How to approach SUB + L/R measurement?

[Mehdiem]

Hi, I’m a newbie to REW. I have some confusion about sub measurement as follows:

- When I perform the measurement of L+R should I keep my sub on or off?
- if I should keep it on, what should I set the sub volume and crossover to?
- If I should turn off the sub and measure it separately (with L+R off) what should I set the sub volume and crossover to?

 

[JStewart]

Hi, I’m a newbie to REW. I have some confusion about sub measurement as follows:

- When I perform the measurement of L+R should I keep my sub on or off?
- if I should keep it on, what should I set the sub volume and crossover to?
- If I should turn off the sub and measure it separately (with L+R off) what should I set the sub volume and crossover to?

Assuming you are wanting to alignment subs to mains, then you want to first be sure to understand how to measure with a timing reference.

Making Measurements

Starting with your 2nd question, aligning the subs to mains may produce different results for different XOs, therefore the XO must be set and used for the subs and mains to produce a measurement set to use for alignment. Different measurement sets with differing XOs can be checked if desired.

For your first question see here:

Regarding multi-sub alignment, sub to main alignment and EQ set up

Hi, Just want to get a few things clear regarding multi-sub alignment, sub to main alignment and EQ set up. I been using REW a few time and know the software I believe quite good, but don’t always know how to set up measurements or how to do the analyses. Just did some playing around a few...

www.avnirvana.com

For the 3rd question the short answer is REW’s alignment tool will help see the relative levels, but final level is adjusted to individual taste.
As a starting point, if you’re using an AVR, I’d recommend the trim level of the sub be -5 dB (or so) in the AVR and the gain on the subs amp be used to adjust the sub output so listening to music sounds balanced to you. This has nothing to do with alignment, but has to do with leaving some digital headroom for the subs (help reduce potential for digital clipping).

 

[DanDan]

Sub On. Do L+Sub R+Sub L+R+Sub

 

[Mehdiem]

Sub On. Do L+Sub R+Sub L+R+Sub

I don't see the +SUB option. I use RME-ADI2 as my preamp and this is what I connected to REW (only L &R output to my amp).

Anyways, I made a measurement (with my SUB on at a balanced level - how I usually listen to my music). Please see the result as attached. I am very confused about how to generate an EQ. In particular, I have the following questions:

1- What should be the LF Cutoff under the Target setting? (speakers KEF LS50, SUB KEF Q400)
2- I use RME as my EQ. It gives me a 5 (+2 T/B) option. How can I generate a 7-line EQ (5+2) to be able to implement it with RME? When I use Generic EQ option, the result is a 5 line EQ as opposed to 7 line EQ. I need 7 line.
3- In one EQ generated, recommended gain for 20 Frequency is -33.6. This is too much, it doesn't make sense. Why did this happen and how can I fix it>

 

[dotnet]

Sub On. Do L+Sub R+Sub L+R+Sub

That’s for EQ, right? I believe for subwoofer alignment the speakers (L, R and Sub) need to be measured separately.

I don't see the +SUB option.

How exactly you do it depends a bit on how you’re cabled up. In my case (2-channel system, with subwoofer connected to both L and R output of the pre-amp) I measure like this:

• L: turn sub off, measure L in REW using L as timing ref
• R: turn sub off, measure R in REW using L as timing ref
• Sub: turn sub on, disconnect R speaker, measure R in REW using L as timing ref
• L+Sub: turn sub on, measure L in REW using L as timing ref
• R+Sub: turn sub on, measure R in REW using L as timing ref
• L+R+Sub: turn sub on, measure L+R in REW using L as timing ref

If your subwoofer is connected via a single cable you have to make sure it’s connected to the right pre-amp output during L+Sub and R+Sub measurements. Take care when you disconnect a speaker, don’t short your amp. Keep the amp and subwoofer switched off during all cabling changes.

 

[Mehdiem]

Hello, I took amok measurement, I would appreciate it if you could guide me through generation of EQ.

My gears are as follows:
- Speakers: KEF LS50 Original
- Sub: SVS Micro 1000 (with Param EQ)
- Pre-amp/DAC for EQ: RME ADI-2

My setup: Streamer-> RME DAC/EQ ->AMP (NAD C209) -> L&R output to Speakers and L&R RCA output to SVS SUB

I took measurement as follows:
(1) L (2) R (3) R+L
(4) L+Sub (5) R+Sub (6) L+R+ SUB (without internal sub EQ)
(6) L+Sub (5) R+Sub (6) L+R+ SUB (with sub internal EQeed as I would regularly listen to)
(7) Sub without EQ
(8) Sub EQeed


I have a few confusion regarding how to generate EQ as follows:

1- RME has a 5 line parametric EQ, plus 1 bass and 1 treble. RME does not allow me to go bellow 12 for gain change. So I need to create an EQ that doesn't fall bellow RME's limit. I don't how to set limit for REW to generate EQs that fall within RME range?

2- When I use generic eq on REW there are many lines, how can I limit REW lines to 5 line plus 1 for base and 1 for treble?

3- Which of the above mentioned mreasuet should I use to generate EQ (i.e. R+L or any other combination with SUB) Please note that I can EQ the sub separately, however, the signal to going my sub would be from my amp (so it's been already impacted by EQ on RME)

Note: I would like to set Harman Curve as a set target.

I post my measurements here. I would greatly appreciate it if you can take a look and help. @jv