Why Di Apolito

[sumsound]

Just wondering what the arguments for Di Apolito, speakers is??

I know they suffer from Xover Lobing.

What are the Pro's and Cons???

[SY]

Less and more symmetrical vertical lobing, at least when done correctly.

[sumsound]

Yah but you get 2 lobes instead of one, when you go diapolito.

So I don't see the benefit Vs. Vertically aligned drivers.

[SY]

Symmetry. And I think you only get one primary lobe, not two, because of that. There's a nice illustration of this in Dickason's LDC.

[RobWells]

IIRC the arguement proposed that the 2 lobes reduced reflections from the floor and the ceiling, resulting in better imaging.

Rob.

[SY]

Subjectively, I've found the imaging to be quite a bit "tighter," but often the soundstage can seem a bit compressed. Trade-offs, trade-offs...

[sumsound]

I mainly started this thread because of the guy who wants to build his

ultra Low z
passive 1st order filter
4 way
Di Apolito

I think a 2 way would be acceptable, for tight listening positions.

I think a 3 way would probably have really nasty polar patterns

and a 4 way would just be chaos.

[SY]

Passive first order filter? d'Appolito is the least of your lobing worries!

[The golden mean]

There are some common misconceptions about a true D´Appolito
configuration. There are some criteria to be meet as MTM drivers can´t be spaced wide apart, crossover slope should be third order etc. Crossover frequency between midrange drivers and tweeter must be low enough if I recall right.

http://en.wikipedia.org/wiki/Joseph_D'Appolito

[SY]

Note though that d'Appolito currently recommends a 4th order acoustic crossover. Other criteria still the same, especially tight driver spacing. My last MTMs were made that way and I sorely miss them.