# My First REW Sub Calibration



## Cowboydude99 (Apr 9, 2015)

http://postimg.org/image/9yen83or9/








Hi all,
This is my first attempt using REW. I believe I have calibrated it properly and I'm using the UMIK-1 with the 90 degree calibration file. I'm not 100% sure if this is the right one to use.

Please see attached image. Not sure why at 80hz the db are so low.

Any advise?


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## fusseli (May 1, 2007)

Welcome to HTS!

Overall does your bass sound full and adequate to you? Look up "loudness curves," your sweep looks about right.

BTW, you can attach images directly to your posts after you exceed five posts. Post padding


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## Cowboydude99 (Apr 9, 2015)

Sounds good for movies. When playing the sweeps it seems dead at around 80hz.


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## willis7469 (Jan 31, 2014)

I'm gonna take a complete shot in the dark. It looks like your crossover is set at 60hz. It would be helpful to see a sweep of your mains too. Try it at 80. I would also guess it sounds unbalanced, even with movies, since both sides of 60 taper off. Id would try moving the sub around and remeasuring. Tell us about your setup a little more. That way someone smarter n me can help too.


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## Cowboydude99 (Apr 9, 2015)

Hi and thanks. 

Crossover is set to 80hz. 

I'll try to figure out how to measure the two mains plus the sub. 

What other info would be helpful?

I'm guessing 80hz should be around 75db.


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## willis7469 (Jan 31, 2014)

Ok. Yeah I would expect it to be around 75 too. Well, info like type of sub, and placement etc. is there any chance you have the crossover on the sub enabled? (I'm just assuming you're using the AVR for bass management) For graphs, I think you'll take measurements separately and use the overlays tab to merge them. Or set your sweep to go from 10-20k. Or full range iow. Not sure the best way. I'm a little bit of an rew noob. It's far more granular than my brain...lol


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## Cowboydude99 (Apr 9, 2015)

My Setup:

Pioneer SC-1523-K
Polk RTi8 Fronts
Polk CSi6 Center
Polk Monitor 30 Rear (mounted on the sides)
PSA XS15se (30 day trial)

Room - (See images below)
The gray boxes are the other places I've tested the sub.
The ceiling starts at 8' on the left side and rises to about 10' to 75% of the room, then the last 25% drops again to 8'. hard to show...

I have setup my Windows 7 media center using HDMI and USB UMIK-1. I can take the measurements, as you can see I posted 1 above. I will buy a 20' sub cable today for testing it on the other side of the room.

The room is a converted garage. It is a ceramic tiled floor on a slab, elevated about 1'. I tried running the tests using the foam inserts as a sub riser (Tom's suggestion from PSA).

AVR Settings:
Speakers set to small.
Sub crossover 80hz.
I turned off all THX settings.
I am testing with "Direct" which does utilize the MCACC settings.
I have already run the MCACC prior to using REW.
Channel levels are already set.
Distance/Delay is already set.

My REW Measure Settings:
SPL Window: SPL , C , S
5hz - 150hz :: -12dB :: 512k :: 2 sweeps

The MIC is placed at my MLP. It is straight forward. I have used both the specific (serial number) calibration files, standard and 90degree.

When running the sweeps, I can hear the sub kick in and then almost go silent when the meter reads 40hz. What doesn't make sense to me is that my test was to 150hz, but the frequency meter shows 300hz at the end.... so I'm taking that 40hz to mean 80hz on the chart, which is where I hear it go silent for a second.

Ambient room noise/floor was around 56dB.

80hz = 68dB
60hz = a rise to 81dB
40hz = seems normal
30hz = another drop
20hz = rises again...

The only other place I can move the sub to is at the lower left corner of the room. It is the only place with power. I may be able to also test using the top left corner, but will have to run an 8' power cord.

Any suggestions? Should I be testing using different settings?


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## Cowboydude99 (Apr 9, 2015)

Also, does it matter what sub cables I use?


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## willis7469 (Jan 31, 2014)

Well, tom is a smart cookie. Did he have any ideas? Cables shouldn't matter for testing, but using direct mode in avr's with audyssey bypasses audyssey. I think my pioneer works that way too. I'll check. If that's true, and the bump at 60 is related to placement, but mcacc is bypassed by direct mode. Even if mcacc EQ'd it down, it wouldn't matter. My gut says placement is gonna go the farthest, then mcacc can clean up. Id surely be hitting up Tom. You have nice gear. Once you get it dialed, it's gonna be awesome.


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## Cowboydude99 (Apr 9, 2015)

Latest graphs - how is it looking? Any suggestions?


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## muzz (Nov 30, 2006)

Not entirely sure what these are, except the last 1 is the sub.
If you haven't tried it yet, it looks like the distance setting of the sub could possibly help that deep dip ~ 80hz.


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## Cowboydude99 (Apr 9, 2015)

Sorry, I didn't realize the name of the file doesn't show...

It was:
Left
Right
Center
Sub
Sub Waterfall

The delay on the sub is already set. The MCACC EQ asks to set so that it sound like it is coming from between the left and sub.

Between the left and sub, is my center channel. So I have the delay/distance set so that it sounds like it is coming from the center channel.


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## muzz (Nov 30, 2006)

Cowboydude99 said:


> Sorry, I didn't realize the name of the file doesn't show...
> 
> It was:
> Left
> ...


OK
Regardless of what MCACC wants/adjusts, adjusting the subwoofer distance manually has been proven to sometimes help get rid of dips at the crossover, by folks that are far smarter than me!
I had a dip at 80(that's where I cross as well), and I went up and down in distance until the dip went away, which just happened to be ~ 1' less than what was set by Audyssey.
Didn't take long at all with Rew, so I figured it was worth it to me.

Not sure what the sub sounding like it's between the left/right speaker is, is that how they explain it in MCACC?

Thanks


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## Cowboydude99 (Apr 9, 2015)

muzz said:


> OK
> Regardless of what MCACC wants/adjusts, adjusting the subwoofer distance manually has been proven to sometimes help get rid of dips at the crossover, by folks that are far smarter than me!
> I had a dip at 80(that's where I cross as well), and I went up and down in distance until the dip went away, which just happened to be ~ 1' less than what was set by Audyssey.
> Didn't take long at all with Rew, so I figured it was worth it to me.
> ...


Yeah, in MCACC when setting distance it tells you to adjust the distance of the sub until you hear the sound between the two speakers. Which for me is sounding like it comes from the center speaker.

I tried the distance tweaks, but I tried at 1' intervals. It is not going anywhere... I can try a few inches and see what happens.


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## willis7469 (Jan 31, 2014)

Try adjusting the phase in the sub.


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## Cowboydude99 (Apr 9, 2015)

willis7469 said:


> Try adjusting the phase in the sub.


From what I understand the phase shouldn't come into play, unless I'm testing multiple speakers at the same time.


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## willis7469 (Jan 31, 2014)

Yep. Your right. I had somehow thought you were. Note to self. Think before hitting send lol.


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## Cowboydude99 (Apr 9, 2015)

Here is a look at a few graphs...


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## muzz (Nov 30, 2006)

I measured with L/R/Sub, that's where I could actually see the dip, and then changed the distance to get rid of it.


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