Speaker calibration help?

[acstech]

I am finally going to try and calibrate my speakers. I picked up an analog spl meter. My JVC receiver (which I will be replacing soon) only allows me to adjust the speaker levels for the center and surround left and right. Will this be a problem? I does send the test tone to all speakers. I assume I will have to set the level for the center and surround speakers to match the fronts. I also want to calibrate my sub JVC 10’ 110w (which I will also be replacing soon). I have a volume control on the sub and I can adjust the sub level on the receiver from -10db to +10db. Do I set the volume level on the sub to the normal listening level and then use the receiver to have it match the speaker. Is this correct? I don’t have Avia or any other setup cd so I will have to use the test tones from the receiver. I have Star Wars DVD which has test tones on the DVD. Which would be better to use? Any other info you can give me to help would be greatly appreciated. I have no clue what I am doing? Thank you and thank God for this forum. I almost forgot my receiver allows me to adjust my speaker from -10db to +10db. My volume goes from 0 to 50. I typically have it at 20 or 23 depending on what my wife lets me get away with.

 

[MDS]

Actually you do have a pretty good clue what you are doing. Because the receiver doesn't have independent level trims for the front channels, you will be adjusting the center and surrounds relative to the fronts.

1. Set the center, surround, and sub levels to zero before you start.

2. Start the test tones and turn up the master volume until the meter reads 75 dB or thereabouts [I'm assuming the receiver is like most and the internal test tones are at -30 dB and you want to calibrate to Dolby Reference Level (75+30=105 dB peaks]. You will probably end up somewhere around 80% of the volume range (40 on your receiver) to get there. The meters should be set to 'C' weighting, 'Slow' response.

3. Now for the other channels, adjust the levels so that the meter reads around 75 dB. Speaker placement can affect the levels so you may have to experiment a bit with that, but just try to get them within +/- 1 dB of each other.

4. The same deal for the sub but you have the additional control of the sub volume control itself. It's generally a good idea to start with the sub at about half volume. With a combination of adjusting the sub's volume control up or down and adjusting the receiver's sub level you should be able to get the sub level to the same as the other speakers.

Note that 75 dB of pink noise is a little annoying. What really matters is that you get each channel to be similar in level. You can calibrate to any level you want. If you are able to get 75 dB on the meter when the receiver volume is at 40ish but find it too distracting, turn the master volume down a bit and calibrate to a lower level on the meter.

 

[acstech]

Mds

I forgot to mention that my receiver does not send a test tone to the Sub. If I remember correctly the one on the Star Wars DVD does but I don't think it sends a pink noise. Is there anything I can do? I plan on getting the Avia DVD in the future which I am sure will help but i would like to make do with what i have for now. Is there something I can download and burn to cd to calibrate the sub? Thank you for your help i really appreciate it.

 

[MDS]

I'm not familiar with the Star Wars DVD but if it includes the THX optimizer and has test tones for the sub it will almost certainly be pink noise (equal amplitude at each octave). That should work fine for calibration.

 

[acstech]

Thanks

Yes it has THX optimizer. I will give it a shot in a little while and hopefully not have to ask anymore questions. Thank you for your help.

 

[acstech]

follow up question

Where do i set the range at? I was playing around and set the range at 80. I then brought the volume up on my receiver untill the neddle was at 0 for the fronts or as close to 0 as i can get. I then adjusted my center and rears untill they where all at 0. Is this correct? I held the meter at head level and left it pointed streight at the speakers. Should i point it towards each speaker or leave it pointing streight. One of the problems i have is the receiver goes through the test tone to the front speakers pretty quick. I can maually do the tones to the other speakers so they are easy. I used the THX optimizer for my sub and i did the same thing. Thank you for any help you can give me. P.S. Is there any other uses for the SPL meter.

 

[MDS]

Analog meter, right? When the dial reads zero, the measured SPL is whatever you set the range at, so if you set the range to 80 and the needle hits zero, the measured SPL is 80 dB. If the meter reads +5, the measured SPL is 85 dB, etc.

You want the meter at ear level and pointing straight up. Ideally, it's best to use a tripod to mount the meter so you can get away from it and minimize any changes in SPL from sound reflecting off of YOU instead of directly reaching the mic. I don't have a tripod and usually slouch down on the couch with the meter around ear level (not so scientific, but it's close enough. )

On most receivers, you can manually hit a button labeled something like 'ch sel' (channel select) to advance the tones to whatever channel you want. They play for a few seconds and then automatically advance so sometimes you have to keep hitting it if you want to concentrate on one channel at a time.

You can use A weighting and Fast response to measure absolute sound pressure levels if you are ever in the mood to see the maximum SPL your system is producing.

 

[acstech]

Thank you

I think i have it know. What i did was set the range at 80 and adjusted the volume untill the needle was at -5 which means i am at 75bd. The only pain i have is my fronts because the test tone goes by them pretty quick. When i adjust the center and rears the test tone stays at those speakers so it is pretty easy. I used the THX optimizer to do the Sub and i guess if i want a little extra bass during movies i will adjust the volume as needed. Thank you for all you help.

 

[MDS]

Glad it worked out for you. When you do upgrade, things will be slightly different because most receivers now have independent channel trims for each channel. The procedure is basically the same though so you should be good to go.

 

[acstech]

MDS on last question?

Thank you for all your help. I have on last question. I read on a few pages that you should set your subwoofer 4bd higher then your other speakers. Is this true or should they all be set the same?

 

[MDS]

It's personal preference - some people like to boost the bass a bit.

The RS SPL meter is supposedly off by an average of 2-3 dB (too low) in the low frequencies and that is why there are correction charts available (svsubwoofers.com has a chart). So when the meter reads 72 dB it is actually more like 75 dB. If you calibrate so that the meter reads the same as the other channels, the sub will actually be slightly hotter than the rest.

IMO, it isn't worth worrying about. The ear is extremely insensitive to changes in amplitude at very low frequencies. In other words, it takes a huge increase in amplitude of low frequencies for us to detect a real change. You aren't likely to notice a difference if the sub is a few dB hotter than the other channels (at least I don't).

 

[acstech]

Thank you

THank's I think I will leave it where it is. If during a movie I want more bass I can always adjust the volume on the sub. Thank you for all your help.

 

[Vaughan Odendaa]

I asked the same question and I never got a response for like 1.5 weeks.

--Sincerely,

 

[Vaughan Odendaa]

MDS, there are some articles on the web that state that the subwoofer should be calibrated 4 dB's over the mains to be accurate with all other main channels. Tom Holminson states as much (in one of his books) as do Dolby Labs.

--Sincerely,

 

[MDS]

If the sub is 4 dB hotter than the other channels, then it won't be 'accurate'. Do you have any links to said recommendations? I'm sure there would be other context stating when and why it would be beneficial because as a general rule it cannot be true unless every room and subwoofer is identical.

 

[daniel_h]

A different sort of surround problem

First posting...be gentle please!
This may be kinda related to this thread...
I have run the Avia calibration DVD and when i do the basic speaker tests, everything goes fine until i have the signal go to left surround and right surround speakers. Any time the signal is supposed to go to one of them, the both make the sound. I checked with a THX optimizer on one of my DVDs as well. When a signal is sent to one surround channel, both make the sound.
I tried all of the different surround settings on my receiver (all Dolby settings, DTS, etc...) while doing the test , triple checked that the wiring for the speakers was correct...don't know what else to do.
Here's the situation:
I have HDMi running from my DVD to the AVR, and standard 14 gauge speaker wire from the receiver out to all speakers. The SW is hooked up to the pre out for SW from the AVR (no SW problems).
My system:
Marantz SR 4001
Polk Monitor 60s (front)
Polk CS2 (center)
Polk Monitor 40s (surround)
Polk PSW12 (subwoofer)
Anyone ever run into this? Any suggestions?

 

[Nick250]

on one of my DVDs as well. I tried all of the different surround settings on my receiver (all Dolby settings, DTS, etc...

You did not mention going to the "speaker setup" menu which on the receivers I have owned is separate from the surround mode setting. The speaker setup menu would usually have options like, sub yes/no, or speakers set large/small and so forth. Perhaps there is something there that addresses your problem. aa
Nick

 

[daniel_h]

I forgot to mention that...sorry.
Yeah, i have the front set to "large", the center and surround set to "small", and the sb speakers set to "no" (and sw set to "yes").