Done. I have made the wall mounting as simple as possible with attention to possible transmission of vibrations.
Damping material cut to fit
What it looks like behind the construction. There are three soft rubber dampers on the rear panel of the sub. The sub is not touching the absorber's frame.
Find the subwoofer ...
I am more than satisfied with the outcome. Sitting on the couch I have punchy and precise bass tone, but two meters away (and especially in the neighboring apartments, I may assume) you can barely hear any of it. I shouldn't praise myself, but I've really struck lucky with this. ✌️
Measurements will follow ...
Damping material cut to fit
What it looks like behind the construction. There are three soft rubber dampers on the rear panel of the sub. The sub is not touching the absorber's frame.
Find the subwoofer ...
I am more than satisfied with the outcome. Sitting on the couch I have punchy and precise bass tone, but two meters away (and especially in the neighboring apartments, I may assume) you can barely hear any of it. I shouldn't praise myself, but I've really struck lucky with this. ✌️
Measurements will follow ...
I once integrated an 8 cm fullrange driver in a small box behind the headrest in the car. Headrest was from VW T3 car, ideally suited for that.
So the music playing close to my ears.
Omitted like that buying some more powerful amplifier.
So the music playing close to my ears.
Omitted like that buying some more powerful amplifier.
Quick 'n dirty stepped sine measurement 10 - 200 Hz. Measurement mic (Beyerdynamic MM1) -> USB interface (Audient ID14 MKII) -> PC with JRiver MC 30 (no filters at all) and multichannel USB DAC (Topping DM7) -> Sub amplifier. Mic distance 10 cm.
Quick 'n dirty 2M sweep, everything else as before.
Quick 'n dirty 2M sweep, everything else as before.
Another measurement: Stepped sine 10 - 150 Hz, this time in ASIO mode instead of JAVA. Shortest possible path - Measurement mic (Beyerdynamic MM1) -> USB interface (Audient ID14 MKII) -> Sub amplifier. Mic distance 10 cm.
What do you think about that?
What do you think about that?
Last measurement: Measurement mic (Beyerdynamic MM1) -> USB interface (Audient ID14 MKII) -> PC with JRiver MC 30 (subwoofer with 30Hz/24dB highpass and 70Hz 24dB lowpass) and multichannel USB DAC (Topping DM7) -> Sub amplifier. Mic in listener's head position.
Nice work, looks great!
Response dropping ~12dB per octave below 40Hz.
Do you run out of headroom at the listening position if the sub is EQd flat to 20Hz and high passed at 20Hz rather than 30Hz?
How does the response look/sound at the left and right ends of the sofa ?
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Thank you!
I'm nowhere near the end of the optimization process. So far I've been too lazy to familiarize myself with the DSP software of the Hypex amplifier, so I haven't exhausted all the possibilities.
My listening room is open to the hallway, and everything below 30 Hz is booming surprisingly loud there.
But I like to do a measurement without 20 Hz high pass and some at the ends of the sofa. A little patience please ...
I'm nowhere near the end of the optimization process. So far I've been too lazy to familiarize myself with the DSP software of the Hypex amplifier, so I haven't exhausted all the possibilities.
My listening room is open to the hallway, and everything below 30 Hz is booming surprisingly loud there.
But I like to do a measurement without 20 Hz high pass and some at the ends of the sofa. A little patience please ...
I grasped the Hypex software, it wasn't that difficult. The crossover (now 10Hz/24dB highpass and 80Hz/48dB lowpass) and DSP for the subwoofer are now running on the Hypex amp alone. I have also equalized the dips in the frequency response and compensated for the necessary digital signal attenuation (so as not to exceed digital zero) with the gain control at the input of the Hypex amp. This works very well and so the digital resolution of my main DAC is not affected.
Here are a some measurements for the sub alone. I'm not sure which microphone orientation is the right one for my particular listening situation. The most plausible way seems to me to be the average value from a measurement in the head position with the microphone vertical and a measurement on the left and right with the microphone horizontal to the center, i.e. pointed directly at the ears at a distance of 20 cm from each other. This average is therefore the basis for the EQ and the resulting measurements up to 200 Hz.
Mic horizontal, pointing like straight to ears, 30 cm distance to sub, average from two measurements with the microphone horizontal to the center at a distance of 20 cm from each other
Mic vertikal, like in middle of head, 30 cm distance to sub (virtually no difference to the previous one)
Mic horizontal pointing straight to sub, 30 cm distance
Mic horizontal pointing straight away from sub, 30 cm distance
Mic horizontal, like sitting on outer left of sofa with right ear pointing to sub, 70 cm distance
Mic vertical, like sitting on outer left of sofa with right ear pointing to sub, 70 cm distance (virtually no difference to the previous one)
Here are a some measurements for the sub alone. I'm not sure which microphone orientation is the right one for my particular listening situation. The most plausible way seems to me to be the average value from a measurement in the head position with the microphone vertical and a measurement on the left and right with the microphone horizontal to the center, i.e. pointed directly at the ears at a distance of 20 cm from each other. This average is therefore the basis for the EQ and the resulting measurements up to 200 Hz.
Mic horizontal, pointing like straight to ears, 30 cm distance to sub, average from two measurements with the microphone horizontal to the center at a distance of 20 cm from each other
Mic vertikal, like in middle of head, 30 cm distance to sub (virtually no difference to the previous one)
Mic horizontal pointing straight to sub, 30 cm distance
Mic horizontal pointing straight away from sub, 30 cm distance
Mic horizontal, like sitting on outer left of sofa with right ear pointing to sub, 70 cm distance
Mic vertical, like sitting on outer left of sofa with right ear pointing to sub, 70 cm distance (virtually no difference to the previous one)
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The orientation of your Beyerdynamic MM1 omni mic only makes a slight (2dB) difference at 20000Hz, no difference at all below 5000Hz:
The mic capsule positioned center between where your ears are in your usual seated position would be a good target.
Nice position choice, the center couch sub response looks great!
With a +3dB lift ~ 25Hz, move the HP up to a BW24 ~20Hz, voilà: +/-2dB 25-75Hz.
The L/R couch sub response ~ -6dB on average, about the expected near field inverse distance drop from 30-70cm. Moving the couch a bit further from the woofsorber would reduce the variation a bit, though might screw up the center response.
What EQ filters were used to remove the dips in the frequency response ?
Art
The mic capsule positioned center between where your ears are in your usual seated position would be a good target.
Nice position choice, the center couch sub response looks great!
With a +3dB lift ~ 25Hz, move the HP up to a BW24 ~20Hz, voilà: +/-2dB 25-75Hz.
The L/R couch sub response ~ -6dB on average, about the expected near field inverse distance drop from 30-70cm. Moving the couch a bit further from the woofsorber would reduce the variation a bit, though might screw up the center response.
What EQ filters were used to remove the dips in the frequency response ?
Art
There will certainly be enough days with shitty weather this summer to fiddle with REW. Enough for now ...
The filters:
F Q Gain
35,40 18,29 -07,55
43,40 04,99 -15,90
49,80 17,65 14,87
55,00 20,00 -05,55
57,70 11,20 12,72
69,90 04,99 -15,90
71,90 13,63 10,38
89,90 14,56 15,00
99,70 04,99 -15,90
The filters:
F Q Gain
35,40 18,29 -07,55
43,40 04,99 -15,90
49,80 17,65 14,87
55,00 20,00 -05,55
57,70 11,20 12,72
69,90 04,99 -15,90
71,90 13,63 10,38
89,90 14,56 15,00
99,70 04,99 -15,90