# trouble integrating my sub using spl meter



## jwynne5227 (Mar 13, 2013)

The trouble is that when i set my reference level to 75 db using the pink noise, then when i use say an 80 hz tone or lower to set the subs level then i cant get the 75 db level without turning the sub completely off because of the bass thats coming from the front speakers, anything added by the sub registers too much on the spl meter, and thats with the speakers set to small, and the crossover at 80 hz, I've even tried in pure direct mode and the same problem. I'm totally stumped and any help would be greatly appreciated 

Receiver: Yamaha RXV 671
Fronts: Polk Rti A5's
Center: Polk Csi A6
Sub: Polk PSW 505
Surrounds Tsi 300's
Back Surrounds: Tsi 100's


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## AudiocRaver (Jun 6, 2012)

Working with tones like sine waves can be tricky. Your main front speakers could have a peak right at 80 Hz that gives a much higher reading than you see with pink noise. It sounds like you have only an SPL meter to work with, so you cannot see the individual frequency peaks/dips and their contribution to frequency response.

Assuming you have a computer you can use for analysis, download and start up Room EQ Wizard to use as a filtered pink noise source. Select Generator, Speaker Cal to check your Speaker level. Then choose Sub Cal and set your sub level to match. With only an SPL meter to work with, that should give you a decent setting. You might hear boominess at individual frequencies, but that should not be a problem with most music/movies. To go beyond this level of tuning, your would need a calibrated mic/audio interface setup working with Room EQ Wizard. Then you could perform spectrum analysis and see what is happening with extremely narrow frequency resolution. Of course that takes you to the next step of implementing equalization to make corrections, and at this point we have opened up Pandora's Box of possibilities and ways to spend money. Unless you have money and time to dedicate, do the calibration as mentioned above and call it good,.


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## jwynne5227 (Mar 13, 2013)

Thanks AudiocRaver, I do have REW but i need a to get a usb sound card to use it, i haven't bought one yet because like you said opening the Pandora's box of needing a mic and phantom power etc. etc. but for now I'll stick with your advice and just use my meter and maybe later down the road try to finely tune it some more, thanks again and I'll post back here with my results


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## AudiocRaver (Jun 6, 2012)

Do you have access to filtered pink noise media files you can play back for your calibration source?


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## AudiocRaver (Jun 6, 2012)

To be more specific, you should have a 500 Hz to 2 KHz filtered pink noise file for your main speaker levels, and a 20 Hz to 80 Hz filtered pink noise file for your sub levels. If you don't have access to anything like that, let me know, we'll get something created and available where you can download it.


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## jwynne5227 (Mar 13, 2013)

Yes I have an Avia test disc and used it, it has one test that plays high frequency pink noise simultaneously through the front left speaker and sub and then it changes to low frequency pink noise and there's where i get a big jump unless i turn the sub all the way down, also theres one that uses (subwoofer phase filtered pink noise, LF) and that plays simultaneously through the front left and sub and they say is supposed to be used to make sure your sub is in phase by flipping the phase switch while its playing, then there's low frequency pink noise 5 channel pan and 6 channel pan, its actually a really good dvd, with a lot of test tones but i think the only one that says specifically filtered pink noise is the phase checker, but i bet i could find a download for some with a quick google search


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## jwynne5227 (Mar 13, 2013)

I got my tones and some pink noise from Wavtones com but it doesnt specify that its filtered though


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## jwynne5227 (Mar 13, 2013)

Ok i see what you mean, i found a filtered pink noise download from realtraps com think i could give it a try now or wait till i get the sound card to run it through REW??


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## asere (Dec 7, 2011)

AudiocRaver said:


> Working with tones like sine waves can be tricky. Your main front speakers could have a peak right at 80 Hz that gives a much higher reading than you see with pink noise. It sounds like you have only an SPL meter to work with, so you cannot see the individual frequency peaks/dips and their contribution to frequency response.
> 
> Assuming you have a computer you can use for analysis, download and start up Room EQ Wizard to use as a filtered pink noise source. Select Generator, Speaker Cal to check your Speaker level. Then choose Sub Cal and set your sub level to match. With only an SPL meter to work with, that should give you a decent setting. You might hear boominess at individual frequencies, but that should not be a problem with most music/movies. To go beyond this level of tuning, your would need a calibrated mic/audio interface setup working with Room EQ Wizard. Then you could perform spectrum analysis and see what is happening with extremely narrow frequency resolution. Of course that takes you to the next step of implementing equalization to make corrections, and at this point we have opened up Pandora's Box of possibilities and ways to spend money. Unless you have money and time to dedicate, do the calibration as mentioned above and call it good,.


How can you user spl meter with REW and have no mic?


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## AudiocRaver (Jun 6, 2012)

I see their broadband file, not a filtered one.

It is something you could use now along with your SPL meter to balance your sub with the rest of your system. To get good results, you need two separate files, and each needs to be the same number of octaves wide, within the band of the speaker it is used for. Then they will contain equivalent energy and will help you balance your system.

A 30 Hz to 80 Hz filtered noise band is 1.4 octaves wide. A 500 Hz to 1.333 KHz noise band is also 1.4 octaves wide. Set your main speakers (sub turned off) using the higher band, to 80 db SPL, then (with the mains turned off) set the sub level to 80 db. Then your subs and mains should be fairly well balanced. Short of doing detailed analysis with REW, this will get you started.

Let me know if you need those files created and uploaded, I can do it later today.


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## jwynne5227 (Mar 13, 2013)

I've done a search online and i have found some but it seems all the filtered pink noise ones are ones that i would have to buy, if you could upload those for me AudiocRaver that would be extremely helpful, I have to go to the mother n laws later, but I'll definitely get it done and post the results here tomorrow


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## jwynne5227 (Mar 13, 2013)

Asere from what i understand you can use the spl meter as your mic but that it's only accurate at the lower frequencies, its just that my computer doesn't have the inputs to hook it up so i would have to buy a sound card


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## jwynne5227 (Mar 13, 2013)

I started to repost what i wrote earlier, what wrote back wasn't showing up on my computer


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## AudiocRaver (Jun 6, 2012)

OK, in the downloads area there are 2 files you can download that will help you calibrate your subwoofer with your SPL meter. FLAC and MP3 versions are available. Instructions, if you need them, are included. Hope it helps.

Download from here.


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## jwynne5227 (Mar 13, 2013)

I appreciate it AudiocRaver, I'll put them to use today, and let y'all know soon how it goes


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## asere (Dec 7, 2011)

If I use REW to see only the sub lower frequencies can I just play the avr's test tones? Also do I place the spl meter at listening position and how far does pc need to be from the meter?


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## jwynne5227 (Mar 13, 2013)

I dont know much about REW, Ive never actually used it, I just read up on it asere so Im not sure about the test tones, but to use it you have to have it hooked to the PC via a cable, so as long as the is as far as you can be from it, but theres a lot of info on it in the help section of REW and on the REW forum here


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## jwynne5227 (Mar 13, 2013)

I got it calibrated AudiocRaver!!!! Thanks a lot for the advice it sounds a LOT better, So this is pretty much what I did, I downloaded the files on my computer, and then used PS3 media player to stream them to my playstation (didnt think it made much difference since the PS3 media player supports FLAC,and it would keep me from having to burn a disc, so I used those files) and the Playstation is hooked up via hdmi to my receiver, I unplugged all my speakers except for the front left and right, put it in stereo mode and played back the files and calibrated it to 75 db, I then unplugged those speakers and plugged in just the sub, i calibrated it using the volume knob on the back, it seemed a little strange to me though that it was only 1/4 of the way up, but its the psw505 and has quite a bit of power so maybe that's why, I plugged everything back in and then went to my receiver test tones and calibrated the rest of my speakers to the same as the fronts, I then watched some blu rays like Avatar and Jumper and found the sub didn't quite have that kick that i like to hear in the action parts so I used the receiver controls to turn it up some (since I made sure it was set to 0 before I started) and now its sounding the best it ever has, some good sounding bass without drowning out the characters voices  we're going to do a little bit of rearraging the living room by pulling the coach off the wall and putting the surround back speakers behind us instead of directly above and I think that will help some too, I'll keep ya'll posted and plan to put pics up when it's done  If anyone has any other suggestions or if I did't quite do something right here, just let me know, Thanks


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## AudiocRaver (Jun 6, 2012)

jwynne5227 said:


> I got it calibrated AudiocRaver!!!! Thanks a lot for the advice it sounds a LOT better, So this is pretty much what I did, I downloaded the files on my computer, and then used PS3 media player to stream them to my playstation (didnt think it made much difference since the PS3 media player supports FLAC,and it would keep me from having to burn a disc, so I used those files) and the Playstation is hooked up via hdmi to my receiver, I unplugged all my speakers except for the front left and right, put it in stereo mode and played back the files and calibrated it to 75 db, I then unplugged those speakers and plugged in just the sub, i calibrated it using the volume knob on the back, it seemed a little strange to me though that it was only 1/4 of the way up, but its the psw505 and has quite a bit of power so maybe that's why, I plugged everything back in and then went to my receiver test tones and calibrated the rest of my speakers to the same as the fronts, I then watched some blu rays like Avatar and Jumper and found the sub didn't quite have that kick that i like to hear in the action parts so I used the receiver controls to turn it up some (since I made sure it was set to 0 before I started) and now its sounding the best it ever has, some good sounding bass without drowning out the characters voices  we're going to do a little bit of rearraging the living room by pulling the coach off the wall and putting the surround back speakers behind us instead of directly above and I think that will help some too, I'll keep ya'll posted and plan to put pics up when it's done  If anyone has any other suggestions or if I did't quite do something right here, just let me know, Thanks


Sounds like your process was right on. No harm in bumping the sub level up a bit for personal taste. Now you know where the "calibrated" setting is as well if you want to return to it for music or whatever.

Glad you are enjoying your system.:bigsmile:


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## AudiocRaver (Jun 6, 2012)

asere said:


> If I use REW to see only the sub lower frequencies can I just play the avr's test tones? Also do I place the spl meter at listening position and how far does pc need to be from the meter?


Except in SPL mode, when REW is analyzing, it is looking for a return of its own output signal, not sure what useful indications it would give you looking at your AVR's signals with it. If you are looking for SPL readings, your SPL meter alone will give you that.

PC a few feet away is fine, mainly out of the way of the sound path - behind the mic is always best.


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## Macattack (Mar 20, 2013)

asere said:


> How can you user spl meter with REW and have no mic?


I will jump in on this question as a newb who has read and learned over the last few weeks.

The SPL meter acts as a mic and is pretty effective for the 'low end'. In the case of my Radio Shack meter, it works very well up to about 3K HZ but creates wierd art above that. So, I am on the hunt to buy a mic that allows me to do full spectrum testing and an infinite amount more of 'tweaking'.


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## asere (Dec 7, 2011)

Macattack said:


> I will jump in on this question as a newb who has read and learned over the last few weeks.
> 
> The SPL meter acts as a mic and is pretty effective for the 'low end'. In the case of my Radio Shack meter, it works very well up to about 3K HZ but creates wierd art above that. So, I am on the hunt to buy a mic that allows me to do full spectrum testing and an infinite amount more of 'tweaking'.


Can someone guide me on how to measure the sub and where to go on REW after the sound card and spl is installed ? I have read REW before but for me it is complicated. I don't know were to begin!!!


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## AudiocRaver (Jun 6, 2012)

> I will jump in on this question as a newb who has read and learned over the last few weeks.
> 
> The SPL meter acts as a mic and is pretty effective for the 'low end'. In the case of my Radio Shack meter, it works very well up to about 3K HZ but creates wierd art above that. So, I am on the hunt to buy a mic that allows me to do full spectrum testing and an infinite amount more of 'tweaking'.


Well spoken.



> Can someone guide me on how to measure the sub and where to go on REW after the sound card and spl is installed ? I have read REW before but for me it is complicated. I don't know were to begin!!!


Follow this link to the main list of REW online help files. Sounds like you are ready to start with step 6, calibrating the sound card. That is a big step, see how you do with that. If you can get through step 9, taking measurements, you will practically be a pro. If you have trouble, look for the best "EQ/Calibration" forum/thread (including this one), or start a new one, and ask away.

Also:
Cabling Basics
Calibration Files
REW Tips

Edit: Remember to start out measuring the sub by itself, all other speakers shut off.


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## asere (Dec 7, 2011)

AudiocRaver said:


> Well spoken.
> 
> 
> 
> ...


Thank you for the information. It is pretty self explanatory now. As far as pink noise can I use the REW one?


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## AudiocRaver (Jun 6, 2012)

asere said:


> As far as pink noise can I use the REW one?


Absolutely.


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## asere (Dec 7, 2011)

AudiocRaver said:


> Absolutely.


I might have to post the graff so someone can interpret for me lol


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## jwynne5227 (Mar 13, 2013)

Cool asere, I'd like to see the graph myself so that when I'm ready to use REW, I might have some kind of idea of what to expect


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## asere (Dec 7, 2011)

What is the the difference between a sound card and sound box? I'm not sure if my laptop has one.


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## AudiocRaver (Jun 6, 2012)

The term "sound box" usually refers to a chamber - in an acoustic instrument like a guitar, in a speaker assembly, or in a laptop - that enhances the sound somehow by way of its resonance. Some laptops have a small - very small - sound box to enhance their bass response.


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## asere (Dec 7, 2011)

Is this sound card the one I need in order to use REW with SPL?

http://www.bestbuy.com/site/Startec...76?id=1218475496152&skuId=4323997&st=external sound cards&cp=1&lp=6


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## jwynne5227 (Mar 13, 2013)

The one I was going to use, and they recommend on the site is the Behringer UCA202 I think it's $30 on amazon but not sure


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## JohnM (Apr 11, 2006)

asere said:


> What is the the difference between a sound card and sound box? I'm not sure if my laptop has one.


To use REW you need an audio output (such as a headphone jack) and an audio input. The input needs to accept line-level signals, not be only a PC mic input. More recent laptops (last few years) have inputs that automatically switch between mic and line depending on what is plugged into them. Some laptops share the same connector between audio input and audio output, if that is the case you need an external soundcard, such as the UCA202 that has been mentioned. The card doesn't need to be anything special.


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## Macattack (Mar 20, 2013)

http://www.hometheatershack.com/for...ound-cards/52505-rew-sound-card-database.html

Take a gander at this thread to see what others have found that works and in some cases, what doesn't.


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