1st attempt to use REW on SVS PB12+/2

**etcarroll** · **07-11-08, 02:28 PM**

Attempting initial run on Friday afternoon while I have house to myself, real work done tomorrow when my first batch of questions get answered, and here's one now;

- d/l the cal. file for my RS analog meter, but where do I upload it to?

EDIT: disregard, found it.

Meanwhile, here's what I have.

Pio AVR that only goes down to xo of 100, but replacing it soon.
SVS sub.
Rocket setup of RS1Ks front, Bigfoot, and RS250MKIIs in rear.
REW 4.11 on my XP MCE htpc with M-Audio soundcard

I have a new house, my gear is in family room on 1st floor that is open to kitchen, so its a big space. The sub is on side wall, next to opening to living room that is open to second floor.

I'm a Product Designer for a healthcare software company, so kinda literate on things electronic, though could always stand to learn 'just one more thing'.

Recently attended an AV123 GTG where I watched Mark Seaton tune a pair of MFW-15s for theater use, and have since found myself unhappy with the 'flabby' sound of my sub. I doubt its the sub, all I ever did was run AVIA 3 years ago, that's it.

TGIF - Gene

**etcarroll** · **07-11-08, 03:21 PM**

Stumped already - soundcard calibration.

At the first stage, using 1Kh tone to set levels, how do you know when this process is done? It ran 10 mins, no message of any sort, though there are values in sweep level, wave volume and output volume.

I made sweep volume -6 for a second try, but after a few minutes there's no message that says I've accomplished anything.

Wave volume is 1.0, Output is .5, both are greyed out.

The values in 2 columns for output are aprox -80 on top and -90 on bottom.

Guess I'll hit next and see what else happens.

**etcarroll** · **07-11-08, 03:35 PM**

No better at next screen, I can't see how to adjust the input and output volumes to get them w/i 3 Db of each other. I pulled up the M-Audio control panel, moved the sliders, but the meters are not remotely close to being in the same neighborhood.

I'll try to post a screencap, but not sure I can as I have less than 10 posts.

**etcarroll** · **07-11-08, 03:58 PM**

What I have so far;

**JohnM** · **07-11-08, 07:03 PM**

Quote:

etcarroll wrote:

At the first stage, using 1Kh tone to set levels, how do you know when this process is done?

The instructions on what to do at each stage in the process are in the help box on the settings panel, it updates at each step to explain how to proceed.

From your screenshot it looks like either the input you are connected to is not set as the default (i.e. not selected via the Windows sound control panel or the soundcard's mixer) or your loopback is connected to the wrong channel (i.e. left instead of right).

Can you select the output and input you are using from the input and output drop-downs in the settings panel? If you can, you may then also find you can check the boxes to control input and output volume and use the level controls in the REW settings panel, otherwise you will need to use your soundcard's controls or the Windows level settings.

**etcarroll** · **07-11-08, 08:37 PM**

Quote:

JohnM wrote:

The instructions on what to do at each stage in the process are in the help box on the settings panel, it updates at each step to explain how to proceed.

From your screenshot it looks like either the input you are connected to is not set as the default (i.e. not selected via the Windows sound control panel or the soundcard's mixer) or your loopback is connected to the wrong channel (i.e. left instead of right).

Can you select the output and input you are using from the input and output drop-downs in the settings panel? If you can, you may then also find you can check the boxes to control input and output volume and use the level controls in the REW settings panel, otherwise you will need to use your soundcard's controls or the Windows level settings.

JohnM -

Flipping the loopback wire to use the other channel did it, but now I get the clipping error, at a sweep level of -6db, but input and poutput are within 3db. I have to go to -11db sweep level to get enough headroom that I don't clip, but now input and output values are 7db apart.

I can select the M-Audio card in the device dropdowns, they were in my screencap.

**etcarroll** · **07-11-08, 09:03 PM**

think I figured it out, here's 2 new screencaps;

Edit: Looks like I'll have to wait till tomorrow, Sunday, to get back to this, my son and his friends have invaded.

**JohnM** · **07-12-08, 06:04 AM**

Looks good.

**etcarroll** · **07-12-08, 02:48 PM**

I ran through the steps for testing my sc eq, ie, unchecked c-weighting, cleared the cal. file, and got this graph, but it doesn't look like what the help file shows to me;

**brucek** · **07-12-08, 03:01 PM**

Well, it's actually correct, except you only measured to 20Hz. You need to set the end frequency to 20KHz in the Measure routine to test the full spectrum. See how nice and flat the line is to 20Hz (red line). That's the measure of the loopback cable with the soundcard cal applied in reverse to the measurement, so it's flat.

brucek

**etcarroll** · **07-12-08, 03:42 PM**

bruce & john -

Thanks for the patience. I originally tested my eq @ 20,000, but that graph looked even worse. Just so you know, I'm using a Tosh 57" RPTV as my monitor, as it's attached to my htpc which has REW installed. Its tough to read text this way.

So, when I didn't like the look of the 1st graph, I went into help to look at the process closer, and thought it showed 20, not 20,000 in the example, so I retested at 20, which is how I got to the screen cap I posted.

So looks like next step for me is to begin the eq process tomorrow.

Here's a question, I went to the F2 help, clicked on the graph, and went through the tabs to understand them, but can't find an explanation for the blue vertical line. Mine is at 1.5k, but reading other threads, its at different locations. Just what is that blue line/reading significant for?

Gene

**salvasol** · **07-12-08, 03:50 PM**

Quote:

etcarroll wrote:

... can't find an explanation for the blue vertical line. Mine is at 1.5k, but reading other threads, its at different locations. Just what is that blue line/reading significant for?

Don't worry about that line ... it comes up when you use your mouse and click the graph you can move it anywhere (usually when I post a graph I try to keep it at the begining of the graph)

I couldn't resist to ask you this: What happenned with the invasion???

**etcarroll** · **07-12-08, 04:12 PM**

A group of 13 yr. old boys drinking soda, playing xbox, blasting music and generally being stupid/goofy.

I'm hiding at kitchen island with my laptop typing this.

My wife works tomorrow, I'll throw my son out, and get down to the real work.

**brucek** · **07-12-08, 04:24 PM**

Quote:

can't find an explanation for the blue vertical line.

It's a cursor line for your convenience.

If you move the mouse around the screen you can observe the level and frequency in the bottom right hand corner as shown in the attached jpg.

If you click and hold the left mouse button, then cursor line will glue itself and track the mouse until you let go.

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burcek

**etcarroll** · **07-12-08, 09:17 PM**

Thanks Bruce, now a 'theory' question.

I read through all the help file so I'll understand what I'm doing tomorrow, and hopefully ask less stupid questions. But here's what I thought at the end, it's neat that REW will build me a table of the peaks, and provide feedback on taming them. But all I have on the back of the SVS is a single band PEQ, so after I attack the worst peak with that, then what?

Move the sub around to try to find the best location for an already fairly flat response so the PEQ only has to deal with the worst of what's left?

Is this why folks buy the BFD, because it will allow dealing with numerous peaks?

Gene

EDIT: Was just looking for the settings for BFD in REW to see what they offer, and saw R_DES, and remembered I have one, it came with my RS1Ks. So, to amend the above post, is the theory to position the sub in best spot, (I really only have two), then use PEQ for worst offender, and R-DES for up to 5 more peaks?

**brucek** · **07-13-08, 10:23 AM**

Quote:

Is this why folks buy the BFD, because it will allow dealing with numerous peaks?

Yes...

Quote:

is the theory to position the sub in best spot, (I really only have two), then use PEQ for worst offender, and R-DES for up to 5 more peaks?

Yes...

brucek

**etcarroll** · **07-13-08, 11:04 AM**

Quote:

brucek wrote:

Yes...

Yes...

brucek

Thanks, after 5 tries to get a good measurement, (realized FINALLY I had meter plugged into wrong channel), I got a good reading/graph just now.

Have to go into TIPS I think to see how to space out graph lines, I only set reading for o to 200, so my reading is all 'scrunched into a small space of a 0 to 20,000 graph.

**etcarroll** · **07-13-08, 11:20 AM**

So here we go, 1st sweep of SVS pb12+/2, one port blocked and subsonic filter set at 20Hz, Peq off, XO off as set at 100 at AVR, (that's the lowest it goes).

**brucek** · **07-13-08, 11:48 AM**

The graph axis is set by clicking the Graph Limits icon in the top right corner of REW.
Set the vertical to 45dB-105dB and horizontal to 15Hz-200Hz. Once entered, you can simply click that icon and apply without re-entering the values.

Normally, the best way to test and find the best location for a sub would be to remove the mains and run the sub alone. Use your standard crossover in the receiver and be sure it's in stereo mode with all effects and soundfields off. Once you have the sub eq'd, then add the mains and check the integration between the sub and mains.

You do seem to have a bit of a peak around 60Hz.

brucek

**etcarroll** · **07-13-08, 12:06 PM**

I ran a cord direct from my htpc to sub, so mains are not engaged.

Sub is on a sidewall, only other location is corner on opposite wall, which was my original location but it met with poor WAF as it blocked access to windows.

I'm interested in the fact that the 1st thing you noted was the peak at 60Hz, I thought that 3rd most important in things to note, after the small plateau at 22 to 26HZ, followed by the peak at 33-34Hz.

My main concern is the boominess/muddiness in music. Do you think the 60Hz peak is what's doing that?

Meanwhile, I'm going to move sub over to original install location in corner and run another sweep.

Quote:

brucek wrote:

The graph axis is set by clicking the Graph Limits icon in the top right corner of REW.
Set the vertical to 45dB-105dB and horizontal to 15Hz-200Hz. Once entered, you can simply click that icon and apply without re-entering the values.

Normally, the best way to test and find the best location for a sub would be to remove the mains and run the sub alone. Use your standard crossover in the receiver and be sure it's in stereo mode with all effects and soundfields off. Once you have the sub eq'd, then add the mains and check the integration between the sub and mains.

You do seem to have a bit of a peak around 60Hz.

brucek

**brucek** · **07-13-08, 12:34 PM**

Quote:

I ran a cord direct from my htpc to sub

This results in not being able to observe the sub through the crossover, which is something you really want to see. The crossover affects the level of the sub as the frequency increases. Peaks near or above can be greatly reduced (and perhaps ignored) as a result. You need to see this. Run REW through the receiver with the mains off.

Quote:

My main concern is the boominess/muddiness in music. Do you think the 60Hz peak is what's doing that?

A lot more than a peak at 25Hz would be affecting the music. There is very little content at 25Hz in music.

brucek

**etcarroll** · **07-13-08, 12:43 PM**

Quote:

brucek wrote:

This results in not being able to observe the sub through the crossover, which is something you really want to see. The crossover affects the level of the sub as the frequency increases. Peaks near or above can be greatly reduced (and perhaps ignored) as a result. You need to see this. Run REW through the receiver with the mains off.

A lot more than a peak at 25Hz would be affecting the music. There is very little content at 25Hz in music.

brucek

RE: crossover - OK then, that's next. Glad I saw this before I moved the sub, its a monster.

RE: 60Hz peak - actually that had occurred to me already. This sub is really for movie viewing, or, being the .1 in a 5/7.1 setup.

I've ordered a 10" sealed sub for my 2 channel listening. I'm learning REW on my present .1 sub so I can really dial in the expected 10" sub for music listening, it will be mated to a pair of bookshelf speakers in a 2.1 setup.

**etcarroll** · **07-13-08, 01:05 PM**

Through the AVR, mains off, reset levels and recal. the SPL meter prior to this sweep;

**etcarroll** · **07-13-08, 02:58 PM**

Following the directions in the SVS manual, I set the PEQ filter for the 60Hz peak, then tweaked it twice, got the following;

**salvasol** · **07-13-08, 03:15 PM**

Quote:

etcarroll wrote:

Following the directions in the SVS manual, I set the PEQ filter for the 60Hz peak, then tweaked it twice, got the following;

Looking better

I would not worry about getting a flat frequency response ... but play with REW, your sub placement , etc. to find the best spot and learn what you have to do to adjust/change the frequency response

I'm sure you'll think: Why is he telling me this??? ... so I

Quote:

... Pio AVR that only goes down to xo of 100, but replacing it soon....

Just learn a lot, so when you get your new AVR you'll be able to get the best frequency response and the best from your system

... most newer AVR have a PEQ already, that combined with your sub PEQ filter and you're okay ... maybe you won't need a BFD

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