PDA

View Full Version : How to set an EQ?



JBLAddict
02-05-2008, 04:09 PM
sorry for such basic question, but here it is. Does each slider control the gain for all frequencies between itself and the next lowest frequency, next highest, or just that specific frequency (which wouldn't make much sense)

e.g. if I adjust the dB on the 6kHz slider, what range am I adjusting 2.5kHz-6kHz, 6kHz-10kHz, 6kHz only?

Thanks much!

johnaec
02-05-2008, 05:15 PM
All graphic EQ sliders affect the frequencies next to them, some more so than others. If an equalizer has "Constant Q" it affects adjoining frequencies much less than ones that don't. Here's a good tech doc explaining this: http://www.rane.com/note101.html

Take a look at the other tech docs at the Rane site - 'some really good info!

John

Mr. Widget
02-05-2008, 08:59 PM
if I adjust the dB on the 6kHz slider, what range am I adjusting 2.5kHz-6kHz, 6kHz-10kHz, 6kHz only?A constant Q design helps... the actual Q of the filter also plays a huge roll here. Different brands will have different out of band characteristics. Another thing to realize, as you increase the gain for any type of equalizer you are also introducing phase shift... typically an increase of 3dB or less is best and more than 6 dB is really pretty bad.

In general a high quality parametric EQ is superior to a graphic, though White made some excellent graphics.





Take a look at the other tech docs at the Rane site - 'some really good info!:yes:

I really like them as a company... not so crazy about their gear though. :(

Yep, that's how I really feel. ;)


Widget

JBLAddict
02-05-2008, 09:40 PM
thanks guys, I had no idea the bandwidth effect was so wide.

here's the thing, I'm trying to dial down the midrange on my L100A using a cheap EQ, but when I adjust the 2.4kHz slightly I can hear loss across too wide a freq range, the presence dial turns the mid on/off when I turn it so it's not an option, the treble adjust on the receiver kills too much, so not sure what to do?

Skywave-Rider
02-06-2008, 01:46 PM
Hi!
We're assuming you're using a graphic eq, that is one with a number of frequency passbands, usually of fixed Q (bandwidth.) So if you're hearing too wide an influence on adjacent frequencies or octaves, perhaps you need a graphic with more bands. More bands will give each band a narrower range or focus. How many bands is your EQ?

Filter circuits can be modified, but I am not qualified....:p
That is, I'm fine ruining my own equipment, but not yours....

boputnam
02-09-2008, 01:10 AM
...I had no idea the bandwidth effect was so wide.That depends upon the EQ.


...here's the thing, I'm trying to dial down the midrange on my L100A using a cheap EQ, but when I adjust the 2.4kHz slightly I can hear loss across too wide a freq range, the presence dial turns the mid on/off when I turn it so it's not an option, the treble adjust on the receiver kills too much, so not sure what to do?That there sounds like a "cheap" EQ.

If you're serious about this, and don't have too many frequencies that are troubling, you'll be better off with a parametric EQ. These are infinitely adjustable - freq, Q, and gain. But, they usually only have 5 filters per channel, so if you have a bunch of anomalies, you might be frustrated - otherwise, you'll be pleased.

But, back to your original question, the filters are centered on the frequency marked. They are a bell-curve shaped correction, width being dependent upon the Q of the filter. Some GEQ's have variable Q - the Q narrows (focusses) with increasing correction, the engineers thinking if you are sucking out -6, -8 or -12dB, you must have an narrow anomaly of some strength. The Klark Teknik DN370 is one such GEQ, and it is a beauty.

JBL 4645
02-09-2008, 05:49 AM
All graphic EQ sliders affect the frequencies next to them, some more so than others. If an equalizer has "Constant Q" it affects adjoining frequencies much less than ones that don't. Here's a good tech doc explaining this: http://www.rane.com/note101.html

Take a look at the other tech docs at the Rane site - 'some really good info!

John

I concur several of my mismatched EQ have drastic decline or incline on the neighbouring frequencies. I noticed far less with the EQ on the DCX2496, canít wait hardly wait until I get my paws on several DEQ2496.

Skywave-Rider
02-09-2008, 09:08 AM
The Klark Teknik DN370 is one such GEQ, and it is a beauty.
Check it out:
http://cgi.ebay.com/NEW-Klark-Teknik-DN370-Stereo-Graphic-Equalizer-DN-370_W0QQitemZ110221943575QQihZ001QQcategoryZ23788Q QssPageNameZWDVWQQrdZ1QQcmdZViewItem
It's pricey. But nice, eh?

You might find these Orban units to sound good and give flexibility, plus they are getting old and cheap on ebay:
http://cgi.ebay.com/Orban-674A-Stereo-Paragraphic-Equalizer-EQ_W0QQitemZ110195575169QQihZ001QQcategoryZ3278QQr dZ1QQssPageNameZWD1VQQ_trksidZp1638.m118.l1247QQcm dZViewItem
I have one of those and it is a "paragraphic," that is, it has graphic style bands and vertical pots for boost and cut, (oriented in stereo pairs per band,) but also has variable Q and selectable center frequency points. The tradeoff with that is you have less bands to work with, but as bo indicates, you might not need all those bands anyway. And you can adjust the Q to your needs.

Here's another model, cheaper, which I have not used:
http://cgi.ebay.com/Orban-622B-Dual-Parametric-EQ-V-good-condition-Works_W0QQitemZ190195832635QQihZ009QQcategoryZ2378 8QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Skywave-Rider
02-09-2008, 09:36 AM
JBLaddict,
I forgot to mention, and this will probably stir up some emotion, :flamer:
but the Behringer DEQ2496 has a very good parametric section which is easy to use. It's digital, of course. But on the up side, there are no pots to get scratchy and stereo link mode makes it easy to do both L&R simultaneously and with precision. It's also cheap and has a very good meter. Other features include a graphic eq, pink noise, analog and digital in/out, RTA features, and some other processing you'll likely not use.

Some members using this:
http://audioheritage.org/vbulletin/showthread.php?t=19843

The first 2 I bought were from a bad batch, but now I own 2 and could not be happier at this price point.

boputnam
02-10-2008, 03:29 AM
...the Behringer DEQ2496 has a very good parametric section which is easy to use. ... The first 2 I bought were from a bad batch, but now I own 2 and could not be happier at this price point.All that is true - 'specially the bit about the "bad batch" (watch that Quality Control :scold: ).

If you like the way they sound, they can be fun. :)

Zilch
02-10-2008, 09:08 PM
Join the DEQ2496 Club.

Get the mic.

Push "AutoEQ."

Done.

[We're talkin' L100s here, gang.... :yes: ]

Fred Sanford
02-11-2008, 05:03 AM
All that is true - 'specially the bit about the "bad batch" (watch that Quality Control :scold: ).

If you like the way they sound, they can be fun. :)

That's something I have to tell people when they ask about buying a Behringer- every single product of theirs that I can remember buying/borrowing/renting/testing/etc. has failed while in use at some point. I don't mean failed when putzing around, I mean failed when gigging or recording or mixing or, best yet, demoing for a sale. Every single one, can't think of an exception. Compressors, large & small mixers, gates, EQs, everything. I can't convince myself to ever buy another one (still have a 4-way compressor that lives in a low-use low-stress studio yet has been out for repair twice) or recommend one for anyone else.

You got it and you like it, that's great and I honestly wish you great luck with it. They lost me quite a while ago.

je

whizzer
02-11-2008, 08:26 AM
I bought an MXR Dual-15 (2/3-oct per band) EQ in 1979 shortly after they appeared on the market. It was, in 1979 dollars, not exactly cheap, but was far more affordable than what I really wanted (a White). Here we are, 29 years later, and it's still in use every day. It's been used to EQ monitors, sometimes even main PA, and, for the last 15 years or so, the home stereo. The adjacent-band effect is minimal, and none of the linear pots have developed any noise. It just works. The 31 band model (maybe it was 30 bands) was also pretty well-made and reliable. These units, if you can find them, are generally available now at pretty low prices.

boputnam
02-13-2008, 06:16 PM
They lost me quite a while ago.Me too.

I gave them a fair trialing about 10-yrs ago. New to the market, GREAT pricing - why not?

Uh, they sucked. And, they are not robust. They fail at a rate nearly equal to Mackie's low-level VLZ line of mixers. Now, clubs all around the world are littered with gear from both makers - gear that long-ago ceased to be fully functional.

However, quietly I praise them. When I arrive as Band Engineer at a club "featuring" such gear, and there is no way to get any of my racks in there, I must work around dead inputs and crapped out outboard gear. It helps me stay nimble, thinking and inventive. I have more adapters and turnarounds in my kit than most anyone I know... :rotfl:

scott fitlin
02-13-2008, 08:05 PM
I hear you Bo. It never ceases to amaze me at how many clubs that are making SERIOUS money have the cheapest and worst equipment going.

One club in Miami I worked for, was purchased by a European man, who thought he purchased US with the club as well.

I get a call from Yves around 1 in the afternoon on Satruday, the Friday guest DJ in the lounge blew the JBL tweeters. How many are out? 4. Can I fix them? Yeah, Ill go to Ace Music, get parts, and be there in a hour or so. I laid out the money for 4 JBL 2402 phragms, 85bucks a pop, get to the club, spend about an hour an a half doing the work, and I go upstairs to get reimbursed my $340, + $100 labor.

This guys says "Why did you buy new ones"? I wanted you to fix the old ones!

Yves, a blown diaphragm is like a lit match, once you burn it, thats it, it never works again! He tells me he dont believe me. And he wants the old diaphragms. I had to pull em out of the garbage, and HE FUCKIN DID TRY to find someone to repair them! I had to wait 4 days for my money, when after calling EVERY sound company in Miami to find out WHO repairs JBL diaphragms!

I got my money and told him next time shit breaks, call somone else! Every DJ, and every sound contractor laughed about this, and it wasnt like the club wasnt making money.


:blink: