buying them way back then I lost one to a lightning strike and had to get a replacement. Since then no problems.

 

[Espiritiv]

Currently using 3 S150-THX as my main LCR, and the newer MP-150s for my side surrounds mounted up from the listening position. Those MP's have 6 degree down angle built into them. Rocking the old MX350 still, and have a "custom" version i put together when the company went bankrupt and i picked up an empty enclosure, and added my own amplifier.
I will post some pics soon.

 

[Muddywaters]

Currently using 3 S150-THX as my main LCR, and the newer MP-150s for my side surrounds mounted up from the listening position. Those MP's have 6 degree down angle built into them. Rocking the old MX350 still, and have a "custom" version i put together when the company went bankrupt and i picked up an empty enclosure, and added my own amplifier.
I will post some pics soon.

Nice

I'm running S100B's across the front and 150THX Tri Poles as side surrounds elevated but I modded and mounted them on adjustable brackets to fire at the primary listening spots

 

[lewdish]

Ive always wondered how do they not have comb filtering issues compared to other line arrays?

 

[sandeep_s300]

I have s300 kit which replaced the Martin Logan montis . The S300 being neutral works great for music listening . I paired with Eversolo A8 streamer and DAC with Apollon hypex ncx500 ST power amp for music.

 

[pras1011]

Are the s300 better than the s150?

 

[Sam Ash]

Anyone had any experience or own the IW500? Any idea how they compare to the S150 and S300?