4" midwoofer for mini 2 way

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Measure off-axis response of tweeter. The dip should fade away as you go 15 degrees off axis or more.

If not, then it's not a diffraction problem.

Here is measurement of my very old project - small mini-monitor with some test crossover. 4KHz crossover point, tweeter at the middle of front baffle and midwoofer is 4". Although the dip is visible on axis (3.5KHz to 5KHz), 15 degrees off axis and the dip is gone.

An externally hosted image should be here but it was not working when we last tested it.
 
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If not, then it's not a diffraction problem.

I've tried to measure off-axis about 30 degrees and dip have almost gone.

I want to say that first impressions about SB12PAC are very good. I think it is beatuful driver for the price with great clarity in midrange. I don't hear any issues with metal cones rings or something like that. So we've got some potential definitely but have to pull it out :).
 
Those are nice drivers, good to hear you like them (accidentally, I am waiting for a delivery of the same units...).
What box loading are you using?
If you have time and are willing, could you try adding "wings" made of simple cardboard, taped to the front baffle, say 4/5 cm wide, on one side, or both sides, or with slanted outer sides, and re-measure? To see how the response will change, and if the 5K dip will improve?
 
Have a look at Jeff Bagby's write up on the Sopranos about the notch at 4kHz on the same tweeter.... edge diffraction. It still shows up in the final build and I can't hear an issue with it (I have a pair here). You'd be crossing over higher I imagine so would be less of a concern. Don't get too hung up on it as it can waste your time.

https://meniscusaudio.com/wp-content/uploads/2016/02/Sopranos-Write-up.pdf
 
Don't get too hung up on it as it can waste your time.

Wise advice :).

Meanwhile I'm in search of ideal crossover. Simulation and working samples. Have some progress but a lot of work to do. But I like the process itself :).

The one thing that bothers me is some kind of shouty sound I get when freaquency response is flat. 5-7kHz is a region that gives me some trouble. Comfotrable smooth sound is impossible without dip in the region.

It's a constant problem in my room with different speakers. DIY or factory assambled no matter.
 
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