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How to start measurements when you have multiple subs

16K views 97 replies 6 participants last post by  thsmith 
#1 ·
REW is working for me now and no more manual measurements, yahooooo!

My room (Living room)as most everyone elses is challenging, 4200cf, 8' to 12' sloping ceiling, hardwood floors, fireplace is 10' wide and 12' high. 6' frech door, all windows have heavy drapes and large opening in back of the room to the right from sitting position.

I have a HSU VTF3-MK3 Turbo in front left corner and HSU MBM-12s behind each main.

When I start my measuring I know I need to remove the mains, should I also turn off the MBMs and focus on just the 3 3 T and then turn off 3 3 T and turn on 1 MBM at a time to find best location for subs ?

3 3 T XO is in set at 55hz
MBMs XO out (50hz-150hz)
AVR (Denon 2808) XO set to 120hz

Thanks
 
#67 ·
Also don't forget to change your graph axis to the standard of:

Vertical = 45dB-105dB
Horizontal = 15Hz-200hz.

Had to get that in before brucek.
 
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#69 ·
Yup, looks like you could still turn the 3.3 up a little more.
 
#70 ·
You should be using shelf EQ's if you want tone control...
 
#72 ·
The 1124P cannot do shelfing filters. You would need a better eq. for that capability.
 
#76 ·
You should also try Eagles "Hell Freezes Over".... Hotel Cali. and Life In The Fast Lane are great! :bigsmile:
 
#79 ·
What are your plans for your second MBM? :bigsmile: ;)
 
#81 ·
Too bad... :gah: :bigsmile:
 
#83 ·
I have a couple of follow up questions.

this link has my latest graph and I am now wondering if I did it incorrectly.

http://www.hometheatershack.com/for...when-you-have-multiple-subs-3.html#post119443

I have my 33T XO engaged at 45hz, 1 MBM behind Right main (3 3 is on left side of room), AVR XO 120hz. 3 filters on BFD.

Questions are:

I have my house curve set at 30hz 4 db and 80hz 0 db. Since I have my crossover set on the AVR at 120hz should I have used 120hz at 0 for the house curve ?

On the toolbar Target settings I had Cutoff HZ set at 80hz should it have been set at 120HZ since I had the AVR XO set at 120HZ?

Should I set the values above to 120hz and rerun REW and setting filters accordingly ?

Thanks,
 
#88 ·
I have my house curve set at 30hz 4 db and 80hz 0 db. Since I have my crossover set on the AVR at 120hz should I have used 120hz at 0 for the house curve ?
You start the house curve at the frequency where you find (subjectively) that it sounds better to have a bit more bass. It is not connected to your crossover frequency except that it would not make sense for it to be higher than the crossover.

On the toolbar Target settings I had Cutoff HZ set at 80hz should it have been set at 120HZ since I had the AVR XO set at 120HZ?
Yes, but remember that if you are measuring with a main speaker running as well as the sub(s) the target should be set to Full Range, not subwoofer. The subwoofer target is only valid when the mains are off.
 
#84 ·
I guess the easiest way to check, although it may not be correct, play a sine wave at 120Hz and one at 80Hz and see if they sound the same "volume". If you have to turn up the 80Hz, then move the 0 to 120Hz. I believe you have said that you like the way that it sounds now. I believe that is what is most important.
 
#85 ·
I do like the way it sounds. IF I change the house cuve to 120hz at 0 and cutoff hz to 120hz againest the referred to measurement file as sort of a simulation it would appear I could raise the volume on the MBM a bit.

I was just curious if I needed to have made the referred to adjustments originally or not.

Tonight I will try it and see how it looks and sounds.

You just have to love REW with its flexibility and real time results.
 
#91 ·
Not sure what to do about the above 80hz dips.
Have you tried graphing the different results after playing with the two subs phases?
 
#93 ·
Also, it seems to be better to have your target line centered through your response. This will help reduce how much you are cutting/boosting certain frequency ranges. With that, you may be able to turn up the 3.3 a tad more.
 
#94 ·
In the case of running a sub and a MBM is it possible to use a y cable to feed the sub in from the AVR to both the right and left channels of the BFD so you could use different filters for the sub on say the right channel out of the BFD and left channel out to the MBM ?
 
#95 ·
About the only thing you may gain from doing that is an additional 12 filters. I have both my main sub and MBM fed to the left input only. Then again, I have only had to use 4 filters for both subs.
 
#96 ·
I have 2 filters on mine but I was wondering if you wanted to you could target specific freqs for specifc subs using this method but what you say makes sence.

I was discussing this with a friend of mine that has two of the big Outlaws and an MBM. He is considering using this approach but as you say I am not sure of the value in doing this.

Thanks weverb !:T
 
#97 ·
I was discussing this with a friend of mine that has two of the big Outlaws and an MBM. He is considering using this approach but as you say I am not sure of the value in doing this.
Lucky friend! :R
 
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