M&K S-150THX Speaker Review

[Pio]

So nice to know M&K did it right back then.

 

[dasdoing]

they basically made a linear source. It's unfortunate that it doesn't function properly at around 4k.

By the way, I always feel like the reviews lack information about the size of the drivers. The pictures can be misleading.

 

[617]

Amir, first of all, thanks for the review. My favorite thing on ASR are detailed measurements of old speakers with interesting driver combinations. My dream would be some DCM Timewindows or maybe some Ohm Walshes.

This is a great speaker for its era. I think to contextualize this speaker's design you need to look at where driver design was in the early 90s.

Nowadays you can get a 28mm Peerless tweeter for fifteen dollars, having tons of power handling and a low resonant frequency, but in 1994 these drivers were quite expensive. The Scanspeak 'Revelator' D2905 only came out in 1995, and it still costs $280 today. These tweeters, in my estimation, were created to pair with the woofers that were coming out of Denmark at the time - 5-7" woofers with large amounts of Xmax and a low resonant frequency. These enabled you to get lots of bass from a small box, and really defined the 'high end' compact speaker market for the next twenty years. Even today, there are 'high end' speakers which are nothing doing little more than putting a burly Scanspeak or Seas or Morel woofer with a matching tweeter in a small veneered box.

So if a Scanspeak 2905 blows your parts cost out of the water and you want high power handling, what do you do? M&K took a very different approach, and one which is in some ways very contemporary. One, rather than using huge beefy midwoofers, they started selling 'subwoofers' which relieved these speakers of bass duties. Nowadays we accept that subwoofer arrays are the best way to make bass, but people are still reluctant to design limited LF speakers. So, assuming your listener has a subwoofer, you can trade the one very big woofer for three small, high resonance woofers, producing a ton of midrange output.

This leaves the problem of the high frequencies - with all that woofer radiating area, how do you keep up? Padding your woofers with resistors is generally a Bad Thing, so M&K made a tweeter array. The woofers are small and play high, so the tweeter's resonance doesn't have to be too low, and you end up with a superpowered small satellite speaker.

The only question of course is what exactly the directivity of the system is, which we can now see - it was quite good. These were very good speaker designers. Designing a side by side array like this is not easy and M&K did a very good job. There was a school of thought that said avoiding floor and ceiling reflections was a good thing, and these speakers do a better job of that than most.

I would bet that this design is still very competitive if you want a small, loud speaker for use with subwoofers.

 

[RMW_NJ]

I was actually expecting worse considering the time period it is from, but this doesn’t look half bad. And considering the reasonable sensitivity and distortion numbers, seems like it would do well in a home theater.

Side note, Dave Fabrikant was an engineer at M&K before he started Ascend Acoustics.

 

[Martin]

I remember these and Atlantic Technology were the THX speakers to have when I first got into home theater. They were both just a little out of my budget.

Martin

 

[MZKM]

Preference Rating
SCORE: 3.9
SCORE w/ sub: 7.0

Sensitivity: 89.4dB (300Hz-3kHz ; spec: 91dB)
Frequency response: +/- 4.5dB 80dB-20kHz

 

[DualTriode]

I don't know. Klippel is pretty smart and @amirm knows it pretty well. It can exclude a bunch of stuff in processing I'd expect. Say the mike (mic) is right in front of the driver doing its thing and the rear terminal plate is vibrating to the stimuli. It will be delayed and maybe excluded.

APx500 Rub and Buzz plots do a very good job of showing things that shake and vibrate.

Things that shake and vibrate also show up as peaks on the distortion plots. See the peak at ~ 375hZ (in post #9). That peak is typical of vibration noise.

Thanks DT

 

[krabapple]

This is the kind of speaker that stomps a subjective reviewer.

Stomps like Godzilla, or stumps like a paradox?

 

[MoreWatts]

I gave M&K a bit of a shout-out in the 'Speakers From Last Century That You Love' thread. Subs were mandatory. The satellites were designed to have no output below 80 Hz. This frequency restriction let those little boxes handle quite a bit of power. The active version of the tested speaker, had 250-300 watts built into a box that measured 31x26x35 cm. The active monitors were meant to be placed above and just behind the large mixing boards used in film mixing, and they had a neat stand system design to accomplish this.

I just used them at home in a 2.1 system, and they sounded fine and loud in the sweet spot. For home theater use, Erin tested a slightly newer version of this speaker, with wave-guides, and also an in-wall version, both by original, not current, M&K, I think. He mentioned the problematic 'sounds different depending on which side you sit on' issue. Sure would be interesting to see if the new M&K addressed these issues, since they now have 3 speaker models (2 passive, 1 active), 2 in-walls and 2 on-walls that have this driver configuration.

While at a stereo shop in the early 80s, browsing at upper mid-fi, the dealer said "listen to this new-fangled satellite speakers plus a subwoofer system by M&K." Took 'em home. Used 'em for over 20 years, replaced satellite drivers twice and crossovers once, subwoofer driver and plate amp once, always with help from the factory.

In the early 2000s, I upgraded to their active studio monitors, the MPS-2510, and a MPS-5410 sub (also 20th century models), and used these for ~15 years, until a lightning surge ended their life.

If you remember, "bookshelf speakers" in the 1970s were actually kinda large, if you wanted any bass at all, at least. M&K (Miller & Kreisel, MKSound, M&K Sound) downsized the box by limiting the satellite/bookshelf to 80 Hz bass, and made the subwoofer handle the rest. And the move towards 5.1 was born. I don't know if they were "first" in any of this, but they were pretty influential.

The company has a neat history, About MKSound, was integral with the development of early THX speaker standards, and has an important legacy in digital recording. The original company bankrupted ~20 years ago and some Danes bought the rights. They still exist, and apparently thrive, with many similar and pricey designs, and are popular in home theater in Europe and Asia.

Ken Kreisel still has a company that makes and markets subwoofers, primarily in Asia apparently: KreiselSound.com

And to be an official, old-school, Los Angeles area, audiophile, almost requires one to have a story about Jonas Miller's audio emporium.

The Satellite II:

The Volkswoofer 1a:

The MPS-2510 with their custom stands, which still might be the coolest speaker + stand system ever:

The MPS-5410 subwoofer:

 

[JohnnyNG]

I remember wanting these back in their heyday. It appears I wouldn't have been disappointed.

 

[Mart68]

I wondered if these would live up to the hype. I went to a dealers with a friend who was heavily into home theatre. He was looking to buy them, but wanted a second opinion.

When we got there the dealer explained that the pervious customer, left alone in the demo room, had decided on impulse to swap the M&K in for whatever speakers he had been auditioning, and had managed to blow all the tweeters.

They had ordered replacements but it was six to eight weeks wait or something ridiculous. My pal ended up going with B&W so I never did get to hear the M&K

 

[norman bates]

Does anyone have a push pull m&k of kreisel subwoofer they could send in?

Shipping would be pricy.....

Sub review from 2012.

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

I've made 2x12, 4x12, and 2x18's, low qts tuned at ported f9 then +6db boost there (high pass q of 2 at tuning).

PiSpeakers Forum - Push-pull versus shorting rings - Wayne Parham, June 21, 2006 at 16:18:33

 

[MoreWatts]

Sound & Vision review and measurements of the new M&K X15+ sub. It's the 2nd sub tested, at the time, to get THX Dominus certification (really LOUD in really BIG rooms). Reviewer is a M&K dealer/fanboy, btw, active on AV(S)Forums.

I posted about M&K push-pull subwoofers in the 'Speakers Deconstructed' thread:

M&K X10 dual-driver subwoofer. Dual 10 inch here, also made in 12 and 15 inches. Their new X15+ has 700 watts and is the 2nd THX Dominus rated subwoofer released, with Perlisten the other. Perlisten’s flagship subwoofers, the D215s and D212s, also use this design.

M&K has done this design for ~30 years, commonly with 350 watts of AB amplification (for 10 inchers). This is a "push-pull" design, vs. the more discussed here "dual opposed." From AVSforum: "Push/pull reduces second order distortion, dual opposed just helps cancel out cabinet vibrations." And, I found this on ASR, for some more info.

 

[restorer-john]

APx500 Rub and Buzz plots do a very good job of showing things that shake and vibrate.

Things that shake and vibrate also show up as peaks on the distortion plots. See the peak at ~ 375hZ (in post #9). That peak is typical of vibration noise.

Thanks DT

Yes, my DATS V3 unit also has a very effective rub and buzz utility:

 

[rynberg]

M&K obviously had excellent engineering...one wonders how good of a speaker they could have designed without THX constraints and with slightly more modern tools/knowledge. I never found their subwoofers to be good value, but they were also excellently engineered.

 

[DualTriode]

After M&K went under I purchased an surplus empty dual 12 inch sub enclosure and a M&K surplus sub-amplifier.
If I recall correctly it is ScanSpeak 12 inch drivers that are now installed in the enclosure. The thing pounds.

DT

 

[amirm]

FYI I did make a near-field measurement of one of the woofers and middle tweeter:

As you see, it doesn't align with the woofer. So the other tweeters must be driven differently.

 

[Steve Dallas]

Woo hoo! At long last! A speaker review!

 

[Chilli]

Great to see how they did it back then, and how it measures. I remember mirage had a play with 3 diagonal tweeters for their hdt range of lcr speakers. It didn't last, though, so not many around.
It is interesting to see that they really were aiming for directivity, rather than dispersion for Ht speakers.

 

[SegaCD]

It is interesting to see that they really were aiming for directivity, rather than dispersion for Ht speakers.

The general benefits of studio sound design aside, this was still the era of "matrix" surround encoded into stereo tracks (a la Dolby Surround) with mediocre channel separation. Speakers with narrow directivity would definitely help enhance channel separation.