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Discussion Starter #121

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Discussion Starter #122
The Radio Shack meter is being tricked by using the test tones in the receiver when you're setting the speaker level trims. The huge peak you have is what the meter is reading and so the mains get set low. You will have to use REW to set your levels between the mains and sub.......
I was thinking about this some more. I understand how it could influence the L/R mains because they can play down to 40Hz. If this is true about the receiver's pink noise and RS meter, why does it sound the same when being played by the center and surrounds. Both speakers can only go to 100Hz. They are both set only 1-2dB higher than the mains. Wouldn't they need to be "boosted" by more than a couple dB?

It is late and I am :snoring:. Maybe I am thinking about it too much.
 

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Don't the LFM-1 and the MBM have their own crossover settings? Try making measurements with both turned off and with one or the other switched on to see which is making the biggest contribution to that peak and try adjusting the crossover settings on the subs.
 

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Discussion Starter #124
Don't the LFM-1 and the MBM have their own crossover settings? Try making measurements with both turned off and with one or the other switched on to see which is making the biggest contribution to that peak and try adjusting the crossover settings on the subs.
Both graphs in post #101 and #107, the subs were turned off. The LFM xo is set to about 50Hz and the MBM is bypassed right now. I can switch the MBM to 80Hz but from the previous graphs, the 50Hz spike was done by the mains (L/R) only.
 

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Don't the LFM-1 and the MBM have their own crossover settings?
It's my understanding that an MBM's crossover is a high pass that controls its mix with the main subwoofers internal low pass (for example, at 50Hz). Then the receiver/processors crossover is set to 80Hz for example to feed the mixed pair.

This means that the MBM would not have its upper limit controlled if a receiver/crossover was not engaged...

brucek
 

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Discussion Starter #126
It's my understanding that an MBM's crossover is a high pass that controls its mix with the main subwoofers internal low pass (for example, at 50Hz). Then the receiver/processors crossover is set to 80Hz for example to feed the mixed pair.

This means that the MBM would not have its upper limit controlled if a receiver/crossover was not engaged...

brucek
The MBM design naturally rolls off at 45-50Hz, therefore no xo needed (just one on the main sub to blend). It is capable up past 120Hz. The typical set-up is to use the receiver's xo (usually set to 80Hz for nearfield placement) to blend with the mains and not be localized. There are set-ups where two are placed up front with the mains and are xo at 120Hz. Still though, the receiver's xo is used.
 

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Discussion Starter #128
Ok, this is strange. I went into the receiver and played with turning the sub off and on. Then messed with xo setting. I pushed it up to 200Hz. I ran REW again and made a graph just like in post #101. I then played the HSU disc with the different frequency tones and got this:

50Hz - 64dB
63Hz - 57dB
80Hz - 57dB
100Hz - 60dB
125Hz - 67dB
160Hz - 72dB
200Hz - 71dB

:huh:

Is it possible because the disc is through optical versus REW is through an analog connection there is a difference?
 

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Discussion Starter #129
I think I am on to something here. Just ran REW through a digital connection and......
 

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Discussion Starter #130
Looks like the xo works in digital! Here it is at 80Hz.
 

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Is it possible because the disc is through optical versus REW is through an analog connection there is a difference?
Doesn't seem likely, but easy to check. Connect the output of the soundcards digital output to the digital input of the receiver instead of the analog line-out.

Run the subwoofer test through the receiver like you did and see if there is a crossover..

brucek
 

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hehe, you're ahead of my suggestion...........

Yeah, maybe the firmware in the receiver is a bit glitchy on the analog input?
Retry the analog input again...

That looks better..

brucek
 

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Discussion Starter #133
hehe, you're ahead of my suggestion...........

Yeah, maybe the firmware in the receiver is a bit glitchy?

That looks better..

brucek
:yay: Thank goodness all my connections are through digital and not analog. I guess I better double check the subs!
 

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I am trying to start using REW. Can you please help point me in the right direction on measurments. This is the graph I am getting. What am I missing? :huh:
I'm having the exact same problem, yet even with the advice Brucek gave you, I cannot figure it out?! Hmm...Any helpers, please.

Yeah, I've never used anything like this before. So I'm a bit ignorant.:huh:
 

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Discussion Starter #136
Well I just set-up Wayne's hard knee curve. Now I need to go listen. My next step is focusing on the highs. I have a Yamaha YDP2006 on the way for my L/R mains.
 

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Discussion Starter #138
So far it sounds real good with music. I have not had a chance to watch any movies yet. I am curious to see what the ECM8000 mic says it looks like. I never thought I would say that I could not wait for Monday! :newspaper:
 

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Discussion Starter #139
New toys arrived. :nerd:

I don't think the WAF will accept pic #1!
 

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Discussion Starter #140
Wow! The ECM8000 is getting a total different response for the highs. The 1st graph compares the ECM to the RS meter. The second is the result by itself. :nerd:
 

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