Has Anyone Heard of This Re: Spkr Callibration

[Adz]

On another forum, a member suggested the following:

"If you set your mains to -5 on the calibration tones, then calibrate everything else around that -5 - instead of passing above 0, this would allow for a much cleaner signal to go to the centers AND mains. Since that 0 is basically 12 oclock, putting it far below it would let the preamp section of your receiver or your preamp pass a cleaner signal on to the amp section since its not a "hot" signal from the get go."

Does this make any sense?

[ajpoe]

I've also seen this tactic done when calibrating a sub and then compensating with the gain on the sub amp. I have not tried it but could see where it may reduce noise for a single speaker. If you were to do all of your mains then you'd still have to turn them up louder to get the same volume and still get the same amount of noise? I'm interested in seeing more information about this!

[eddiem67]

I have always calibrated with the mains set to 0 and matching everything else around them whether its plus or minus, my spl meter reads 83db's when the mains are set to 0. I never try to reach a certain decibal like alot of manuals tell you to do. As long as they all have the same output.

[Snap]

:agree:

[Sithlord]

I thought when setting the spl meter you set it to 75db (at the zero point) and mains and sub are at 0. You then raise the volume on your amp until the meter reads 75db then thats the reference point then you keep that volume and then adjust all other channels accordingly. Is this correct? Just curious why 83db? Is everyone different with the spl meter set point? I have always been a bit unsure when doing this so is there a right way or not. I'm very interested in what others are doing to calibrate their systems.

[aud19]

As far as I know, that's what you do SL :T

[Azeke]

I utilize 75 db for my readings , as per the Avia disk calibration. I have used the test tones on my Rotel RSP-1098, and have found that there are calibrated incorrectly, therefore I use the Avia disk as my SPL reference calibration.

I have not tested your theory, but it seems as though that would put more strain on the amps. Just my thoughts

BTW, Jason, nice father day pics, I digress.

Regards,

Azeke

[ajpoe]

I utilize 75 db for my readings , as per the Avia disk calibration. I have used the test tones on my Rotel RSP-1098, and have found that there are calibrated incorrectly, therefore I use the Avia disk as my SPL reference calibration.

I read that AVIA should be calibrated at 85 db for reference since its recorded -20 db and 75 db for general receiver test tones which are recorded at -30 db. That may be why you have variations between the 1098 and AVIA as well.

[aud19]

BTW, Jason, nice father day pics, I digress.

Regards,

Azeke

Thanks Azeke :lol: (Am I in the wrong thread...? :unsure: )

Yeah, I'd think if you were supposed to do that or if it helped, they'd just design the system that way to begin with

[Bachelor]

I have also heard of people adjusting the speaker levels at the normal listening level because they find that the 75db is too loud for them.

[Azeke]

I read that AVIA should be calibrated at 85 db for reference since its recorded -20 db and 75 db for general receiver test tones which are recorded at -30 db. That may be why you have variations between the 1098 and AVIA as well.

Ajpoe,

75db is the reference level for AVIA, as stated in the video, I haven't heard about 85db. However, the variations experienced in the 1098 have been noted as a flaw.

I'm curious to know who stated that the level on the AVIA disc is 85db, that certainly would prove to be an interesting read.

Thanks for the heads up though,

Azeke

[ajpoe]

I found the info on the same site a lot of people link to for actual receiver/amp wattages vs. what they are rated. He has several interesting articles, calibration infomation, some bose bashing, etc. etc. I have no idea where he got his information or how accurate it is but I've read through a lot of it just taking it as another opinion. Here is what he posted about calibrations:

*SPL NOTES:
Use 75 dB SPL for the following test tones that are recorded @ -30dBFS :
- AV Receiver/AMP internal test tones
- Dolby Labs DD-EX DVD
- Original & Digital Video Essentials DVD's
>>>>><<<<<
Use 85 dB SPL for the following test tones that are recorded @ -20dBFS :
- AVIA DVD
- Sound & Vision HT Tuneup DVD

Here is a link to his site:

http://www.geocities.com/p_iturra/index.html

[Adz]

I have also heard of people adjusting the speaker levels at the normal listening level because they find that the 75db is too loud for them.

Who are those people? Their HT systems should be confiscated! :lol:

[Sindhu]

Spkr Calibration

I would tend to agree. I have a Denon 3805 and using the test tones from DVE if I set the reciver to 0dB the roof gets lifted. I was earlier struggling to get the center stand out and was not not happy at all with Denon's auto calibration. Bought a Radio Shack SPL meter and calibrated the system around 75dB. I was surprised to see that in almost all the speakers I had to go below 0dB to equalise - I understand that it depend on the room. I was a bit spektical of the results when I had to set the Sub at -4.5dB. I had been playing it at 0dB for the last couple of weeks.

WOW ! The results were beyond my expectations. The center has jumped out. Galdiator never souned so good. Black Hawk Down was wonderful. And the headroom is significant.

Regards

Sid

[sprout]

Ignoring db/spl levels for a mo, the original question is a simple but interesting concept.

What do you want to strain most? surely that is it!

If you have the cleanest most powerful amp in the world and a poor preamp it would make sense to back off the preamp and let the amp do more of the work. The converse would also be true of course.

So surely this is all about "base it on the strengths and weaknesses of your system"

Zero is a starting point for experimenting? I think so.

sprout

[Adz]

I would tend to agree. I have a Denon 3805 and using the test tones from DVE if I set the reciver to 0dB the roof gets lifted. I was earlier struggling to get the center stand out and was not not happy at all with Denon's auto calibration. Bought a Radio Shack SPL meter and calibrated the system around 75dB. I was surprised to see that in almost all the speakers I had to go below 0dB to equalise - I understand that it depend on the room. I was a bit spektical of the results when I had to set the Sub at -4.5dB. I had been playing it at 0dB for the last couple of weeks.

WOW ! The results were beyond my expectations. The center has jumped out. Galdiator never souned so good. Black Hawk Down was wonderful. And the headroom is significant.

Regards

Sid

Doesn;t make sense to me. As long as all the speakers (at least the front 3 across and the sub) are callibrated to the same dBs, then it should just be a matter of turning up or down on the pre=amp/receiver volume to suite your taste for each movie. 75 or 78 or 80 or whatever shouldn't matter.

[hidefdvd]

The way I do it is to use the test tones in my NAD T773 and calibrate my speakers to 75db. As far as the reference point I used to pick 0(zero) on the dial and +/- the trim for each speaker till all levels are the same. Now I pick one speaker and adjust my main volume(trims at zero) till that speaker outputs a 75db test tone. Then I leave the main at that setting and adjust the other speakers trim to match the 75db.

[sprout]

On another forum, a member suggested the following:

"If you set your mains to -5 on the calibration tones, then calibrate everything else around that -5 - instead of passing above 0, this would allow for a much cleaner signal to go to the centers AND mains. Since that 0 is basically 12 oclock, putting it far below it would let the preamp section of your receiver or your preamp pass a cleaner signal on to the amp section since its not a "hot" signal from the get go."

Does this make any sense?

Any other opinions on the original question?
I have already given mine, would appreciate seeing other members thoughts as would the thread starter I assume

sprout

[Sindhu]

To ADZ's point. Absolutely right theoritically at least. What dB level you choose to calibrate should not matter - choose one and then you can push the volume up/down to your taste. Practically however I think 75/80 db is a decent and audible level to work with. Also, at a way higher or lower volume the sound may behave differently due to the acoustical nature of your room so the calibrations may not hold good? At say 75dB you will get a reference volume on your amp and then it is best for you to stay with that (mostly). If you like it loud then calibrate around 90dB. But be aware of the safely standards.

Sid

[Adz]

As I've stated I callibrate my speakers to the un-adulterated test tone produced at the left speaker which in my room with my equipment is dead-on 80dBs using my RatShack digital SPL meter. So, I callibrate my front three and my sub to 80dBs (I can't get my center channel spot on 80 so I actually let it hover around 80-81 as opposed to 79-80 to keep the center on the higher side).

However, with my rear and side surrounds, I am finding that I like them a little bit higher to enhance the surround envelopement so I callibrate those to all read 83-84 dBs. Does anybody else do this?

[Azeke]

However, with my rear and side surrounds, I am finding that I like them a little bit higher to enhance the surround envelopement so I callibrate those to all read 83-84 dBs. Does anybody else do this?

Yes Adz, I do something quite simular. I increase the center backs by 1db, after calibration.

Regards,

Azeke

Edit: I also add 1 db level via the test tones to the front channel, works like a charm.

[booktrunk]

I understood that THX "test tones" should be done at 85db but most seem to do it to 75db.

I personally go for around my listening level so I set it with my amp Rotel RSP1068 ending up at around 65 on it's volume control.