MTM - TMM Shoot Out

[ODougbo]

Which is better.
This has been an ongoing project for a long time now, and finally at the point where I can AB boxes that are almost identical, except:
* Baffle
* xo desing (slightly different)
* Woofer inductor (14g vs.12g)

MTM:
Never heard anything I didn't like, very nice clean sound, very natural sounding. As most know best to keep them at ear level.

TMM:
Well this interesting, from the moment I hooked them up they had more defined bass. There is also a noticeable large hall/venue sound. The TMM xo is shown, the foil coil is 12g, maybe a characteristic of this type of inductor.
The vocals are amazing.

 

[Bill poster]

Polar response is better with MTM?

 

[chris661]

Polar response will be different with the MTM - a little narrower in the vertical plane from say 500Hz up to the HF crossover point.

Chris

 

[boswald]

Are they both two ways, or is the tmm a 2.5?

 

[TNT]

Polar response is better with MTM?

No - always worse.

//

 

[Boden]

I am afraid you are comparing apples with oranges: because of the different locations of the woofers/midwoofers in relation to floor and ceiling. Reflections (e.g. floor bounce) and interference patterns will be different.

Eelco

 

[plasnu]

I have tried MTM vs TM just unwiring top M of the MTM and send 2x power to remainning M, and I noticed the same thing as OP. Good thing about MTM is the vocal and instruments does not move vertically depends on the frequency, deadly still, but I believe audiophiles would prefer slightly vertically moving image because the movement makes the listener feel more vibe.

 

[augerpro]

I have tried MTM vs TM just unwiring top M of the MTM and send 2x power to remainning M,

With a passive crossover you've changed the impedance, and therefore the crossover filter by doing that. So not apples to apples.

 

[ODougbo]

Polar response will be different with the MTM - a little narrower in the vertical plane from say 500Hz up to the HF crossover point.

Chris

Thank you for the interesting replies.

Polar Response, that sounds applicable here.

2.5? not on this build. But that reminds me how this all got started, which was a 2.5 in a much taller box. Abandoned that project. These are smaller and easier/move around, and didn't feel that I didn't give up much.

Location of the woofers, is approximately the same.

So the "foil coils" are a upgrade or a detriment? There are long threads on the topic and some folks were bashing them. The heaver 12g "wire" appears to enhance the bass, but I don't want to invest in another pair (for the mtms) if they have some drawbacks.

thanks again!

 

[Bill poster]

Considering the thickness of wire in parts of the chain, I don't worry too much about gauge of inductor

 

[system7]

Another fun project, ODougbo! 🙂

I always tell people it doesn't matter much if you build MTM or TMM style. It ends up with the same filter. And the benefits of the PA sound projection (inverse distance loudness falloff rather than inverse square) and theoretically lower distortion of doubled drivers.

Minor differences in vertical lobing/combing if you are not phase-aligned, 90 degrees in the d'Appolito BW3 style.

Are we looking at 6" or 8" bass here? Parallel or series wired? What is the filter, or is it all HushHush and on the QT... I like the details. 😀

 

[ODougbo]

7" Anarchy, some have said it is the best mid bass out there, I'm tuning into a believer.
[very affordable btw] Attaching measurements from the website.
I'm thinking the tweeter is a little hotter then the MTM pair, which is ok, the mid is shining through a bit better.
Or maybe something else, but things like movie/TV dialog is better with the TMM.

The mtm xo is very similar.

Tweeter? Looks like they stopped making these, but this is the 4 I have:
Dayton RS28F-4

 

[wushuliu]

Hard to tell anything without measurements. I think the MTM would have some low midrange suck out say in the 100 to 300hz range. The TMM with the Anarchy I imagine to be a lot fuller and perception of greater 'slam'.

I thought about the anarchy but opted to build an MTM with the Eclipse/W6520R, which I can't believe more people aren't using.

And from personal experience the one with the 12awg inductor will have more low end presence (when used for woofer BSC). 12 is almost double the wire of a 14. I say definitely swap with 14awg and reassess.

 

[reggieSf25]

My first love was a mtm because the sound was more focused and effortless with the right wattage. the tmm seemed to have a brighter presence.

 

[phivates]

Psychoacoustics rule at this level of choosing, IMO. I bought into MTM in the 80s and I need bias confirmation on this one. Even though KEF did it both ways...

 

[wushuliu]

My first love was a mtm because the sound was more focused and effortless with the right wattage. the tmm seemed to have a brighter presence.

Agreed. I've had mine built with the tweeter offset and oriented on the outside which with the right tweeter provides a wide presentation from behind the speakers as well as focus.

 

[norman bates]

I had luck with 3 mtm's across the front for a home theater.
Rca (rat shack) pro cs550's I think.

 

[ODougbo]

Very good Wushuliu, all this sound correct, but I'll need to measure and upgrade the crossover. However the mtm does sound like it is working harder than the tmm.
My work buddy saw both pairs of boxes, he flipped over the style of the mtm, said he wanted "That Pair". So the man on the street likes the look symmetric style more.

Eclipse/W6520R interesting, what size box are you using?

Hard to tell anything without measurements. I think the MTM would have some low midrange suck out say in the 100 to 300hz range. The TMM with the Anarchy I imagine to be a lot fuller and perception of greater 'slam'.
[]
And from personal experience the one with the 12awg inductor will have more low end presence (when used for woofer BSC). 12 is almost double the wire of a 14. I say definitely swap with 14awg and reassess.

he coils.

 

[AllenB]

the mtm does sound like it is working harder than the tmm.

You mentioned a slightly different crossover. Are you throwing a little more at the ceiling in the xover region?

 

[ODougbo]

AllenB how would I know if that is happening?

I did work on the TMM this weekend, found a xo mistake: used a .33ohm instead of a 3.3ohm at one tweeter which explains the extra high end, even tho it was only one side.
One thing about mtm's, the sound will focus/converge in the center of the room at different lengths. Which is very subtle, but works very nicely for movies. I could see manufacturing companies using this as a marketing ploy for two channel surround sound. Some may grumble at this idea, but it is not bad by any means and keeps things interesting.

Well ordered more xo parts, and more lights for the shop (ugh). I'll go over both pairs and use as many as the same xo parts possible and also weigh the fill in all the cabinets.