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AUDIO FORUMS >> Room Treatment >> Too Many Diffusers?
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Message started by Palomino on 03/06/19 at 18:15:05

Title: Too Many Diffusers?
Post by Palomino on 03/06/19 at 18:15:05

Well, Raven is cleaning house and asked me to take his Rolling Diffusers lab Styrofoam diffusers with the prospect of fixing them up and selling them or keeping them for a very reasonable price.

My room is now basically lined with diffusers. Listening in that kind of environment is kind of disorienting as much of the sound is, well, diffused. The imaging is great and the clarity of the sound is fantastic. I am just trying to sort out how I like it.

Title: Re: Too Many Diffusers?
Post by glineus on 03/07/19 at 01:27:01

Hi Palomino.

I envy your position, I am in need of some room treatment. After your have made an assessment of your requirement it may be possible for me to take some off you.

Regards

Title: Re: Too Many Diffusers?
Post by Lonely Raven on 03/07/19 at 15:19:48

glineus, are you in the Chicagoland area?

If so, I do have more stuff I'm parting with - but a lot of it is real wood and rather heavy, so shipping isn't really an option.

Title: Re: Too Many Diffusers?
Post by glineus on 03/07/19 at 15:26:32

Hi! Lonely Raven,

Sorry but I am in Trinidad & Tobago, West Indies.I normally have purchases shipped to my US shippers in Miami, Florida.

Thanks

Title: Re: Too Many Diffusers?
Post by Palomino on 03/07/19 at 15:27:05

My son was over last night and he listened for about an hour. I wish I had written down his first response because I think he nailed it.

He said something like it was quieter, allowing you to hear more of the music. This was also his first time hearing the 25th anniversary amp as well so I don't know which to attribute his comment to. Probably both the amp and the diffusers.

Title: Re: Too Many Diffusers?
Post by Acetone on 03/07/19 at 23:40:26

Palamino, You can never have too many Diffusers.....Cow Bells as well. (damn, where's that cow bell emoji when you need it).

Title: Re: Too Many Diffusers?
Post by Steve Deckert on 03/24/19 at 05:41:48

Inspired by the image of your room, an obvious on-going science experiment that reminds me of some of my past rooms...

In any case, when I look at this image that you have posted and apply the "how can I make this sound better" without complicating it with costs, effort or practicality I come up with some ideas I'd like to share with you. This is kind of my methodology, which is to set the goal high and work backwards from there to a point somewhere in-between the two.

1) six foot wide thing on the ceiling starting about 2 feet behind (and above) your head going toward the speakers. Could be more diffusers, could be bubble wrap, could be fiberglass or lambswool.

2) put 3/4 MDF or particle board panels that are 1 inch smaller than the ceiling tiles above each tile to add mass. Trust me you'll hear this one.

3) replace the carpet with a heavy commercial carpet pad and 1/2 inch plush carpet on top from corner to corner. At a minimum create a large area rug with the same pad under it on top of the carpet you have.

4) Everywhere you see wall paint/drywall cover with 2 inch acoustic foam tiles.

5) foam tiles on top of the sub woofer cabinets to improve imaging.

6) the 360 wood diffusers leaning up against the back wall on each side should be re-located to the floor in front of the audio rack leaning back against the rack like the speaker grill on the left. Alternately and perhaps even better would be to put them flat on the floor directly in front of each speaker no farther than 2 inches away.

7) create some diaphragmatic bass traps that are 12 x 12 x 48 and put them on the floor along the baseboards on side walls to give you a linear broad-band bass trap down to 60Hz for the room.

If you make it this far and by some chance complete all of the above, you'll have to re-adjust the speakers back slightly.

Also, pointing the subwoofer at the back wall and flipping the polarity both ways to listen to result might be an interesting evening. Also rotating them 90 degrees to face the side walls and then putting diffusers on the surface facing you might also work well. Keeps the woofer cone isolated from the back wave of the open baffle which should improve focus.

Your room is too bright at the present. So as not to dull the diffusion by stretching fabric in front of the diffusers, lets get the remaining flat surfaces softened so they absorb down below 1K. The floor carpet enhancement is diaphragmatic. It will make an insane improvement in focus. The ceiling will make an insane improvement in the bass quality which will in turn enhance midrange focus.

Title: Re: Too Many Diffusers?
Post by Palomino on 03/24/19 at 12:14:16

Thanks Steve. Certainly several things to try. My problem is once my butt hits the seat to “evaluate” a change, with the 25th zen I may not get up again for a couple of hours. At the rate I am going, this could take a few years :)

Title: Re: Too Many Diffusers?
Post by Steve Deckert on 03/27/19 at 06:32:54

The journey is the experience. Why rush it, I agree.

Title: Re: Too Many Diffusers?
Post by Palomino on 03/27/19 at 12:38:35

The amp is sounding so good the last two days!

I did play around with the subwoofers and achieved a little better focus. I have a good amount of mdf laying around so I may try that on the tiles.

Those drop ceiling are a pain because certain frequencies can cause a rattle.

Title: Re: Too Many Diffusers?
Post by Brian on 03/27/19 at 23:45:44

This is not room treatment, but I wondered:
Would placing the tweeters beside the mid drivers instead of above them be worth a trial?

Brian

Title: Re: Too Many Diffusers?
Post by Palomino on 04/10/19 at 20:53:10

Sorry Brian, just saw this.

I'm not sure. I just cleaned up my garage though, so I won't be making new baffles soon.

Title: Re: Too Many Diffusers?
Post by Brian on 04/14/19 at 05:30:38

I don't know if it would help or hurt. But it is the sort of thing I wonder about. :)

They certainly look like speakers that would have great sound.

Brian

Title: Re: Too Many Diffusers?
Post by Palomino on 04/14/19 at 05:44:42

They held up pretty well to many of the speakers I heard at AXPONA today. Certainly better than some.

Title: Re: Too Many Diffusers?
Post by Brian on 04/15/19 at 19:27:11

That is good to hear!

Title: Re: Too Many Diffusers?
Post by anzaanimal on 05/23/19 at 00:38:12

Wow thats a lot of room treatment. I found that the low end response was improved by removeing some of the treatments I had in corners. Sort of like when the phase is out vs in.
Steve

Title: Re: Too Many Diffusers?
Post by Palomino on 05/23/19 at 12:21:07

I found that to be true with absorbers but not with diffusers.

Title: Re: Too Many Diffusers?
Post by Lonely Raven on 07/07/19 at 03:04:20

I'm missing my diffusers - I'm kinda wishing I had them for the future house...I may need to make new ones from scratch!

Title: Re: Too Many Diffusers?
Post by Palomino on 12/11/20 at 22:31:23

I've built 3 different types of QRDs and found this on youtube:

https://www.youtube.com/watch?v=W3Wv9eB6wrg

If you have a nail gun, this looks easier than any of the others I've built. I'm going to build a couple QRD13s using this method.

I priced out the materials and think I can build a pair for less than $80.

Title: Re: Too Many Diffusers?
Post by JBzen on 12/12/20 at 14:05:44

Interesting video. His method of assembly is haphazard though. I used nail guns many many years building cabinets. Trying to judge the placement and holding a tool tethered with a hose placed on a point leads to blowouts when the trigger is pulled. It happens no matter how hard one try’s to avoid it even with a alignment mark.
John

Title: Re: Too Many Diffusers?
Post by Palomino on 12/12/20 at 17:13:48

Well, I’m going to give it a whirl. I am going to use clamps to hold the wood in place and turn the pressure on the gun way down. I cut wood this morning and out $40 if it goes bad.

Title: Re: Too Many Diffusers?
Post by Donnie on 12/12/20 at 17:53:38

I really need to build some of these.
Even though my room sounds Okay-ish, I figure that is just me being used to it.

The stupid winter weather is keeping me from building anything. I'm itching to build the next speakers, my mind is full of interesting ways to make all of these fancy cuts.

Title: Re: Too Many Diffusers?
Post by JBzen on 12/12/20 at 18:10:01

A dremel tool with a cut off disk will come in handy to cut the protruding nail points on a blowout. No matter how hard I tried it always seemed to happen sooner or later.

Title: Re: Too Many Diffusers?
Post by Palomino on 12/12/20 at 18:26:02

My issue is they go too deep. I have 1 1/2” staples that sometimes don’t go all the way in but the nails penetrate the underlayment nearly all the way. I do have dremel I can use if they don’t work.

Donnie, I’ll send you my spreadsheet with the dimensions, depths etc if you want to give it a try. I’m working in the garage today and it’s not too bad.

Also Donnie, I never was able to find someone with a CNC to cut to your specs on that drawing you sent me. If I ever do, that would be the ticket.

Title: Re: Too Many Diffusers?
Post by JBzen on 12/12/20 at 19:04:19

Well the staples can be set with a nail set but the nails can create a lot of frustration. The staples can play hell with the first laminate layer, lifting it with pressure under the crown. I think setting the air pressure to get most of the nails seated just under the surface is the best play. You can always go back a set the nails that are raised. Trail and error! Have fun.
John

Title: Re: Too Many Diffusers?
Post by Palomino on 12/13/20 at 14:21:41

Well I like this build but it’s not really any faster than other methods.

You have to be extremely precise in your cuts for every piece. I did a 48” X “24 diffuser meaning the sides, fins and faces had to be exactly 26.5”. Even if you are off by a 16th it can be trouble. With the routed groove for the fins method you at least have a little play.

Overall I ended up trimming most pieces just a hair to make sure they fit or could be placed. I had good luck with the Brad nailer with only one blowout.

I am filling the holes prior to painting. In terms of quality these are only second to the QRD13s I did in Baltic birch. Not bad for $40 and some of my time. I am going to build another so I have a matching pair. Sorry about the large image size. Not sure how to resize on my phone.

Title: Re: Too Many Diffusers?
Post by Donnie on 12/13/20 at 14:25:10

Fixed!

Title: Re: Too Many Diffusers?
Post by Donnie on 12/13/20 at 14:28:50

The only problem I ever have with these diffuser thingies is the prime number stuff.

One of my little OCD things is that I try to only use even numbers.

Yeah I know, weird, but it is my thing!

Title: Re: Too Many Diffusers?
Post by JBzen on 12/13/20 at 16:23:54

You must mean 46.5". I placed 8 of my 1312s on each first reflection point on the sides of the Chariot. Immediate benefit, vocals became more intimate.
I may use this process to build a movable panel covering the big screen. Looks to be light weight.
Good job Pal!
John

Title: Re: Too Many Diffusers?
Post by Palomino on 12/13/20 at 16:58:54

Thanks. Yeah 46.5” Don’t know why I typed 26.5.

Donnie the first well is flush so maybe you can get rid of it if it’s next to something. I the the acoustic fields diffusers are even number.

Looks like the other diffuser won’t get built today. My wife wants me to build a little house for the neighborhood stray. All the wood is cut at least.

Title: Re: Too Many Diffusers?
Post by Palomino on 01/07/21 at 22:31:31

I built the second one over the break. It went a lot faster. Get your fins a face pieces cut to the right length and it goes pretty quick.

I'd endorse this build method for cost and ease of build if you had a pneumatic nailer.

My only other caution is get the length of your top and bottom frame pieces correct. i actually screwed the top, bottom and one side of the frame together first, placed all the pieces in to figure out exactly how wide it needed to be and then trimmed the top and bottom pieces before I started nailing.

I calculated it based on the wood dimensions but with cheap lumber, you can have some variance. I didn't on the first one, but did on the second.

It's a bummer to get to the end and realize that you made the top and bottom too long/short so its not the right width.