# sub hums if I turn on SPL meter



## subby (Aug 17, 2007)

Hi, I'm about to calibrate my SVS PB10.

But my sub starts humming if I turn on my spl meter. If I turn the spl meter to 80 db it hums so hard my ears almost pop. :scared:

I also have trouble calibrating the soundcard. If I measure and the sweeping sound comes it only measures about -78db fs. But almost whole my house depresurizes from the sweeping sound. is that to load or to quit?

I'm using the M-audio Delta 44 soundcard btw.


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## brucek (Apr 11, 2006)

> But my sub starts humming if I turn on my spl meter


This would indicate that the cable ground is bad. Are you using an RCA type connector at the meter and a 1/8" stereo phono connector at the soundcard with a proper shielded coaxial type cable between?



> I also have trouble calibrating the soundcard. If I measure and the sweeping sound comes it only measures about -78db fs. But almost whole my house depresurizes from the sweeping sound. is that to load or to quit?


When you do a soundcard calibration there should be no sound at all, since it involves hooking a single stereo jumper cable from line-out to line-in of the soundcard. Where is the 'sweeping' sound coming from?

brucek


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## subby (Aug 17, 2007)

I've hooked up my cables exactly like it shows in the picture with the help files.

I've hooked up the cables like you said just from the 1 line in to the line out and I don't heard the sweaping sound anymore indeed. But I still only get a measure of 53 db wich is still too low.

I Can hear everything from the sub that the spl meter hears. If I hold the spl meter to my chest I can actually hear my heartbeat.


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## subby (Aug 17, 2007)

Ok, it was indeed a bad connection. The coacial input was to thick at the edge for the input on the RS spl meter (wich is kinda turned more inside the spl meter itself. But I took a nife and cut a piece of the edge away and now the distorting rumble is gone.

now only remains the problem with the soundcard calibration where the measured sweep seams to be to low (only 53 db fs). So I get that warning every time after the sweep.


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## brucek (Apr 11, 2006)

> now only remains the problem with the soundcard calibration where the measured sweep seams to be to low


Tell me about the cable and connectors you're using for the loopback here. 

brucek


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## subby (Aug 17, 2007)

well, the cable should be quit decent. it's just a coax cable with a phono to 1/8 RCA plug at both ends. 

I have more doubts about the sound card or maybe the soundcard settings. As I said I have the M-audio delta 44 soundcard wich has a break out box with 4 line ins and 4 line outs. the break out box is connected to the soundcard. you think this soundcard should do the trick? I don't want to spend any more money as needed if this soundcard already is all I need.

http://www.m-audio.com/products/en_us/Delta44-main.html


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## brucek (Apr 11, 2006)

> well, the cable should be quit decent. it's just a coax cable with a phono to 1/8 RCA plug at both ends


This confuses me somewhat.

The soundcard (which should be fine BTW) uses a breakout box that has 4 line-out and 4 line-in channels using 1/4" TRS (for balanced) or 1/4" TS (for unbalanced) connections. In your case you will be using a single channel for REW. You will also have to be aware of the monitor mode, which you want to shut off.

So, tell me again how you have channel one configured and wired (connector and cable) to setup the soundcard cal? Why do you have phono to 1/8" ?

brucek


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## subby (Aug 17, 2007)

lolz, guess I might be confused with all the different connections :bigsmile:

It's indeed coax to 1/4 I'm using, that's the connector.the cable is just coax.


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## brucek (Apr 11, 2006)

> guess I might be confused with all the different connections


Yep, no problem.

I think you only need to use channel one with a TS unbalanced 1/4" connector and cable between line-out and line-in. I assume that your equipment will be unbalanced and (of course) the meter is unbalanced, so this should work fine.

Be sure to shut down the monitor mode of channel one before attempting anything. This is a standard problem with soundcards and REW. The monitor mode allows the simultaneous monitoring of the sound while recording, and it should not be used when using REW. Be sure this is disabled before attempting the soundcard calibration.

Do you think this may be your problem in trying to create a soundcard cal file?

Does REW recognize your card and allow you to select the channel in question on the Settings page?

brucek


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## subby (Aug 17, 2007)

No, I can perfectly save a soundcard cal file. It also reconizes my soundcard and I can choose both left and right input channels

at the input and output device I have the option to choose between Delta 44 1/2, Delta 44 3/4 or Delta 44 multi. At the intput device I only have line-in when I choose delta 44 multi. with Delta 44 1/2 and 3/4 I only get wave. at the output I can choose SPEAKER in all 3 options though.

I unselected the monitor mixer option but I still don't get below 59 db fs.

I don't really know what you mean by unbalanced TS connector though.


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## brucek (Apr 11, 2006)

> I don't really know what you mean by unbalanced TS connector though.


Unbalanced TS is a two position 1/4 " connector (shown in the bottom of the two connectors) with the Tip and Sleeve connected as opposed to balanced TRS (top picture), which is a three position Tip, Ring, Sleeve connected. Your device allows both, and automatically compensates for the correct levels (like a BFD).

You would use TS, since the meter is unbalanced and likely your equipment (receiver) is unbalanced....










brucek


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## subby (Aug 17, 2007)

Oh, you mean I'm going to have to buy new coax to TS 1/4 connectors? :doh:

I doubt the problem lays there


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## brucek (Apr 11, 2006)

> Oh, you mean I'm going to have to buy new coax to TS 1/4 connectors?


How do you propose to connect an RCA unbalanced SPL meter to the soundcard without an unbalanced TS connector?

brucek


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## subby (Aug 17, 2007)

But were not even in that stage yet. The problem is now that the soundcard is measured to low. The spl meter isn't connected yet, only line in with line out. Or has it anything to do with the soundcard being unbalanced?

I wonder why this isn't mentioned in the REW guide that you need a ST 1/4 jack if it's so importent.


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## brucek (Apr 11, 2006)

> But were not even in that stage yet.


Yeah, I realize that, and you're correct. I was only responding to your statement that you would have to purchase new connectors. I meant that in the end, there is no getting around it. The meter is unbalanced, so you'll eventually require the unbalanced hookup. 



> The problem is now that the soundcard is measured to low. The spl meter isn't connected yet, only line in with line out. Or has it anything to do with the soundcard being unbalanced?.


Yeah, the soundcard cal is definitely the first problem at hand, and that can be accomplished with a balanced (or unbalanced) conection between line-out and line-in of one channel.

Are you able to make that connection and select it in REW. In other words, is the channel one selected when you select LEFT in REW or RIGHT. Try both.



> I wonder why this isn't mentioned in the REW guide that you need a ST 1/4 jack if it's so importent.


Because 99.9 % of soundcards simply use a 1/8" unbalanced connector which supports left and right channel. Your breakout box is unusual. 

brucek


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

subby said:


> The problem is now that the soundcard is measured to low. The spl meter isn't connected yet, only line in with line out. Or has it anything to do with the soundcard being unbalanced?
> 
> I wonder why this isn't mentioned in the REW guide that you need a ST 1/4 jack if it's so importent.


1. If the soundcard is unbalanced you don’t need a “ST 1/4 jack.”

2. Probably because few of us home audio types have pro sound cards.

Regards,
Wayne


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## subby (Aug 17, 2007)

I use about 4 phono to 1/4 jack sockets right now. Do I have to replace them all 4 with a ST unbalanced phono to 1/4 socket or should one be enough to unbalance the signal?


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## subby (Aug 17, 2007)

Ok, I found a 1/8 jack to 1/4 TS jack plug. So I took 2 stereo cinch cable that leads to a 1/8 ST plug and put the 2 SRT plugs on the cinch cables and plugged them both into a line in 1 and 2 input. the other end I put the 1/8 ST plug into the 1/4 ST plug and put it in a line out. Now REW measures 9db witch should be enough. If I do it the other way around it doesn't work anymore though.

But do I still ned to buy 3 other ST plugs or is one enough? And is it alright that I had only 1 ST plug into the line out but 2 stereo cables in the line ins? they're both the same cable though.


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## brucek (Apr 11, 2006)

> a 1/8 jack to 1/4 TS jack plug. So I took 2 stereo cinch cable that leads to a 1/8 ST plug and put the 2 SRT plugs on the cinch cables and plugged them both into a line in 1 and 2 input. the other end I put the 1/8 ST plug into the 1/4 ST plug and put it in a line out.


I'm somewhat confused by what you're telling me. 

Hopefully when you say 1/4 ST you mean 1/4" TS (Tip Sleeve) connector and when you say 2 SRT you mean, quantity two 1/4" TRS (Tip Ring Sleeve) connector? And does 1/8 ST mean 1/8 " phono stereo? I'm also not familiar with the word cinch cable either I'm afraid.


Here's the simplest solution.

You need to get - quantity two, adapters like this one at Radio Shack - very cheap. It's an RCA to 1/4" TS adapter.










They accept a standard RCA cable (which is a mono coax interconnect with RCA connectors on the end). Everyone has lots of them lying around.

Simply connect channel one line-out to channel one line-in of your breakout box as seen below, by using the two adapters shown above and an RCA cable.









brucek


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## subby (Aug 17, 2007)

Well if you explain everything like that. I must say I have done what was your instructions from the start. So I'm doing everything right.

Think I got unbalanced confused with unbalanced. Because the picture what you show of that coax to RCA is what I've been using from the beginning. Cinch cable is the same as a phono cable. sorry about all the spelling mistakes though.

Actually I just meant mini jack that weant into a 1/4 jack (with the 2 black rings, so that must've been a balanced one). funny, the soundcard got calibrated with that cable but after that the cable was full of noise and I couldn't check the levels of my subwoofer properly. Also my soundcard couldn't hear my spl meter during the calibration (and that was connected just as you told, coax cable with RCA plug). the spl meter works fine though.

I think the problem might be with my soundcard because I tried all different settings. I might e-mail M-audio and ask about the question. But they don't know REW probebly. I just hope I don't have to spend money on another sound card.


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## brucek (Apr 11, 2006)

> I must say I have done what was your instructions from the start. So I'm doing everything right.


OK, that's great - I just wanted to make sure we were on the same page.

So, with just the one mono unbalanced cable hooked between line-out and line-in of channel one, and REW recognizing the presence of the card, and selecting Right or Left in REW (depending on whether Right or Left corresponds to Channel one of the 44 breakout box), are you able to get a decent soundcard calibration? and save that file as soundcard.cal............

brucek


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## subby (Aug 17, 2007)

It still only get's to 59 db fs wich should still be too low according to REW, but I can save it as a soundcard.cal file.


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## brucek (Apr 11, 2006)

And how does the file look?

Can you post it?

Example - here's my soundcard file. Set the Graph axis limits from 2Hz to 25Khz and check the soundcard box....









brucek


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## subby (Aug 17, 2007)

This is what it looks like if I push ok when I get the error message.


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## brucek (Apr 11, 2006)

That shows an oscillation. Be sure you have all the 'effects' including equalizers, surround, etc turned off.

Are you not able to increase the Wave and Output level and the sweep level higher and get a decent signal into the line-in?

brucek


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## subby (Aug 17, 2007)

I can only increase the sweep level. Do get to 50 db now instead of 59 db if I turn the sweep level to -3.0db

Nothing else is connected but the line input to the line output.


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## brucek (Apr 11, 2006)

> I can only increase the sweep level.


Aha, maybe we're getting somewhere.

Why can't you control the Wave and Output level?

Here's what my Settings screen looks like during a soundcard cal routine. Are you not able to change the levels?











brucek


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## subby (Aug 17, 2007)

brucek said:


> Are you not able to change the levels?


nop, only the sweep level.

I can also choose "intel(r) integrated audio" as soundcard and then I do can increase wave volume, output volume and input volume. In this case I get to about 38db witch is already better but still not enough. I also don't know if this is right because I don't know if I still use Delta 44 or the break out box then.

I also see u use the realtek AC97 soundcard. We also have it my dad's laptop but it only has a microphone and headphone input.


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## brucek (Apr 11, 2006)

> it only has a microphone and headphone


Nope - no good - can't use a microphone input. People with laptops have to purchase external USB soundcards..



> nope, only the sweep level


OK, sometimes REW can't see the volume controls of some drivers. No problem, go to the soundcards own mixer (usually found in Control Panel) and adjust the Wave volume and line-in volume from there. 

Failing that, control it from the Windows mixer itself. Give that a try. It should make a difference

brucek


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## subby (Aug 17, 2007)

on the pannels both soundcards (intel(r) integrated soundcard and Delta 44) were already set to it's highes level possibles. Both the wave volume and the line-in volume.


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## brucek (Apr 11, 2006)

I wonder if you tried another one of the four channels if it would make a difference - probably not.

Seems strange that a soundcard as good as that one can't get enough level to loopback to itself.

I'm kinda stumped here.......... :thud:


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## subby (Aug 17, 2007)

brucek said:


> I wonder if you tried another one of the four channels if it would make a difference - probably not.


Yes, I already tried that before without any result.

But I tried something else this morning and it might be I'm on to something.

I took a regular stereo cable and I plugged all 4 the phono to RCA plugs at both ends.
So in the line outs 2 cables and in the line ins 2 cables. And again it worked and got to 9db fs wich is enough. I think the break out box or soundcard only reads the signal if it comes from 2 cables. This is only so with the line ins though. So I might have some good news and bad news.

the good news is that we may have solved the problem this time. the bad news is that I may need to find a plug that has a phono in at both ends and a cable that devides a mono signel into 2 cables. wich means only one cable at the one end and devides into 2 cables at the other end. So even though the signal from the spl meter is only mono I might still have to devide over 2 cables. I think the soundcard only reads a signal if it comes from to cables.

The line out shouldn't be a problem with only one cable that goes out to the BFD.

very strange though.

any sugestions to make it easier that have to buy a new cable and phono to phono plug?(the cable from my spl meter to my soundcard is 10 meters so I can't replace that cable or I have to move my whole pc equipment to my room)


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## brucek (Apr 11, 2006)

I don't understand the logic behind this working, but can't argue if it's successful. Have you examined the soundcards software application in the areas of channel balance etc to find a clue?

Either way, it's easy enough to split a line-out signal to two with a Y-splitter. They come in all varieties from Radio Shack like this RCA one:










Have you been able to create a decent soundcard calibration file?

brucek


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## subby (Aug 17, 2007)

Nice, I still had such plug as seen on that picture of you somewhere deep in a closet.

The soundcard calibration went fine and I could succefully save it as a cal.file. The measure without the C weighting wich you have to do after the soundcard calibration also at 9db.

Now comes the tricky part: Checking levels. There seems to be a signal coming in from the spl meter. I just don't when I have the right level and how to read it. I find the instructions of the REW helpfile a but vague at this stage. The only thing I know is I have to get to 75db, but where do I have to read it? Do I have to look to the input peak level or at the spl meter? Or do I have to read 10db on the input peak level while my spl meter level indicator and range shows 75db?


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## brucek (Apr 11, 2006)

> Now comes the tricky part: Checking levels. There seems to be a signal coming in from the spl meter. I just don't when I have the right level and how to read it.


Here's a shorter version of the important steps left to do......

You have removed the loopback you used to create the soundcard.cal file and hooked up the Line-out of the soundcard (left and right) and connected both channels to your receiver AUX or CD input and put the receiver in stereo mode.

Hook up the SPL meter to the Line-in and select that same channel in REW in the Settings icon.

1. Ensure the soundcard and SPL meter calibration files are both loaded (the soundcard.cal you already created and stored). 

2. Run the Check Levels routine (in Settings icon) selecting Subwoofer in the Levels pull down, with the SPL meter at the listening position and the dial of the meter at 80dB position. 
Ensure the REW output VU meter is at -12db and the sweep level at -12dB. 
Set the Wave Volume at 1.000 and the Output Volume about ~0.500 or higher if needed. 
Then adjust the receiver volume control so the actual standalone SPL meter reads ~75db at the listening position. 
Then adjust REW input volume to end up with -12dB on the REW input VU meter.

3. Run the Calibrate SPL routine (in the meter tab) to match REW's SPL meter to the real SPL meter to ~75dBSPL.

4. Run the Set Target Level routine, which will set the target to ~75dB.

5. Run the Measure routine and set the End Frequency to 200Hz for subwoofers.

6. Measure.................... (use a larger number of sweeps and longer length for more accuracy and less noise)

7. Using the Graph Axis Limits icon, set the vertical scale to 45dB to 105dB and the horizontal scale for subs to 15Hz to 200Hz.

brucek


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## subby (Aug 17, 2007)

brucek said:


> You have removed the loopback you used to create the soundcard.cal file and hooked up the Line-out of the soundcard (left and right) and connected both channels to your receiver AUX or CD input and put the receiver in stereo mode.


Is it also ok if I just plug it in the BFD? Because I'm planning to calibrate my sub and then finally just set my receiver's sub level to 0.0db.


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## brucek (Apr 11, 2006)

> Is it also ok if I just plug it in the BFD? Because I'm planning to calibrate my sub and then finally just set my receiver's sub level to 0.0db.


You really need the receiver in play for a several reasons.

It provides a very convenient volume control over the signal to set your 75dB for the test.

It provides the bass management of the sub and mains signal, so you are able to integrate the two together. This is quite important to the final result.

The subwoofer speaker level trim set by the receiver is adjusted as per the BFD Guide and should be set up first. See the BFD Guide on Setting the Input Levels of the BFD.

brucek


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## subby (Aug 17, 2007)

brucek said:


> You really need the receiver in play for a several reasons.


Ok, I understand. But is it ok if I use my BFD as a piece for in between because my kinda out of Coax cables that are long enough from my line out to my receiver. So is it ok if I send an RCA cable from my line out to my BFD and then a coax cable from my BFD to my receiver? Or is it important that the BFD doesn't interfier in that signal. I have the impression that the BFD doesn't change the signal volume unless you change the frequentie volume.

So I'm basivly only going to use the BFD as piece to connect the wires in this stage because I'm out of cables that are long enough.

edit: I started the check level routine through my receiver. I set the level of my receiver so that my spl needle was set to 75db but on the VU meter in REW it only reads 40db.


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## brucek (Apr 11, 2006)

The BFD is connected between the output of the receiver and the input of the subwoofer. 

I'm a bit confused about what you propose. If your cables aren't long enough to reach the receiver, then you could simply extend them with another set of cables using in-line couplers.

brucek


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## subby (Aug 17, 2007)

I don't understand why the BFD is already necesairy to be connected between the receiver and the sub if all frequenties in the BFD are still set at 0.0db so they won't change anything in the signal.

edit: I started the check level routine through my receiver. I set the level of my receiver so that my spl needle indicated 75db but on the VU meter in REW it only reads 40db.


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## brucek (Apr 11, 2006)

> I don't understand why the BFD is already necesairy to be connected between the receiver and the sub if all frequenties in the BFD are still set at 0.0db so they won't change anything in the signal.


I'm confused about why you are concerned about this. What are you proposing and why?



> I set the level of my receiver so that my spl needle indicated 75db but on the VU meter in REW it only reads 40db.


Sounds like the SPL meter is not connected properly to the line-in of the soundcard. You're not getting a signal from the SPL meter into REW through the soundcard input. Does the SPL meter and cable function properly - you can test the meter and its cable by plugging it into the receiver (AUX input) and test it like any other microphone....

brucek


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## subby (Aug 17, 2007)

brucek said:


> I'm confused about why you are concerned about this. What are you proposing and why?


Well I don't have these in-line couplers at this point. So unless it really necearly I might just do the level check as I'm doing right now. I already set up the level of my sub with the help of my receiver's MCACC function.

Just checked the cables and SPL meter and it works fine. I hope it's not my soundcard again that can't receive the spl's signal properly.


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## subby (Aug 17, 2007)

brucek said:


> 3. Run the Calibrate SPL routine (in the meter tab) to match REW's SPL meter to the real SPL meter to ~75dBSPL.


is it also ok if I just load the RS spl meter cal.file that you can download from HTshack in the download section?


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## brucek (Apr 11, 2006)

> is it also ok if I just load the RS spl meter cal.file that you can download from HTshack in the download section?


You definitely need to load the RS SPL meter calibration file from the download section (pick the model you own), *and* you also need to run the Calibrate SPL routine in REW. These are completely separate issues. Both quite necessary.

The calibration file compensates for known inadequacies that the SPL meter suffer from.
The Calibrate SPL routine in REW matches the REW SPL readout to equal the 75dBSPL set at the listening position, so that they may track accurately.

brucek


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## subby (Aug 17, 2007)

ok, I understand

what concerns the low spl signal. I might not exlude the possibility that I have to devide the SPL's signal over all 4 line inputs of the souncard's break outbox. I know, it wouldn't make sence to me either. But the case that the 2 wires now give only have the volume that I have to get, maybe the soundcard will get the full signal if it receives the signal over all 4 line input. It's going to complicated with all the cables and in line couplers that I have to put in between and I'm probebly going to have to run to the store tomorrow for that. If that doesn't work I see no other option then to e-mail M-audio. My only concern is that they probebly don't know REW and maybe can't help me very far. 

In the worst case scenario I'm going to have to buy an extern soundcard but I hope it doesn't come to that.


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## subby (Aug 17, 2007)

ok, I just found something out.

The reason that I only got a proper signal to the line in with a stereo cable during the soundcard calibration didn't have anything to do with the stereo cable. I just found out that I only get a proper signal if I use the 2nd line in port, only then I get to 10 db. the 1ste, 3th and 4th line in port only get me to 53db.

But during the check levels routine, I only get to 40db as I already said. Connections and all the settings in the control panel are fine though. So I just e-mailed M-audio. I also send them a link to the help files of REW so they can get a better idea of REW and what my settings need to be.

UPDATE: ok, everything seams to be working as it should be. I was wrong about the other line in channels being broken or not working. I just forgot that I had to switch in put channel left or right. 
The only problem now is still the SPL's signal that comes in too weak and the VU input level only indicates 39db while the SPL's needles points to 75db. 

is there maybe a possibility that the SPL meter's build in amp sends out the signal too weak?


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## brucek (Apr 11, 2006)

> is there maybe a possibility that the SPL meter's build in amp sends out the signal too weak?


No, it's a typical line level signal.

brucek


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## subby (Aug 17, 2007)

So it defenetly should be my soundcard? because I already checked with another cable and it's the same result.


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## subby (Aug 17, 2007)

Any suggestions? :dontknow:


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## brucek (Apr 11, 2006)

I can only suggest getting a cheap soundcard. It isn't worth the effort messing around for the price of a soundcard ~$25

brucek


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## subby (Aug 17, 2007)

You know any cheap extern soundcards around that price that will defenetly do the job? Because here in Belgium we don't have the Soundblaster 24bit Live! soundcard and it's already 40$.


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## subby (Aug 17, 2007)

Or is there maybe another possibility how I can know witch frequenties that are too loud and try to do it manually just with the BFD for now untill I have another soundcard and give REW another try?


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## subby (Aug 17, 2007)

Ok, Brucek, I forgot to thank you for your great help so far. I really appriciete it.

After a week of rest I tried our pc's onboard soundcard wich also seamed to have a line in and line out. The problems of the soundcard calibration and spl signal with the checking levels routine were solved. But I stumbled upon some weird measurements that are far from what I expected. And I'm confused if the volume of the sweep level was't too loud.








[/IMG]
This first measure was done right after the checking levels routine and spl calibration. I did the checking levels as was told and got to about 12db fs. When I did the measure routine first I suddenly got to a headroom that got close to clipping (about 1.5db fs). But when I looked at the graph I was amazed that the peak of 20hz was only so small while during movies the bass seamed to boom more towards the subsonic frequenties then the 40hz. I'm even more astound that there is a drop between 25hz and 35hz.








[/IMG]
before I did the second measure I changed the settings on my soundcard volume panel as instructed in the REW help file. I switched Volume and lin in meter to halfway. then I got to a graph that is more alike with REW's graph. I don't know how to enterpret this graph really and I'm confused if I did the right thing with changing the soundcard levels. During the checking levels rumble the volume was fine but the sweep level almost seemed much louder. I also changed the smoothing octaves to 1/3.


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## brucek (Apr 11, 2006)

OK, I see a few problems.

Never use smoothing for subwoofer frequencies. This is only used when measuring full range.

Note that your graphs are in the LINEAR mode. Change them to LOG mode by clicking on the Freq Axis Icon at the top right hand side of the REW screen.

Also set the horizontal axis to 15hz-200Hz and the vertical axis to 45dB-105dB using the Graph Limits ICON at the top right hand side of the REW screen.

brucek


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## subby (Aug 17, 2007)

Ok, I'll try that. But now I still don't know wich of those 2 graphs I did correct. And is it normal that the sweeping sound during the measure routine is louder then the rumble during the check levels routine? 

Also, I turned my receiver to CD mode for the checking levels because in DVD mode it didn't work. But I know that the bass levels in CD mode are a but softer then in DVD mode.









This is a new graph I took this morning. It was done with the normal levels that were set during the checking levels routine. But during the measuring sweep REW recorded clipping. That's weird because during the checking levels routine the level was just 12db as instructed by REW. I also don't if it's the black line or the blue line that's REW refference line.









Does this look ok? I still think it's very weird that there is't really a peak around 20 - 30Hz. I'm sure that the boom I sometimes hear is beneath 30Hz and especially in bass tones in filmscores. Maybe I did the sweep too low?


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## subby (Aug 17, 2007)

ok, I did quit a lot of tweaking during the past week and managed to get rid of the peak at 40Hz, 62hz and 75Hz and push the 51Hz dip up. The result is quit pleasing. The bass is more controled and sounds even more tight and detailed sometimes. But most of all it sound more pleasant to listen at. No more loud booming bass that cause me a headake. this counts especially for the deep basstones in filmscores that previously caused a boom in my room.

I'dd like to thank you very much for your help brucek! :clap:

I'dd might to a bit of experimenting in the future to get to a beter result but it probebly will not get much better then it already is.


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## JohnM (Apr 11, 2006)

Remember to select "Optimise PK Gains & Q" after you "Assign Filters", the initial filter assignments REW makes are just starting points for the optimisation.


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