Volume level for SPL Meter

[DannyD]

I've done a search on this forum and many others and I'm just getting more and more confused. I bought an SPL Meter from the svs website. It's the same one you find in RadioShack. I want to know at what volume level on my HK AVR247 should I be performing this calibration at. I know to start every channel at 0dbs and then adjust them to read 75dbs on the meter but it all depends what volume level you perform the test at. I used -30 on my avr but I don't think thats right is it? I used -30 because that is where I normally watch movies at.(I live in a townhouse...damn neighbours!) I have my fronts at +7 to meet 75dbs and my center at +4 and my surrounds at +5. I think I should be performing this test with my Receiver at 0 volume but isn't that WAY too loud!

[Ron Temple]

I'm using -25 as my reference point on a 245. Try it at -30...if your speaker trims are still in the negative to get a balanced 75dbs, you'll be fine. Actual reference level is 85dbs average, 105 peaks for the 5.0 speakers. + 10dbs for the LFE reaching system peaks of 115dbs or greater. I wouldn't try for true reference levels without separate amps.

[DannyD]

I'm using -25 as my reference point on a 245. Try it at -30...if your speaker trims are still in the negative to get a balanced 75dbs, you'll be fine. Actual reference level is 85dbs average, 105 peaks for the 5.0 speakers. + 10dbs for the LFE reaching system peaks of 115dbs or greater. I wouldn't try for true reference levels without separate amps.

I think that's the problem...using -30 as my reference level forces me to put all the channels in the higher + ranges to get them to 75 dbs. That doesn't sound right to me but I'm not entirely sure:o I should be using 0 on the receivers master volume to perform the calibration for it to be true to Dolby master recordings right? At 0, there's no way my individual channels should be in the + ranges to get 75 dbs which will leave me with a lot more headroom obviously. Does this sound right?

[DannyD]

Is it even safe for your speakers to output test tones with the receivers master volume set at 0? I know you would probably never watch a movie at that reference but is it safe to calibrate at that level? I did a search on this forum and this is coming from Dr.Speck who is a SVS Tech guy according to his signiture who recommends to calibrate your speakers using 0 as your reference point.

[Ron Temple]

It really doesn't matter where you do your calibration. The MV becomes your reference point. So if -25 MV puts you in the low negatives, you're good to go. Some AVRs MV gain will get you reference at -0. Old HKs used to calibrate 75dbs @ -10. Now the gain is hotter so either -30 or -25 works. What's important is knowing that at whatever MV setting you choose to calibrate to 75dbs, it's 10dbs from reference. Playing at reference takes alot of juice...10x the power requirement from your calibration point.

Some folks calibrate at 70dbs because the pink noise tones are annoying any louder. It doesn't matter, you just want a loud enough tone playback to get a good calibration tone for the meter.

Hope this helps.

[DannyD]

Thanks Ron, it's pretty clear now. I think I'm going to try a louder MV for the calibration so I can bring my trim levels closer to 0. Right now at -30MV, I'm too much in the plus ranges as stated above for my liking. Going to redo the cal shortly, waiting for the wife too leave...she hates the pink noise!

[Icarium]

Are those radioshack SPLs pretty decent? I've always wanted to pick one up.

[DannyD]

Are those radioshack SPLs pretty decent? I've always wanted to pick one up.

I have nothing to complain about. it does the job perfect;)

[Ron Temple]

Are those radioshack SPLs pretty decent? I've always wanted to pick one up.

They work fine. Bass frequencies are a bit tough for them. Generally, you are about 2-3dbs louder than the meter shows. So if you calibrate your sub to 75dbs it's really around 77-78dbs. Also, the lower the frequency the further off the meter goes. There are tons of compensation charts and excel spreadsheets out there that will automatically calculate the accurate decibel reading.

[danger boy]

last weekend I moved the subwoofer from in the front left side of the room.. the the rear right of the room. for a week i watched a couple movies and some TV.. and it sounded just a little bit off I could tell.

I ran the auto calibration on the pre amp.. and it reset all the speakers and the subwoofer again. BAM! it sounds so much better again. It makes a huge difference when you recalibrate your speakers. even if you don't move anything around. it's probably a good idea to recalibrate every month or so, just to keep the sound it's best. :D

[DannyD]

I just finished calibrating my speakers using 0 as my reference. I watched some of Ironman and it still sounds good. I must have had my channels too hot before but I still bumped up my center and surrounds a couple dbs...I like them better a little on the hot side.

[tugboat]

I'm not sure about the receivers noted here, but my Denon sets the volume level when you enter the tone section. Once you've calibrated the individual speakers and exit, the volume goes back to what it was set to before you entered the tone section.

It's my understanding is that Denon wants you to use the volume setting they use for the calibration and you either bump the individual levels up or down and not the volume. When I enter the tone section the meter peaks around 84db with my speakers, so I just brought them all up to 85db and called it a day.

[kuntasensei]

If your receiver doesn't use a preset level when you calibrate and you want the volume level to read accurately (i.e. 0 = reference level, -20 = 20dB below reference, etc.), use a calibration disc with a known level for its test tones. That way you know if the test tones are encoded at -30dB, you should get a 75dB reading when the volume is at 0 (calculated by 105dB reference level - 30dB = 75dB). Most calibration discs will tell you the target dB level for the test tones. By doing the math, you could use any volume level to make this adjustment. For instance, if your calibration disc says to shoot for 75dB at reference but you're using a volume level of -10dB, you should aim for 65dB on the meter so that 0 will still equal reference level.

If you don't care that 0 = reference level (which is what you're aiming for on the relative scale, since the volume readout is "relative" to reference level), all that matters is that you get all channels to read the same level.

To the original poster, check your manual and you'll find this on page 54:

You may use a handheld SPL meter (available at most electronics
stores) set to the C-Weighting, Slow scale.
1. Make sure all speakers have been connected correctly.
2. Adjust the size, crossover and delay for each speaker in your system
as described in Step Three.
3. If you are using a handheld SPL meter with source material, such
as a test disc or another audio selection, play it now and adjust the
AVR’s master volume control until the meter measures 75dB.
4. There are several methods of adjusting the channel output levels,
using either the test tone or source materials. In all cases, you may
measure the channel levels in one of two ways:
a) By ear. Try to adjust the levels so that all channels sound equally loud.
b) Using a handheld SPL meter set to the C-Weighting, Slow scale. Try to
adjust each channel so that the meter reads 75dB.

[lorneth1]

Hi Guys,

I just want to make sure that I'm getting this right. I'm about to calibrate my speakers with RS SPL and I know that I can use the AVR's internal test tone to attain my 75db ref level. My question is for the sub, so its suggested that I use the internal tone for the sub as well? Meaning I'll try to attain 85db while the room is rumbling, is this correct? I don't have a test cd yet that's why I want to make sure. Thanks.

[Sami]

Danny, set your left channel at 0dB gain from the channel controls, then turn your master volume until you're at 70 or 75dBm at that channel. If you end up with something like -13, adjust it to -10 for example to get a nice round number if you like. Why this way? It gives you a nice starting point and it does matter since your channels only have limited range (usually +-10dB). If you set it to -20 and then have to pump the channel up to +9dB, it's inconvenient and you might run out of room (plus I prefer to have the channels as close to 0 as possible).

lorneth, you would calibrate the sub to the same 75dB level, unless a) your test tone is incorrect b) you like your sub extremely "hot" (i.e. loud).

[lorneth1]

Thanks Sami,

I did the calibration and I found out that whatever Audessey set it up was close to reference. I might have to bump the levels a few db, should I even use the correction tables? Anyhow, I changed my rtia7 and csia6 from full band to 80Hz and the rest as well. The center and fronts were the only ones decreased, I was a bit hesitant because I read that you can increase but not decrease your frequency?

[tboo72]

I have nothing to complain about. it does the job perfect;)

This

[Sami]

Thanks Sami,

I did the calibration and I found out that whatever Audessey set it up was close to reference. I might have to bump the levels a few db, should I even use the correction tables? Anyhow, I changed my rtia7 and csia6 from full band to 80Hz and the rest as well. The center and fronts were the only ones decreased, I was a bit hesitant because I read that you can increase but not decrease your frequency?

If you don't have a sub then mains should be full, otherwise 80Hz is the recommended (THX recommendation?) but best results vary by speakers. For RTiA7 80Hz should be good.

[McLoki]

Ok, this may have already been answered, but if you are just calibrating the speakers to each other, it does not matter what the volume level of your AVR is.

I would set the SPL meter at 80db and with the AVR setting for the center channel at 0db boot or cut, adjust the volume of the AVR until the SPL meter reads 80. Then without changing the main volume control - adjust each channel + or - until it reads80 as well from your listening position.

I like using 80 because 75 and 85 is a pain in the ass to calibrate to with an analog SPL meter. If you are using Avia to calibrate your system - adjust your main volume control to -5 and adjust each speaker + or - to 80db. If you are using a video essentials disk to calibrate, adjust your main volume control to +5 and adjust each speaker + or - to 80db.

If you are not calibrating using Video Essentials or Avia - just calibrate the speakers to each other as listed in the first method I mentioned.

Any questions just ask.

Michael

[kuntasensei]

Don't use Digital Video Essentials. The test tones are encoded incorrectly and will not give you proper speaker balance or levels.

[lorneth1]

If you don't have a sub then mains should be full, otherwise 80Hz is the recommended (THX recommendation?) but best results vary by speakers. For RTiA7 80Hz should be good.

Thanks again. I do have a sub and that's why I was wondering but I did set it up to 80 across the board including avr's LFE. I'm thinking of increasing the surrounds to 100 we'll see.

[lorneth1]

Thanks McLoki,

I am thinking of recalibrating my speakers and then setting them up to 80. When audessey initially set them up they were in the negatives and after resetting them to 0db, ran SPL calibration they still ended up as negatives. So, 80 might be doable, do you think I need to follow those SPL correction settings?

[mantis]

Don't use Digital Video Essentials. The test tones are encoded incorrectly and will not give you proper speaker balance or levels.

Umm , how do you know that? Do you know who John Cane is? I have used that disc many times and didn't figure this.

Please go into more detail into your findings.

Dan

[mantis]

If your receiver doesn't use a preset level when you calibrate and you want the volume level to read accurately (i.e. 0 = reference level, -20 = 20dB below reference, etc.), use a calibration disc with a known level for its test tones. That way you know if the test tones are encoded at -30dB, you should get a 75dB reading when the volume is at 0 (calculated by 105dB reference level - 30dB = 75dB). Most calibration discs will tell you the target dB level for the test tones. By doing the math, you could use any volume level to make this adjustment. For instance, if your calibration disc says to shoot for 75dB at reference but you're using a volume level of -10dB, you should aim for 65dB on the meter so that 0 will still equal reference level.

If you don't care that 0 = reference level (which is what you're aiming for on the relative scale, since the volume readout is "relative" to reference level), all that matters is that you get all channels to read the same level.

To the original poster, check your manual and you'll find this on page 54:

This is good advice.

Dan

[mantis]

Thanks again. I do have a sub and that's why I was wondering but I did set it up to 80 across the board including avr's LFE. I'm thinking of increasing the surrounds to 100 we'll see.

Increasing the surrounds to 100 over other channels will unbalance your experience. Everyone has a thing for he surround channels. If you take some time and learn what each channel does, you will find that a balanced system will always sound better then one with "HOT" channels.

Most people like the sub "HOT" as well. It sounds like mud.

Dan

[McLoki]

Thanks McLoki,

I am thinking of recalibrating my speakers and then setting them up to 80. When audessey initially set them up they were in the negatives and after resetting them to 0db, ran SPL calibration they still ended up as negatives. So, 80 might be doable, do you think I need to follow those SPL correction settings?

Are you using a disk to calibrate? (like Digital Video Essentials or Avia - Both also have HD versions)

I am assuming not, so while I do recommend them (or at least calling some local video rental places and seeing if they carry one of them) - this is what I would recommend....

1. Play the test tone built into the AVR for the center channel.
2. Set the boost\cut for the center channel to 0.
3. While sitting in your listening position, adjust the main volume control for your AVR until your SPL meter reads 80db. (If your SPL meter has an analog display - if the display is digital, go ahead and adjust it for 75db)
4. Stay in your listening position and use the boost/cut for each channel to make it match as closely as possible the volume used for the center channel.
5. For the subwoofer the volume will jump quite a bit more than the other channels, just set it as close as you can.
6. Once done - put on some music you like and adjust the subwoofer up or down until the music sounds correct. (drums or bass sound right with the rest of the music)
7. Sit down and listen to a movie - it should be pretty good. :)

As far as crossovers go - ususally 80hz works pretty well. In many AVR's (and pre/pro's) if you adjust any speaker lower than 80hz it will also start cutting into the LFE track. (they shouldn't but they do) Above 80hz is acceptable but the more above 80hz you go the better chance you will have of being able to tell the bass is coming from your subwoofer rather than your speakers. You are usually ok if you stay at 120hz or less, but some people can tell where the bass is coming from at crossover levels that high. (I cannot, but some can) that is why the recommended crossover is 80hz, at that crossover setting almost no one can localize the bass.

Anyway - thats all there is to it. Enjoy and Welcome to Club Polk.

Michael

[kuntasensei]

Umm , how do you know that? Do you know who John Cane is? I have used that disc many times and didn't figure this.

Please go into more detail into your findings.

Dan

Yes, I know who Joe Kane is. As far as DVE goes, I can't speak for the HD versions, but the DVD version is completely borked. Me and Ed Mullen (who now works for SVS) ran decisive testing to compare the test tones on Avia and DVE. I did my analysis by decrypting the audio portion of the bitstream from each DVD, then running RTA on each channel. I found that in ideal circumstances with a C-weighted meter, DVE's speaker tones were off by 2-3dB and were not band-limited as test tones should be. In fact, they included sound down below 80Hz, meaning cancellation/phase could cause calibration issues. Also, the subwoofer tone extended down below 20Hz (which plays hell with calibrating, since it's supposed to be a 40-80Hz band-limited tone) and was off by ~7dB (actually 10dBFS but will show as 7dB on a C-weighted meter, presumably because Kane didn't account for the +10dB boost the LFE channel gets during decoding).

Avia, however, checked out 100% correct, with the test tones spot on, band-limited subwoofer tones (though they're encoded in the main channels and rely on your system crossover being 80Hz or higher to work - we knew this), with the subwoofer tones reading 2-3dB lower than the main channels (which is due to the C-weighting compensation). Ed Mullen confirmed my findings on the subwoofer tones with ground plane testing, where he put his subwoofer in an open field and ran each disc's test tones with a professional grade SPL meter.

We confronted Joe Kane, who claimed that it was digitally correct at the encoder and refused to answer any of our questions, despite all our evidence. While he may know his stuff on video, the audio on DVE makes it completely useless. Fortunately, most know now not to use the DVD version of DVE for critical calibration. I hope it was fixed on the HD versions.

[lorneth1]

Increasing the surrounds to 100 over other channels will unbalance your experience. Everyone has a thing for he surround channels. If you take some time and learn what each channel does, you will find that a balanced system will always sound better then one with "HOT" channels.

Most people like the sub "HOT" as well. It sounds like mud.

Dan

Thanks mantis,

Yeah, I've been doing some reading and more reading and it really boils down to listening preference. I do get what you're saying about surrounds though so I'm testing it at 80 right now same with the others although might have to increase the level for center. I always like hearing the dialogue:). The sub will be a different issue because I just ordered an A3-300 from ed which will be replacing my KSW-12 (not the new one).

[lorneth1]

Are you using a disk to calibrate? (like Digital Video Essentials or Avia - Both also have HD versions)

I am assuming not, so while I do recommend them (or at least calling some local video rental places and seeing if they carry one of them) - this is what I would recommend....

1. Play the test tone built into the AVR for the center channel.
2. Set the boost\cut for the center channel to 0.
3. While sitting in your listening position, adjust the main volume control for your AVR until your SPL meter reads 80db. (If your SPL meter has an analog display - if the display is digital, go ahead and adjust it for 75db)
4. Stay in your listening position and use the boost/cut for each channel to make it match as closely as possible the volume used for the center channel.
5. For the subwoofer the volume will jump quite a bit more than the other channels, just set it as close as you can.
6. Once done - put on some music you like and adjust the subwoofer up or down until the music sounds correct. (drums or bass sound right with the rest of the music)
7. Sit down and listen to a movie - it should be pretty good. :)

As far as crossovers go - ususally 80hz works pretty well. In many AVR's (and pre/pro's) if you adjust any speaker lower than 80hz it will also start cutting into the LFE track. (they shouldn't but they do) Above 80hz is acceptable but the more above 80hz you go the better chance you will have of being able to tell the bass is coming from your subwoofer rather than your speakers. You are usually ok if you stay at 120hz or less, but some people can tell where the bass is coming from at crossover levels that high. (I cannot, but some can) that is why the recommended crossover is 80hz, at that crossover setting almost no one can localize the bass.

Anyway - thats all there is to it. Enjoy and Welcome to Club Polk.

Michael

Thanks McLoki,

You're right, I'm not using a disk to calibrate but might have to invest in one but still trying to figure out between AVIA or DVE (currently watching kuntasensei's input). Although what would be the significant difference from the CD against the AVR's test tone, if you don't mind me asking? Thanks for the guidance. I'll be playing with it some more. Man! I guess "comes great speakers, comes great researching":D

[McLoki]

Although what would be the significant difference from the CD against the AVR's test tone, if you don't mind me asking?

Ask away.....

If you calibrate from the CD it is calibrated to reference level (not that it matters that much) and -18db at your house with your speakers from your listening position will be the same volume as -18db at my house with my speakers from my listening position.

The main thing it does is add the transport and audio connections into the loop when calibrating. The other big thing they help with is with the setup of your video. (I know not important for this conversation) but the DVD's really do help you get the most out of whatever display you are currently running.

Michael