[mresseguie]

I'm currently researching for new speakers. Most of my time recently has been spent looking into sealed two-way speakers which will be paired to a subwoofer, but I notice there are a fair number of MTM configurations out there as well. [This may have been discussed before, but I'm curious to know peoples' opinions on this.]

Is the SQ necessarily better in an MTM setup? I think such a setup would achieve lower bass(?). The dispersion would be a bit different as well. My expectation is that most of the time I would not be sitting in a sweet spot as I listen to music.

For example, I could have a pair of speakers using the SS Illuminator 5" 4 ohm drivers paired to a tweeter, or I could use a single 7" Illuminator paired to a tweeter.

I'm more attracted to a TM configuration for its smaller size and lighter weight, but I may yet be swayed into opting for a larger MTM since there are some very nice 5" 4 ohm drivers available on the used market.

Hobbyists, manufacturers, DIYers, and everyone else is welcome to chime in.

Please note: I'm not currently considering single drive speakers, so I do not need any input concerning them.

Have a nice day.

Michael

[ASCTLC]

Well, lets just get this out of the way up front... You should really consider single driv.....oh never mind   

Andy

[rpf]

I've never cared for the MTM configuration. I find TMs more coherent, with at least a chance of being time aligned and phase coherent, things the former can't do.

This may or may not matter to you.

[neobop]

This will give you an idea of what a D'Applito configuration tries to do.  When done properly, they image like crazy.
https://en.wikipedia.org/wiki/Midwoofer-tweeter-midwoofer

neo

[druth53]

I have both TM and MTM from same designer- Selah Audio, SSR and Decennio. They are both ported, both use different ribbons and different mid woofers. They do image differently, TM are more precise, the MTM a bit less focused but the MTM are considerably more dynamic, play louder, are more efficient, and are more tactile. I can also stand by one of the MTM speakers and clearly listen to the other speaker which the TM does not do as well. Do enjoy both. MTM is a 1.5 cu ft tower, the TM is a 1 cu ft monitor.

[JLM]

MTM (D'Applito) vertical arrangement helps eliminate floor and ceiling reflections (helping to comply with THX movie standards), but to avoid phasing issues between the midrange drivers the listener must sit exactly equal distance from both drivers (this is why MTM doesn't work in horizontal arrangement for center channel use).  MTM also allows for greater overall speaker efficiency as tweeters are typically more efficient than mid/woofers.   

A seldom thought of issue is the sound that backwaves inside the cabinet produce.  Delayed/out of phase sound come out ports.  The same is true for any cone (drivers or passive radiators) as their thin/lightweight materials allow much more sound to be transmitted through (like heat going through a window versus an insulated wall).  Having additional drivers is provides more delayed/out of phase sound to come out.

Another seldom thought of issue regarding backwaves is how a sound waves inside a box, especially those with a hole behave.  If you rounded the box and made it smaller you'd have a flute.  Where you blow changes the sound.  If you could blow into two holes at once it'd sound different, as it must in a floor-standing MTM.

Knowledgable listeners look for at least 6 inch drivers to fully support mid/bass frequencies that add solidity/body to reproduced music.  The argument of spending "X dollars" on one better driver or multiple poorer ones comes to mind.

Single order crossovers provide superior imaging for TM design (look at Fritz Speakers for examples).

[mresseguie]

MTM (D'Applito) vertical arrangement helps eliminate floor and ceiling reflections (helping to comply with THX movie standards), but to avoid phasing issues between the midrange drivers the listener must sit exactly equal distance from both drivers (this is why MTM doesn't work in horizontal arrangement for center channel use).  MTM also allows for greater overall speaker efficiency as tweeters are typically more efficient than mid/woofers.   

A seldom thought of issue is the sound that backwaves inside the cabinet produce.  Delayed/out of phase sound come out ports.  The same is true for any cone (drivers or passive radiators) as their thin/lightweight materials allow much more sound to be transmitted through (like heat going through a window versus an insulated wall).  Having additional drivers is provides more delayed/out of phase sound to come out.

Another seldom thought of issue regarding backwaves is how a sound waves inside a box, especially those with a hole behave.  If you rounded the box and made it smaller you'd have a flute.  Where you blow changes the sound.  If you could blow into two holes at once it'd sound different, as it must in a floor-standing MTM.

Knowledgable listeners look for at least 6 inch drivers to fully support mid/bass frequencies that add solidity/body to reproduced music.  The argument of spending "X dollars" on one better driver or multiple poorer ones comes to mind.

Single order crossovers provide superior imaging for TM design (look at Fritz Speakers for examples).

I'm strongly considering a TM design with a high quality midwoofer and high quality tweeter. I have narrowed my search down to two or three of each.

Is single order the same as 'series' crossover (Bud Fried speakers??)?

[JLM]

First order refers to the slope of the crossover (6 dB/octave).  Each additional order adds 6 dB/octave.  First order crossovers minimize phase issues between drivers, but require the drivers to cover a wider frequency range.  In recent years DSP or extremely high sloped crossovers have been used to accommodate lesser drivers while addressing phase issues.

Series crossovers (as an old Fried fanboy, thanks for the reference) instead refers to basic circuit design.  In series circuit the signal (filtered by the crossover) passes through each driver versus parallel circuits that split the signal between drivers.

Good idea to invest in better/fewer drivers IMO (you're getting closer to that single driver concept).   

Other good concepts are concentric (coaxial) drivers and active designs (crossover prior to power amps with one power amp per driver).  Active design allows for the amp to be optimized to the driver and to "see/sense" (react to) it more clearly/directly, providing much improved dynamics, flatter frequency response (a revelation in itself), and amazingly deeper/fuller bass.  It was an absolute epiphany years ago to be able to audition passive versus active version of the same 2-way stand-mount.  Coaxial design translates into improved imaging, especially beyond the listener's sweet spot.  (Now you'd be getting really close to that single driver ideal).   

[ricardojoa]

My experience with the MTM Salk  songtower versus the TM and TMW of the sierra 2 and the Selah tempesta, is that I think the MTM has different presentation. In simple words, the MTM seems to have more of an enveloping effect. While the TM design is "flatter"?
 
If you are crossing to a sub with the best possible location, I might think the MTM give a slight advantage on efficiency. If the sub are cross very close to the main, the TM might be better, since you have to worry phase issue with one woofer versus the second that is at different distance.

[EzraS]

I am very happy with my Salk Continuim 2 way sealed monitors coupled with a REL sub although I am interested in trying a single driver speaker system. The Salk is an updated take on the LS35A by Jeff Bagby and is constructed of  solid maple. My old Rogers LS5As  were great speakers until a tweeter fried due to a bad preamp. I understand Falcon acoustics has them in production again to BBC specs. See current Stereophile review.