[sailor]

Hi, Interesting development. Regarding the temporary experimental baffles forming U frame, if they splay outwards 1" for every 6" of depth you will not have problems with standing waves.  When I experiment I take mods to the extreme so there is no mistaking the effect the new tweak is having and then tune from there. Perhaps revisit the U-frame with side panels about 15'' deep and lined with some carpet or underlay or similar. I suggest not making them too tall so as to not interfere with the upper range and consequently the imaging.

I use Omnimic from Parts Express to measure, great value, simple and has a forum for questions and guidance. Think I paid about $350  Have to say this: a mediocre mid and tweet properly configured will sound better than using the world's best and most expensive mid range poorly integrated.

[Bumpy]

Thanks Sailor, for a long time I have been convinced I am talking to myself on here

I have noted your comments on a mild flair for the U frame, it makes good sense, and I'm sure I will revisit it. I have already discovered the need to limit the height so as not to affect the mid/high frequencies.

I agree on the need for proper integration and is one of the arguments for finding, say a mid driver, that can be run over its full range without the need for crossovers to remove distortions at the frequency extremes. Unfortunately this type of driver does not come cheap.

My philosophy, that relies on good listening, is to find a mid driver that can play to its full range and then bring in the tweeter and bass outputs to 'kiss' it. It’s pretty easy to tell when you have gone too far as the mid range magic is sat on.

[sailor]

I way back had a Fostex 103 running full range in a Zigmahornet making surprisingly good sound but a 4" driver will obviously be bass challenged so I inserted a notch filter consisting of a cap, resistor and inductor all wired in parallel and this combo in series with one speaker connection to driver. This is not a crossover as such but was used to tame an annoying rising response in the upper mids. By attenuating a narrow band of higher frequencies there was a fuller sound by creating an apparent increase in bass and for background music was OK but it totally killed the little speakers sparkle and fun and was soon removed.
 
This is a long winded way of saying that everything matters and if you can use your mids full range do so but its seldom possible. I have found just using resistors to attenuate colour the sound with the ubiquitous sand-cast ones being the worst offenders. Measurement will reveal the effect of tweeter overlap on the mids.

I have not played with my kit for some while, busy trying to sort out a leaky house. When I get started again I have a pair of Tannoy MG15's to try out OB and to install some room treatment, speaking of which, do not underestimate the dramatic effect correct acoustical treatment will have. This is something overlooked by most!

[Bumpy]

I am currently pretty happy with how my OBs are sounding. Recording made on iPhone.


https://youtu.be/RmQFTLxx3d8]https://youtu.be/RmQFTLxx3d8]https://youtu.be/RmQFTLxx3d8