Parametric EQ Help

**iriegnome** · #1 10-05-2009, 01:39 PM

I have decided to delve into great EQ possibilities. In other words I have 1 open space on my rack. Anyway, I was thinking about being able to dial out some specific frequencies to eliminate some bad vibes coming from my bass, the kick drum and some of the lower notes of one of my guitarists (he plays a wide hollow body PRS). So, I thought Parametric...
Questions - Are there Parametric EQ designed for bass? If so, which ones? I am not interested in a pedal either, single rack space units only. What are some of the different models you are using and why? Is there a difference between a instrument Parametric and one used for PA or FOH? Do different units come with different frequency sweeps? If so, how the hell do I figure out which one I need without actually putting it into my rig? Thanks

**iriegnome** · #2 10-05-2009, 01:47 PM

Oh, just in case any of this matters my rig is a SWR Bass 750, and a Korg DTR-1 Tuner. I took out my TC Electronics Compressor since I play through all 12's and I just don't need it.. Oh, I play a Modulus Bassstar 5 string with Barolini pup's and Preamp (9v)

bongomania · #3 10-05-2009, 02:34 PM

Quote:

Originally Posted by iriegnome

Are there Parametric EQ designed for bass?

Not really. There are semi-parametric EQ's out there (especially on bass amp heads and on pedals) where the parameters are designed with limited range or function, but even then they aren't really "bass specific" as much as they are "not ideal for every purpose".

Quote:

Originally Posted by iriegnome

What are some of the different models you are using and why?

I use an Ashly DPX200, but I've also had great results from products by Rane, ART, Aphex, Symetrix, and Speck. The Ashly is nice because it also features a good compressor channel, and the EQ is noiseless and each band can be switched in or out independently with no noticeable sound degradation. Of the brands I named, only the ART tube parametric sounded significantly different from the others, the rest were essentially identical (for non-critical purposes).

Quote:

Originally Posted by iriegnome

Is there a difference between a instrument Parametric and one used for PA or FOH?

No, except again that some units marketed for instruments are only semi-parametric, or their bandwidth control is limited to two or three widths.

Quote:

Originally Posted by iriegnome

Do different units come with different frequency sweeps?

Yes, but with a decent studio unit the sweeps will well encompass your entire bass signal, so no worries. It's only on the ones with limited function that you'd need to wonder. For them, figure your bass signal occupies 30 Hz to 10 KHz (give or take), and you'll want at least one band that can encompass the 30 and another band that can encompass the 10K. Remember too that the nominal center frequencies shown on the front panel are not a literal description of the limits of the EQ.

Emibass · #4 10-07-2009, 09:56 AM

OK, any parametric eq works on bass, but that´s not the most important thing. What matters is how you use it.

If I had to design an Eq for bass only it would´t have boost filters, only cuts. E.G: if you want more lows just low down highs and vice-versa

PilbaraBass · #5 10-09-2009, 02:14 AM

Quote:

Originally Posted by Emibass

OK, any parametric eq works on bass, but that´s not the most important thing. What matters is how you use it.

If I had to design an Eq for bass only it would´t have boost filters, only cuts. E.G: if you want more lows just low down highs and vice-versa

I don't disagree witht the concept, only if you do that, you must make sure that you have an overall gain adjust for your EQ...

for instance if your filters cut 12dB make sure that you can boost at least 12dB overall...etc...

Emibass · #6 10-09-2009, 08:15 AM

Quote:

Originally Posted by PilbaraBass

I don't disagree witht the concept, only if you do that, you must make sure that you have an overall gain adjust for your EQ...

for instance if your filters cut 12dB make sure that you can boost at least 12dB overall...etc...

right, but I was´t talking about the averall gain or make-up gain, I was talking about an eq band. So for eq band I´d use only cuts, after that IF I need to boost the level I could do it with the output level if any on the eq, if not boost up the pre-amp to compensate for the gain lost of that eq band (if only necessary)

Boosting eg on the bass only gives me problems, at least for me

SwamiRob · #7 10-09-2009, 08:34 AM

A 32 band graphic would be easy enough to find, and since it's so precise in terms of going up in very very small increments can get the kinda of precision cuts your after.

What's the problem with boosting? I read the explanation once but I really can't remember why it's a problem, is it something to do with adding harmonics?

bongomania · #8 10-09-2009, 09:52 AM

Every band of an EQ has the potential to introduce phase interference at the edges of the neighboring bands. The more bands you have, the more phase interference. The more you boost, the more phase interference. Also every individual gain stage, when boosted, will add a slight amount of extra noise and (potentially) distortion. If you use the individual bands for cutting only, and then use the master gain to bring your overall signal level up to where you want it, then you only get the noise and distortion of the one gain stage, the master gain.

It's all very subtle and arguable stuff. I'm not pretending this is the ultimate one right answer, or that boosting bands is "always bad". And in fact there are instances where boosting an individual band or two could get you better results on a subjective basis, depending on the specific EQ design and whether you like how it sounds.