Diffuser for Front Wall

[Walnut Horns]

Since it’s a dedicated room, I can shift the speakers to the left a couple of feet, which should mitigate any issues with the right corner, though I will still add a bass traps there.

I’m hoping to keep the speakers at least two feet off the wall, but still need to experiment.

 

[Gunnar]

I am not an expert on acoustic but having a professional company measuring my room thought me a lot.one thing I took with me from them is as lower the frequencies the loudspeakers go the more important is treating the bass in the corners. My conclusion would be, if your loudspeakers goes down to 20 hz as mine, you will need a few absorbers and high up. One absorber might not be enough. See my photo. Alternative something from PSI AVAA. But another budget

 

[Maxim]

Seeking recommendations for the best type and manufacturer of diffuser for the front wall where the rear of the speaker is approximately 12”-18” from the wall. Thanks!

You will get different advises like you need tuned bass traps, or absorbers or diffusion or change speakers position or ....

The truth is that you need all of them, but first you need acoustic project for your room.

You need to study your room and only after exact understanding what happens there you may take right decision - what kind of panels you need and what are exact amounts, acoustic specifications and exact locations for each panel.

You need a matching set of different panels to match your room to get the best of it: good RT60 with right ratio of absorption/diffusion to make the sound natural.

 

[Gunnar]

You will get different advises like you need tuned bass traps, or absorbers or diffusion or change speakers position or ....

The truth is that you need all of them, but first you need acoustic project for your room.

You need to study your room and only after exact understanding what happens there you may take right decision - what kind of panels you need and what are exact amounts, acoustic specifications and exact locations for each panel.

You need a matching set of different panels to match your room to get the best of it: good RT60 with right ratio of absorption/diffusion to make the sound natural.

I agree. Myself, I bought the Omni microphone downloaded the REL software ….. and “concluded”my technical skill was not good enough to get the room measured by myself. So got home a professional company. Worked well. But if you don’t have the skill or the equipment to measure yourself I think you should start working with the low frequencies. For sure measuring the room prior starting is the top.

 

[Tangram]

My personal experience is that it is very hard to tame bass if you don't have the right room. My solution was changing my speakers to open baffles. Ported box speakers consistently overloaded the room, regardless of their size.

 

[Walnut Horns]

I’m not having bass issues. I moved from rear ported speakers to front ported transmission line speakers that allow for much easier placement. I also moved the speakers to the long wall so that they would have a solid wall behind them that not only improved the bass performance but essentially eliminated side wall reflections as well.

 

[Iamrael]

Acoustical Treatments Master Thread

OK, this seems straightforward from searching AVS and studying theater wall treatment... FRONT WALL: Acoustical treatment (1" Insul-Shield) floor-to-ceiling. CEILING: No acoustical treatment - none, nada. FLOOR: Thick, plush carpet is fine. But here's where it gets confusing, and I need...

www.avsforum.com

This is a link to thread on AVS that has a lot of good information/ideas.

 

[Maxim]

I’m not having bass issues. I moved from rear ported speakers to front ported transmission line speakers that allow for much easier placement. I also moved the speakers to the long wall so that they would have a solid wall behind them that not only improved the bass performance but essentially eliminated side wall reflections as well.

The diffusors work on different frequencies - for example, some may work with max efficiency on 1200-2500Hz. If your room rings on that frequency (what is very common) you will get extra decay in a the area where you do not need. This may result worse sound.
If your speakers are not perfectly flat and have slightly increased response in same region where your room rings, the result will be worse.

You may think that you do not have problems with bass, but 2nd, 3rd harmonics go into midrange and may ring there. If your room rings on that frequencies you will have summ of room modes with 2nd 3rd harmonics caused by bass. You need to find your room modes and see what happens there. Once you remove problems there, your midrange will opens.

To get a good sound you need to understand what is your room acoustics and what is your speakers do.
And only after you have full picture you can select matching diffusers and absorbers and bass traps.

 

[DHT4ME]

I bought several types and tried different distribution scenarios. I have skylines, QRD's, abfusors and ceiling traps.
The best setup was when I put the abfusors directly behind the speakers. in the center I got slightly better soundstage from the skylines. Outer areas did not seem to be very picky what was there.

 

[TooCool4]

I might be mistaken, but I’ve always understood that what really matters is the distance between your listening position and the quadratic diffusers not the distance between the speakers and the diffusers. The key is that the wavelength needs enough space to fully develop before it reaches your ears.

Before spending money on treating your room, I’d suggest checking out and experimenting with the information in this link first. Room Coupling Method. It won’t cost you anything but your time.

 

[DHT4ME]

I might be mistaken, but I’ve always understood that what really matters is the distance between your listening position and the quadratic diffusers not the distance between the speakers and the diffusers. The key is that the wavelength needs enough space to fully develop before it reaches your ears.

Before spending money on treating your room, I’d suggest checking out and experimenting with the information in this link first. Room Coupling Method. It won’t cost you anything but your time.

The frequencies that a QRD is operating at have much smaller wavelengths than the typical listening distance to speaker or first reflection point. The frequencies that would be involved with QRD's or skylines are fairly high. For instance a 500hz signal would be at the bottom range for a large skyline or QRD and that wavelength is about 28".

 

[TooCool4]

DHT4ME, depends on how deep the QRD's are.

 

[DHT4ME]

DHT4ME, depends on how deep the QRD's are.

They would have to be 4 to 5 ft deep (completely impossible for someone who is talking about speakers that are under 2 ft from the wall) to even begin to have a full wavelength effect with a 10 ft listening distance and a speaker 2 to 3 ft from the back wall.

 

[MarkusBarkus]

...things are happening at the speed of sound, so the few-inch difference in depth of the chambers, if you're a couple of feet away, never really manifest as intended, insomuch as our ears can discern. That is my understanding of that math, FWIW.

 

[TooCool4]

DHT4ME, yes that is true but what I am saying is still correct depends on the depth of the QRD. A 4 ft deep QRD would be about 141 hz which would be about 8 ft in length.
Saying the frequencies a QRD works is about 28", the frequency a QRD works at is dependent on the its depth. So in the OP's case any QRD he puts in the space behind his speakers will be fine as the wave will be fully formed by the time it get's to him. In this case the OP cannot put anything really deep there, so I think he is safe.