[brucek]

Re: been awhile, hooking up stuff again. Need Cal file.

Attaching an mdat file isn't something that most people would download and view.

If you want to show your measurement responses, attach a jpg of the graphs.

brucek

 

[brucek]

Re: been awhile, hooking up stuff again. Need Cal file.

Next time you post, for a sub, use a graph scale of vertical = 45dB-105dB and horizontal = 15Hz-200Hz. The icon to change this is called Graph Limits and is located in the top right corner of REW.

is it better to EQ it for a middle position between the two?

That's a personal choice. Many simply take several readings (up to 8) and press the Average button to create an average of all the readings you want included. Then they EQ the average plot.

brucek

PS. Stick to one thread. I renamed this one and deleted the other.....

 

[brucek]

Are you able to move the subs you have to create an overall compromise in the plots. I wouldn't recommend adding another.

brucek

 

[brucek]

Since REW is a mono signal, you can't utilize any soundfields in your processor. You must use stereo mode only. This means the two mains and sub will be active, and none of the other speakers will be active.

To measure a sub, disconnect the mains speakers. To measure the mains, turn off the sub.

If you wish to measure the rear speakers for example, connect them in place of the mains.

If you wish to measure the center speaker, connect it to the right or left main position and shut the other mains off.

When you measure the mains, use the usual vertical scale of 45dB-105dB, and use a horizontal scale of 15Hz-20000KHz (if you have a full range mic).

Yes, for full range plots, you need to turn on smoothing to hide the comb filtering (scratchy).......

brucek

 

[brucek]

I will disconnect all rca inputs on my amp, except one, the left or right channel, and move it to each amp input in sequence until I have a full measurement of all the speakers. Does this sound correct?

Yep, but remember, in addition to this, you may want to test for interaction. It's fine to measure a single main, but with two mains running, there may be some negative interaction between them that you might want to be aware of. So, at the least, feed the two mains and take a measure.

Also, you want to see how the mains integrate with the sub(s), so you want to do a sub + mains measurement.

brucek

 

[brucek]

Anything you can deduce from this?

Yep, you have a nasty peak at 100Hz.... That's why it was clipping.

Anyway, I would start by adjusting the phase control of the sub(s) and see if you can get the peak down. I would also measure sub plus each main individually to see if there is a single culprit.

brucek

 

[brucek]

Any sharp dips can be ignored, you won't notice them. The extra sub only eliminated the sharp dip...

I like the green plot better........

brucek

 

[brucek]

I know room treatments are recommended before EQ

Treatment doesn't help a lot in the modal region. The traps have to be too large to be practical. It's movement or EQ. But there's really not a lot wrong with your response.

brucek

 

[brucek]

What is the modal region?

This would depend on the room, as it refers to the modal frequencies for the standing wave resonances set up between parallel surfaces in your room. There are axial modes (two surfaces), tangential modes, and oblique modes. Long story short - these cause the peaks and dips in your subwoofer response.

These types of acoustical questions are better asked in our acoustics forum section. We try and limit discussion here to REW specific questions.

brucek