What's possible with a modern 3" Midrange ... 3way Prototype

[mayhem13]

I have done indoor ground plane measurements of woofers. If the woofer is near the floor and the mic is on the floor, the effect of room modes is reduced. reduced by a lot actually.

When using STEPS, I find it helpful to smooth the fundamental before calculating the percent distortion. 1/3 or 1/2 octave smooths the response out quite a bit. Many people do not like STEPS because it is slow, but I am not bothered by this.

I’ve often wondered about this……say a 2x12” bass section with one fwd facing woofer and one firing down to the floor…..it would seem rational that less room modes would result compared to either single driver solution……i‘m assuming a .5 coil in between the woofers of course

 

[mayhem13]

In the light of discussion what is possible with 3 inch midranges...Joachim Gerhard made new speaker with two beryllium Bliesmas. Interesting that he chose ScanSpeak 6640 tweeter instead of Bliesma brothers...and only one bass unit...


View attachment 1273613

That’s the way to do it……imaging at its finest! If only more folks would get on board with the narrow baffle…….interesting case here is actually no baffle required

 

[IamJF]

Hi IamJF,

I do not understand how do you get so much noise on the top of 2nd harmonic after 20kHz if you have LOT of absorption. The noise on the top of the 3rd around 13-16 kHz may have the same origin... but what is it? May I ask for the time-domain IR?

We talk about frequencies of 40-60kHz here. There is a big membrane resonance at 50kHz and the mic is going down after 50k. It looks pretty calm for that. I don't think it's noise but simply out of the useful range for H2 measurements.

I would even question the meaning of H2 after 10kHz ... (technical it's maybe interesting)

 

[youknowyou]

Im building as we speak a 100l ported cab
dual 12br70
dual hivi dm 7500
hivi rt2c

wmtmw

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