New to REW calibration problems

[nordr]

I am using a macbook and the internal sound card for calibration. I have the settings as indicated in the macbook primer post. I am running a stereo cable from the line out to line in. I don't have any Y connecters of anything just the one cord going from in to out.

Below is the calibration file.


I thought this looked ok. So to check I ran a 0-20000hz measurement and got this...


That's not right, right?

[nordr]

Also just ran the first measurement. Not sure if it is valid considering the soundcard configuration. But this is what I got using the RS meter with the cal file loaded.

[brucek]

That's not right, right?

Wrong, it is right.

Not sure if it is valid

It is.

brucek

[nordr]

Ok, thanks. Moving on...

Could a BFD fix that huge dip around 56hz? Seems like I am getting almost no sound there. I'm guessing that the hump between 70-100hz can be fixed. Also going to try to move the sub around some but I have very limited options.

The sub is from a HTIB it is JBL 10' 150W. It's going to be the next thing I will upgrade but in the meantime I was going to fill in the gaps with a BFD. Looking at my graph, do you think I am a good candidate for this?

[brucek]

Could a BFD fix that huge dip around 56hz?

Nope, absolutely not. Dips like this are caused by phase cancellations, where the sound reaching the measurement point is a combination of an original direct soundwave and a reflected sound that is 180 degrees out of phase at the dip (one half wavelength).

All your trouble spots are around the crossover. Phase and distance can usually solve these. You must first measure the sub alone and find the best position for it that creates the smoothest response. Then you need to measure the mains alone to see how they look and adjust positioning if there's any cancellation or addition that appears bad. Then you measure the sub + mains and adjust the phase and distance of the sub to obtain the smoothest response.

brucek