Questions about impulse response

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#42
gabdx said:
You need the ZMA and the FRD, as installed in the final box. Measured from the same point.

It takes years to design proper XO. It takes wisdom, patience and experience.

These are only good to design the XO, then it must be built and adjusted a lot, XSIM helps a bit looking at what happens when values change, but you have to test everything in real life to confirm everything in the simulator.
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So I have been taking measurements ad nauseam and its true, I find it takes a LOT to sink in. I agree (and can see from the measurements that the mid arrives before the woofer and the need go go higher order on the mid. Not sure if that will resolve it completely. I do have questions and will post one at a time. Also I have folders full of jpegs, impulse, frd, zma etc. It may be just better to email the folders rather than post here online and we can post only what we need. dm me so I can forward the folders
 
#43
there is a wicked dip at 220hz could this be diffraction from the front baffle? see champfer on mid baffle it is about 1/2 inch 45 degree?
 

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#44
Back story, this speaker was built in 2022. My memory of this is starting to come back lol. I was asked if I used measured or manufacturers data. It was and is a mix. I measured the mid. I used the FR from the manufacturer because I was having problems getting good results measuring low frequency and I used the manufacturers data for the tweeter as well. so I traced the Fr.
 
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#46
jimbones said:
OK I remembered from 3 years ago I have measurements I took using DATS3. However when I try to attach them they are an unsupported file (.dats) Looks like they are text files and zma only. see examples
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I take a look to these measurements :
SB34 : 1. Box resonance near 35Hz could be lower, adjust to have the best sound depend on your room. I saw two resonances 700Hz normal and 130Hz, your box is not enough damped ?
AC10F1 : Should not be use below 200Hz, I notice a resonance at 2kHz, I don"t see where it comes from but you should have a crossover frequency above 2kHz. Keep the crossover point above 2.5kHz

To work fast you should work by section : Woofer-Mid and Mid-Tw. I think you should start to work on the Woofer-Mid section.

jimbones said:
and can see from the measurements that the mid arrives before the woofer and the need go go higher order on the mid
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No because you need take into account the wavelength at the crossover point. 300Hz λ=1.1m the offset between the acoustic centers is negligible to 1.1m. This is my physicist part talking. But with the tweeter it is an other story.
 
#47
I will sim woofer and mid. Also good observation, I did remove stuffing from box during the measurements I needed to remove it to access xo lol. The diameter of the vent is big. If I go down in diameter I can get a lower Fs. I dont think 35 is too bad, I ran Win ISD and I think optimal was 32 or 33hz. I dont see that as a major factor maybe I am wrong?
 
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