All rooms obviously act differently....I have a large window with an acoustic curtain to the whole length of the left hand side of the room, my image never moves its in the same position with the curtains open or not, the only thing mine does with the curtains fully closed is reduce the noise floor from outside, which does sound better overall, but the image dose not move, the signer is still in the centre regardless.

 

Its all good....within your budget/WAF installing treatment, speaker positioning, layout etc, to get your room to work better than it did, but there comes a time where enough is enough, especially if you can see a dip or problem on a certain frequency which was in the REW measurement/graphs etc, but cant hear the difference from the change once fixed on the graph, then what's the use....the time has come to just play your music & enjoy.

2 hours ago, Toeknee said:

I’ve thought about this a lot, having non parallel walls is occasionally mentioned by the experts as a positive move. My fear however is that I can’t create a trapagon, they’re too extreme in space wastage and I don’t have that luxury anyway.
So it would be a mild narrowing of the side walls which is experimental and therefore could be an expensive failure. 
Has anyone done this? 

 

@Grizaudio if you still have your EASE license, would you be able to throw up a quick simulation of these two rooms? Just model the high frequency reflections only, not room modes. Assume that the speaker is placed on the shortest wall in both cases. 

 

 

I have thought about designing a listening room similar to the trapezoid on the right. Theoretically the reflections should go away from the listening position, which will increase the path length and delay the reflections even more. 

 

Maybe i'll spend a bit of time in Sketchup and see what I get. 

 

I just drew it up on Sketchup. If we angle the walls as shown, the reflection is shifted by 46mm. For there to be significant delays in path length, the trapezoid would have to be far more aggressive than what I have drawn. Oh well. 

10 hours ago, Keith_W said:

 

Well, you and I both know the difference between an overtreated room and a lively room but with delayed reflections. From our discussions it does appear that you prefer a more damped room than I do. I think I mentioned somewhere in my first post that target RT60 is a matter of application and also taste. I tend to prefer about 450-500ms but with reflections delayed. Others may prefer less. 

 

Of course, everyone has a preference. 

But my example does show there are alternative ways to address reflections, which are also used by professional engineers, mixing your music.   

 

Typically, I enjoy a studio level RT60, which aims to maximise direct field energy and absorb primary reflected energy. 

Somewhere around 200-300ms for everything above Schroder. I think somewhere around 300ms is about ideal. 

 

Additionally, achieving a low RT60 is easier in a small room, and cheaper v's large.. Combine this approach with a nearfield seated position and you can easily maximise a direct to reflected energy ratio.   

 

For me, I enjoy the improvements in clarity, and feeling of immediate presence to the music.   

I don't typically like hearing the room, which is essentially just another form of distortion. 

 

This was my left channel RT60 

 

RT60 right 

 

As you can imagine the spectrogram is clean [No DSP applied]... 

 

Impulse becomes very clean 

1 hour ago, Keith_W said:

 

@Grizaudio if you still have your EASE license, would you be able to throw up a quick simulation of these two rooms? Just model the high frequency reflections only, not room modes. Assume that the speaker is placed on the shortest wall in both cases. 

 

 

I have thought about designing a listening room similar to the trapezoid on the right. Theoretically the reflections should go away from the listening position, which will increase the path length and delay the reflections even more. 

 

Maybe i'll spend a bit of time in Sketchup and see what I get. 

 

My opinion...

 

What is the point of designing a space, without modelling the actual speaker/subs in model? 

 

The directivity, bandwidth, position, etc of 'your' speaker setup will dictate in room energy / behaviour. 

 

Take directivity for instance, directivity will dictate where side/ceiling/floor primary reflections occur, and how much energy is being reflected. 

Without considering the speaker, you can't accurately predict, location, intensity, or timing of primary reflections. 

 

Edit.... Here's a basic example of two speakers which have varying directivity, covering the same area. 

They are both going to interact with the space - very differently. 

 

Speaker A - direct field in room - Speaker uses dual drivers and waveguide for directivity control 

High frequency 1/3 octave 8khz 

 

63hz 1/3 Octave 

 

 

Speaker B same space - direct energy. 

High frequency 1/3 octave 8khz 

 

63hz 1/3 octave 

 

Edited October 12, 2025Oct 12 by Grizaudio

Thanks for those sims, but both of them are free-field sims. Would you be able to put the speaker closer to the wall and model the reflections? And specify the dimensions of the room? 

1 hour ago, Keith_W said:

Thanks for those sims, but both of them are free-field sims. Would you be able to put the speaker closer to the wall and model the reflections? And specify the dimensions of the room? 

Not so easy buddy. 
you need to build the room, surfaces etc… 

 

The point I was trying to make is the speaker matters 

6 hours ago, Toeknee said:

I’ve thought about this a lot, having non parallel walls is occasionally mentioned by the experts as a positive move. My fear however is that I can’t create a trapagon, they’re too extreme in space wastage and I don’t have that luxury anyway.
So it would be a mild narrowing of the side walls which is experimental and therefore could be an expensive failure. 
Has anyone done this? 

In the early 90’s I got a small recording studio built within a rehearsal  complex ,a friend of a friend did the mixing room , he said at the end ,it’s very neat but partly because of enchantment medication the angles were not good ,but would help with acoustics ,which it did ,

I think any relatively small deviation would be better than none , if practical ,to modify after a build may be cheaper , there are so many products out now , it is easy to cover a wall to reflect haphazardly like a diffuser ,maybe not perfect but   pleasing to the eye , like this product below 

 

Edited October 12, 2025Oct 12 by colinm1

2 hours ago, Keith_W said:

Thanks for those sims, but both of them are free-field sims. Would you be able to put the speaker closer to the wall and model the reflections? And specify the dimensions of the room? 

 

Knock yourself out.