comparing denim, blackhole tiles, and fiber mat/batting for midrange deadening
i have sealed midrange pods, i wanted to see what the different usual suspects had for an impact on midrange frequencies.
i also wanted to see how they compared to no deadening in the enclosures.
so i grabbed some fiber mat and blackhole tiles from resonix. i already had denim installed.
so let's start with the pictures:
empty enclosure:
https://agitated.net/gallery3/var/al.../IMG_2726.jpeg
blackhole-tile installed:
https://agitated.net/gallery3/var/al.../IMG_2729.jpeg
batting installed:
https://agitated.net/gallery3/var/al.../IMG_2727.jpeg
and finally denim installed. it was typical for both sides but i forgot to take pictures of the passenger side while it was apart:
https://agitated.net/gallery3/var/al.../IMG_2730.jpeg
microphone setup:
https://agitated.net/gallery3/var/al.../IMG_2719.jpeg
Setup:
- Ambient temps like 55*f in the garage.
- Scanspeak 12m in the sail pods.
- Mic is about 0.5m from the front of the speaker, facing the speaker
- Sound generated by REW through a Topping D10, toslink/spdif from the D10 to PS8Pro DSP
- Volume controlled by the computer.
- All speakers muted but the midrange
- All measurements were done w/ the newer driver, doors closed
- Measurements were done w/ a 250hz high-pass crossover. No low-pass crossover
- EQ work was my usual SQ tune but unchanged for this mic position
- Volume was the same on all the measurements
- Between tests and changing deadener, I ran 85db of sweeps for 15min to warm the suspension and coil back up.
Deadeners tested:
- One measurement loosely filled denim, new midrange (new-rmid-denim)
- One measurement with no deadener installed (new-rmid-empty)
- One measurement with the enclosure lined with Resonix fiber mat. About 76 sq inches installed. (new-rmid-batting)
- One measurement with a blackhole tile cut to fit. One half of a tile was fit to one side, the other half was cut into quarters and fit on the other side (new-rmid-blackhole-tile)
REW measurements were default signal generation.
Re: comparing denim, blackhole tiles, and fiber mat/batting for midrange deadening
frequency response was basically the same for all the deadening materials, so it doesn't seem like it had any impact on tricking the driver into thinking it's in a bigger box. probably has more to do with the highpass crossover frequency.
https://agitated.net/gallery3/var/al...y-response.png
let's look at the decay graphs for each. nothing really sticks out here either.
empty:
https://agitated.net/gallery3/var/al...mpty-decay.png
denim:
https://agitated.net/gallery3/var/al...enim-decay.png
fiber mat/batting:
https://agitated.net/gallery3/var/al...ting-decay.png
blackhole-tile:
https://agitated.net/gallery3/var/al...tile-decay.png
i expect waterfall to look about the same as well. main visual differences seem to be like 16khz and above? way out of the passband for a midrange anyway.
empty:
http://agitated.net/gallery3/var/alb...-waterfall.png
denim:
http://agitated.net/gallery3/var/alb...-waterfall.png
fiber mat/batting:
http://agitated.net/gallery3/var/alb...-waterfall.png
blackhole-tile:
http://agitated.net/gallery3/var/alb...-waterfall.png
Re: comparing denim, blackhole tiles, and fiber mat/batting for midrange deadening
next up is the distortion graphs.
empty:
https://agitated.net/gallery3/var/al...distortion.png
denim, the scale is off on this one, sorry:
https://agitated.net/gallery3/var/al...distortion.png
fiber mat/batting:
https://agitated.net/gallery3/var/al...distortion.png
blackhole-tile:
https://agitated.net/gallery3/var/al...distortion.png
observations:
- no changes in frequency response.
- no changes in decay.
- however, there was changes in distortion. it's a bit easier to flip back and forth in REW to see the differences. i can post the .mdats if anyone's interested.
none of the materials seem to have an impact on the distortion peak around 1.2khz.
doesn't appear to be much difference between empty and denim. fiber mat/batting seems to reduce distortion 200hz - 1000hz pretty evenly. it also seems to pull down 1400hz-2000hz where the graph stops.
denim and blackhole-tile seem to similarly affect midrange distortion
conclusions:
- maybe not enough denim to have a difference
- chopped up blackhole tiles may be impacting performance, but i had no space for whole tiles.
- anything inside the enclosure seems to help distortion :)
- the home-audio tried-and-true fiber mat/batting lining the enclosure works in reducing midrange distortion. :)
Re: comparing denim, blackhole tiles, and fiber mat/batting for midrange deadening
and finally: my fresh blackhole-tiles needed to be aired out before installing them. i left them in the garage for a few days before playing with them. :)
https://agitated.net/gallery3/var/al.../IMG_2711.jpeg
Re: comparing denim, blackhole tiles, and fiber mat/batting for midrange deadening
I love this kind of experiments.
Thanks for sharing.
How do you conect the computer to the Topping?
J.
Re: comparing denim, blackhole tiles, and fiber mat/batting for midrange deadening
the d10 is a usb dac. Usb input with toslink, coax, and analog rca output. In this case, it’s acting as a usb to toslink bridge.
Re: comparing denim, blackhole tiles, and fiber mat/batting for midrange deadening
Great test. If I had to guess, you would have seen more impact if you had not set a highpass for this test.
Best regards,
Kelvin
Re: comparing denim, blackhole tiles, and fiber mat/batting for midrange deadening
Re: comparing denim, blackhole tiles, and fiber mat/batting for midrange deadening
Quote:
Originally Posted by
subwoofery
Great test. If I had to guess, you would have seen more impact if you had not set a highpass for this test.
Best regards,
Kelvin
tempted to do another one soon with my kickpanel midbasses. blackhole-tiles, denim, and empty. 55hz+