Explination needed (frequencies and shiit)

[DieselNuts]

Okay, I have a general question about the adjustable information in an equalizer. I know the basics of stereo systems, but when it comes to, "whats the difference between 80hz & 125hz", my only answer is "about 45htz..." I'm assuming that the higher the number, the higher the frequency, but since that seems to make sense, its probably the other way around...

I know there are some very knowledgeable people out there. Learn me something please :D

[AnthonyF]

^im right there with u. I can sometimes hear a difference but I dont really know what is "really" occuring.

-Ant.

[Sport1.3]

31 bands are:

20Hz, 25Hz, 31.5Hz, 40Hz, 50Hz, 63Hz, 80Hz, 100Hz, 125Hz 160Hz, 200Hz, 250Hz, 315Hz, 400Hz 500Hz, 630Hz, 800Hz, 1kHz, 1.25kHz, 1.6kHz, 2kHz, 2.5kHz, 3.15kHz, 4kHz, 5kHz, 6.3kHz, 8kHz, 10kHz, 12.5kHz, 16kHz & 20kHz.

On a thirty-one band graphic equaliser, each band covers one third of an octave (you can work this out from the fact that one octave represents a doubling - or halving - of frequency, and there are ten octaves between 20Hz and 20kHz: on a 31-band graphic there are three steps between each doubling of frequency). Ten-band (octave) and fifteen-band (2/3 octave) graphics are not generally adequate for live applications, as each frequency band is too broad to allow more than approximate tone shaping.

What it does
It boosts or cuts a signal in one or more narrow parts of its frequency range. A line taken across the faders gives a graph-like view of the approximate overall effect, which is why this kind of equaliser is called a graphic EQ.

How it works
Each fader controls the level of an individual bandpass filter circuit, dealing with its own specific frequency range. Moving the fader up boosts that range, and moving the fader down reduces it. The combined effect of the filters is to change the overall balance of frequencies.

How do you use it?
If all else fails, read the manual! You can also find general guidelines on many manufacturer websites.

A graphic EQ can be connected to a system in one of two ways: on inserts, or in-line. Using the main (left & right or group) inserts will mean that any changes to the graphic settings will be seen on the channel meters, and heard on headphones or listen wedge. This is considered an advantage by many sound engineers. If a graphic EQ is connected in-line (i.e. between the mixer outputs and the crossover or power amp inputs), changes will only be heard through the main or monitor speaker system, and the mixer's meters may not accurately represent the signal strength at the controller or amplifier inputs.

The main use of a graphic EQ in live systems is to correct anomalies in the overall sound, and (to a limited extent) control feedback. Overall tone shaping (largely a matter of individual taste) is another common application.

As a corrective measure, cutting a particular frequency is generally more effective than boosting other frequencies. There are several technical reasons for this, but a simple thing to bear in mind is that the peaks stand out, and are therefore more noticeable (imagine a level floor - the theoretical ideal - and think of the difference between stepping on a nail and stepping on a nail-shaped dent in it). Taking out the peaks will have more useful effect (and is easier) than trying to fill the holes. Boosting is the equivalent of creating a more spiky floor, while cutting is the equivalent of creating a more dented one.

The anomalies EQ was designed to address arise from peaks and dips in overall frequency response.

Generally, peaks are caused by resonance. Where resonances arise from instruments or the PA itself, EQ can limit the damage, but it cannot eliminate them, or remove room resonances (often a major culprit). Also, resonance is a design feature of most musical instruments, and while reducing the most obvious "honk" from a harmonica will help it sit more comfortably in the mix, trying to remove it altogether will rob it of what makes it sound like a harmonica.

Dips in response often result from phase cancellation (over which EQ is completely powerless), masking by obstacles (pillars and walls, over which EQ is relatively powerless), or inefficiency of the sound system in that frequency range (microphones and speakers are the most likely contributors here). The higher frequencies will not reach listeners at the back if the speakers are on tables at waist height, and EQ will be a much less useful solution to this than speaker stands. Try changing the type and position of speakers and mics first.

As a rule of thumb, use any EQ as little as possible. Only resort to EQ if no other remedy is available, and apply it sparingly to the most obvious problem frequencies. A thirty-one band graphic gives you reasonably precise control. If you apply drastic cut to most of the mid-band (the novice's "smile" EQ), you are wasting its precision.

If your experience of using a graphic EQ is limited, try the following (start with all the graphic faders at their mid - 0dB of cut or boost - position):

1. Corrective. Using a CD player or similar source, play some material that has detail throughout the useful frequency range (i.e. 40Hz - 16kHz) through one channel (left, right, or one monitor channel) of the system. Boost each frequency range in turn on the graphic EQ. If the effect of boosting it simply makes that frequency stand out, return the fader to the mid position. If boosting it makes it boom, honk, squawk, shriek or whistle (or if boosting it makes it seem uncomfortably loud), move the fader below the mid position. How far below you move it is a judgment call, and depends on how badly it boomed, honked, squawked, shrieked or whistled. Either repeat this procedure for each channel individually, or copy the settings from the first channel to other channels using the same amps & speakers.

2. Corrective. Using a CD player or similar source (or the mixer's pink noise generator, if it has one) play some pink noise through one channel of the system. Use a calibrated microphone and spectrum analyser to view the output in the listening area (preferably, do this in more than one room position). Use the graphic EQ to reduce the level of any obvious peaks. It is usually unnecessary to get a flat reading (& it might sound a bit grim if you do), so after you have done this check the sound using some material that has detail throughout the useful frequency range, and if necessary reduce the biggest cuts by a few dB until it sounds OK. Either repeat this procedure for each channel individually, or copy the settings from the first channel to other channels using the same amps & speakers.

3. Feedback control. With most of the mics you will be using in place, set up with appropriate gain, & with all relevant input channels open, raise the fader of an output channel until it is on the verge of feeding back. Boost each frequency range in turn on the graphic EQ. If you can get it to the top without feeding back, return it to the mid position. If you can't get it to the top, move it as far below the mid position as it was below the top when it started feeding back. Check the sound using some material that has detail throughout the useful frequency range, & reduce the biggest cuts a little if it doesn't sound OK. If the system feeds back at a lot of frequencies (more than ten, say), you are pretty much at the limit of your usable headroom, and getting it any louder will only be achieved at the expense of noticeable colouration.

4. Overall tone shaping. Using a CD player or similar source, play some material that you know well (preferably with some detail throughout the useful frequency range), and have heard through a high quality sound system. Boost each frequency range in turn on the graphic EQ. Return the fader to the mid position unless boosting that frequency sounds horrible, in which case cut it a bit (in proportion to the horrible).

With any frequency alteration, bear in mind in mind that any change is relative: the effect of boosting or cutting one frequency range will be heard in relation to the overall sound. For example, substantially boosting bass frequencies will make the higher frequencies less noticeable in comparison (so it may sound "duller" or "muddier"). Similarly, cuts in the lower frequencies may make the overall sound "clearer" or "crisper", as well as "thinner".

[Sport1.3]

Got that from this site:

http://www.astralsound.com/graphic_eq.htm


no i have no clue what it means either lol

[DieselNuts]

HOLY HELL!! Thats a lot of Info!


Got that from this site:

http://www.astralsound.com/graphic_eq.htm


no i have no clue what it means either lol

lawl :D

Thanks a lot for the info. REPS :goodjob:

**EDIT** You must spread some Reputation around before giving it to Poz McDouche again.

I'll get you again :cheers:

[okra1981]

I was about to ask you where you got your degree from, I understood all of that post, but I wouldn't have a chance in hell of actually writing any of that out.

[Sport1.3]

I was about to ask you where you got your degree from, I understood all of that post, but I wouldn't have a chance in hell of actually writing any of that out.


lol no, i'm electronically retarded, but i know how to use the FVCK outta google!! :lmfao:

[BanginJimmy]

unless you have a high end EQ here is the simple breakdown.

100hz and below subs
80hz-400hz midbass
300hz-5khz midrange
4khz-20khz tweeter

these adjustments can typically be made on your average head unit or component x-over.

[DieselNuts]

Oh, I forgot to mention, i have the built in EQ in my Pioneer AVIC-Z1

[BanginJimmy]

the x-over points I mentioned should give you a decent sound. If you dont have a dedicated midbass, just set your midrange to fill the gap,