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Forum Index » Profile for Jerryd » Messages posted by Jerryd
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Live Sound » Spectrum Analyzer2 » Go to message
Here is a great discussion on measurement mics. This is coming from Harry Brill a Rational Acoustics instructor. Even a cheap mic will get the job done. Don't spend a lot of cash on something like this when your cash can go to other things that will make a bigger difference. Here is his take on cheap measurement mics:

http://www.dbxpro.com/Forum/viewtopic.php?f=28&t=1894

It is 2 pages and Harry comes in at the end. Read the whole thing.

Live Sound » Spectrum Analyzer2 » Go to message
Kibo -- This is Dr. J. I guess I won't be able to use "Dr. J" anymore since Presonus made an executive decision. Anyway my name is Jerry. Just like one of the other guys stated -- system tuning, optimization....etc. is a touchy subject BUT there are some real principals here to learn that will help you a bunch.

First thing you need to know is that the audio spectrum has been typically describe as going from 20Hz to 20kHz. With the typical BAR PA is it most likely 40Hz-45Hz up to 15-16K. So now if you can imagine a GRAPH that has dB level running up the left side of a page at -15dB to 0dB & from 0dB to plus 15dB & across the page from left to right 40Hz on up to 16k. This is your audio spectrum. Sounds pretty basic so far right?

Now, your speakers are going to exhibit some kind of response across that spectrum. Since there are thousands of frequencies across the spectrum -- do you know where all of them are at and what their dB levels are? This sounds like a crazy question doesn't it. It is important because you have to understand that more than likely -- your speakers are going to demonstrate a response across that spectrum that IS NOT anywhere balanced in dB levels. In other words -- your speaker boxes may be really loud at 500 Hz and very low in volume at 300Hz, 3K....etc.

So what a lot of people do without knowing what the spectrum looks like FIRST is insert a graphic EQ and start tweaking. It makes sense if you don't know what else to do. So with the Graphic flat (which really isn't at this stage of the game) adjustments are made by ear.

The FFT programs like Smaart and Systune take into account everything that is electrical AND acoustical in your system. Part of it is going at the speed of light and the other at the speed of sound.

Tuning your system in a nutshell is making adjustments to your speakers response until the response has been smoothed out to where the dB levels are balanced with each other. The only way to do it is with a dual FFT program. I helped LowTech do his system and I think he really likes it.

The tool of choice for correction and is the STANDARD -- is the parametric. The Parametric EQ is powerful in the fact that it allows to specifically correct the part that needs correcting. Not everything will need to be corrected. You can use a Graphic EQ (GEQ) but it will be a nightmare. You will try to correct a certain area only to find yourself wrecking another area.

The best affordable tool I have run across for this is the Driverack. There are many others out there so get yourself what ever you want but the idea is the same -- Speaker Management. Your speakers will have to be told what to do. You can equally say they have to be told what not to do as well. To assume a speaker in a box is fine as long as my crossover is set right isn't good enough.

Many say "Science can never replace the ear!" So should you rely on your ear only or on what your FFT program says? The answer is BOTH. Your ears will be the final judge BUT the FFT program will help you figure out how to balance frequency levels for a flat smooth response. It will help you have balanced levels between amps (Amp volume levels) & help you to have a phase aligned crossover which makes a huge difference.

After you go thru all of this and your system sounds like garbage -- then something happened that you overlooked. If done properly -- your system will almost always sound better as a starting point. So YES use your ear as the final say.

Don't run Auto EQ's in venues where you push a button, run pink noise thru the system into the room until it completes and think you have just "Tuned" the system to the room. It doesn't work that way & the system will sound horrible and sterile. I can't believe companies market that & is their selling point.

If you are serious about doing this Kibo -- I will help you set it up. I have a list of action steps for you to get you started if you are interested.

JerryD aka: Dr. J
StudioLive General Discussion » Migration...? » Go to message
The one feature that I do like about this is anytime someone replies to your post -- you get an email with the link to it. I have brought this subject up many times over the last year so thank you Presonus! This is the way DBX does it and it is very nice.

I still hope I can get my old screen name back.
Live Sound » Had to do it » Go to message
First Post!
StudioLive General Discussion » Migration...? » Go to message
jonathan wrote:I know it's kind of a pain, but in the end we feel it's better to have one username/pass to access everything you need at PreSonus.


Ok -- can I have my old screen name back without it saying, " there is already another user with that screen name?"

The original username and password would have been just fine for the "My Account" section.
StudioLive General Discussion » Migration...? » Go to message
What I already don't like about it is the fact that I had a username and password for the forum which I was accustomed to - then came along the software "Log In" section that wouldn't let me use the same username and password so I had to come up with a different one. Now -- to log on here -- I couldn't use my normal username and password BUT had to dig up the other one that allows me to download software from "My Account".

Geesh! Now I am ready for a beer!
 
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