Inter-Driver Phase Audibility

[SubSoniks]

Originally Posted by ErnieM View Post
This is a key point. It becomes more noticeable on systems capable of live dynamics. Listen to a well recorded drum kit, slap bass guitar, symphony, acoustic, etc. on a large system outdoors and compare.

I play bass guitar and the difference is very noticeable in the impact coming from a linear phase 3-way PA stack, and the same stack with a typical LR24 implementation. Typical crossovers sound "over processed" and less coherent in comparison.

This is exactly where up-to-date research needs to be conducted imo....
With equipment capable of high dynamics, and in an environment that takes the room out of play.

I agree, it's often a very noticeable change in impact (even back indoors).
Heck, sometimes it sounds/feels like certain tunes can drive nails or rip air in two 😀

This is what I have found with my setup, sounds very much more real, my system here is a Fane 12-250TC with a 12MB on lows, using linear phase (subtraction delayed Bessel) crossover and a little touch of FIR on the 12-250.

 

[mark100]

Yes, measurement at 1m and phase correction based that measurement. I have separate mag and phase corrections for this experiment. I keep the same mag correction and turn phase correction on/off.



This is a very good point and one I question all time. It's a 3D sound field and we can only measure a "point" with a mic. So, have we optimized a point at the expense of the field? A few graphs below show how well the phase correction holds over distance. It was interesting to see. It's a mute point for me as I can't hear the difference, so its rarely used 🙂




Also a good point. However, gating is really the only option if you're measuring indoors. As long as you're far enough away to include the baffle effects and driver blending its still valid IMO. Averaging over several listening area spots is also preferred.

Thx for the replies Don,

Looks like you are getting very consistent performance in the close-up field.

What do you consider the minimum distance necessary to mic from?
I've been taught and have come to agree with, that measurements need to be at 3X longest baffle dimension for drivers to sum sufficiently to enable valid corrections.
Theory seems to be, until a -6dB SPL attenuation per distance doubling occurs across the full frequency range, we are measuring too close.

Which pretty much explains why i only trust outdoors, huh? 🙂
And I just plain can't gate, even indoors...screw pretty graphs ...but that's totally my issue...Lol
(Heck, i don't even like using FDW )

Anyway, it seems we are easily on the same page.
I do think/agree we are making a mistake when we optimize to a point at the expense of the field.
Put's the balancing/tuning/listening point/sweet spot/etc ....on the head of a pin.