calibration, schmalibration.... (1 Viewer)

[Tom Vodhanel]

If anyone feels the need to *recalibrate* (whether by meter or ear) the system with each DVD,something is seriously amiss. This is like saying we need to *eyeball* the color,tint,contrast,sharpness settings on the video with each DVD. Just like in audio...someone can claim *accuracy* cannot be defined...but why bother with AVIA,VE or ISF calibration then? I guess if the system is totally out of whack to begin with...changing it constantly could be of some benefit(the law of averages sez you might hit a good combination every now and then?)

Some major gaffes in this thread me thinks...

TV

 

[Tony Genovese]

Some major gaffes in this thread me thinks...

Tom, it seems the problem here is that most folks either are unaware of the fact that there is a reference, or they don't care. And no amount of talk about calibration is going to convince those that don't care. Seriously, who are we to rain on their parade? If it makes them happy, great. I am happy when I hear T2 shake my room just like it did in the theater, 'cause I got two whomping TN1220HO's getting goosed by a Samson S1000. I'm sure your subs do the same !!!

 

[Bob_A]

"If anyone feels the need to *recalibrate* (whether by meter or ear) the system with each DVD,something is seriously amiss."
I don't see anyone who claimed that you need to recalibrate for each dvd. But I think it should be obvious that, depending on how loud someone wishes to play a dvd, and depending on how the dvd was recorded, they may prefer to do something like bump up the center channel a bit. How this can be interpreted as a knock against "calibration" is beyond me.
Take a look at:
http://www.hometheaterforum.com/htfo...803#post464803
http://www.hometheaterforum.com/htfo...threadid=52064
Clearly, what some people claim is "accurate" (ie perfectly flat frequency response or reference level output) is not what everyone prefers.

 

[Tony Genovese]

Clearly, what some people claim is "accurate" (ie perfectly flat frequency response or reference level output) is not what everyone prefers.

Whether people prefer to listen to a movie at reference does not negate the fact that "reference" is the way the sound engineer intended. Hearing it the way the sound engineer intended, is certainly more "accurate" than hearing it the way he/she did not intend it. Hey, some of us are trying to "replicate" theater sound at home, hence the home theater nomenclature. Both THX and Dolby have set up a beautiful system to give you the opportunity to do so. This is not a "claim", this is a fact. It is factually accurate to say that listening to a movie at reference with a properly calibrated system is the best approximation you're going to get to what the sound engineer intended. Now, if you prefer it some other way, great, but again, do not claim that how you like is how the sound engineer intended. For me this is what home theater is all about, for you, your call.

 

[Bob_A]

Should we not trust our preferences?

I guess that is another debate for another time.

 

[Jeffrey Forner]

trust our preferences?

I don't think anyone is saying that you shouldn't and/or can't adjust the settings on your system to your own preferences. Just don't pretend that your preferences acurately reflect the way the system should sound, especially if you don't use and SPL meter.

 

[Tony Genovese]

Should we not trust our preferences?

I think you should like what you like what you like. But the discussion here was about why we should calibrate our system. Again, I offer the advice that if you want to attempt to replicate what the sound engineer had in mind, then calibration is an absolute must, and listening at reference, a given. Whether you enjoy the movie as much at reference is immaterial, if you're trying to hear what the sound engineer heard (or as close as possible in a home theater). How you play your home theater in your home is obviously up to you. But just realize that if you're not listening at reference with a calibrated system you are not hearing the movie as intended.

 

[Bob_A]

"Just don't pretend that your preferences acurately reflect the way the system should sound, especially if you don't use and SPL meter. "

How exactly should an "accurate" system sound? What is the definition of "accuracy"? People do not buy loudspeakers based simply on flatness of frequency response, do they? Who are we to tell someone that what they enjoy and prefer is not "accurate".

 

[Tony Genovese]

What is the definition of "accuracy"?

For starters: measured at 30db below reference: 75db, C weighting using a sound pressure meter, for each of the 6 (or 8) speakers in a surround setup, using your internal test tone. This will begin to define at least sound level accuracy. An accurate system should hit 105db peaks at the listening seat with low distortion and 115db peak from the LFE. If your system can't do it, it can't be termed accurate, at least with respect to playing back a movie the way the sound engineer intended. No personal attacks, just the facts .

 

[Jeffrey Forner]

Who are we to tell someone that what they enjoy and prefer is not "accurate".

Well I don't know about you, but I'm Jeffrey Forner, and I think I've stated my case fairly well in this post.

 

[Steve Stogel]

You've got to admit, Bob, that that's a pretty good definition of accurate. Someone may prefer a sound that is not accurate (and there is nothing wrong with that), but to say something is accurate because you prefer the sound just doesn't cut it. Preferences and accuracy are not one in the same. Nicely defined, Jeffrey and Tony, and without any personal attacks, I might add .
Steve

 

[Bob_A]

"but to say something is accurate because you prefer the sound just doesn't cut it."

Steve, I never made such a claim. What I do claim is that there are different ways to look at accuracy. How about naturalness or life-like nature of the sound? Would this not be one way to look at accuracy? Also, what about DD mixes which include bass information sent to each channel. I could argue that routing everything below, say, 90Hz to a corner-loaded external sub is not "accurate" because this is not what was intended by the mixer. Ultimately, isn't this hobby about our sonic preferences, not about our notions of sonic "accuracy"? I guess that is just my opinion...some people may feel differently.

Keep in mind that I still feel that it is perfectly fine to calibrate a system with a meter.

 

[Jeffrey Forner]

Keep in mind that I still feel that it is perfectly fine to calibrate a system with a meter.

That's cool. Have you ever tried it?

 

[Steve Stogel]

Bob...
>>>What I do claim is that there are different ways to look at accuracy. How about naturalness or life-like nature of the sound?>Also, what about DD mixes which include bass information sent to each channel. I could argue that routing everything below, say, 90Hz to a corner-loaded external sub is not "accurate" because this is not what was intended by the mixer.

 

[Yohan Pamudji]

To me, an accurately calibrated system is a good base from which one may "salt to taste". I think I run my center channel and sub a couple decibels hot. Is it completely accurate? No, of course not. I started with a standard calibration but then modified it slightly for my own pleasure. Yeah, it sounds good to me, but I'm not going to claim that it's as accurate as I could've gotten it.

On the other hand calibrating completely by ear is not a good idea, unless you just don't care if your system is performing as well as it can. It's an easy and cheap way of maximizing your system's performance, and if you don't care enough to do someething so simple and cost-effective then all the care that you put into selecting your equipment was a waste of time and energy. Avia/VE and an SPL meter are essential tools for any HT enthusiast.

 

[Bill Lucas]

The ability of a speaker to hit an SPL mark does not make it an accurate speaker, it makes it a LOUDspeaker. Accuracy is a monitor that puts out what it receives without coloring or voicing the sound, nothing more nothing less. Combine that with a speaker that is capable of reference level peaks and you have one fine speaker.

 

[Rick Radford]

It appears to me that accuracy is a pretty subjective term. One man's accurate speaker is another man's warm or bright speaker.

Or is there some speaker that everyone agrees is accurate?

A while back I asked about this term "accuracy" as it relates to speakers, and iirc, it was considered a pretty vague term.

The idea of accuracy sounds nice, but how do you determine it (other than for yourself)?

 

[Tony Genovese]

Bill:

Agreed. Ability to play loudly is certainly not the only measure of accuracy. In the context of home theater, though, it is one of the measures.

Rick:

There are certainly measurably accurate speakers. John Dunlavy designs accurate speakers. On the pro side, there's the Mackie HR824, the JBL LSR speakers, among others. Now whether accurate speakers are to be preferred in one's home is subject for another thread.

 

[John Doran]

rick,

The idea of accuracy sounds nice, but how do you determine it (other than for yourself)?

i think the accuracy of a piece of audio equipment is the measure of its ability to output a signal it receives with as little change to the signal as possible.

there obviously needs to be a further definition of what counts as a relevant "change" to the signal, since the very nature of amplification is to increase the amplitude of a signal, thereby making it, at least in one respect, different at output.

at any rate, as it concerns loudspeakers, the more what comes out of the speaker is like what's fed into the speaker, the more accurate it is.

the most accurate loudspeakers not only have a flat frequency response (the flatter the better/more accurate), but are also time and phase correct.

measurements that indicate speaker (in)accuracy are : frequency response, impulse response, step response, and cumulative spectral decay.

however, many people are of the opinion that much of what contributes to the accuracy of a speaker is actually inaudible and cannot therefore appreciably contribute to the perceived acoustic performance of the speaker. for instance, if i'm not mistaken, tom vodhanel of SVS considers the phenomenon of group delay to be irrelevant (group delay is the arrival at the listening position of different the different groups of frequencies that make up an acoustic event (e.g. horn note, drumbeat, musical passage) at different times - high frequencies first, low frequencies last).

i have no idea which features of a speaker's accuracy are actually audible - it's a highly controverted issue.

there are very, very few really accurate speakers - speakers that are accurate all the way down - dunlavy, thiel, vandersteen, and meadowlark are a few.

none of this is to be confused with what sort of speaker-sound a particular individual may prefer - some people derive more enjoyment out of horribly inaccurate speakers than they do accurate ones. all the more power to them.

- jd

 

[BruceD]

As a well documented phenomenon, the acoustic effect of a room on a speaker's sound can overwhelm other individual speaker "accuracy" issues.
This means a careful assessment of the speaker/room interface for;
- frequency response anomolies (room caused frequency peaks and nulls, echo, first reflections, etc.)
- phase response matching of the sub
- SPL ouptut level matching of all speakers at the listening position
is essential to obtain the best realistic soundscape possible.
How far anyone wants to pursue these goals is their personal preference.
But, make no mistake, without measuring, evaluating, and correcting for these issues accuracy is a relatively moot point.