Ok ... so I'm primarily interested in brass music and brass instruments. Two EQ's issues puzzle me though they're not stopping me from working as such:
Q1. I can understand now how "corrective" EQ might generally be necessary to correct relatively small defects brought into recordings or either full pieces or samples during the recording process ....
(obviously this should be minimised by using good recording engineers)
... I can understand how EQ is used to "creatively" alter the recorded sound to either make it more pleasant/realistic than it originally was, or just give a specific effect, by reinforcing different frequencies in the instruments sound spectrum ...
... and I can understand that samples are recorded "dry" so that we might need to add some [convolution] reverb to them to simulate playing in a real room ...
... and I can use my EQ/convolution tools to enhance the Garritan (brass) sounds quite effectively now (well, I think so anyway)...
BUT ... I just don't understand why the [Garritan] brass instruments (I can't speak for other libraries) need so much more EQ'ing than non-brass instruments to get the best sounds out of them?
Is this something inherent in the nature of brass instruments or is it due to differences in recording techniques used in different instruments, pehaps?
Q2. I understand now how compression works and is used to bring different sound levels closer together, so making a mix sound louder overall even though the loudest levels are no louder than before ...
... and I can understand that this can therefore change the EQ of the sounds because it alters the relative sound levels of different frequencies within the sound spectrum of any individual note ...
BUT ... I don't understand why I can EQ a brass instrument, say, to get a good sound when listened to loudly on its own, but when I then drop the volume/gain for the instruments track to balance it with other instruments in the mix, there comes a point at which the sound ceases to sound so good (and further EQ might be required).
Unlike compression, changing the overall gain applies equally to all frequencies in the sound so shouldn't alter the overall EQ of the sound.
Is there something I'm missing here or is it perhaps highlighting the limitations of the headphones I tend to use for monitoring?
Hi, Peter - I'll briefly touch on some of the things in your post. I didn't expect to find an actual music-related post to respond to!--so I'm not prepared to spend much time at the moment. I'll try to get back. Hopefully others will reply to you also: "... I just don't understand why the [Garritan] brass instruments (I can't speak for other libraries) need so much more EQ'ing than non-brass instruments to get the best sounds out of them?..."
That was a good list of EQing purposes you started, but you missed the biggest one - the use of EQ to balance all the instruments together in a mix. And the EQ needs will vary from piece to piece.
As with so many aspects of the way a recording sounds, you're not going to find universal agreement about what sounds good and what sounds bad. You apparently feel the GPO brass need a lot of EQing, but it's not as if everyone would agree with that. Me for instance - I've used GPO for years with very good success, but I've never done anything special with the brass EQ. I feel what your struggling with could be due to other things, such as the balance of your instruments in a mix.
"... I don't understand why I can EQ a brass instrument, say, to get a good sound when listened to loudly on its own, but when I then drop the volume/gain for the instruments track to balance it with other instruments in the mix, there comes a point at which the sound ceases to sound so good (and further EQ might be required)..."
That's because instruments when soloed sound one way, and when they're sitting where they need to with other instruments, they sound different. You don't EQ an instrument while it's soloed. You'll get the results you described - you'll get a great sounding solo setting that doesn't work with the ensemble. Skip the step of EQing while soloing--the task at hand is to get each instrument to fit in the mix.
"...Is there something I'm missing here or is it perhaps highlighting the limitations of the headphones I tend to use for monitoring..."
Using headphones to monitor is severely limiting. You're not going to hear what your music sounds like on speakers, you can only make guesses. Headphones are good for late at night, any time you don't want to disturb others, but otherwise, you must mix with speakers.
As to if you're missing something - I would say you're only missing the realization that none of this is easy and it takes a great deal of time. You can't expect any musical software to work instantly "out of the box." Lots of trial and error is involved with mastering the software.
IMPORTANT - Don't assume everyone would agree about ANYTHING in regards to EQ and orchestral instruments. A current thread at the Sonar Forum has a number of people very adamantly insisting that EQ should never be used on orchestral instruments - and a lot of people feel that way. I feel EQ should be used on any recording, but used carefully, gently.
Our ears are tricky. Did you ever notice the "presence" button or knob on an amplifier? It has most effect when the volume is low, and almost nothing at higher levels. That is because our ears register soft sounds in a different way than hard sounds. Take a look at this page: http://www.audioholics.com/education...itivity-part-1. You'll see that low and high frequencies need much more pressure to register at the same level, and that the curve gets flatter at higher volumes. So compression should affect your EQ. And when you play a solo brass voice at a higher volume, it will sound differently then when it's in a mix, where it will be 10dB to 20dB softer than solo (if the final mix is at the same level).
Why GPO's brass instruments need more EQ for you than other instruments, I can't tell. I usually only apply EQ to the strings, so perhaps its personal, either something with our preferred sound or the way we work.
FLWrd is right on the money with that. Human perception of sound is nonlinear. If you take a look at the Fletcher-Munson curves, you can see how the human perception of loudness depends on frequency (probably no surprises there, as most of us are aware that we can't hear extremely high frequencies). Conversly, the human perception of frequency response, or timbre, is dependant on loudness.
The figure above is a Fletcher-Munson curve. The lower the curve dips, the louder the sound appears to be at that frequency. The graph may not be straightforward to read as it has a logarithmic frequency scale--but the frequency which we percieve as loudest is ~4000 Hz. You can see that for frequencies between 500 and 1000 Hz, the shape of the curve changes significantly if we increase the level (i.e. move upward from the bottom of the graph). As a result, we can expect the percieved timbre to change when things get louder/softer.
Also, if your headphones don't have a relatively flat frequency response, they will have a curve similar to this of their own. So, in this case you can expect some big changes in timbre when cranking the level up or down.
Looks like Randy covered pretty much everything else. And yes, listening through speakers is the way to go when mixing, but headphones are sometimes used when EQing, particularily in rooms with less than desirable acoustics. One thing I'll mention is that if you are listening through speakers, the acoustics of your room can also have a big effect on the frequency response that you hear. If it's a small room without acoustic treatment, you can expect to be driven nutty by the frequency response due to resonant room modes. I'm not going to explain room modes right now, but they can cause the percieved timbre to change significantly as you walk around in the room (or simply as you move your head around).
So, lots of variables at play.
"If a man does not keep pace with his companions, perhaps it is because he hears a different drummer. Let him step to the music which he hears, however measured or far away." – Henry Thoreau