# REW 5.1 with UMIK Mic - First Measurements



## JimmyLeggs (Jul 28, 2012)

Room is 22*13
Subwoofers are 4x Sealed SI 18" D2 
I have two placed in the front of the room and 2 placed in the rear.
The only EQ I am using is on my AVR - XT32 

I am getting a weird hump near the crossover (80hz)
I had the same problem with only 2 of the subs and an Anthem MRX 300. The placement was completely different but the seating was +/- 5ft of where I am sitting now. 

Is this an EQ issue or more of an absorption issue.

At the moment there is NO absorbing panels in the room whatsoever.

Are the subs overpowering the mains?
I've played with the phase and changing it to 180 made the hump worse.
I've also played with changing the speakers from 40hz to 80hz and that made no difference.
I changed the mic position thinking it was a seating position or null at my seating position and didn't notice enough of a change to say that was causing the issue.


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## Blacklightning (Nov 22, 2011)

I have a few questions. Is this all 4 subs and speakers at the same time? I see average as the file name, is this an average of the sub and speakers?

I would ask that you re-run this with Sub only, left and right speaker only and then both. Add the REW file as an attachment so we can analyse your data.


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## Wayne A. Pflughaupt (Apr 13, 2006)

JimmyLeggs said:


> I am getting a weird hump near the crossover (80hz)


It’s not showing up on your graph.




> Are the subs overpowering the mains?


Impossible to say, you didn’t show us a full range graph! 

Regards, 
Wayne


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## JimmyLeggs (Jul 28, 2012)

@Wayne
Full Range
1/6 smoothing

Also I should have said dip rather than hump in the 70-100 range


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## JimmyLeggs (Jul 28, 2012)

Blacklightning said:


> I have a few questions. Is this all 4 subs and speakers at the same time? I see average as the file name, is this an average of the sub and speakers?
> 
> I would ask that you re-run this with Sub only, left and right speaker only and then both. Add the REW file as an attachment so we can analyse your data.


Those measurements was everything from 0-80hz so I don't think the mains came into play.

Is it a setting in REW to play just the subs, just the speakers and just the L/R/Sub?


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## JimmyLeggs (Jul 28, 2012)

Attached my MDAT file


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## Blacklightning (Nov 22, 2011)

What I see so far is very good. Bass problems should be very low on your list of things to work on.

Just looking at your file the things that stand out to me are. (I'm just going to point things out, overall your setup and room look really good).

All SPL: Graph looks good, Bass is very even -3 to -5db would level match it to the speakers but that is not fun.

Distortion: Your distortion seems high 2nd and 3rd Harmonic start to rise after 10000hz, 2nd harmonics jump at 150hz and peak really high at 72hz. Are things rattling in your room??? It would be nice to see your speakers only. I think your speakers (or room) are creating a lot of distortion.

Impulse: Looks really good for and untreated room you must have Carpet and a few soft chairs. You have a big reflection at 4ms (I'm guessing the back of the chair or maybe you are have a wall about 2 feet behind you. You can see your side reflections around 6-8ms. Again it would be nice to see left only and right only for this.

Waterfall: This shows the fact that you need some panels to control your room. It's not bad but I see a lot of trailing peaks. Your bass is fine. No "need" for bass traps.

I'm not an expert so do not take me too seriously, keep learning. Your bass is really good. Work on your speakers.

For measuring Sub only, left and right. Just unplug your speaker cable to the other speakers (easy way). Run Left and right with and without sub.


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## JimmyLeggs (Jul 28, 2012)

Thank you su much for the feedback!!

*Bass problems should be very low on your list of things to work on.*
Good to know. Last thing I wanted to break my head over.

*All SPL: Graph looks good, Bass is very even -3 to -5db would level match it to the speakers but that is not fun.*
I like running my bass a little hot (after calibration)

*Distortion: Are things rattling in your room??? It would be nice to see your speakers only. I think your speakers (or room) are creating a lot of distortion.*
Things do rattle but mostly on HEAVY bass scenes. I would think it was the room causing the distortion rather than the speakers. Room is "echo-ey" as it stands right now.

*Impulse: Looks really good for and untreated room you must have Carpet and a few soft chairs. You have a big reflection at 4ms (I'm guessing the back of the chair or maybe you are have a wall about 2 feet behind you. You can see your side reflections around 6-8ms. Again it would be nice to see left only and right only for this.*
The mic was in between 2 big leather chairs. Maybe 6 inches away.
The room is hardwood floors with a small 6*9 carpet underneath the chairs, nothing else. Might be the chairs making something act funny because the rear wall is about 9ft away.

*Waterfall: This shows the fact that you need some panels to control your room. It's not bad but I see a lot of trailing peaks. Your bass is fine. No "need" for bass traps.*
My next project. Reason I bought the UMIK was to "measure" the "need".


*For measuring Sub only, left and right. Just unplug your speaker cable to the other speakers (easy way). Run Left and right with and without sub.*
That won't be possible with the equipment in it's rack.


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## Blacklightning (Nov 22, 2011)

JimmyLeggs said:


> *For measuring Sub only, left and right. Just unplug your speaker cable to the other speakers (easy way). Run Left and right with and without sub.*
> That won't be possible with the equipment in it's rack.


Are you speakers in wall?


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## JimmyLeggs (Jul 28, 2012)

Blacklightning said:


> Are you speakers in wall?


lddude: I didn't even think of that. No they are not


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## JimmyLeggs (Jul 28, 2012)

Attached the 3 files


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## Blacklightning (Nov 22, 2011)

If you do:
Sub only
Left only
Right only
Left with sub
Right with sub
Left and right only
Sub with both speakers

Do this and the guys here will help you out. That is what they did for my. Also include some pictures of your setup.

good luck.


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## Blacklightning (Nov 22, 2011)

JimmyLeggs said:


> Attached the 3 files


That was fast!!! :yikes:


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## JimmyLeggs (Jul 28, 2012)

This is all of them. Still not understanding the drastic drop off at 80hz for the subs. Is that to meet the speakers for a smooth transition?

I tried uploading all the measurements in one file to make it easier but keep getting the "Your submission could not be processed because a security token was missing." error.


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## JimmyLeggs (Jul 28, 2012)

Front Soundstage


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## JimmyLeggs (Jul 28, 2012)

One more question, 100db at 11hz is normal?


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## Blacklightning (Nov 22, 2011)

JimmyLeggs said:


> One more question, 100db at 11hz is normal?


Not sure what you are asking? Normal? 

Room gain is the easy answer... you have very good subs but take them into a field and you will not be pulling those numbers. This is the advantage of sealed subs. As you can see from your decay chart your *room* is holding on to 11hz like crazy.


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## Blacklightning (Nov 22, 2011)

JimmyLeggs said:


> Front Soundstage


I think the next thing you should work on is getting some panels up on the wall.

And I would think with your room size a 11.2 system would create too much energy in that room.
Just because you can does not mean you should. :nono:
But I do not think anyone here follows that. :heehee:


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## JimmyLeggs (Jul 28, 2012)

Blacklightning said:


> I think the next thing you should work on is getting some panels up on the wall.
> 
> And I would think with your room size a 11.2 system would create too much energy in that room.
> Just because you can does not mean you should. :nono:
> But I do not think anyone here follows that. :heehee:


:innocent:I don't need 4 subs either :bigsmile:

Panels will be next after a riser for the second row seating. Have some odds and ends to tie up also like raising the center channel properly.


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