I just installed an Xtant 603x with the PQM 1 module. Can anyone explain the principles behind adjusting Q and the PQM 1. Or if anyone has a link to a good site that explains all this stuff I would appreciate it also.

Hib Red 1.8T tip

 

Parametric eq's are quite hard to tune... best bet find a shop...

 

Seriously, I can get into an in-depth discussion on equalization and Q values, and all that sort of stuff. It is what I do for a living.
(Pro audio -- recording & PA systems mostly, not really car audio. But the premise is the same.)

I don't know the specific XTant unit you have.
But if you have any questions about equalization, feel free to drop me an email.

But here's something to get you started...

When you adjust a frequency on an equalizer, say for example 1kHz, you are not only adjusting that frequency. But you are also adjusting the neighboring frequencies, depending on the slope (bandwidth) of the EQ filters.

Q is the bandwidth of the EQ filters.
There is a specific formula for Q, but it really does not matter. (Read: I haven't committed it to memory.) Suffice to say that Q is a measure of bandwidth.

Assuming that you are adjusting the 1kHz frequency, a bandwidth of 1 octave would also affect the 2kHz and 500Hz frequencies (and everything in between). A bandwidth of 1/3 octave is much more accurate.

(Aside: Notice that the upper octave is 1000Hz away from your center frequency, whereas the bottom octave is 500Hz away from your center frequency. The actual numbers will change depending on what frequencies you're working with.
But the ratios remain the same: up an octave is always twice the frequency, and down an octave is half the frequency.
Q is a number used to represent a "standard" bandwidth, regardless of frequency range.
And like I said above, I forget the formula.)

Parametric EQs are usually used to compensate for less-than-perfect acoustic environments.
Try to find the frequency that is resonating, and attenuate it.
Or find the frequency that is missing, and try to boost it electronically. Yes, you can do both of these tasks with a graphic EQ, but parametric EQs are much more accurate, and since you can adjust the bandwidth (Q) the net effect is a smoother sound.

With this information, you should be able to turn a few ***** and know what they are doing to your sound. Beyond that, your ears are your best guide. Experiment and see what works best.
Don't waste your money going to a shop. They aren't listening to music in your car every day.
They'll tune it to their preferences. Or if they are really good, they'll give you a flat EQ sound using meters and test tones.
I say hogwash to all that. Use your ears and tune it how YOU like it.

And if you have any other questions, feel free to drop me an email !

Have fun,
Peter

 

i was told parametric eq'n is alot harder. I have an xtant amp and am choosing to avoid the parametric eq for it and buying equipment im more familiar with, and was recommended for ease of tuning by my former installer. He has been doing car audio for about 15 years and recommended i skip the parametric eq... advised that tuning it would require someone familiar with parametric eq's to tune correctly, much harder for a "novice" to tune.


Darren

 

I am an audio professional, and I don't even use parametric EQs all that often.
If there is a glaring problem with the sound, like a 60Hz ground hum, or a really obnoxious resonant frequency in the room, then I would use a parametric EQ to remove it.

But for simple room tuning (and this would also translate into vehicles), a graphic EQ works just fine.

As I said before, I am not familiar with the specific XTant unit and its equalization options.
Heck -- I don't even have an EQ in my car.
I don't believe in them. My home system does not even have bass/treble controls!

But for setting up PA systems or cleaning up recordings, EQs are a valuable tool.

I did not mean to suggest that uku should use a parametric EQ over a graphic. But if he wants to play with it, I told him how they work.

Given the option of a graphic or parametric EQ, personally, I would choose a graphic EQ 90% of the time if I am working with live sound, and a parametric EQ 90% of the time if I am doing a recording.

But as Foo pointed out, use whatever you are comfortable with.

-- Peter

 

Thanks a lot for the info Peter. I will post how my tuning went.