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Calibration Using Naked Senses vs Using Tools


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19 replies to this topic

#1 of 20 Arnel

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Posted April 15 2002 - 01:34 PM

I’m already used to calibrate speaker levels of my HT using the AVIA DVD with RS SPL meter. I’m just wondering that we are actually using our naked ears to perceive the sounds from our HT system. We have different sensitivity to sounds; moreover, our own two ears have different sensitivity. I mean our left ear might be more sensitive than our right ear. With these facts given, don’t you think its is just rightful to calibrate our system according to our own naked ear, i.e., your Front Right Speaker is louder than your Front Left, as the case maybe. What is your comment on this?

#2 of 20 Steve Zimmerman

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Posted April 15 2002 - 03:19 PM

Whatever works for you, I guess. I think figuring out the relative volume level of the L, R, and C channels might be sufficient by ear, but my feeling is that for EQ-ing your subwoofer there's really no effective way to do so without an SPL meter.

--Steve

#3 of 20 Harold_C

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Posted April 15 2002 - 03:30 PM

Quote:
don’t you think its is just rightful to calibrate our system according to our own naked ear, i.e., your Front Right Speaker is louder than your Front Left, as the case maybe. What is your comment on this?


I have had many years of involvement in the audio industry and have owned a lot of good audio equipment. I'm probably better than the average bear at judging the sound of a system. I don't have any confidence in my ability to calibrate a 5.1 channel surround system by ear. The SPL meter and pink noise test tones will be better than what I can do every time. Furthermore, it makes a really big difference in the performance of the system to get it right.

I recently screwed up the levels of my system inadvertantly hitting buttons on the remote in the dark. I thought something sounded a little funny with a couple of movie soundtracks, but it took me several days for it to register that my front left speaker was set 5 dB too hot.

#4 of 20 Cees Alons

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Posted April 15 2002 - 06:54 PM

From your post, I understand that you didn't mean using naked ears only. I think it's very important to use the SPL meter for a first and thorough calibration.

But I agree with you that the final taste is in the listening.
E.g. if someone prefers to listen to his audio at levels below reference level (which is not too bad), he/she will have to adjust some frequencies according to the sensitivity level of the human ear.
If you have an anomaly in your perception curve, you may want to compensate for that, but beware: (1) other people may think (hear) differently, and (2) your anomaly is what you're used to!

Personally, I still better use my ears to (almost immediately) decide whether or not two drivers are in phase or not.

Cees

#5 of 20 Arnel

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Posted April 16 2002 - 12:58 PM

Thank you very much for all the reply.

Quote:
Personally, I still better use my ears to (almost immediately) decide whether or not two drivers are in phase or not.
I agree with you Cees, it's better to use our ears testing the phase and I just use the meter to verify it (greater deflection).

#6 of 20 Geoff L

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Posted April 17 2002 - 02:04 AM

Interesting point you bring forward.

I will always trust the meter and Avia to first set up, but after that small adjustments are made for my hearing loss in my left ear.

I never new that I had some hearing loss in my left ear till I got into 5.1.

My job prior to what I do now was in concrete. Walls to be exact. After pouring the walls the forms have to be pulled and cleaned. After 15 years of pounding out steel pins with my body turned with my left ear nearest the steel form while cleaning it (along with 5 to 7 other guys beating the shit of these forms at the same time) and no where for the sound to escape, the damage to my left ears hearing is now noticed.

My left main and left rears have to be run 1 to 1.5-db hotter on the receiver for things to sound correct for me.

The meter doesn't lie!

There is no question that I have lost hearing in my left ear and being young and an idiot, I pay for my stupidity now!

So in conclusion, I think that using VE or Avia needs to be the way to start calibration of your 5.1 system but by all means minor adjustments can be made due to things like what I just explained.
The other being, at lower spl levels as Cees pointed out, adjustments can and more often than not do need to be made because of the way our hearing works with lower spl levels.

So to the young people, protect your hearing, --->if you don't it will eventually catch up with you.....
~{ Speak of what you know, listen to what you don't.! }~  

#7 of 20 Jeremy Anderson

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Posted April 17 2002 - 06:35 AM

Realistically, a 1dB variation between the hearing in your ears is probably not due to any kind of hearing loss injury. That can just be a natural occurrence. If I remember correctly, 3dB objective differential is when an ear injury is suspect.

A SPL meter is great for finding an objective baseline, but in the end you should always trust your own subjective perception of the sound. For instance, in my room when I calibrate all channels equally with Avia, the left main sounds louder than any speaker and the surrounds overshadow the front soundstage. This happens no matter where I position the meter. But if I take that objective baseline, then lower the surrounds by 1dB each and bump the center and right main 1dB, the whole soundstage becomes very cohesive sounding without the surrounds overpowering the mains. I'd initially presumed that this was a result of variations in my hearing, except that others have verified this for me since then. Plus, if you have one speaker next to an open hall (as I do) it may calibrate out the same but still sound quieter than the other speakers.

#8 of 20 James Bergeron

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Posted April 17 2002 - 06:49 AM

Well I use a meter, cause I think I'm becoming anal about my system.

But to be honest when I purchased the meter I had already calibrated it by ear. Although volume was incorrect since I did not know what "75db" was I was damn close with all the speakers. I believe I had them all at 70db except for my left surround which was at 69db and my sub was at 72db.

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#9 of 20 Arnel

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Posted April 22 2002 - 05:45 PM

How about the use of equalizers to flatten room's response? I know others don't recommend this because of some drawbacks. Anyway, it was then a preference to set it in V-shape because our ears were more sensitive to 1khz. There were many times when I try to do sweep of the frequency spectrum from 20khz down to 20hz on my system, I find that my SPL meter has a different result with what I really hear. There were frequencies that was mark way up on the scale but I hear just a faint, while others were too loud but registers a small db. I know that RS meter is not that accurate but what I'm trying to say is do we really need to rely on the meters/freq analizers to check if our system is flat throughout the frequency spectrum or just rely on the actual response of our ear?

#10 of 20 Steve_Ma

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Posted April 23 2002 - 12:48 AM

James,
That's fairly impressive. I tried calibrating my stuff prior to getting an SPL meter and I was way off. Esp with my sub. But even my mains were pretty far off. I agree with tweaking tto preference after calibration via SPL for the reasons stated above.

--Steve

#11 of 20 Larry B

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Posted April 23 2002 - 01:09 AM

Jeremy:

Quote:
Plus, if you have one speaker next to an open hall (as I do) it may calibrate out the same but still sound quieter than the other speakers.

The physics of that eludes me. Can you shed some light on it?

Larry

#12 of 20 Bill Lucas

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Posted April 23 2002 - 01:39 AM

Arnel,

I'm not sure who these people are that don't recommend EQ'ing a Home Theater. If you want optimal sound EQ and acoustic treatment is a must. It carries a price tag and many don't do it because of cost and asthetics but without treatment and EQ there *will* be problems. I know of no pro in the field that is worth his salt that doesn't include these basics when he designs a home theater.

#13 of 20 Harold_C

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Posted April 23 2002 - 03:30 AM

I would shy away from EQ to the greatest possible extent. Equalization is not a free lunch; it definitely creates its own set of problems.

I can think of very few high quality home systems that really need EQ above 200 Hz and I believe most systems would probably sound better without it.

Subwoofer EQ is a different animal. I think that MILD EQ, used to knock down a couple a resonant peaks, can be beneficial. Here again, I don't believe that slavishly trying to get ruler flat response is necessarily a good idea. But, if you could tame a 12 dB peak, great. I wouldn't use the EQ to try to boost valleys.

#14 of 20 BruceD

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Posted April 23 2002 - 06:36 AM

I think this is the critical point about Parametric EQ, and expect it would benefit many, if not all, of this forum's users in their own HT.

Quote:
Subwoofer EQ is a different animal. I think that MILD EQ, used to knock down a couple a resonant peaks, can be beneficial.


#15 of 20 Jeremy Anderson

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Posted April 23 2002 - 09:53 AM

Quote:
The physics of that eludes me. Can you shed some light on it?
Placing a speaker near a doorway doesn't necessarily lower the actual decibel level the speaker is outputting, but it can change the tonal characteristics of the sound coming from the speaker in a way that makes it seem quieter, despite it being at the same level. In my room, I can calibrate all channels to the same level with the meter and EVERY SINGLE PERSON who listens to it says the right main isn't loud enough. You can even hear the tonal change with Avia's white noise 5 channel pans. With my old speakers, I tried swapping the left and right mains to see if it was a bad speaker, and it did the same thing. To make sure it wasn't a problem at the amplification stage, I swapped the left and right leads at the receiver and the right side was still changing tone. I even swapped speaker phase to see if I had a problem there. Since then, I've gotten new speakers, with the same problem. Boosting the right main +1db from reference makes it sound balanced.

As for the actual acoustic reasons for this, I'm no expert. But the above is my experience and I am just offering that as a possibility. A SPL meter is great for objective measurement, but in the end, how it sounds to the user is the ultimate test.

#16 of 20 Cees Alons

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Posted April 24 2002 - 01:43 AM

Arnel,

Quote:
How about the use of equalizers to flatten room's response? I know others don't recommend this because of some drawbacks

There ARE some drawbacks, especially when you try to apply a big difference here and there. EQ-circuits never come without a penalty: phase shifts. And you may also become more dependent of your actual position in your room.

But apart from all that, here's the underlying and all-important question: do you want it to sound as if they are in your room, or do you want it to sound as if your room isn't there (and perhaps accoustically you seem to be in the recording studio)?

In the latter case, EQ-ing is only part of the job. Severe accoustical measurements to make your room as "dead" as possible are needed then too!

But if you did a good accoustical job on your room (not having too much parallel reflecting surfaces, etc.), the first option may be as attractive!

Cees

#17 of 20 Harold_C

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Posted April 24 2002 - 02:41 AM

Quote:
But apart from all that, here's the underlying and all-important question: do you want it to sound as if they are in your room, or do you want it to sound as if your room isn't there (and perhaps accoustically you seem to be in the recording studio)?


I don't much care. I want it to sound pleasant, musical, and involving.

I have never found highly-damped rooms to be particularly good for hi-fi. Quasi-anechoic listening environments are good for measuring loudspeakers and for analytically determining what signal you are recording in a channel, but generally lack the liveliness of a really involving dynamic home stereo system.

Nor due I think that ruler flat frequency response from DC to light is particularly important characteristic of a great hi-fi system. I have heard some truly magical audio systems that have dreadful frequency reponse curves (like the old Quad electrostats.) The ear and the perception of sound is a funny thing.

#18 of 20 Larry B

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Posted April 24 2002 - 02:47 AM

Jeremy:

Thanks for the response. An intriguing (and annoying!) phenomenon, to say the least.

Lassry

#19 of 20 Arnel

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Posted April 24 2002 - 06:00 PM

Quote:
There ARE some drawbacks, especially when you try to apply a big difference here and there. EQ-circuits never come without a penalty: phase shifts. And you may also become more dependent of your actual position in your room.

Cees, if the only drawback is being limited with the actual position in my room, this is somewhat acceptable because that is the only position I'm using while listening to my system. In every system, EQ'ed or not, there is a sweetspot where we love to seat and where we here our systems at its best. Don't you think it's also limited on that spot?

Quote:
Placing a speaker near a doorway doesn't necessarily lower the actual decibel level the speaker is outputting, but it can change the tonal characteristics of the sound coming from the speaker in a way that makes it seem quieter, despite it being at the same level.

I agree with you Jeremy coz I've also experienced the same. I have observed that the effect is just like passing that speaker for some EQ-ing. Some frequencies were boosted while others were reduced, thus making it tonally different from other speakers without affecting the level. Meaning we can't correct this by increasing its level but by EQ-ing that speaker or changing its placement.
Tonal balance is as important as level setting in our system. We wanted to tonal match our main L&R speakers with our center and surround speakers. But even speakers of the same brand and model, placed on different spot in our room will produce a different tone because of room interaction. This is now what I'm trying to experiment in my system - to find the closest placement for my main L&R speaker wherein they would produce the same tonality or frequency balance, afterwhich I can balance its level. The resulting placement is not in equidistant (but close to equidistant), which is somewhat different from what we believe in, but I admit, there was an improvement. But still in my head (psychological effect) I can't accept it because it was against the norm. Maybe I only need your concurrence, what do you all think?

#20 of 20 Bill Lucas

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Posted April 25 2002 - 01:56 AM

I know of no home theater that demands that only one spot is "sweet". Posted Image The term home theater implies (to me) that more than one person at a time may be using the theater.

EQ'ing a home theater allows one to smooth out the frequency response to yield solid results in *various* seats in the room. That way, your wife isn't sitting next to you yelling at you to turn down the bass while you are sitting in a null wondering where the hell the bass is. I absolutely agree that gross adjustments should not be made and that they will do more harm than good. This is why a professional acoustician should be hired if a room is to be EQ'd. It is not a task for novices, enthusiasts and those that think they know a little more than they may actually know. Posted Image The dimensions of the room will dictate whether or not the room can be EQ'd without making large adjustments. Regards.


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