When volum goes up, which freqs ranges get more prominent?

[BluesWithoutBlame]

I was just wondering. If you (artificially and arbitrarily like they do on amp controls) only kept to the main staple three bands, Bass, Mid, and Treble in answering this...

 

If you have a certain tone at "bedroom levels" and you raise the levels to gig level, I always heard it was the bass and treble that get more prominent...mid range less prominent.

 

But in my experience with several amps, it seems to me that it is bass and miderange...I seem to be usually turning up the treble at higher volumes, getting it compensated so I can retain the tone I want.

 

Is there anyone here that knows what the theory, or accepted wisdom is once and for all? It could be that I am remembering wrong.

[BillWelcome Home Studios]

Your mind naturally compresses as a form of protection. Your mind is telling you that it is too damned loud. As protection, it doesn't work. As a warning that you are doing (probably permanent...) damage to your hearing, it should work. But like any red light, it's only asking you to stop, it cannot force you to stop. Things get muffled. You turn up, then you turn up the treble. Nobody else hears that 'tone that you want' except you, unless their ears are compressing exactly the same as yours.

 

Bill

[Corner Pocket]

As far as your ears go, google fletcher-munson equal loudness contours.

 

As far as your amp goes, sometime there is a circuit built into the amp to compensate. Many home stereo systems have a "loudness" button. The "loudness" button turns up the bass as you trun down the volume, this is to compensate for the perceived drop in bass that the human ear hears. With "loudness" on the extra bass boost is reduced as you turn the volume up. The stereo manufacturers are making a SWAG when they desing the loudness circuit. They have no idea what speakers you will be using, or how efficient they may or may not be.

 

Now, over the course of the night, listening at high volumes, (and it doesn't take as much as you think), your ears will fatigue, and you will need to turn up the treble to get the same percieved tone. If somebody walks into the club hours after the PA got cranked up, he'll notice that everything is too bright, too trebly.

 

Peace,

 

Paul

[Caevan O’Shite]

Well, there's more than one thing going on here:

 

It's true that your ear- and brain- will perceive more treble and bass at higher volumes, with a pseudo copmression coming in as levels get very high.

 

-BUT-

 

The response of your amp and speakers and room acoustics all figure in here, too.

 

To get a scientific answer, you have to use scientific measures- including isolating and addressing the factors that you are interested in, and effectively neutralizing those that you aren't, so that you've got a reliable, repeatable, measureable set of circumstances and parameters to reference to.

 

On a classic "tweed", "blackface", etc. Fender tube-amp that has Bass and Treble (but no Middle) controls, if you turn both up all the way and especially if the volume is high, a perceived mid-boost occurs. But that's largely due to the response of the tone-stack circuitry for the most part, and has less to do with the oft cited Fletcher-Munson (Munson-Fletcher? Sp?) effect of the ear's and brain's psychoacoustic perception of higher volume levels, where highs and lows are exaggerated at high levels, etc.

[fantasticsound]

The Fletcher-Munson curves shouldn't come into play much between bedroom levels and gig levels. The equal loudness curves are pertinent between really low levels and moderate levels. But that is what I think you're referring to, BWB.

 

As everyone else, so far, has mentioned, room acoustics, physiological compression of your ears, etc. will make a difference.

 

But I highly doubt you'll have to make changes if you play softly then loudly for a few moments to compensate for equal loudness curves. Your amp and speaker/speaker cabinet will react differently at different levels, though. Take compression and fatigue out of the mix and you would still have to compensate for changes in your timbre when you turn up because the gear is far from linear as you go from relatively quiet to relatively loud operation.

[Dr. Ellwood]

I find that as I increase my volume from rehearsal volume to performance volume I always end up rolling back the higher frequencies. I don't run allot of bass anytime so that does not seem to need adjustment.

[BluesWithoutBlame]

Lots of replies, thanks all...

 

But..I wasn't really going for what is perceived loudness changes, Fletcher-Munson or any of that. Not due to ear fatigue, but I thought this was a well known measurable phenomenom.

 

I mean, look at a THD HotPlate. They have switches, one bass one treble, that "make up" the frequencies that aren't as present when you attenuate (turn down) the volume.

 

Just as one here mentioned about "loudness" buttons, but this is over a range of two frequency ranges...bass and treble.

 

I am pretty sure this has slightly to do with the OT and output tubes, but moreso by the speakers themselves.

 

Just thinking about it now, loudness equals more travel for the speakers which I am thinking would mean they would lose highs at higher volumes since they couldn't react, bounce back, out again at the higher frequenxies as well as they can at low. This would bear out my experiences also with bass and middle being slightly higher with relation to the treble as volume goes up...but this is also at odds with the engineers apparently at THD who saw fit to use low AND high boost to get that "loud sound" at lower attenuated volumes.