Why can't a MMT be 2-way?

[Juhazi]

I think it is doable, on the edge... Can you use 48dB/oct xo slopes?

This Edge simulation has on-axis and roughly 15¤ vertical and 30¤ horizontal responses

 

[GM]

Lot of good input here, thanks;-)

According to some simulations in Edge I think the dual woofers could work up to about 2kHz..........

You're welcome!

A lot depends on how far away you are and where the two arrays are focused at as to how well they will 'gel' [to become clear and definite], though even more so is personal preference, i.e. I prefer the XR290's parallel [tandem] arrays while speaker dave prefers the series aligned XRT24, so I would have the tweeter beside the woofers and the speakers laid out 'mirror imaged', then toe'd in or out and/or HF in or out as required to get the desired sound-stage:
http://www.diyaudio.com/forums/multi-way/269668-distance-between-mid-tweeter.html#post4223496
http://www.diyaudio.com/forums/multi-way/269668-distance-between-mid-tweeter.html#post4224007

GM

 

[annerholm]

I would have the tweeter beside the woofers

Intersting thought, but IMO this destroys the desired dipole pattern throughout the range.

Can you use 48dB/oct xo slopes?

Thanks for taking the time do that simulation... I'm have a very basic understanding regarding filters, so here you can see the options in the current Hypex module intended for the project:

As far as I can see I only could go 12dB. Or there are other ways to create 48dB...? Of course this module could be replaced by something else, since it's limited to pure 3-way (it has a sub ot).
I still wonder about the lobing issues in the setup. Does it has to be 3.5 way or can it be 3-way? And if you could have some more input about pros and cons/consequenses here Juhazi, I would be very greatful!

 

[markbakk]

I'd stay away from B&G right now. That company has been taken over and delivery to the DIY market likely comes to an end. But crossing the upper mid to the AMT at 1,8 to 2kHz should'nt be a problem.

 

[Juhazi]

Ok, the Hypex dsp is limited to 3 channels. I am not familiar with the UI, sorry I use minidsp. I don't think ther is any reason to use .5 with midwoofers in your project.

These simulated and by-theory assumption are just guidelines. Every speaker is a compromise. Since this is a diy project, I warmly welcome you to just start, go, measure, listen, tweak etc. etc. several iterations! It is a learning-by-doing process. Make a simple prototype first from leftover boards. I had at least 5 different baffle/frame protos with my AINOgradient before MkI, and now after 2 years I am running MkIII, with different mids, tweeters and baffles!

It comforts me that even the dipole gurus Linkwitz and Kreskowitz have gone throuh same kind of development processes (Orion(LX, NaO Note), and specially SL's web pabes tell the story very openly.