1st REW Measurements KEF LS50 Wireless II with KC62 sub

[Ogoript]

Hello ASR -

I have been trying to figure out REW and finally made some measurements. I mostly read through posts and various YouTube videos.

Speaker settings are the default "expert" settings in the KEF app, Bass Extension Settings = "less"; Subwoofer Gain (-1.0); Sub High Pass 70.0Hz; Sub Low Pass 45Hz

The Raw Data file is liked below in Google Drive

I'm thinking of getting another KC62 sub at some point, but is there anything specific I should be tackling first by looking at these measurements? It doesn't sound bad in general and. the bass peak (Mode?) at 40Hz isn't bothering me.

raw data file from REW

 

[Matias]

I would reduce some 6-7 dBs that 42 Hz peak and that's it.

 

[Ogoript]

I would reduce some 6-7 dBs that 42 Hz peak and that's it.

Thanks for the reply That's it, just the 42Hz peak? Would it just be a PK filter in REW? I'll need to figure out how to create filters.

 

[Matias]

This is the best tutorial I know.

But instead of auto-fixing everything I would only fix the bass peak if I were you. It's what I do with mine too.

 

[Ogoript]

This is the best tutorial I know.

But instead of auto-fixing everything I would only fix the bass peak if I were you. It's what I do with mine too.

Thank you. I'll watch that and play around with REW a bit more. Is the 42Hz peak a room mode that might be calmed down with a 2nd sub or is that overkill?

 

[Matias]

Thank you. I'll watch that and play around with REW a bit more. Is the 42Hz peak a room mode that might be calmed down with a 2nd sub or is that overkill?

Not sure. I guess that it is a room mode is enhanced by the sub being closer to the walls, less by moving it into the room, but that is just guessing. You may try to move and measure though.

 

[Flaesh]

room mode that might be calmed down with a 2nd sub

How exactly?

 

[Ogoript]

I think I was asking the question as to IF a 2nd sub would calm it down. Not making a statement that it would.

 

[Flaesh]

IF

In special cases (DBA [CABS] or SSS) it calms very effectively. In general, no (or a little). That's why I asked.
I support the suggestion in #2 as the simplest solution.

 

[Ogoript]

In special cases (DBA [CABS] or SSS) it calms very effectively. In general, no (or a little). That's why I asked.
I support the suggestion in #2 as the simplest solution.

I will try to move th sub around the room and re-measure. It doesn’t sound too bad as is even with the room mode as it is.

 

[Flaesh]

It doesn’t sound too bad

I think so. But it may be better))
BTW IMO\IME adding some conventional room treatment will be usefull for MF\HF. Some 4" absorbers in its simplest form.

I will try to move th sub around the room and re-measure\

Don't forget to listen. Not all and not always [approximately] the same frequency response is heard the same way))

 

[kejar31]

So why are you setting a LP filter on a sub? do I understand you right in saying that the HP filter rolloff for the sub is 70 and LP rolloff is 45? my guess is that you dont have your timing aligned for your sub and those speakers causing a cancellation between your crossover point between the speakers and the sub.. Then when the cancellation ends your LP filter rollofff starts causing what looks like a peak.

I would remove the LP filter.. Then take a measurement (R+L) of your speakers without the sub followed up by taking a measurement of the sub alone.. use REW to cross correlate the sub measurement and the R+L measurement (ensuring the R+L is on top in the left tabs) then look at the delay you need to set on your sub by using the measurement info button on the sub measurement and referencing the "Cumulative IR Shift". This should help with your FL/FR integration with that sub..

 

[Ogoript]

The KEF app automatically sets a high pass and low pass based on the sub used (Kef Subs).

https://assets.kef.com/documents/ls50/LS50WII-Subwoofer-Setup.pdf

 

[kejar31]

The KEF app automatically sets a high pass and low pass based on the sub used (Kef Subs).

https://assets.kef.com/documents/ls50/LS50WII-Subwoofer-Setup.pdf

Ahh I see now.. thanks for the link.. Yeah I wold def raise that low pass filter up until maybe you close the gap a bit.. that app looks very limiting though. Can you change the high pass and low pass filter order? Can you set delays on the sub other than just invert it?

 

[kejar31]

Also, where have you placed the sub? is it up front near those speakers? Reason I ask is because it might help to try and invert the sub polarity and see if that helps too.