Pros and cons of an MTW layout vs TMW?

[alecf]

Hi, I'm wondering why Spendor choose to use a MTW layout for their Classic 3-ways and what the pros and cons are for this vs TMW? Is anyone a fan?

[billfitzmaurice]

I can't think of any advantages of an MTW.

[Steve Lee]

Could be a myriad of reasons.

1. Aesthetics?
2. Dispersion pattern of chosen T and M at X-over?
3. It is different?

[fpitas]

OK, I went and looked at the Spendors. They may simply be trying to get the tweeter about 36" off the floor.

[billfitzmaurice]

They use the same arrangement with cabs of various heights, both floor standing and bookshelf.

[fpitas]

Well, maybe it is just their look.

[jhollander]

I've done MTW when I want the mid range open baffle. Might also give improved vertical off axis performance for a shorter speaker.

[Drummer]

Could it be a time alignment reason assuming the mid is the listening axis ear height on a flat baffle?

[djg]

Why do Triumphs leak oil?

[fpitas]

That's a feature to insure clean crankcase oil at all times.

[JRT]

Unrelated to alignment, or to lobing...
At shorter propagation distance, the higher altitude above the floor of the upper midrange can be perceived, and some have expessed a preference. For example, in discussions here many years ago I recall Dave Dal Farra expressing a psychacoustic effect related preference for upper midrange above tweeter. At longer propagation distance that effect would become more difficult to discern in comparisons.

[fpitas]

Any guess why that should be? Less floor reflection, or...?

[JRT]

I suspect that some of the effect might be affected by changed interference from the reflection from the floor, maybe shifting the associated interference to somewhat lower frequencies, maybe below more of the telephonic frequencies affecting speech intelligibility. But also I have some vague recollection of someone (maybe DDF, not sure) experimenting with removing that floor reflection and found that the effect in perception remained.

Note that I am not an expert on the subject of psychoacoustics, however DDF is an expert on the subject as a matter of both education and practical application in his work.