New to REW and looking for some info.

**watsonte** · **02-19-08, 07:48 AM**

So last weekend I finally got a RS SPL and attempted to test the response of my subwoofer, however, an error message popped up every time telling me I had to much head room. The volume was not great enough? Then yesterday evening I tried the same setup and found that the volume was too great.

I am using an X-FI Xtreme Music sound card and the line in is the same as the Microphone, I think, but have read in numerous posts that the Microphone jack is not suitable for testing when connecting the SPL out to the sound card.

More or less I have been reading for a couple of days now trying to figure out what I am doing wrong and was interested in knowing if the Sound Card could be the problem.

Also should I be hearing audio from the L/R channels when testing the subwoofer? Or could I only send sound to the subwoofer using the analog input on the back of my AVR?

Thanks to any who reply. I am very new to this so please bare with me.

**brucek** · **02-19-08, 08:16 AM**

Quote:

have read in numerous posts that the Microphone jack is not suitable for testing when connecting the SPL out to the sound card.

Correct, the mic input is not suitable unless it's the type that can be toggled with software between line-in and mic. Generally, you require a simple line-in since the RS meter outputs a line level out. Note that an SPL meters output is dependant on the scale used.

Quote:

if the Sound Card could be the problem

No, that soundcard is fine. Be sure you're using stereo plugs, since the jacks are stereo. Be sure to turn off all effects and soundfields, and use two speaker stereo mode for the soundcard only.
If you're able to complete the soundcard calibration routine, you're good.

Quote:

Also should I be hearing audio from the L/R channels when testing the subwoofer?

The analog line-out of the soundcard should connect to the AUX or CD in of your receiver. You can use a Y-splitter if you want at that point to enable both left and right mains.

brucek

**watsonte** · **02-19-08, 08:19 AM**

Quote:

brucek wrote:

Correct, the mic input is not suitable unless it's the type that can be toggled with software between line-in and mic. Generally, you require a simple line-in since the RS meter outputs a line level out. Note that an SPL meters output is dependant on the scale used.

No, that soundcard is fine. Be sure you're using stereo plugs, since the jacks are stereo. Be sure to turn off all effects and soundfields, and use two speaker stereo mode for the soundcard only.
If you're able to complete the soundcard calibration routine, you're good.

The analog line-out of the soundcard should connect to the AUX or CD in of your receiver. You can use a Y-splitter if you want at that point to enable both left and right mains.

brucek

Alright thank you for the quick reply I will be certain to go through connections and attempt to get a new sweep.

**watsonte** · **02-19-08, 05:24 PM**

Alright I have finally begun testing again and I think I have an issue when using the line in/mic input on my sound card. I can hear it as though the SPL is a microphone I dont think that should be the case any info in regards to my situation would be greatly appreciated.

**brucek** · **02-19-08, 05:47 PM**

Quote:

I can hear it as though the SPL is a microphone

This is a feature called monitoring that has to be disabled before REW can be used. Every soundcard calls it something different, but it results in the situation you describe. Look in the cards application to find out how to turn it off....

brucek

**watsonte** · **02-19-08, 06:22 PM**

Quote:

brucek wrote:

This is a feature called monitoring that has to be disabled before REW can be used. Every soundcard calls it something different, but it results in the situation you describe. Look in the cards application to find out how to turn it off....

brucek

Is there anything standard when it comes to finding this. I have googled and searched and found practically nothing regarding this and my X-Fi card.

**Canadian_Dude** · **02-19-08, 07:09 PM**

Are you using Vista or XP?

In Vista it will look like this. Make sure the one I circled is disabled

**watsonte** · **02-19-08, 07:19 PM**

Quote:

Canadian_Dude wrote:

Are you using Vista or XP?

In Vista it will look like this. Make sure the one I circled is disabled

Im using XP and I see nothing similar to the menu you have shown. This is actually kinda sad, I am fairly tech savy and have built a number of PCs, I am 1 year away from being an Electrical Engineer and yet I can't seem to turn off my Mic on my PC.

**Canadian_Dude** · **02-19-08, 07:26 PM**

If you open up your volume mixer and go to options I think it is, and then properties, you should see a couple radial buttons with one that says recording and see if you can turn it off there.

**brucek** · **02-19-08, 07:36 PM**

Also see this thread with regard to CMSS and also the red + symbol above the line-in slider. The Soundblaster external may operate the same as the one in the thread I mention.

Either way, post a pic of your soundcard mixer and also the Windows Playback and Record mixer.

brucek

**watsonte** · **02-19-08, 07:45 PM**

Quote:

Canadian_Dude wrote:

If you open up your volume mixer and go to options I think it is, and then properties, you should see a couple radial buttons with one that says recording and see if you can turn it off there.

Im beginning to wonder if it is the sound card, I have tried muting it and disabling the microphone in the properties and nothing seems to work. It seems as though the Mic/Line In is only both and never just one or the other.

**watsonte** · **02-19-08, 07:46 PM**

Quote:

brucek wrote:

Also see this thread with regard to CMSS and also the red + symbol above the line-in slider. The Soundblaster external may operate the same as the one in the thread I mention.

Either way, post a pic of your soundcard mixer and also the Windows Playback and Record mixer.

brucek

Will do. And I did check out that thread and for whatever reason my Mixer is not similar to the one used in that thread.

**watsonte** · **02-19-08, 08:08 PM**

http://i58.photobucket.com/albums/g253/watsonte/REW.jpg

Here are the Mixer play control and mixer properties menus.

**brucek** · **02-19-08, 08:15 PM**

Yeah, I can't see that picture too clear.

Can you just post it on the site like the pics below of Playback and Record.

I do think I see the Line-in not muted in Playback. It should be.

See mine below and the Line-in is muted in playback (no monitor mode), but selected in Record.

PLAYBACK
Windows MIXER Playback.jpg

RECORD
Windows MIXER Record.jpg

brucek

**watsonte** · **02-19-08, 08:26 PM**

Quote:

brucek wrote:

Yeah, I can't see that picture too clear.

Can you just post it on the site like the pics below of Playback and Record.

I do think I see the Line-in not muted in Playback. It should be.

See mine below and the Line-in is muted in playback (no monitor mode), but selected in Record.

PLAYBACK
Attachment 6321

RECORD
Attachment 6322

brucek

Yeah... sorry about the pic, but, I will do as you suggested.

**Canadian_Dude** · **02-19-08, 09:02 PM**

I also see that you don't have the Line-in checked in your properties menu.

**watsonte** · **02-20-08, 07:29 AM**

I had gone through a series of menus attempting to turn off the microphone, but was unable to do so. I did try using only the Line-in for Recording and still it did not turn the Microphone function off.

I had manage to edit enough menus to disable the sound card so after starting up the PC today I had no sound. I will try going through the whole process again later on this afternoon.

Thanks again for all your help.

**watsonte** · **02-20-08, 05:14 PM**

Alright so started over entirely and sure enough your suggestions did work thanks again for the help brucek and canadian dude...

Now I just have to figure out how to calibrate my sound card.

After the first couple of runs I was getting a pretty consistant graph, any thoughts on the graph below would be greatly appreciated, the sub I am using is an Epik Knight, I have the crossover set to 80hz and all of my speakers set to small-80hz, using an HK AVR 445.

**brucek** · **02-20-08, 05:37 PM**

The first thing you need to do when measuring a sub is set the vertical axis to 45dB-105dB and horizontal axis to 15Hz -200Hz. This is the standard values we use here and allows for easy comparisons for everyone. The Graph Limits are set with the Graph Limits button in the top right corner of REW and you simply recall it anytime the axis changes.

When you measure a sub first, you want to measure it alone without the mains so you can see its singular response. So, disconnect your mains. (be sure the power is off

). Also be sure the receiver is in stereo with all effects off and the crossover set.

brucek

**watsonte** · **02-20-08, 05:49 PM**

Quote:

brucek wrote:

The first thing you need to do when measuring a sub is set the vertical axis to 45dB-105dB and horizontal axis to 15Hz -200Hz. This is the standard values we use here and allows for easy comparisons for everyone. The Graph Limits are set with the Graph Limits button in the top right corner of REW and you simply recall it anytime the axis changes.

When you measure a sub first, you want to measure it alone without the mains so you can see its singular response. So, disconnect your mains. (be sure the power is off

). Also be sure the receiver is in stereo with all effects off and the crossover set.

brucek

Alright will do, thanks again.

**watsonte** · **02-20-08, 05:58 PM**

When measuring only the Subwoofer how close should the SPL meter be to the subwoofer? Or should the volume of the subwoofer or AVR be adjusted to account for the difference in volume when only measuring the sub?

**watsonte** · **02-20-08, 06:05 PM**

Well, here is the response with MV @ -25db...

**brucek** · **02-20-08, 06:10 PM**

Quote:

When measuring only the Subwoofer how close should the SPL meter be to the subwoofer? Or should the volume of the subwoofer or AVR be adjusted to account for the difference in volume when only measuring the sub?

The mic should be at your normal listening position. REW is set up to 75dB at the listening position. Your target is way off. Set the target level to 75dB.

Also set your graphs to LOG and not LIN.

brucek

**watsonte** · **02-20-08, 06:33 PM**

Quote:

brucek wrote:

The mic should be at your normal listening position. REW is set up to 75dB at the listening position. Your target is way off. Set the target level to 75dB.

Also set your graphs to LOG and not LIN.

brucek

When I am attempting to set the target level I should use the AVRs volume to match that target level correct? Also, I seem to have an issue when setting the target volume, but, I am not sure how to correct it as all connections are made and are correct to the best of my knowledge.

Edit: More issues, no feedback from the SPL Meter, it seems as though my SPL meter has stopped working, I get zero input readings when running REW now. Any reason this may have occured?

**brucek** · **02-20-08, 06:52 PM**

Quote:

When I am attempting to set the target level I should use the AVRs volume to match that target level correct?

Yes, just run the Settings Check Level routine and set the level at the listening position to 75dB using the SPL meter. Then set the Input Level correctly and then run the Calibrate SPL routine, which just matches the REW SPL meter reading with the real SPL meter (so they track).

No idea why your meter isn't working. Plug it into the AUX of your reciever and see if it works - it's a microphone - talk into it.

brucek

Advertisement