[Rick Craig]

Best sounding alarm clock of all time 
That's an interesting question. I discussed the performance of the MLs tested by Harman, with Dr Toole and clarified a few issues. Turns out that particular ML tested had a nasty resonance in the panel. He showed me the impedance measurement. I would hesitate to translate that result to "all dipoles". It's also clear Dave Smith has misread Bech, a very common thing.
He also stated that during his time at the NRC (prior to Harman), the highest rated speaker in their blind testing program, was the Mirage M1 bipolars.
In fact, they became his personal reference speakers at home, prior to him moving to his now home.
The key of course, is understanding reflections and perception and not misinterpreting the 50+ years of research.

cheers,

AJ

That's interesting about the M1 because of Floyd's comments since then about speakers with any rear radiation.

[FullRangeMan]

What you experts say about the MTM D'Appolito is?

[Davey]

What you experts say about the MTM D'Appolito is?

You wouldn't like them 

There are tons of articles on the MTM configuration.  The symmetrical vertical radiation and lobing patterns are well understood, but that design never had any sort of "constant directivity" objective as is being discussed here.
I think the primary advantage of the MTM configuration is the sensitivity increase it provided.  Generally, two paralleled woofers bring their combined SPL in line with a typical tweeter so minimal/no tweeter padding is needed.

Your query is off-topic.

Dave.

PS.  If somebody in the Seattle area has a set of JBL M2's, I would love to audition them.

[AJinFLA]

That's interesting about the M1 because of Floyd's comments since then about speakers with any rear radiation.

Floyd's comments are often misunderstood, misinterpreted and misconstrued, hence my preference to communicate with him directly, if ever needed.
His M1s are pictured in this great read: http://www.audioholics.com/room-acoustics/room-reflections-human-adaptation

cheers,

AJ

[Rick Craig]

Floyd's comments are often misunderstood, misinterpreted and misconstrued, hence my preference to communicate with him directly, if ever needed.
His M1s are pictured in this great read: http://www.audioholics.com/room-acoustics/room-reflections-human-adaptation

cheers,

AJ

Obviously testing at Harman would be different than the NRC because of sales and marketing being involved. Example - they test a different type of design that the listeners prefer but is not what the marketing department wants to sell (or thinks isn't viable to make money on).

[JLM]

I believe Harmon wants to hear/compare/learn from the competition.

[AJinFLA]

Obviously testing at Harman would be different than the NRC because of sales and marketing being involved. Example - they test a different type of design that the listeners prefer but is not what the marketing department wants to sell (or thinks isn't viable to make money on).

Tooles research from the NRC was incorporated into many Harman products and naturally they would want to test the result vs other well selling brands/class leaders in the marketplace, otherwise there would be scant reason to allocate budget on it.
The article I linked was neither marketing nor sales related. It involves loudspeaker directivity, room reflections, human perception and a great deal of misunderstanding of what Toole really said, as he states himself. 

[dB Cooper]

Coolness.  Now, does this have any impact on "taking the room out of the equation"?  If not entirely successful, does this at least reduce the effect of room impacts?  Or is that still a different kettle of fish?

Thanks, -dB (who will never get to put audiophile room treatments in his house)

Main techniques (some mentioned already, but summing up) :
-Narrow or controlled dispersion designs like FR or planar designs. FR aren't 'constant' directivity, as mentioned earlier, but both types tend to beam which may help the sound at the sweet spot (although it may also be worse even a little bit off of the spot). And although they are probably a non'starter' owing to the small room size you mention, I'll just note that planars are renowned for being tricky in terms of managing room interactions due to their dipole radiating traits.

-Nearfield, which often works in combination with the above.

I'd probably get a pair of Omega monitors with the 6.5" or 8" drivers, which beam somewhat, and....

Noting your last statement: If 'audiophile' room treatments would help but don't pass WAF muster, I have an alternative suggestion: Use 'non-audiophile' room treatments. Hanging some attractive rugs, quilts, or the like can make the room sound and look better, and probably cost less too. You might even get wifey to help pick them out.

[jtwrace]

Use 'non-audiophile' room treatments. Hanging some attractive rugs, quilts, or the like can make the room sound and look better

They really don't though.  This has been proven many many times. 

[Folsom]

The woofers on MTM's actually greatly reduce the tweeter reflections from the roof and ceiling, so they have a a beneficial directivity, to a lesser degree than others with big wave guides etc.

Having a tweeter on top of a woofer is actually somewhat problematic onto itself. Part of the M2's design it to combat exactly that, so the two place nicely together like they are one.





But for the gain is direction, you lose off-axis response as it will have more nulls. Nulls are less frequent from a waveguide of a CD design.

[Duke]

That's interesting about the M1 because of Floyd's comments since then about speakers with any rear radiation.

I really should be up on whatever Floyd has said about speakers with rear radiation, but I'm not... I recall that some hybrid electrostats scored poorly in the Harmon blind evaluation, but can't think of anything else offhand.   Would you mind enlightening me?

Thanks!

[jtwrace]

I really should be up on whatever Floyd has said about speakers with rear radiation, but I'm not... I recall that some hybrid electrostats scored poorly in the Harman blind evaluation, but can't think of anything else offhand.   Would you mind enlightening me?

Thanks!

Not to mention IIRC Dr. Geddes did measure a Maggie was blown away how poorly it measured.  Not surprising however. 

[Duke]

Not to mention IIRC Dr. Geddes did measure a Maggie was blown away how poorly it measured.  Not surprising however.

I missed that too!

Going back to Toole's testing, in my opinion those hybrid electrostats (Martin-Logans?) were at a disadvantage in the Harman room, for two reasons:  First, the surface behind the speakers was absorptive (thick curtain as I recall), so if there was any potential benefit from the backwave energy, it didn't have a fair chance of happening.  Also, the reflection path length may have been too short even if the surface had been reflective. 

Second, listening distance plays a disproportionately large role in the tonal balance of a hybrid electrostat.  This is because SPL falls off more slowy with distance from the line-source-approximating panel than from the point-source-approximating woofer.   So in a big room, and/or where the listening distance is greater than what the designers intended, the panels will be louder than the woofers, and that will show up in measurements and perceptions. 

BTW, congrats on your M2's!!

[dB Cooper]

Never mind

[Rick Craig]

I really should be up on whatever Floyd has said about speakers with rear radiation, but I'm not... I recall that some hybrid electrostats scored poorly in the Harmon blind evaluation, but can't think of anything else offhand.   Would you mind enlightening me?

Thanks!

Mostly errors of omission but when he mentions them it's typically not that positive. Given some of the newer DSP-driven speakers (such as Harman's new Lexicon SL-1 ) it would be interesting to see some new tests but since Floyd is retired that may never happen. Sean Olive could help but now their emphasis is on headphones and wireless pill boxes.

[Rick Craig]

Not to mention IIRC Dr. Geddes did measure a Maggie was blown away how poorly it measured.  Not surprising however.

I would guess that most Maggie owners buy them for the radiation characteristics and not for tonality - same is true for single-driver speakers. As a friend of mine says "people tend to hear with their eyes" and this plays a part as well.

[Davey]

I would guess that most Maggie owners buy them for the radiation characteristics and not for tonality....

I tend to think the opposite actually.
Regardless, nearly every design aspect of Magnepan speakers says they shouldn't sound nearly as good as they do.  Complicated polar response, lots of energy storage, low efficiency, etc, etc, etc.  Go figure. 

Dave.

[AJinFLA]

Mostly errors of omission but when he mentions them it's typically not that positive.

Direct quote/link please?
What I linked earlier is pretty unambiguous. It of course, coincides with all the research, if correctly read.