just because something is set at a reference level or calibrated by a machine to be flat, doesnt mean it will be the way you prefer something to sound. we have hearing loss, personal taste, etc. i recommend using reference settings as a "reference" of where to start rather than the perfect setting for everyone. no one is going to tell me how i like to listen to my movies or music. also you will have to adjust settings sometimes because all media is not normalized in sound or in sound quality. one dvd might sound great, but another needs more volume in certain ranges, etc. make yourself happy rather than let references or standards rule your listening habits.

The problem with meters is that they only take a measurement in one spot. With bass issues, you can move the meter a few inches one way or the other and get a different reading. I think the best meter today is to get a laptop with a measurement microphone and use a spectrum analysis program. This way you can compare different results to get the best average level for your room.

As for the Ratshack meter, I remember reading about a chart that will adjust the curve to make its readings more accurate in the bass range. Here's a link:

http://www.svsound.com/questions-faqs-rscomp.cfm

Thanks, Jason J. I have heard about this conversion table before, but could never find it. One question though -- if one uses the speaker calibration test tones in the 990 or some other receiver/processor for setting levels, what is the effective frequency for determining the correction of the meter's response for the sub level?

Me too. I use the 2 channel offset to "cool" it down by 6dB for 2channel listening and leave it at 0dB for movies.

Perhaps the original poster has a placement issue? With "boomy" movies, my LFM-1 literally rattles the walls at anything close to reference levels.

Cheers,

To add to the chaos .... I prefer throwing the Video Essential disk in the DVD player and use the test tones on the disk. This way i am testing the entire audio path.
I have found a difference between the dvd player and the 990 test tones (up to a couple of dbs).

Jason J,
Thanks for the chart. good stuff.

When using low frequency pink noise to level match a sub, should placement matter?

Depending on its position in the room, the sub may sound more or less loud to a meter at the same gain setting. However, once the sub gain (or trim) is adjusted to compensate, so that the meter indicates the loudness of the sub is the same as the rest of the speakers in the room, you'd end up with more or less the same result regardless of where the sub was placed. Wouldn't you?

To be clear, I do understand that placement does matter for a sub, just not how it matters when level matching relative to other speakers with pink noise and an SPL meter.

I have used the Velodyne SMS-1 parametric equalizer and found that moving the mike (pickup) around does make a significant difference in the readings. I am sure that an SPL meter is even less sensitive. When it comes down to the nitty gritty I think Curegeorg is right, it's best to use the end results in determining what sounds right via the ear. The mechanical method, although we all want to get it as close as possible, is a second guess in comparison with the EAR, opps, I mean END results.

Yes. Even though multiple frequencies are being played at even levels, when your room interaction is added to the mix some might be much higher and/or lower than others. Most people, except in the extremest of situations, will not be able to hear enough of a difference between those levels at individual frequency bands. With that much extra energy (or possibly not enough depending on cancellation/enhancement) the meter is going to misread as it will detect a lot of energy, even though much of it is at specific bands instead of even across the board.

Now if you had an RTA (real time analyzer) which would be able to show you the amount of sound pressure at different bands, you could potentially compensate for those issues, or even have a visual guide to moving the sub around until you find the spot with least problems. Most people do not have that capability as stand alone units that would have any reasonable bass accuracy are very expensive (>$1000), and easily available software solutions are not terribly accurate either, and depend heavily on the mic and other hardware hooked into your machine.

As attested to in other parts of the forum, getting the sound right in any room has just as much to do with room interaction as it does with the reproduction equipment – a little spent on room treatment can go a long way.

With mid and high frequencies, there can be reflections and multiple signal paths in a room that detract from the accuracy and intelligibility of the sound. For the lower frequencies, there are the added troubles of room resonances and standing waves in different places that result, depending on frequency, in near nulls or huge boosts in sound pressure level.

Without room treatment, what’s a poor person to do? Even on a small budget, an SPL meter is a worthwhile investment. Some reputable free versions of software can allow you to generate tones. While sine waves have disadvantages in some ways, they can be very helpful in others. One can set up steady tones or slow sweeps through the subwoofer range and watch the SPL meter as one moves the meter horizontally and vertically from listening point to listening point. (Aside: I’m not one that says, “if I have consistent levels in the middle of the room 3.5 feet above the floor, I have the best sound in this room.”) Moving the subwoofer a foot at a time, then 6 inches at a time, then 3, 2 or 1 inch at a time and watching the meter at various low frequencies as one moves the meter through the same listening positions over and over again can help a person determine which subwoofer location presents the least variance in overall level. Likely one can reduce wide variances, but it is unlikely that anyone can achieve, without additional treatment, a near flat response in multiple seating positions. Go for reduced variance in the more likely listening positions.

Once you have found the best compromise position for a subwoofer, the level setting(s) for your subwoofer will probably need some adjustment once again. Whether automated or by manual means, placing the meter’s microphone, or the auto EQ microphone, at a point of least variance, and in the most likely listening positions, is best. Some auto EQ equipment will allow the user to obtain ‘readings’ at more than one point and then make adjustments to tame the worst of any variances. If your budget and significant other allow, room treatment would be the next step.

If one expects perfection, they are likely in for disappointment. On the other hand, one can obtain meaningful improvement by reigning in nulls and peaks with the methods they have at hand.