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Old 05-01-2007, 02:04 PM   #3
scottdru
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Quote:
Originally Posted by anytime732 View Post
hi,
i am curious to know if the sound that i get from my monitor speakers (fostex PM2 mk2) is true enough to mix a good song on.
The Fostex monitors are **OK**, but not great (IMO they suffer from a lack of inner/transient detail, and a fairly shallow front to back imaging), BUT . . . they should be good enough to get some pretty decent mixes on.

HOWEVER, from reading your description and looking at the picture, I can *guarantee* that your acoustics problems are BY FAR greater than any possible weakness in your monitors.

To give you a starting point, have a read of my post in this thread (I make a chunk of my living as an acoustics consultant):

http://www.cockos.com/forum/showthread.php?t=7794

The original query in that post was slightly different from yours, but the answers are actually very much the same. Between what I've detailed in that post and what is contained in the linked articles, this should give you a good starting point.

Quote:
i do not currently have any bass traps or any other acoustic treatment, however i do have the walls and the ceiling covered in carpet.
Using carpet all over your walls like this is a VERY imbalanced way to treat the acoustics of a room. Not that you should never use carpet for absorption, mind you . . .

The problem here is that carpet will only absorb high and mid frequencies, and it will not absorb low frequencies. Unfortunately, if you put in a whole bunch of high and mid frequency absorption without putting in equally as much low frequency absorption, you end up with an unnaturally dead, and MUDDY sounding room!

Quote:
if any one knows of any way to est or improve the quality of the acoustics in the room please comment.
In fact I DO know of a way to substantially improve the acoustics in your room!

The answer is bass traps . . . as many as you can afford to buy or build in your room.

While you can most definitely put too much high and mid frequency absorption in a room, it is pretty much impossible to put in too much low frequency absorption in a room, especially when we're talking about small rooms (i.e., the size rooms you find in a typical house or apartment).

This may seem counterintutive, but the fact of the matter is that the low frequency sound waves that are reflected off the room boundaries (walls, floor and ceiling) will cause acoustic distortion of the direct sound from your speakers by either enhancing (increasing the amplitude) or cancelling out (causing dips or even outright nulls in the frequency response) the direct sound waves coming from your monitors.

ALL rooms, and ESPECIALLY small rooms, need bass traps to get anything even close to a flat response. Most rooms will have peaks and nulls at numerous frequencies across the entire frequency spectrum having a range of a good 30 to 35 dB from top to bottom. If you address the room modes that cause the problems at those particular frequencies, you will not only reduce the amplitude (and also even out the decay time) of those problematic peaks, but also help to minimise or eliminate the dips/nulls. This means that, even though you are *absorbing* low frequency sound energy, you will actually be getting MORE bass (and and tighter, more accurate bass) than without the absorption.

So . . . it becomes a more than a little bit inconsequential to be worrying about whether your monitors are +/- 1 dB or +/- 3 dB of flat, if your room is acting like a huge filter/EQ that is skewing the frequency response of what you hear by 30 to 35 dB!

You will get more improvement (i.e., much greater accuracy) in that room by spending even $500-1000 (especially if you DIY) on proper acoustic treatment (i.e., broadband/bass traps, and balancing out the amount of high and mid frequency absorption so that you are not killing ALL the ambience in the room) than you will get in that room by spending even several thousand upgrading your monitors.

Another few articles that may be helpful to you:

http://www.realtraps.com/facts.htm

http://www.ethanwiner.com/acoustics.html

So . . . the short answer . . . fix your acoustics, and I wouldn't worry too much about your monitors until you treat the acoustics properly first.

Oh . . . and one other thing . . .

I would highly recommend getting those monitors OFF the desk, as I can guarantee you are getting some serious comb filtering from the sound reflected immediately from the speakers right off the surface of your desk. This will be skewing your frequency response, but it will also be playing havoc with your imaging.

I highly recommend to put them on stands, with the tweeters at ear height (or as close to it as possible).

Speaker stands should be as heavy and solid as possible, to avoid any low frequency resonances that could also cause your tweeters to move just enough to cause time smearing (which again mucks with your imaging).

The cheapest, easiest, and best solution for this I know of is to get a bunch of concrete breeze blocks and stack them up (you can glue them together with construction adhesive if needs be, to avoid instability and/or the potential that someone could bump into them and send the whole stack tumbling).

Concrete has a very low resonant frequency (somewhere down in the single digits) -- much lower than the lowest frequencies your monitors are capable of producing. This will give your speakers a very stable pedestal to work against -- this can also help tighten up your low end (as well as your imaging), because the speaker cabinet will not have the freedom to move ever so slightly when you get powerful kick drum hits -- which it can if you have your speakers sitting on unstable stands/furniture, or stands/furniture which might have a higher resonant frequency.

Hope that helps!

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