Hello,
Not sure this is in the right forum : I have a pb with a DCS205-4 as part of a WAW speaker.
The sub part is 11 liters closed. Microphone is a calibrated UMIK, source is a macbook, pre-amp is direct (Marantz) and AMP is a Gremlin (T-AMP) running on 36V. I don't have problems with other speakers using the same chain.
The problem is that the response has nothing to do with the specs nor closed box simulations:
There are huge peaks around 750Hz and 2k
So I tried to measure the baffle only w/o the box :
The peaks > 600Hz are still there. So I did measure the speaker alone, magnet on some absorbing material, cone facing up, mike on top of it (maybe not the best, but that was to get a rough idea):
And even if measurement conditions here are really bad, the peaks are still there (BTW it's the second driver, so they are all the same)
The problem is that i'd like to go passive first order, and here I'm stuck with using bi-amping and a dsp.
What am I missing ?
Not sure this is in the right forum : I have a pb with a DCS205-4 as part of a WAW speaker.
The sub part is 11 liters closed. Microphone is a calibrated UMIK, source is a macbook, pre-amp is direct (Marantz) and AMP is a Gremlin (T-AMP) running on 36V. I don't have problems with other speakers using the same chain.
The problem is that the response has nothing to do with the specs nor closed box simulations:
There are huge peaks around 750Hz and 2k
So I tried to measure the baffle only w/o the box :
The peaks > 600Hz are still there. So I did measure the speaker alone, magnet on some absorbing material, cone facing up, mike on top of it (maybe not the best, but that was to get a rough idea):
And even if measurement conditions here are really bad, the peaks are still there (BTW it's the second driver, so they are all the same)
The problem is that i'd like to go passive first order, and here I'm stuck with using bi-amping and a dsp.
What am I missing ?
Looks pretty much as the datasheet. Why do you even bother measuring this driver above 500Hz? It's a classic SUBWOOFER
This is the same driver in a 34 liter ported box and 2nd order low pass at around 200Hz
Last edited:
😳
OK thanks... didn't use the proper source for getting the response curve . Only trust the manufacturer, not loudspeaker database...
I did measure it full range to view if first order would be sufficient to push the peaks below a level where they would impact the mids... and that's unfortunately the case with first order
Seems I'll have to add a second T-AMP and a 1701 in the amp box for a true fullrange + stereo sub setup (wanted to avoid it to keep freedom of choice for mains amp... will probably build a filtered sub amp using high level inputs, no stereo sub output on preamp and I need to up to 170Hz)
OK thanks... didn't use the proper source for getting the response curve . Only trust the manufacturer, not loudspeaker database...
I did measure it full range to view if first order would be sufficient to push the peaks below a level where they would impact the mids... and that's unfortunately the case with first order
Seems I'll have to add a second T-AMP and a 1701 in the amp box for a true fullrange + stereo sub setup (wanted to avoid it to keep freedom of choice for mains amp... will probably build a filtered sub amp using high level inputs, no stereo sub output on preamp and I need to up to 170Hz)
100?
Yes based on the various chart's average and if audible, which often wasn't an issue in my time, then in the good old days we solved acoustic problems with acoustic solutions; but yes, if you want to do it all with the XO point, then working from ~ 1200 Hz = ~ 75 Hz to get ~ -25 dB/2 kHz.
Yes based on the various chart's average and if audible, which often wasn't an issue in my time, then in the good old days we solved acoustic problems with acoustic solutions; but yes, if you want to do it all with the XO point, then working from ~ 1200 Hz = ~ 75 Hz to get ~ -25 dB/2 kHz.
Last edited:
A possible alternative is to use a passive notch filter to remove that peak at 2kHz. But yes, the filter becomes a bit more complex than a simple 1st order 6dB filter (which I'd not advise be used for any subwoofer, much less this one).
