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  #1  
Old 01-09-2002, 08:01 AM
ckerian ckerian is offline
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Default Anyone out there using 31 band EQ\'s and Pink noise to calibrate monitors to the room?

I have in the past connected a stereo 31 band EQ between my Mackie 24-8 control room outputs and my power amp. I then hook up my pink noise generator to the inputs on the mackie and have it output pink noise so the pink noise is coming out the monitors. I then hook up a microphone (in my case it's a supposedly flat Peavy elektret (or something like that) up to the spectrum analyzer input on the pink noise generator/spectrum analyzer and it displays what the mike is picking up. I assume this is showing the defiecencies of my monitors and the characteristics of the room. I then use the 31 band EQ to shape the sound coming out the monitors so the pink noise is that the mic has picked up is flat across all bands on the spectrum analyzer.

I try not to EQ too much as I dont want any delays or phase problems to occur. is this OK? seems to me that even if I got the flattest monitors I could find I would still have to deal with the characteristics of the room. should I shy away from this practice or am i a complete stud for coming up with this practice on my own. no one suggested this to me but it's obvious to me that this is exactly what a spectrum analyzer/pink noise generator is for. I really need some good monitors. my system has practically no bass but is very clear in the high end. they are 6.5 inch 'Gold Sound' speakers from Denver, CO. Gold Sound is a hi fidelity speaker and amp shop and he claimed these are pretty good for their buck and accurate too (i told him I didnt want exagerated anything). I probably need some good 1000 dollar speakers but I cant afford them right now. any great speakers for under 500 bucks? I see all kinds in the musiciand friend catalog for cheap but I bet they arent too accurate. PAR did a review of the carvin monitors and they look good as long as you dont turn on the stupid hi fi simulator.
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Old 01-09-2002, 10:52 PM
where02190 where02190 is offline
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Default Re: Anyone out there using 31 band EQ\'s and Pink noise to calibrate monitors to the room?

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by ckerian:
I try not to EQ too much as I dont want any delays or phase problems to occur<HR></BLOCKQUOTE>

An analyser shows only energy in DB SPL, and will give you no useful information for your issues.

Save your money until you can afford two(yes 2) decent pair of professional monitors.

Learn about TEF, (time/energy/frequency) calibration, physics, acoustic energy absorption and reflection.

Tune the room to the speakers, and leave the graphic eq's for the touring live sound world.

Less is more....
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Old 01-09-2002, 11:57 PM
lwilliam lwilliam is offline
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Default Re: Anyone out there using 31 band EQ\'s and Pink noise to calibrate monitors to the room?

Yeah, using a parametric (or especially a 31-band) EQ is a little like putting a band-aid on a cut that never heals.

I spent several hours getting to grips with the combined response of my room and monitors using a little Radio Shack SPL meter and the Digi signal generator plugin. I plotted the whole thing out three times, averaged the results, and graphed it.

I then went to an pro audio specialist (Sound Control Room) and got some acoustic foam and bass traps. That seemed to have done the trick.

The problem with EQ is that it doesn't handle things like RT60 time for given frequencies, i.e., one frequency will resonate a room node and "reverberate" longer than another frequency. Reducing the level of that frequency doesn't handle the resonance. If you handle the resonance, then you're much less likely to need to raise or lower the frequency.

The trade-off in using an EQ is that there WILL be some phase shift as well as usually some additional noise and distortion/coloration added by the unit. The improvement in the frequency response may or may not result in an overall improved sound. If you already have a 31-band, it won't hurt to try it and see if it's better overall, but I wouldn't go out and buy one - get better monitors and tune the room first.

In short, I'd have to agree with where02190: tuning the room is better than modifying the signal. Having good monitors AND a tuned room is even better.

I've heard of some people having limited success with a Behringer Ultracurve or something similar to at least get the worst resonances out, but I've decided not to go that route myself.

On a side note...have you EVER seen a bad review in PAR? Not me.
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Old 01-10-2002, 09:15 AM
guitates guitates is offline
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Default Re: Anyone out there using 31 band EQ\'s and Pink noise to calibrate monitors to the room?

I have used the Behringer 8024 with Great success. You must use their ECM 8000 mic.
$50...You cannot just use Any old Mic.

I do Not understand some advise on this DUC...When you place a mic, it Hears the speakers and the room. How can anyone say that the mic only "hears" the speakers??

In other words, you can imagine that the mic is actually your ears...Right?? I place the mic exactly where I sit, with the chair in place, for exact duplication of what I will hear.

Also, I have my speakers suspended from the ceiling, aboul 3 feet from the wall, and exactly 1 arms length from my head (ears) Y..

You will have to really study to learn how to EQ the "room" with the 8024, but I have cheap-Alesis M1 actives, $600 and for $500 more (beheringer + mic) I have my sound Dialed In. (very little EQ adjustment)

I do not have Subs, so the bottom end is raised at 50-63-80, with 50 being the highest and down from there.

If you can afford $3000+ go for the Genelec's but, I would think any speaker could be more TRUE with the Dual 31 bands. my $.001 [img]images/icons/cool.gif[/img]
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Old 01-10-2002, 11:05 AM
Barnabas Barnabas is offline
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Default Re: Anyone out there using 31 band EQ\'s and Pink noise to calibrate monitors to the room?

Back in the days before I could afford "real" monitor speakers, I used pink noise to calibrate my system. I had a cheap pink noise generator, dual 15-band EQ, and 15 band RTA all in one unit. I found that EQing the cheap speakers was better than not EQing the speakers at all. Now I have decent monitors, but I still ran some pink noise through them just to see how flat they were.

After EQing your speakers, listem to some CDs you are familiar with on those speakers, and train your ears to accept those reference CDs as "normal sound."
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Old 01-14-2002, 07:32 PM
DC2light DC2light is offline
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Default Re: Anyone out there using 31 band EQ\'s and Pink noise to calibrate monitors to the room?

When EQ'ing a room I use a combination of pink noise and signal sweeps. Sweeps are important because any one freq. does not have time to build up so you can see the real eq of a room. Before you apply any electronics in line always try moving the monitors around. It's amazing to see what a few inches let alone feet can do with the modal response of a room. Search google.com for room EQ'ing and you should be able to come up with many web sites or go check out a good book from the library. You can have million dollar monitors and in a crappy room they'll still sound like crap. I would always spend money on the room before the monitors. There are some great sounding +$300 monitors out right now. NO room is perfect but EVERY room can be improved.
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Old 01-14-2002, 08:22 PM
where02190 where02190 is offline
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Default Re: Anyone out there using 31 band EQ\'s and Pink noise to calibrate monitors to the room?

Unless you plan on spending thousands of dollars for great eq's, don't bother. tune the room, not the speakers.
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