PG Music Home Forums General Discussion Off-Topic A few mastering questions?

Hello all,

I'm having a play around with the demos of t-racks and ozone and mainly using the presets in them. Overall I have just limited knowledge of the concept behind mastering i.e. don't really have an in-depth knowledge but will have an idea if I twiddle a button and it doesn't sound great.

A few questions if anyone has the time and patience to answer, many thanks.

If for example I have done a reasonable mix and have no clipping etc.

1 Will the presets in t-racks or ozone preserve this no clipping or is it possible that one of the modules will introduce clipping, and I will have to adjust either the input or 0utput on one of the modules, even though there is a limiter at the end of the chain?

2 Is it mainly volume changes on a track that cause clipping or do other factors cause it as well?
3 what is the ideal db upper limit on a mastered Mix?

Thanks very much to anyone who can help?

Joe

1. Yes it is possible to induce clipping in these programs. Some of the presets do not have limiters in a given effect and even the EQ module can induce clipping/distortion if abused. Keeping the main mix feeding into the mastering software down a little will often help. Overpushing the input is the easiest way to get Ozone to clip, more so than pushing the output.
Many of the presets do have plenty of compression/limiting protection, but some do not.

2. It is volume that causes clipping, but how that volume is created can be many ways. As mentioned above, simply boosting a given frequency in the EQ section can unintentionally cause clipping on a certain frequency even if the rest of the frequencies are well below any clipping level..

Listening closely and trusting your ears and your monitors is the solution.

3. dB upper limit is often misleading and there better tools for analyzing the power of a mastered file. Read up on other ways to measure loudness such as RMS, Peak-Average, spectrum analyzers, etc.

Again trusting your ears is a big part. Ears should mean more than meters in the final judgement, but meters can help. It would be common to find a recently mastered piece that is in the -.5 to -.2 dB range. But these too can vary in actual percieved volume.

Joe,

First, a point on terminology:

Mastering: This is normally the process reserved for the assembly of an album of material, giving that album a progression in volume, and a 'flavor' of spectral content that pulls the whole thing together as a cohesive unit, and prepares that album for a finished product to be distributed on the market.

There are lots of plugins that call themselves 'mastering' plugins, because you can use them, with a trained ear and proper equipment, to do the above.

The key element, as rharv pointed out a couple of times, is critical listening. A/B compare the presets with uneffected tracks - try to discern exactly what those presets are doing.

I have a couple of 'mastering' plugins at my disposal and while some look down their noses at using the presets, I have found them to be quite instructive. These are all pretty complicated plugins in that they usually involve EQ, multiband compression and limiting of some kind. The one I use the most has the following signal chain:

6 band parametric EQ
3 band dynamics/compression
6 band parametric EQ
Limiting

Now, for me to get some kind of golden combination of all of these 4 parts of a signal chain, on pure intuition alone, would probably be somewhat unsuccessful. But, when I use the descriptively named presets and audition various kinds of music through them, there have been some real 'AHA!!!' moments.

The most interesting thing with this particular plugin is to study the pre-and post dynamics processing EQ settings.

There are some that just look strange, with a little spike in the EQ at a certain frequency but when I go in and noodle with that peak, it really does matter for the character that is being intentionally imparted to the sound.

One of the best things you can do to avoid clipping an overall mix, is to record in 24 bit format; keeping your individual tracks peaking well below 0 dB. Use enough gain in recording your individual tracks to keep them perhaps 12 dB down or so. This will allow you to still keep your overall mix low enough so that when you want to engage some of the more extreme presets in 'mastering' software, there's ample remaining 'digital' headroom left to avoid clipping.

Recording in 24 bit basically reduces the quantization noise floor by 48 dB compared to 16 bit mode. Quantization noise is the noise introduced by simply the A/D converter deciding when to flip the bit from zero to one on the least significant bit of the digital data. It doesn't lower the actual noise floor of your system, but it does on the digital side of the house. It doesn't require all that much more disk space than 16 bit either. The benefits far outweigh the slight bump in disk space required.

Also, go back to your original mix and individual tracks and try to make sure you've done everything for those tracks from a mixing and EQ perspective that can be done to avoid over-cramming the mix. A classic example - strummed acoustic guitars, if mixed in with some other rhythm instruments like piano or electric guitar, often don't need any signal content below perhaps 750 Hz or so, even though a raw mic'ed acoustic guitar will many times have content even down below 100Hz. Cut that stuff out of there and the mix will begin to sparkle. Vocals are another area where a good high pass filter is almost always called for if it's not solo voce.

Spend enough time in the mix and 'mastering' in the sense of final eq/dynamics processing, becomes less and less necessary. Listen to what those presets do to your final mix and if they seem to affect a certain instrument or drum, etc. go back to the original track and try to impart the same character.

Don't be afraid to remove instrumentation altogether, at least in certain sections of songs. Give your song dynamics through arrangement of orchestration.

I know this has varied far from your original question, but often times folks that ask around about mastering really need to work on mix and arrangement first - but with the hope that there's some magic plugin that will sprinkle pixie dust on their tracks to make them sound professional.

I'm not saying this is what you are doing. But I bet if you ask rharv about this, who is running a mastering side business, he would agree that many of his clients probably needed some mix and arrangement help first, before mastering became the real task of the day.

-Scott

Thanks very much guys for your thorough replies with all the helpful advice. I have saved them to my band in a box tutorial folder so that I can have a read up when I need it.

Thanks again
Joe

I read it twice and fell asleep both times. But I read big bad wolf to the grandson yesterday and they found us both asleep on the couch. I think I went first. At least MY britches didn't leak...this time.