1st REW SubWoofer measurements

Pogre

Pogre

Audioholic Warlord
Looks good, that null at 45~46hz probably cannot be fixed even with the miniDSP or correction though, that's likely the room itself, you'd have to move the speakers physically to correct/improve that I think? The big mode next to it is nearly 12db delta followed by a pretty significant null. Granted, I imagine your subs cover that up so it doesn't matter likely. Still learning.

Very best,
Yes, it's a very stubborn, hard to fix null. The first chart I posted in this thread shows what I can achieve with a mini and subs in the mix tho. Right now +/- 1.5 dB from 100 hz down to about 15 hz. The null is still there with the subs too, but between the 2 of them I can smooth it out without having to get ridiculous with PEQ.

I tried the mini on the towers by themselves before and I think I remember being able to make it work with them too, but with probably too much eq so I switched the mini back to my subs. I actually emailed back and forth with Ed Mullen at SVS with some questions and I did a bunch of measurements for him. Here's a short thread about it.

 
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PG55

Audioholic Intern
Do you have a MiniDSP also, or are you using room correction and positional eq? No sub in the mix?
Hello,

Here are my measurements using Flex ASIO. Room is 20 feet long by 20 feet wide opening into the kitchen with vaulted 12-14 foot ceilings. All measurements are of both front and rear sub together taken with a Mic stand at a 40 inch height which is 4 inches above the couch back.

I am not sure what this is telling me? At 114 inches from the front wall there is minimum cancellation and as I go further to the back wall to 171 inches it is a big dip. My couch back is about 150 inches from the front wall and MLP is 146 inches from front wall. Seems the closer I get to the back wall and rear sub the dip is more pronounced?

Tomorrow I will be moving the subs to see if I can get better frequency at the MLP unless there are better suggestions.

Thanks,
 

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MalVeauX

MalVeauX

Audioholic
Hello,

Here are my measurements using Flex ASIO. Room is 20 feet long by 20 feet wide opening into the kitchen with vaulted 12-14 foot ceilings. All measurements are of both front and rear sub together taken with a Mic stand at a 40 inch height which is 4 inches above the couch back.

I am not sure what this is telling me? At 114 inches from the front wall there is minimum cancellation and as I go further to the back wall to 171 inches it is a big dip. My couch back is about 150 inches from the front wall and MLP is 146 inches from front wall. Seems the closer I get to the back wall and rear sub the dip is more pronounced?

Tomorrow I will be moving the subs to see if I can get better frequency at the MLP unless there are better suggestions.

Thanks,
Heya,

Your 2nd placement looks like it was the best of the four your recorded.

Your 114" placement has a trough at 30hz, but two nulls at 60hz and 75hz, that's significant.

Your 153" placement has two very large nulls at 40hz & 60hz, not good.

Your 171" placement has a big rowdy null at 37hz.

Your 137" placement only has a minor null at 60hz.

If you look at 114 then 137 then 153, the same 60hz null is happening. It's at the 171" position that the 60hz null is not captured. Try your 114" placement, but move the sub a little to the sides (off center a touch) rather than farther back/forward to the MLP/wall. You might find that null moving off your frequency response.

That 114" placement response curve would be a good flat curve with a gentle EQ and while it has a 60hz null, it's a small null, and if you had a 2nd sub you could make up for it with a 2nd placement. Otherwise, move the sub just a few inches in the other directions you have not moved it to see if that null moves. The rest of the curve is good.

Very best,
 
P

PG55

Audioholic Intern
Oops I missed the s "All measurements are of both front and rear subs together" in sub. The measurements are with both subs together. One in front middle wall and one in rear middle wall. Also to be clear and give you all the info the distances are where I was placing the mic. I haven't started moving the subs yet. MLP is at 146 inches.
 
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PENG

Audioholic Slumlord
It's a Yamaha, nothing special, 100wpc 8ohm at 2 channel. In the living room we don't have a surround, it's just for TV, games and some movies (kids mostly). Nothing serious in there. But I like to use it for measuring because its a complex room, a living room, with a family, not a dedicated room. I'm soon to build a house and will gain a dedicated larger room, so practicing on learning how to measure, interpret and treat or correct so that I can get the most out of things. The mains on that living room setup are some 15 year old Monitor 70 II's, inexpensive, but sound good when placed and corrected.

With multiple subs, its eye opening to measure. Something the room correction softwares on the AVRs don't seem to do well enough.

My primary listening room (music) currently is a 2 channel setup without an AVR, just stereo integrated amp with bookshelves and I do run a sub with those. Some old Monitor 30 II's and a PSW505, again, nothing special at all, stuff I got 15 years ago before kids. I had a lot of fun measuring that system and manually tweaking everything and blending since it has no processor doing any of that.

View attachment 37009

Very best,
Flat? I don't know, may be, but would need to see no smoothing and vertical scale with minimum 50 or higher and maximum 95 or lower. Your -20 to 140 does not do justice at all, especially when combined with 1/6 smoothing.
 
MalVeauX

MalVeauX

Audioholic
Oops I missed the s "All measurements are of both front and rear subs together" in sub. The measurements are with both subs together. One in front middle wall and one in rear middle wall. Also to be clear and give you all the info the distances are where I was placing the mic. I haven't started moving the subs yet. MLP is at 146 inches.
In that case, same thing, your 2nd graph (137") has only 1 minor null at 60hz. Move one sub an inch at a time in whatever direction and re-measure. Map it out like a cardinal direction clock with the two subs moving just a little bit at a time and see where that 60hz null moves to or if it goes away. Once you get it covered in the measurement, it's done and you found a good placement with no major nulls and no major modes to correct for.

Very best,
 
William Lemmerhirt

William Lemmerhirt

Audioholic Spartan
Flat? I don't know, may be, but would need to see no smoothing and vertical scale with minimum 50 or higher and maximum 95 or lower. Your -20 to 140 does not do justice at all, especially when combined with 1/6 smoothing.
Exactly.
The window should be 45-105. Or a 60db window, however it fits.
 
Pogre

Pogre

Audioholic Warlord
Flat? I don't know, may be, but would need to see no smoothing and vertical scale with minimum 50 or higher and maximum 95 or lower. Your -20 to 140 does not do justice at all, especially when combined with 1/6 smoothing.
Agreed. I suspect that flat sweep isn't so flat with proper scaling and no smoothing.
 
Pogre

Pogre

Audioholic Warlord
Hello,

Here are my measurements using Flex ASIO. Room is 20 feet long by 20 feet wide opening into the kitchen with vaulted 12-14 foot ceilings. All measurements are of both front and rear sub together taken with a Mic stand at a 40 inch height which is 4 inches above the couch back.

I am not sure what this is telling me? At 114 inches from the front wall there is minimum cancellation and as I go further to the back wall to 171 inches it is a big dip. My couch back is about 150 inches from the front wall and MLP is 146 inches from front wall. Seems the closer I get to the back wall and rear sub the dip is more pronounced?

Tomorrow I will be moving the subs to see if I can get better frequency at the MLP unless there are better suggestions.

Thanks,
I'm not sure why you're taking measurements so far apart, but you have a couple of good sweeps in the bunch there. Are you finding a "best spot" for your mlp? 114 to 137 looks pretty darn good. As far as the dips becoming more pronounced in some spots those are just room modes. You'll see anomalies like that in almost every room.
 
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PG55

Audioholic Intern
Asio allows me to access all the speakers from REW and actually FlexAsio was a breeze too set up. ASIO4ALL was a nightmare. I wanted to see what happenned to the big dip at different distances from the front wall. Unfortunately due to WAF I am stuck with the MLP at 12 feet from the front wall with a little bit of leeway side to side. I am finding a best spot for my two Millenia subs which are currently placed at the center of the front and rear wall. They are wireless so I have several options. I am going to start moving them later today.
 
William Lemmerhirt

William Lemmerhirt

Audioholic Spartan
Have you tried switching the phase on the rear sub? FWIW, the 37hz dip looks like a phase thing.

Might not worry about it but it’s pretty wide. At least to my eye. Like 32-42hz.
 
Pogre

Pogre

Audioholic Warlord
Asio allows me to access all the speakers from REW and actually FlexAsio was a breeze too set up. ASIO4ALL was a nightmare. I wanted to see what happenned to the big dip at different distances from the front wall. Unfortunately due to WAF I am stuck with the MLP at 12 feet from the front wall with a little bit of leeway side to side. I am finding a best spot for my two Millenia subs which are currently placed at the center of the front and rear wall. They are wireless so I have several options. I am going to start moving them later today.
Sounds like you're on the right track. Room and sub placement are so important and you seem to understand that. Good work!
 
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PG55

Audioholic Intern
Sounds like you're on the right track. Room and sub placement are so important and you seem to understand that. Good work!
I moved the front sub in inches to the right and as I moved it the dips seem to disappear. The 3 and 4 inches to the right look pretty good to my inexperienced eye. Am I reading it correctly?

PG55
 

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Pogre

Pogre

Audioholic Warlord
I moved the front sub in inches to the right and as I moved it the dips seem to disappear. The 3 and 4 inches to the right look pretty good to my inexperienced eye. Am I reading it correctly?

PG55
It does look like a slight improvement. Maybe even an audible one. Your dips in the first one are pretty narrow tho and might even disappear with a little smoothing. Have you done any eq or run room correction of any kind or are you getting there with placement alone? If that's what you're getting with positional eq only you should be able to dial in a really nice smooth response without a lot of eq.
 
William Lemmerhirt

William Lemmerhirt

Audioholic Spartan
Would it be super hard to corner load in opposite corners and measure(audyssey off)?
The thing I don’t like is the graphs are centered at 60hz. Then roll off towards 20hz.
Also, how about a deep with the center or mains with subs?
 
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PG55

Audioholic Intern
@Pogre-1st one referring to the 3 inch movement?
@ William-Unfortunately I can't do corners.

This was done without Audyssey correction
 
William Lemmerhirt

William Lemmerhirt

Audioholic Spartan
Ok. Did you do any phase adjustments to the back sub?
 
Pogre

Pogre

Audioholic Warlord
Yes see photos-Thanks!
Boy, 180 sure is ugly, lol.

@Pogre-1st one referring to the 3 inch movement?

This was done without Audyssey correction
1st one referring to the original position. You gained a little moving but I'll bet those dips are way less pronounced in the original spot with a touch of smoothing, so not sure if they were all that audible to begin with. A little bit of smoothing is okay and I think a little closer to what we actually hear. I don't use smoothing at all when I eq, but when I get it as good as I can I'll apply 1/12 smoothing for a "final" chart.

With no room correction or PEQ adjustments that's a great start.
The thing I don’t like is the graphs are centered at 60hz. Then roll off towards 20hz.
By this you mean the graphs peak at 60 hz then start rolling off early, robbing it of some deep bass extension?
Also, how about a deep with the center or mains with subs?
What?? Do you mean "sweep"?
 

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