# 1st attempt at REW



## cburbs (Mar 27, 2007)

So I have a chaintech av710 - and this is some of my first info - 

1st pic is Souncard settings, then Soundcard Calibration , and then check that the calibration has been successful.

Sample rate: 48000Hz
-3dB points: 7.3Hz, 20.612kHz
Input device: Envy24 Family Audio (WDM)
Input: LINE_IN (Line In)
Channel: Right
Input volume: 0.133
Input RMS target: -12.0dB
Actual RMS at 1kHz: -11.9dB
Output device: Envy24 Family Audio (WDM)
Output: SPEAKER
Sweep level: -12.0dB
20Hz .. 20kHz flatness: +0.1, -0.7dB
1kHz 2nd harmonic: 0.001%
1kHz 3rd harmonic: <0.001%


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## brucek (Apr 11, 2006)

Is there a question?


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## cburbs (Mar 27, 2007)

These graphs are correct for the 1st part right?


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## Otto (May 18, 2006)

Yep, looks good for a soundcard cal.


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## cburbs (Mar 27, 2007)

1st graph is amp filter at 20low
2nd graph is amp filter at 20med
3rd grapsh is amp filter at 20high


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## cburbs (Mar 27, 2007)

Now going thru some more stuff I think I goofed...Do I have the correct settings in the following two files. For the soundcard do I need teh test.cal in there from when I calibrated it?
Do I need to use the radioshack cal file for the mic/meter? 
I am hooked up to my preamp with speakers off as of now?


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## brucek (Apr 11, 2006)

> For the soundcard do I need teh test.cal in there from when I calibrated it?


Yes.



> Do I need to use the radioshack cal file for the mic/meter?


Yes.

You don't need to re-measure to load the cal files and apply them to the measurement. If you saved the mdat file of the measure, it contains the impulse response that is used to derive the frequency response.

Simply load the mdat file and the cal files, then click the IR Windows icon and press Apply Windows and the new frequency response will be calculated for the measurement that is selected.

We normally post our graphs with a vertical scale of 45dB to 105dB and a horizontal scale in your case of 10Hz to 200Hz.

Turn off the C-Weight switch since you'll be using the cal file instead..

brucek


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## cburbs (Mar 27, 2007)

Ok so what is the best thing to change if you keep get input clipping detected?

The volume on the receiver or the Level DB fs?

I have an amp that has multiple dampening settings so I want graphs for all settings.

Example for graph below: Receiver volume at 39, crossover 80, sub -5. Amp has crossover maxed - no off option, phase at 0 and volume 1 oclock and setting at 14, Low dampening.Though I had to keep decreasing the sweep level which brings the spl down.

Here is the graph -


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## brucek (Apr 11, 2006)

Change the graph to Logarithmic from Linear. (Freq Axis) icon in upper right corner of REW.

Set the Receiver so the level using the RS Meter is 75dB and then set the input level so it doesn't clip..

brucek


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## cburbs (Mar 27, 2007)

Will make some more attempts tomorrow night...thanks.


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## cburbs (Mar 27, 2007)

Here is one graph that finally worked out - any thoughts....


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## brucek (Apr 11, 2006)

You need some equalization, but overall it's not too bad................

brucek


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## cburbs (Mar 27, 2007)

Attatching Graphs - All grapsh are receiver with a 80xo. 
Without adding a BFD which graph seems to be the best overall? 
Should I run any sweeps at 60xo, 70xo, or 90xo? 

1st one is with amp 14 - Low dampening, 14- Med, and then 14- H.


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## cburbs (Mar 27, 2007)

2nd set is 20-L, 20-M, and 20-H


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## cburbs (Mar 27, 2007)

3rd set is 28-L, 28-M, and 28-H.


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## brucek (Apr 11, 2006)

When comparing graphs, use the ALL MEASURED tab in REW. It overlays all your measurements onto a single graph. It makes comparisons much easier.

_"amp 14 - Low dampening, 14- Med, and then 14- H.
2nd set is 20-L, 20-M, and 20-H
3rd set is 28-L, 28-M, and 28-H."_

Gotta be honest, I don't have a clue what this means?

brucek


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## cburbs (Mar 27, 2007)

I have the A350-Basic Rythmik amp that has different damping control settings - per the site.

A defeatable extension filter with separate frequency and damping control. The extension filter can be bypass with 14 Hz and high damping setting. Frequency is adjustable between 14, 20 and 28 Hz. Damping factor is adjustable between high damping (Q=0.6, or bessel filter), medium damping (Q=1.07, or 1.5 dB boost Chebyshev), low damping (Q=1.33, or 3 dB boost Chebyshev). There are a total of 9 settings available. You can use this filter to boost the bottom end or do minor correction for room response.


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## Guest (May 21, 2007)

14Low looks a better starting point, more level and dips aren't as deep. But then I've only just blown the dust of my DEQ and started playing with this stuff again a week ago.


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## cburbs (Mar 27, 2007)

Yes 14-L is what I was thinking is the best so far.


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## cburbs (Mar 27, 2007)

all 3 14 damp settings


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## cburbs (Mar 27, 2007)

3 20hz amp settings....


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## cburbs (Mar 27, 2007)

3 - 28hz amp settings.


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## cburbs (Mar 27, 2007)

OK I have been playing with RDES and my subs. I have onlyplayed around with it a little. I can't seem to get rid of that 22hz peak. 

Can't really move my subs so I don't know what to do with that. Red is no EQ and purple is EQ it a couple rounds and coming up with that.

Since RDES has 5 filters now will they add one since REQW only has 4 for it right now?


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## cburbs (Mar 27, 2007)

Graphs alone....


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## brucek (Apr 11, 2006)

> Since RDES has 5 filters now will they add one since REQW only has 4 for it right now?


Again I'm a bit lost.

What is RDES?

What does it mean that REW only has 4 for it?

brucek


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## cburbs (Mar 27, 2007)

RDES is - http://www.hometheaterhifi.com/volume_13_3/onix-r-des-subwoofer-eq-9-2006-part-1.html

They updated it a while back to have 5 filters...originally came with 4.


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## brucek (Apr 11, 2006)

> They updated it a while back to have 5 filters...originally came with 4.


Ahhh, OK I get it now.

Yeah, I guess John would upgrade REW to allow 5 filters when using RDES in the next version.

For now it would be fairly easy for you to use another equalizer selection in the REW pulldown that has more filters (such as the TMREQ) and then modify the Q of each filter when finished so it complies with the RDES Q calculation. You can see how the Q of the RDES filters and the Q of the TMREQ filters differ for their bandwidth in Hz at the half gain points. You would use this feature for your calculation.

Or you could also perhaps select RDES and do your filters in two steps by using 4 filters (and enter those 4 filters in REW) and remeasure and then play with a new set of 4 to get the additional filter if needed...

Anyway, it would take a certain amount of fooling around.

brucek


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## cburbs (Mar 27, 2007)

Ok so I got a BFD for christmas and finally got around to playing with it - any thoughts on the following - This is two subs in a smaller room. House curve of 30 8.0 80 0.0. First pic is before and second is after - 3rd both.


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## brucek (Apr 11, 2006)

Your graph #1 unequalized doesn't really look like it needs equalization. A bit of movement in listening position or the sub would likely make it a bit better, but it isn't bad the way it is now... Nothing wrong with tweaking it a bit as you have, but I'll bet you can get rid of the equalizer completely with a bit of work..

brucek


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

brucek makes a valid point. That said, if you’re going to equalize, I’d recommend re-doing it. Your target is nicely between your main response depressions and peaks, but it looks like you applied a bunch of boosting filters to raise the overall signal level. Not a good tact. Not to mention, you’re not tracking your house curve too well (esp. between 40-60 Hz).

I’d re-equalize, using both boosting and cutting filters this time to better track your house curve.

Regards,
Wayne


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## cburbs (Mar 27, 2007)

Wayne,

Can you explain yourself on boosting and cutting filters -


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## cburbs (Mar 27, 2007)

Does this article cover most of it? 
http://www.hometheatershack.com/for...target-levels-hard-knee-house-curve-long.html


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

Sorry to leave you hanging, been out of town the past few days...


cburbs said:


> Does this article cover most of it?
> http://www.hometheatershack.com/for...target-levels-hard-knee-house-curve-long.html


Only vaguely, I’m afraid. I did note that I raised the target level between the peaks and valleys before equalizing, the filter panel shows some boosted filters, but I didn’t discuss boosting vs. cutting filters directly.

Looking at your earlier graph...










...I’d apply cuts below ~38 Hz and boosts above. Your response doesn’t require any drastic boosting or cutting, so it shouldn’t be a problem. If it is, your sub will let you know with lots of nasty sounds during demanding movies, once the level is re-adjusted. You also might take a look at your response with a more the more realistic 20-130 dB window I mentioned in the article, before equalizing. You might find you don’t need any EQ at all, as brucek mentioned, or if so, not as much as you had thought.

Regards,
Wayne


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## cburbs (Mar 27, 2007)

So like this...


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

Yup, but hitting the Target, natch. 

Regards,
Wayne


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## cburbs (Mar 27, 2007)

Ok will take a swing at it again soon.......


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## cburbs (Mar 27, 2007)

To put the bfd in bypass mode I just push in the in/out button and it will blink - this means that there is no filter applied correct?

Is there a way to reset the BFD?


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## brucek (Apr 11, 2006)

If you push the IN/OUT button, the green light will go off. That means the filters are not applied. 

If you push and hold the IN/OUT button, it will flash, that means the filters are not applied, plus the VU meters indicate input level as opposed to output level.



> Is there a way to reset the BFD?


No. What is it you want to reset?

brucek


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## cburbs (Mar 27, 2007)

Ok so here is an update -

Smoothing - 1/3
cutoff 60 (I have my mains crossed over at 60) so this should be at 60 correct?
target level 78.3
House curve -
30 8.0
80 0.0

Graphs - before, after, and both.


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## cburbs (Mar 27, 2007)

Wayne does this look better - 
Also why would the red led lights light up on the right channel when I am using the left channel?


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

Yup, definitely looks better.

As far as the lights, what’s lighting up is what you’re using. The BFD stupidly has the rear connections labeled as 1 &2, while the front meter is L/R.

Regards,
Wayne


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