Differences between TMM and MTM configuration

[ttan98]

I am new in this game, those of you who have experience with the design and construction of these type of speakers please comment.

1. What are the advantages and disadvantages of each
configuration.
2. Which one is easier to design, I think MTM?
3. What is your choice if any?


The above assumes I build a pair of speakers based on the same set of drivers, what configuration should I opt for?

[edjosh23]

Build a Bipolar loudspeaker, no need to BSC, only a single woofer on the front, and can be designed to be active vibration cancelation.

Personally not a fan of the looks of an MTM and you have to watch out for lobing issues.

Josh

[gtphill]

Originally posted by ttan98
I am new in this game, those of you who have experience with the design and construction of these type of speakers please comment.

1. What are the advantages and disadvantages of each
configuration.
2. Which one is easier to design, I think MTM?
3. What is your choice if any?


The above assumes I build a pair of speakers based on the same set of drivers, what configuration should I opt for?

Welcome to the wonderful world of speaker building. I saw the reply you received did not give the answer you were looking for.

Dr J's MTM designed was designed to make a virtual in phase point between two drivers. Lot of interesting crossover designs have "funny" phase response in the crossover region, causing the polar response (ie how the speaker spits sound into the air) to vary through the crossover. By having two drivers that make the same output through the crossover, with the high frequency in between, it keeps the vertical response symmetrical no matter how the crossover phase changes.

1. MTM allows interesting crossover filter designs that would otherwise cause major fluctuations vertically. TMM places the M closer together POTENTIALLY reducing vertical beaming through the crossover frequency.

2. The are about the same difficulty to design properly, but MTMs are more forgiving by their symmetrical nature.

3. For passive or active analog crossovers, MTM. For DSP based crossovers with larger pro-sound drivers, potentially either.

Hope that clears it up for you!