System Calibration vs. Program Compensation: Will a house curve deliver sonic bliss?

[Wayne A. Pflughaupt]

System Calibration vs. Program Compensation:
Will a house curve deliver sonic bliss?

Perfect sound quality forevermore?
Some people have come away from forum discussions on house curves, or perhaps from reviewing my house curve article, with the impression that dialing in an appropriate curve for their room should result in all program material sounding perfect. The following is from a discussion thread here at The Shack, where people voiced disappointment with the results:

“My experience in equalizing for flat response at the listening position with pink noise was exactly like Wayne’s early experience: searing treble and AWOL bass. However, my bottom line is that the amount of HF cut you need will vary from recording to recording, and some recordings will produce correct sound in your room (and mine) with no treble attenuation. So feel free to experiment with target curves, and recognize that different recordings need different EQ. So many recordings are badly done that a fixation on ‘one right setting’ will only bring suffering upon oneself.”

“I agree with what you say but only up to a point. Consider that the TNT channel and certain shows on the SciFi channel have something major wrong with their bass. I don't think you have much choice but to have a different setting (or memory) in your Sub EQ setup. Coming up with a compromise setting that you can use for everything is most likely to result in settings that don't sound good for anything.”

Certainly, these folks are correct: Dialing in a house curve appropriate for your room will not guarantee that every recording or program will magically sound perfect. That’s an impossible goal, since the movie industry’s X curve is not nearly as rigid as one might think, and the music, TV and video game industries have no standard at all.

System calibration...
But let’s take a step back from equalizing programming and focus on the bigger picture: the system itself. Dialing in a playback system so that it sounds natural and balanced is what audio professionals call “calibrating” or “setting up” a system. They accomplish this with various response-measuring tools (and fortunately we non-pros have the awesome REW program available to us). Measurements are confirmed afterwards with program material that the technician has found to be a good representation of an accurate recording, making further adjustments at that point as needed, irrespective of what the measurements may indicate. Therefore, it should be noted – and obvious - that global calibration of the system is not the same thing as compensating for deficient program material.

In the world of home theater, rife with untrained and amateur system “calibrators,” a house curve will naturally reflect the owner’s personal tastes and expectations. For instance, we can anticipate that a basshead fresh from the world of car audio, or someone who’s used to the “boom-sizzle” of smiley-face EQ settings (from one of those 10-band equalizers that were popular in the ’80s), will expect that their home theater should sound the same. That’s not really a problem. Once the system is calibrated, even if it’s intentionally “miscalibrated” to accommodate the owner’s tastes and expectations, it becomes their personal point of reference.

...Vs. program compensation: Just say “no” to endless tweaking
At that point any program material offered up from the cable box, satellite receiver, DVD or CD player – for the most part “it is what it is.” The notion of calling up a different house curve for everything that comes down the pike - or as I’d characterize it, deliberately un-calibrating the system - is not the proper way to do things. If certain discs or TV shows have, for example, bloated midbass – fine. I assume that’s the way the director or producer wanted it to sound, right or wrong. I’m not interested in re-tuning my whole system to “unbloat” his idea of “correct.” I have the benefit of a real time analyzer connected to my system that gives a visual display of all audio-program frequency response, so when I hear something that doesn’t sound right – bloated midbass, limited low extension, screaming treble, what have you - the RTA confirms that is indeed what the program is generating. It verifies my system is calibrated correctly and is accurately reproducing what it’s being fed – a rather satisfying feeling, actually.

Certainly, if you find yourself making the same adjustments on a regular basis – e.g. always dialing up the treble a few notches – then tweaking the system a bit further is in order to finalize your settings. With a properly calibrated system, most program material should be “in the ball park” as far as sounding balanced. That’s the goal, since perfection is unobtainable. Indeed, this is the one downside to having quality electronics and good speakers all properly calibrated for the room: you will quickly find out just how bad a lot of programming really is, especially when it comes to bass.

Addressing problems with poorly-equalized program content – as noted, that’s a whole ‘nother cantaloupe separate and apart from system calibration. There’s certainly nothing inherently wrong with tweaking problematic programming, but adjustments should be general, not wholesale, and temporary - such as overall adjustments to the treble or bass if they sound excessive or deficient. If the bass sounds bloated, then bloated is what it is. But bloated bass should at least be at a balanced level in relation to the rest of the signal, not overpowering or weak.

I typically just use the tone controls or subwoofer remote control (for level adjustment) for times like this, but it would be easy enough to dial in a pre-set curve of some type for certain problematic TV channels or shows that you frequent, if your system has the capability. But even such pre-sets should be recognized for what they are - temporary settings.

[Wayne A. Pflughaupt]

Reserved.