# Home Studio First Measurements



## Manslick (Aug 6, 2009)

Here are the graphs of the first measurements taken with REW. 

I include a scale plan of the room as well.

My hope is to reduce the low end problems but not sure where to start. 

The room has absorbent panels that are indicated by the shaded rectangles on the plan.

All advice and comments welcome.

Thank you


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## sdurani (Oct 28, 2010)

How many subs and speakers are you using? Where are you crossing over (80Hz? 100Hz?) Would you be willing to move them to improve the low end?


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## Manslick (Aug 6, 2009)

sdurani said:


> How many subs and speakers are you using? Where are you crossing over (80Hz? 100Hz?) Would you be willing to move them to improve the low end?


hello sdurani, there are no subs in the room. there are two monitors, Truth B2031A or two JBL E100s on the wall at the long end of the room. of course i would be willing to move them. thanks


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## sdurani (Oct 28, 2010)

Manslick said:


> of course i would be willing to move them.


OK, for the sake of an experiment could you move your Behringer monitors so that the middle of their woofers are 1/4 of room width in from the side walls, and then re-measure them together? Since it is the low end you are concerned with for the moment, adjust the settings on your graph to show up to 200Hz.


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## Manslick (Aug 6, 2009)

the monitors were already at the 1/4 width point. just luck i suppose.

here is the graph of a measurement i took today up to 200Hz.

and thank you again


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## sdurani (Oct 28, 2010)

The peaks and dips every 37-40 Hz looks like a modal problem related to a room dimension. Do you have a room dimension around 14-15 feet? 

If so, can you place your measuring mic at one of the odd divisions (1/3rd, 1/5th) of that dimension and measure again? Your mixing console/desk might have to move to get smoother response in the low end.


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## Manslick (Aug 6, 2009)

Yes the room is 15 feet long as shown in the plan attached to the OP. I will move the mic and test again.

Thanks


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## sdurani (Oct 28, 2010)

Wups, I didn't click on the attachment in the OP because I thought it was the measurements you posted. Hopefully the measurements will yield something better than your current results.


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

Manslick said:


> My hope is to reduce the low end problems but not sure where to start.


You didn’t tell us what you perceive the low end problems to be? If it’s poor sound quality due to frequency response, parametric EQ can do great things in the lower frequencies.

That aside, there are some serious inconsistencies between your Post #1 full range graph and your Post #5 low-end graph. The ~18 dB deviation between 100 and 200 Hz “improved” to only a 12dB problem, and the ~14 dB problem between 80-110 Hz “improved” to only ~ 6 dB. The “shape” of both changed drastically, too. Where these both measurements of the same speakers, or is one the Behringers and the other the JBLs?

Regards, 
Wayne


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## Manslick (Aug 6, 2009)

Wayne A. Pflughaupt said:


> You didn’t tell us what you perceive the low end problems to be? If it’s poor sound quality due to frequency response, parametric EQ can do great things in the lower frequencies.
> 
> That aside, there are some serious inconsistencies between your Post #1 full range graph and your Post #5 low-end graph. The ~18 dB deviation between 100 and 200 Hz “improved” to only a 12dB problem, and the ~14 dB problem between 80-110 Hz “improved” to only ~ 6 dB. The “shape” of both changed drastically, too. Where these both measurements of the same speakers, or is one the Behringers and the other the JBLs?
> 
> ...


The room is used for recording guitars, drums and vocals. When I play a B (123.47 Hz) on electric guitar thru my Marshall amp head connected to a 2x12 1922 cabinet, I get a loud increase in volume which I believe to be a standing wave. It is pretty obvious and easy to perceive. It could be the room, the drums resonating, the acoustic guitars resonating, one or all, I don't know. But I always have issues judging the bass in my mixes. Mixing in this room and then playing the mix in a car, it's like totally different in a bad way.

The inconsistencies, yesterday before measurement two, I did take one of the 2x4x4" absorbent panels and mount it to the ceiling just above the mixer. I am happy to hear this resulted in an improvement. Someone told me not to have untreated parallel surfaces. Thanks you for examining the two graphs so closely.
Yes both measurements were taken with the Truth monitors.

I think I need to move the drums and guitars out of the room. Or is that not worth the trouble? 

Also, Are the adjacent spaces causing insurmountable problems due to coupling?

And, aside from taking a course in acoustics, where can I read information on interpreting these graphs?

Thanks a million.


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## Manslick (Aug 6, 2009)

sdurani said:


> Wups, I didn't click on the attachment in the OP because I thought it was the measurements you posted. Hopefully the measurements will yield something better than your current results.


Thanks for taking a look at the plan. I hope to do the 1/3 mic position measurement today, depending.


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## Manslick (Aug 6, 2009)

Updated room plan attached.

Thanks


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## sdurani (Oct 28, 2010)

Manslick said:


> I hope to do the 1/3 mic position measurement today, depending.


Thanx. If moving your desk 3 or 5 feet (1/5th or 1/3rd of room length) away from the wall ends up helping smoothen things out a bit, then you can go the rest of the way with treatments and EQ (in that order).


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## Manslick (Aug 6, 2009)

Why move the desk? The room is so small that if I move the desk even 3 feet then there's no room in the room. I am going to try to do a measurement tomorrow with the mic at 5 feet from the long wall and 1/4 way between the short wall.
Thanks again


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## sdurani (Oct 28, 2010)

Manslick said:


> Why move the desk?


Figured when you're mixing you would want to be sitting where frequency response is smoothest.


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## Manslick (Aug 6, 2009)

sdurani said:


> Figured when you're mixing you would want to be sitting where frequency response is smoothest.


Right, I was thinking something else. 

Well just sitting at the desk is about the 1/3 spot in the room on the long wall and I have an X on the floor where I read the sweet spot is supposed to be, center of the short wall and 3/8 the distance from the long wall.

So should I measure the room from there?

I'm kind of lost here.


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## sdurani (Oct 28, 2010)

Manslick said:


> Well just sitting at the desk is about the 1/3 spot in the room on the long wall and I have an X on the floor where I read the sweet spot is supposed to be, center of the short wall and 3/8 the distance from the long wall.


The 1/3 spot of room length would be 5 feet from the front wall (the 11.5' wide wall). Is that roughly where your chair is? 

In that case you might have done all you can using placement (speakers and listening position). Consider bass traps to further smoothen out the low frequency response.


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## Manslick (Aug 6, 2009)

yes that is where the chair sits.

last night i was reading the master handbook of acoustics the chapter on listening rooms. there are some nice diagrams of listening room sitting positions and absorbent placement. i have absorbent panels in the room already but may have too much for broadband, but not for the low frequency.

typically what is used to address frequencies below 200 hz down to say 40 hz?

thanks


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## sdurani (Oct 28, 2010)

Don't know how effective treatments will be at 40Hz. For bass trapping in general, you would need thick panels (at least 6 inches). 

Since the peaks & dips on your graphs seem to indicate modal problems due to room length (15 foot dimension), the wall in front of you and behind you (near the drum kit) would be likely candidates to place absorbtion. 

At this point you would be better off contacting GIK Acoustics, since they specialize in room treatments and can help you get what you need to further tame the bass in your room.


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## Manslick (Aug 6, 2009)

thanks for the help Sanjay. i guess its time to start piling money in the corners.


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