Sweet Room

[PeppaPig]

I found this thing is difficult to use without professional knowledge.

It does require a lot of knowledge, enthusiastic amateur level for sure. Most DSP has the ability to make things much worse, there is nothing in what they have given us to stop you doing this, you really are on your own, here are the rules I've been following.

1) Based on measurements made at the listening position limit corrections you make to below 500Hz. If your room is large use a lower frequency.

2) Only make adjustments above the cut off freq in 1) based on anechoic measurements, and these should probably only be broad (low Q) tonal shifts.

3) Make extensive use of the ability to switch between the 2 configs whilst listening, find a minimal set of filters that do seem to address the worse problems, then explore adding other 'fixes' on top of them driven by what you prefer. The instant switching between the 2 filter banks is the killer feature of SR, most other approaches (e.g. Roon) take a second or so to switch, which is hard for the brain to follow, so make good use of this, and let your preference decide which is best, but don't rush the decision.

Thanks.

I just removed the eq.txt because I feel it make sound worse, may be need to learn more about it before enabling it in my system. I am not too sure what kind of Q value I should use too, I just put value like 20, 10, 4. It looks like the smaller the value the larger range of frequency is applied to, which higher the value the narrow range is adjusted.

And I usually don’t sit on the same position to listen, most of the time I play music and I walk around my house. And I found different position of the Mic returns very different measurement results. So I am still not sure how to use this feature in my situation, because I don’t want to optimise it only for a fixed listening location.

[Confused]

If anyone has some spare time during lockdown, this is a link to Austin Jerry's REW "Getting Started" guide. It is 131 pages and far more extensive than it's "Getting Started" title might imply.

https://www.dropbox.com/s/51jpnxet3bvew2...n.pdf?dl=0

[David A]

@PeppaPig ,

What Sweet Room and similar systems like Dirac are designed to do is to compensate for the effects that the room has on the sound. At low frequencies those effects are due to room modes at frequencies related to the dimensions of the room. The effect of those modes on the frequency response you hear depends on where in the room you are, or where you place the mic to make your measurements. There will be some places in the room where you will get strong peaks at the modal frequency, other places where you will get a strong null, and other places where the effect is somewhere in between those 2 extremes. The corrections you make are based on the measurements at a particular point in the room and they aren't valid for other points in the room. You can't make a correction that will work for the whole room because if the same room mode causes a peak in one location and a null in another then you would need a cut in level to fix the peak and a boost in level to fix the null. Sweet Room will let you apply a cut or a boost but not both at a given frequency and it can'd do anything which will create a cut at one point in the room to fix a peak while also creating a boost in other parts of the room to fix a null. All you can do is to correct for the effects of the room at the point where you make your measurements.

When it comes to walking around the house, once you leave the room where the system is and walk into another room you've walked into a space with an entirely different set of acoustic issues because the dimensions of the new space are going to be different and also because the sound source, your speakers, are in a different position relative to the new room than they are in relation to the listening room.

You may not want to optimise for a fixed listening position but you really can only optimise for a fixed listening position. You can make the position you optimise for a little larger by making measurements over a slightly larger area, say within a 2 or 3 foot radius of a central point, but the result of that will be a little worse for the actual point of the listening position and a little better for the small surrounding area that you also measured. The bigger the area you try to fix, the more inaccurate the correction will become for the fixed listening position so the bigger the area you try to fix, the less effective the correction becomes for the fixed listening point and the less effective it becomes over most of the larger area.

There simply is no single correction profile that will work well everywhere if you want to have equally good results while you're walking around your house, or even around the room in which the speakers are located. You're trying to achieve something which is impossible.

[Randy Christie]

Thank you for your post David A. It helped me settle on may next step. I have been considering room correction, ether sweet room or Roon's room correction for some time.
As a person how seldom sits in one sport and listens, your comments interested me greatly and I will now stop thinking about room correction and focus my next interest optical isolation.

for the record my system is a Devialet 220 Pro CI / Magico S1's with DIY subs / Sonore i7 streamer

Randy C.

[markush]

The new UMIK-2 microphone and REW should be good solution.
Maybe someone is updating a step by step recommended process for it & Sweet Room.

[bernardl]

It would be sweet to have an amp able to locate the position of the listener and to dynamically tune room correction based on this location.

It needs face recognition obviously... I wouldn’t want it to optimize for my wife.

Cheers,
Bernard

[Axel]

I quite like the Trueplay function on Sonos products. You use your tablet/phone as the microphone and walk round the room wafting it in front of you, into the corners and covering all of the room in the time allowed, waving it high and low. Sonos then recognises any room modes etc. and tailors the sound output to suit. I use it on my Play 5 stereo pair in the bedroom and it works really well.
I think the Devialet internals are much more sophisticated than the Sonos, so I wonder whether Devialet could implement a similar system?

[David A]

It would be sweet to have an amp able to locate the position of the listener and to dynamically tune room correction based on this location.

It needs face recognition obviously... I wouldn’t want it to optimize for my wife.

Cheers,
Bernard

I know that suggestion is made in jest. I just spend some time working out just what would be required for such a system, especially given that it would have to deal with rooms of all shapes and sizes, with flat or sloping ceilings, with doorways that could be closed and with openings to other spaces that could not be closed, and also with the location and nature of the furnishings, both soft and hard, within the room plus a variable number of listeners in various locations.

What I decided would be a sweeter idea, and much more practical, would be one which could work out where I am, make a cup of espresso, and deliver it to me at my location without spilling a drop. I think Devialet might be able to come up with a system to do that a lot quicker than they could come up with a system to do what you suggest and, in any event, I'd rather have the espresso than electronic room correction.   

[ICUDoc]

I'd rather have the espresso than electronic room correction.   

But DavidA: what if you could have BOTH?

[Confused]

It would be sweet to have an amp able to locate the position of the listener and to dynamically tune room correction based on this location.

It needs face recognition obviously... I wouldn’t want it to optimize for my wife.

Cheers,
Bernard

Wireless headphones ....