Rational Acoustics



TimNT
March 3rd, 2012, 11:05 PM
this is my first post so it may be a learning experience.
My main question is the differences in phase response in the hi end

Red arrow shows fairly uniform freq response in the high end
Does the blue arrow show phase differences because of difference in spk component tolerances and or passive crossover component tolerances or is this reflection, absorption influences. Are these differences that should/can be addressed?
Yellow arrow shows response With different mid range driver. Green shows phase of different driver.
Measurements were taken in small room which was less than ideal We were looking for differences between cabinets not necessarily if they were meeting factory specs.
Biamped cabinets with passive crossover at 3.3k

Thanks for any info on my learning situation.
Tim

Arthur Skudra
March 4th, 2012, 07:03 PM
The difference you see in the high frequency phase is simply the differences in delay time setting in Smaart. Depending on your sample rate, you may be a sample or two off there in timing, nothing to worry about, it's normal and quite expected behaviour.

However the differences in magnitude in the midrange seems to indicate you're using a more efficient device there (increase in amplitude), and of course the slight difference in phase is expected using a different driver, the acoustic center of that device might be ever so slightly different.

Arthur Skudra
March 4th, 2012, 07:04 PM
Grrr, the wifi on this train caused me to double post!

TimNT
March 7th, 2012, 11:30 PM
Thanks for the info Arthur, I know I'll have more in the future when I get time look at my past TF again.

Tim

Kip Conner
May 2nd, 2012, 04:38 PM
If the boxes don't have any EQ on them, that sure is a bummer that you have one box that is going to need some special treatment out of the four. I had four Meyer UPA's and had a similar issue with one of the MS1401 HF drivers. Meyer was kind enough to fix that problem for me so I had identical response curves within a dB.