SyntripP measurement is hot garbage

Edited by SaladDressing - 03 June 2025 at 10:17pm

Edited by SaladDressing - 04 June 2025 at 1:25pm

Looks like a time alignment / delay issue possibly. Did you apply the 0.4ms delay mentioned in that link? I’d look at this and also double check polarity is correct. Ideally use smaart to find the true acoustic delay required.

You can always reverse the HF or MF…….

While your comments are valid for setting up and optimising a loudspeaker, if you re-read SaladDressing’s post, you will see he states that the measurements for the two frequency ranges were done separately. If this is correct, any delay or phase reversal between the two ranges will not affect each response.

Opensoundmeter has a similar functionality to Smaart, no need for sine waves. The easiest way to set delay times is to measure the high frequency,(or whichever frequency range has the longest path) save the response, and then when measuring the mid frequency, adjust the delay until the phase graphs align at the crossover frequency.

And what can i say, it looks like hot garbage

Looking at your measured response, the mid frequency response is not that dissimilar to that of the raw response of the original. Even when simulated, the peak at just below 500Hz, and the sharp drop off at 700Hz is present. That is a function of the design.

The deep notch in response at 63Hz could be due to your measurement set up. Try moving the microphone, speaker or both to see if the frequency of notch varies. Also, you could measure the the loudspeaker with a ground plane, which I believe is how the original was measured, it should smooth out the low end response.

The funky response of the mid drives, at around 1.6KHz, would normally be of little consequence, because it is out of the operating range and filtered out, either by the cross-over filter or a combination of that and an out of band parametric eq to get rid of any residual leftovers. However, that the high frequency driver shows an almost inverse response over the same frequency range is interesting. As a guess, I would suggest that it is due to some reflection or resonance near to the throat of the horn. If you know how to interpret the phase response plot, that may help.

The first thing that I would try is covering the openings for the mid drivers, in the throat of the horn, and re-measuring the high frequency driver, to see if the high frequency response smooths out.

Could you post a working link?

The link works for me.

smitske96 wrote: Could you post a working link? Can't see the measured response. You have any exact details of the setup? Hight from ground, dustance from DUT etc etc.

Yes, all drivers were always connected to teh amp