Mon Acoustic SuperMon Isobaric Bookshelf Speaker Review

S

shadyJ

Speaker of the House
Staff member
SM pair2.jpg
In our review of the Mon Acoustics SuperMon Mini, we found it to be a good little desktop speaker for a luxury office space or a small bedroom. A mini speaker with an aluminum cabinet and an isobaric woofer system made it one of the more unusual speakers that we have reviewed. Today, we look at what happens when that design philosophy is expanded into a full-size stand-mount speaker in the SuperMon Isobaric. The size and weight are increased by a factor of seven and the price is increased by a factor of twelve. The SuperMon Isobaric is a seriously high-end offering with a formidable spec list, but what is it like in practice? That is what we intend to find out in this review…

READ: Mon Acoustic SuperMon Isobaric Bookshelf Speaker Review
 
ryanosaur

ryanosaur

Audioholic Overlord
As always, great write up!

why is it that so frequently we see the more expensive speakers struggle to get basic performance goals right? ;)
 
Eppie

Eppie

Audioholic Ninja
It's an interesting design philosophy tailored for the Asian market and I could see these selling in Europe where apartment living is common as well but I think North Americans are too addicted to their bass to find these attractive except as a statement piece. More often than not my friends tend to have the bass pretty hot vs neutral. Surpised they didn't offer the more affordable PlatiMon Virtual for review.
 
-Jim-

-Jim-

Audioholic General
Thanks for the honest review (as always) @shadyJ . I saw @gene 's YouTube last night, and today the review is here.

Somehow I expected better for $25K USD. At that price (yes => unobtainium for me) they should be perfect. No EQ should be needed. Not for Real Audiophiles IMHO.
 
TLS Guy

TLS Guy

Seriously, I have no life.
As always, great write up!

why is it that so frequently we see the more expensive speakers struggle to get basic performance goals right? ;)
It is because an idiot comes up with a design based on faulty physics and this is a classic.

First of all this is a vented isobarik design in concept. It is a second order vented isobarik enclosure. However, the bass drivers are different. The drivers MUST be identical. You can not design an isobarik speaker with drivers with different Thiele/Small parameters. They must be identical. You can see from the FR that this design does not work.

The next mistake was to cross one of the drivers over. There is a crossover on the rear driver at 130 Hz. This is going to really upset the Q of the alignment of that driver with a passive crossover. Worse the phase shift has put the two drivers out of phase at crossover, at 130 Hz, as you can see from that deep null at 130 Hz.

So that design might have worked if the drivers were identical and the bass drivers crossed over together. There is still a problem though as the front driver would act as a comb filter for the rear driver.

An isobarik design is only of use for a sub or three way speaker. Even then the space saving is relatively small relative to the efficiency loss from lowering the impedance. I know the sensitivity is increased, but it still doubles the power demand from the amp for the same output as the non isobarik version. It is not worth the expense of the second woofer, which essentially contributes zero to increasing spl. per watt compared to the non isobarik version. If you used the second driver and had it output to the room then output per watt would be significantly increased.

I should know as I have walked this walk.
 
TLS Guy

TLS Guy

Seriously, I have no life.
I have been thinking about this design.

There has been minimal work on using different drivers is isobarik configuration and practically no good data, but it is not recommended.

I think the attraction here is two fold. The rear driver is much cheaper than the front driver. The other is that there is some data to suggest you can average the Vas. So if the rear driver has a lower Vas than the front, then cabinet volume is reduced further.

The best suggestion I found was to mount the two drivers front to front, and measure the Thiele/Small parameters.

The drivers must have similar sensitivity. The xmax of the rear driver must not be greater than the xmax of the front, or damage is likely.

One rule they have broken is to use an isobarik configuration above 300 Hz. This is because of rear speaker radiation emanating through the front driver with irregular response as it transits through the front driver.

The designers have tried to get round this by using a 130 Hz low pass filter to the rear driver, but then got a huge null at crossover due to the phase shift of the crossover. This is not solvable with a passive crossover. So they accepted it.

So, this is the front driver. US price is $585.00 each, but with volume discounts.

The rear driver is from Eton. I have looked at the drivers, and this is the only one that looks a possible contender. The Vas is 28 lt. versus 44 lt. for the front driver, and it meats xmax criteria, for he potential to lower total volume compared to using two front drivers.

This is the tweeter. Nothing to complain about. Though obviously "exotic" has a dollar sign.

I would point out that unless the Vas is high, then an isobarik design just adds complication for no discernable gain. My view here is that the designers have added no benefit just problems. This is not a good speaker in terns of value for money. On a value for money rating it is abysmal.

To illustrate the point, it so happens that just before Shady's excellent review we had a member want to build a pair of bookshelves for no more than $500.00. It so happens that I designed with Morel drivers and a Scanspeak tweeters in our in wall system. As you know my policy generally is only to design subs for members except under unique circumstances. In the event I thought I could use a pair of the same drivers and tweeters and give him a reliable design. I think he will build it. He has engaged me to build the crossovers, as he feel confident only with the carpentry. I am attaching the design.

This $500.00 dollar design will be a significant improvement over that 25K effort. True the midbass driver is less sensitive, but it is 8 ohms, so the power drawn by the two speakers from the amp will be virtually identical.

If the owner is not happy, then he can ship them to me for measurement and if necessary tweaking of the crossover. However I suspect he will beat the 25K effort at one fiftieth of the cost.

Now I realize you could not market that design for $500.00, but it would not be near 25K. I think it will also be smaller.

I have told you guys that building speakers gets you way ahead financially!

I enjoy Shady's reviews. I understand that Audioholics needs advertisers and he has a tactful line to walk. Keep up the good work Shady.
 

Attachments

-Jim-

-Jim-

Audioholic General
I have been thinking about this design.

There has been minimal work on using different drivers is isobarik configuration and practically no good data, but it is not recommended.

I think the attraction here is two fold. The rear driver is much cheaper than the front driver. The other is that there is some data to suggest you can average the Vas. So if the rear driver has a lower Vas than the front, then cabinet volume is reduced further.

The best suggestion I found was to mount the two drivers front to front, and measure the Thiele/Small parameters.

The drivers must have similar sensitivity. The xmax of the rear driver must not be greater than the xmax of the front, or damage is likely.

One rule they have broken is to use an isobarik configuration above 300 Hz. This is because of rear speaker radiation emanating through the front driver with irregular response as it transits through the front driver.

The designers have tried to get round this by using a 130 Hz low pass filter to the rear driver, but then got a huge null at crossover due to the phase shift of the crossover. This is not solvable with a passive crossover. So they accepted it.

So, this is the front driver. US price is $585.00 each, but with volume discounts.

The rear driver is from Eton. I have looked at the drivers, and this is the only one that looks a possible contender. The Vas is 28 lt. versus 44 lt. for the front driver, and it meats xmax criteria, for he potential to lower total volume compared to using two front drivers.

This is the tweeter. Nothing to complain about. Though obviously "exotic" has a dollar sign.

I would point out that unless the Vas is high, then an isobarik design just adds complication for no discernable gain. My view here is that the designers have added no benefit just problems. This is not a good speaker in terns of value for money. On a value for money rating it is abysmal.

To illustrate the point, it so happens that just before Shady's excellent review we had a member want to build a pair of bookshelves for no more than $500.00. It so happens that I designed with Morel drivers and a Scanspeak tweeters in our in wall system. As you know my policy generally is only to design subs for members except under unique circumstances. In the event I thought I could use a pair of the same drivers and tweeters and give him a reliable design. I think he will build it. He has engaged me to build the crossovers, as he feel confident only with the carpentry. I am attaching the design.

This $500.00 dollar design will be a significant improvement over that 25K effort. True the midbass driver is less sensitive, but it is 8 ohms, so the power drawn by the two speakers from the amp will be virtually identical.

If the owner is not happy, then he can ship them to me for measurement and if necessary tweaking of the crossover. However I suspect he will beat the 25K effort at one fiftieth of the cost.

Now I realize you could not market that design for $500.00, but it would not be near 25K. I think it will also be smaller.

I have told you guys that building speakers gets you way ahead financially!

I enjoy Shady's reviews. I understand that Audioholics needs advertisers and he has a tactful line to walk. Keep up the good work Shady.
It would be very interesting for @shadyJ or @ErinH to test those Speakers after they are finished. Please!
 
TLS Guy

TLS Guy

Seriously, I have no life.
It would be very interesting for @shadyJ or @ErinH to test those Speakers after they are finished. Please!
That won't be up to me. That would be up to the owner who will be the builder. He asked for a design, and I am just building the crossovers for him.
 
-Jim-

-Jim-

Audioholic General
That won't be up to me. That would be up to the owner who will be the builder. He asked for a design, and I am just building the crossovers for him.
`I realize that, and of course the reviewers too. It would be cool if it happens. Something very different for this Board. Something Fresh and New. Right @gene ?
 
lovinthehd

lovinthehd

Audioholic Jedi
Can't see why I'd ever buy these. Maybe for 1/10th the price. Maybe.
 
D

dftkell

Audiophyte
These might be the most overpriced speakers I have ever seen. For $5,000 you could have KEF R11's or for $4,000 you could have Revel Performa F226be's. Both of which would embarrass the Mon's.
 
T

tonyE

Junior Audioholic
Forget the speakers..... THANKS FOR THE MUSIC hints.
 
gene

gene

Audioholics Master Chief
Administrator
The PlatiMon Virtual Coaxial One stand-mount loudspeaker ($6,500/pair including stands) is the latest offering from MonAcoustic, a relatively new brand from South Korea. Boasting truly superb build-quality and “more natural sound,” the PlatiMon is the most promising speaker so far from this fast-growing company. The 2-way speaker combines a pair of 5” drivers with an AMT tweeter in a vertical MTM configuration with some interesting twists. Read on to learn more.

platimon.jpg


Read our MonAcoustic PlatiMon Coax One Review
 
Bobby Bass

Bobby Bass

Senior Audioholic
Gene thanks the update on Mon Acoustics latest offering. To answer your questions, yes I would love to hear a tower speaker made in the US. Interesting that some of their parts are currently made in the US. Read posts on other sites from people that have issues buying electronics made outside the US. I understand it’s a global economy so it doesn’t bother me but all things being equal I prefer equipment made in the good old US of A.
 
TLS Guy

TLS Guy

Seriously, I have no life.
There is a definite odor of audiophoolery about this brand.

Those ball bearings on the stand for one. That is dangerous and will add no benefit and be a safety hazard. In any event tight coupling to the stand is the best policy.
Those two ports do not have the design advantage they claim. That is more audiophoolery. You would get exactly the same result with one properly sized port.

The FR seems decent, but there is bass peak in the manufacturers data and what was measured. I suspect that warmth is somewhat artificial and actually a deliberate mistuning.

However it does seem a much better effort than that isobarik abortion of theirs.

I am not convinced the expense of the aluminum enclosure provides any benefit sonically, and is really gratuitous bling.
 
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