[JaZZ]

Quote:

Originally Posted by keiron99 What is the difference between a parametric and a graphic equalizer?

A graphic equalizer has a number of controllers with fixed frequencies at which resonances/anti-resonances with fixed bandwidth are introduced to increase or decrease a frequency range to a variable amount. A parametric equalizer has a (usually lower) number of controllers with variable center frequency and adjustable resonance Q-factor (= bandwidth). With the latter, resonances, peaks and dips can be more accurately equalized, as you can adjust the EQ curve exactly to your need, whereas with a graphic equalizer with its usually higher number of controllers you possibly have to use multiple frequency bands (and thus resonances) for equalizing a single dip or peak.
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[keiron99]

Thanks. Wow, sounds complicated. I simply adjust the sliders on my Itunes "equalizer"!

 

[Mastergill]

Quote:

Originally Posted by bigshot ... Recording studios have equalizers built into their signal path and it doesn't add noise there. ...

Yeah sure, but it's pieces that cost between $3k and $10k. Not the kind of stuff you're talking above.

 

[skyskraper]

Quote:

Originally Posted by Mastergill Yeah sure, but it's pieces that cost between $3k and $10k. Not the kind of stuff you're talking above.

actually its precisely the sort of stuff thats being discussed above that is being used in recording studios with no ill effects.

 

[Mastergill]

Quote:

Originally Posted by skyskraper actually its precisely the sort of stuff thats being discussed above that is being used in recording studios with no ill effects.

In your basement studio maybe...

 

[skyskraper]

actually in my home studio i dont use any analog signal processing, only vst type processing but in professional studio's ive worked in (both digital and analog centric rooms), perceived "low end" equipment such as alto, behringer, dod, bbe, art, etc etc etc is used right along side the high end gear ala avalon urei etc. sure they perform differently but in terms of adding to the noise floor they don't behave appreciably differently. of course processing low level signals is a different matter but we're not talking in terms of low level signals in this thread's intended application.

 

[saint.panda]

What does processing in low level signals mean?

 

[skyskraper]

in this case i was mainly reffering to microphone signals but they could also be raw uncorrected turntable signals.

 

[bigshot]

Quote:

Originally Posted by JaZZ This obviously belongs to the same category as «no amp / no cable... should alter the sound, otherwise there's something wrong (audio isn't rocket science)»...

There's a level of order to complexity. A wire is obviously the lowest order, and it has a microscopic effect... a eq board full of volume pots is a little more complex, so it will affect the sound minimally... a power amp is much more complex than that- it will affect the sound a little.

But overall, electronics aren't the things you listen to. The quality of sound is affected most by the acoustic elements (speakers, headphones, cartridges, room acoustics). Every set of loudspeakers is imbalanced, even the most expensive ones. Equalization is how you you correct for these sorts of imbalances.

Worrying about the noise floor of a good quality equalizer is as silly as trying to hear the difference between cables on bookshelf speakers. You're focusing on the ant and ignoring the elephant. The tiny amount of added electronics in an equalizer is going to help you correct a very big problem in your speakers, where it counts.

See ya
Steve

 

[bigshot]

Quote:

Originally Posted by saint.panda What does processing in low level signals mean?

Analogue signal processors work better at higher signal strengths. If you need to work with extremely low level volume, it's better to do that in the digital domain with high bitrates. This is more of an issue in production work, where you might have to boost the volume of certain parts of the recording to balance the mix.

See ya
Steve

 

[bigshot]

Quote:

Originally Posted by Mastergill In your basement studio maybe...

No, he's right. Raine and DBX equalizers are typical pro gear for recording. For live rigs, you might even see the lower end brands used for individual instruments.

See ya
Steve

 

[bigshot]

Quote:

Originally Posted by keiron99 Thanks. Wow, sounds complicated. I simply adjust the sliders on my Itunes "equalizer"!

I think you didn't quite get it from that description. I'll try to explain it a little more plainly.

With a graphic equalizer, like on your iPod, you have a slider for each range of frequencies... dialing one at the left up and down will raise and lower the bass... on the right, it adjusts the treble. The more sliders you have, the more careful an adjustment you can make. 31 sliders is what pros use.

A parametric equalizer operates a bit differently. The sliders aren't in fixed positions, like on a graphic equalizer. By dialing the band back and forth, you can take a slider up and down the frequency spectrum and choose any center point you want.

Once you have chosen a frequency to center on, you can raise the volume of it up and down, just like a graphic equalizer. But you can also adjust the width of the adjustment... in other words you can create a curve across the frequencies, with the highest part of the curve at your center point receiving the greatest adjustment, and a sloping down curve on either side, for as far as you want. This means that one slider can affect all of the bass, or just a pinpoint right on a single frequency. This is what is meant by bandwidth.

Parametric equalizers are best for doing pinpoint notch filtering, for instance, removing a 60 cycle hum. They're also useful for creating gradual sweeps across wide ranges of frequencies. They're a little more difficult to understand at first, and it's possible to royally screw up your eq with them by getting into weird settings that could only exist in outer space... but they're more flexible than a graphic equalizer with fixed center points and bandwidths.

Hope this helps
Steve

 

[JaZZ]

Quote:

Originally Posted by bigshot There's a level of order to complexity. A wire is obviously the lowest order, and it has a microscopic effect... a eq board full of volume pots is a little more complex, so it will affect the sound minimally... a power amp is much more complex than that- it will affect the sound a little. But overall, electronics aren't the things you listen to. The quality of sound is affected most by the acoustic elements (speakers, headphones, cartridges, room acoustics). Every set of loudspeakers is imbalanced, even the most expensive ones. Equalization is how you you correct for these sorts of imbalances.

That's plain wrong. Frequency balance and frequency-based flaws are just one component within the sound. The others -- such as transient response, reflexions, harmonic distortion, intermodulation -- are definitely not fixable with equalizers. Believe me: I have intensively tried equalizing and ended up with renouncing it, after trading off pros and cons according to my own personal valuation key -- which doesn't have to be the same as yours.


Quote:

Worrying about the noise floor of a good quality equalizer is as silly as trying to hear the difference between cables on bookshelf speakers. You're focusing on the ant and ignoring the elephant. The tiny amount of added electronics in an equalizer is going to help you correct a very big problem in your speakers, where it counts.

Nobody is worrying about the noise floor -- that's your personal interpretation, probably deduced from the lack of dynamics saint.panda has criticized. I worry about the things that are important to me, you worry about the things that are important to you. It's that simple. And not the least bit silly.
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[bigshot]

An equalizer can affect the dynamics if you have it set to pull back the frequencies where the energy in the signal exists. For instance, cutting back the mid and upper bass and midrange will flatten out the dynamics of most music considerably.

But an equalizer shouldn't flatten dynamics across the board. If it's doing that, there's something wrong with the equipment. A good way to test is to put all of the settings to flat then compare the sound of bypass to the sound of the eq cut in. Bypass does just that- it cuts all of the electronics out of the signal path and passes along the sound directly. They should sound the same. If eq cut in sounds less dynamic, there is something wrong with the equipment.

I've worked with many equalizers over the years, and I've found several that buzz or hum, but I've never found any that flattened dynamics. The biggest problem with equalizers is grounding them properly.

See ya
Steve

 

[saint.panda]

Thanks a lot for the low level signals explanation.

I think I've found the EQ I need. Based on comments on Steve Hoffman's forum, I'll most likely go for a Behringer T1951 parametric EQ. The unit is said to be pretty good and the reviews on harmony-central aren't too shady either. Costs around $150 new.

To be honest, I doubt a lower or mid-level dbx or Behringer eq can hold its own against heavy-weights such as Manley, GML, Pultec, etc. In any case, it's my first external eq and I don't want to spend too much money.

And since my source consists of a cd player only, a digital eq like the Behringer DEQ2496 doesn't sound too appealing to me since the sound signal would have to undergo an additional and inferior dac conversion by the Behringer unit.

If the Behringer T1951 is any good, I might move towards a better eq since after all the research I have about 10-15 manufacturers on an ebay hunting list anyway.

The best solution is if I could find somebody to build me a diy pultec eq but that's not going to be cheap either.