Testing If Fabric Is Suitable To Cover Porous Absorbers

[Sal1950]

As promised, some data!

I'm by far not well versed in interpreting all the graphs but I would say
the project looks to have been very successful.
Now get some quality speakers in there!

 

[Elder]

I'm by far not well versed in interpreting all the graphs but I would say
the project looks to have been very successful.
Now get some quality speakers in there!

Apparently the RT60 may not really be relevant/applicable in a room of my size, but I still thought the difference was interesting.

Slowly saving up for a pair of Neumann KH150, super excited to hear them in the room now!

Cheers Sal

 

[ozzy9832001]

Apparently the RT60 may not really be relevant/applicable in a room of my size, but I still thought the difference was interesting.

Slowly saving up for a pair of Neumann KH150, super excited to hear them in the room now!

Cheers Sal

It's not as accurate as it could be. Requires a fully diffuse space. However, that doesn't mean the data is useless.

I noticed on the waterfall it cuts off about 500hz. Do you mind posting the 500hz and below?

 

[Elder]

It's not as accurate as it could be. Requires a fully diffuse space. However, that doesn't mean the data is useless.

I noticed on the waterfall

It's not as accurate as it could be. Requires a fully diffuse space. However, that doesn't mean the data is useless.

I noticed on the waterfall it cuts off about 500hz. Do you mind posting the 500hz and below?

it cuts off about 500hz. Do you mind posting the 500hz and below?

The data should be cutting at 50Hz, I had set that as a limit due to the speakers well and truly giving up by then and didnt think the data would be accurate. Maybe it's just the scale of the graph that's making it hard to view, shall I upload another waterfall showing 20hz- around 200Hz?

Thanks for taking a look Ozzy

EDIT: I should also mention that the current treatment is 4x 350mm deep wall panels, 3x 350mm deep cloud panels and 2x floor to ceiling 550mm deep corner traps. All panels the standard 2x4ft. Next will be the rear wall, trying to decide if I need to go super thick or can get away with some thinner treatment which would allow me to put some shelving there too.

 

[ozzy9832001]

The data should be cutting at 50Hz, I had set that as a limit due to the speakers well and truly giving up by then and didnt think the data would be accurate. Maybe it's just the scale of the graph that's making it hard to view, shall I upload another waterfall showing 20hz- around 200Hz?

Thanks for taking a look Ozzy

EDIT: I should also mention that the current treatment is 4x 350mm deep wall panels, 3x 350mm deep cloud panels and 2x floor to ceiling 550mm deep corner traps. All panels the standard 2x4ft. Next will be the rear wall, trying to decide if I need to go super thick or can get away with some thinner treatment which would allow me to put some shelving there too.

Which wall are you closer to when seated? The front or the rear?

 

[Elder]

Which wall are you closer to when seated? The front or the rear?

600mm deep desk pushed hard up against the front wall. I removed the wardrobe doors on the backwall, so there's a little over 3 metres from the back of my head to the rear wall.

Please excuse my current audio setup lol.

 

[ozzy9832001]

600mm deep desk pushed hard up against the front wall. I removed the wardrobe doors on the backwall, so there's a little over 3 metres from the back of my head to the rear wall.

Please excuse my current audio setup lol.

View attachment 314746

9' or 3m is a good distance from the rear wall for some diffusion, rather than absorption or you could try a combo diffuser/absorber.

For my tastes, since your in the nearfield and near the front wall, I'd treat the front wall with some 4" panels, especially behind and in between the 2 speakers. This will treat the SBIR you will likely be getting off the front wall (probably in the 200hz region).

The cool thing about your setup is if you needed to, you could run something like a tuned turbo trap or something like that (that's what GIK calls them) under the sidewall traps and it would fit nicely. Those would deal with some of the lowest frequency issues, if you have them.

Otherwise, I'd say it's probably at the point where you're not going to get a lot of benefits from covering the remaining areas.

 

[Elder]

9' or 3m is a good distance from the rear wall for some diffusion, rather than absorption or you could try a combo diffuser/absorber.

For my tastes, since your in the nearfield and near the front wall, I'd treat the front wall with some 4" panels, especially behind and in between the 2 speakers. This will treat the SBIR you will likely be getting off the front wall (probably in the 200hz region).

The cool thing about your setup is if you needed to, you could run something like a tuned turbo trap or something like that (that's what GIK calls them) under the sidewall traps and it would fit nicely. Those would deal with some of the lowest frequency issues, if you have them.

Otherwise, I'd say it's probably at the point where you're not going to get a lot of benefits from covering the remaining areas.

Was definitely thinking of adding some absorption behind the speakers, will just have to make sure the GFR and depth of the material will help reach low enough to help with the SBIR. Think I did some calculations once, and with a speaker as deep as the KH150, the perfect absorber was only just hitting around 0.6 absorption coefficient at the SBIR frequency. Moving the speaker back would raise the frequency and make it easier to absorb, but then the absorber won't be as effective down low due to being thinner lol. Must be better than nothing though, as people seem to have good results with them.

I was thinking down the track playing around with dual KH750 subwoofers located under the side panels (around middle of wall) but I currently have a single unused PC4000 SVS subwoofer that might do the trick. If a single subwoofer ends up working up the back of the room, using that space for membrane style traps could be a good way to use that space. Since the room is tiny every inch counts!

This whole project has been a real eye/ear opener, I prefer listening to my crappy 4" speakers in here more than my big costly system out in the living area. Renting has always made experimenting with this kind of stuff difficult.

Thanks for having a look over my stuff Ozzy