A word about the testing
This is some simple testing of audio plugins which you can use for comparing, or just to find out more about each one. Each plugin has several charts (see below) and my comments, with occasional hints with I hope are helpful. (Which may or may not be helpful, but it’s my blog and I can do what I want…!) Please visit my Preset Shop as well. I have presets for UAD, SoundToys, Waves, FabFilter Saturn 2 and free gain staging presets. #cool4yourmusic…
Method
All the tests are done at 48/24, not for some nebulous technical reason that we could all start arguments about, but because that is the workflow I have chosen to use. Also, if things test out good at 48k they will certainly be fine at higher rates. (Without going into in-plug oversampling and other things.)The results allow for observing some very specific behaviors that I find are important to assessing programming integrity and overall sound quality. This is not a be-all-end-all, simply a good place to begin any assessment about equipment. The plugins are at their default setting, except I adjust the input (if necessary) to be as close to -18dBFS RMS input as possible. I also adjust compressors to have a slight gain reduction (typically 1-2 dB). This keeps the results consistent, and should be seen as “starting points.”
Let me add that these are not reviews and I try not to make any judgments about quality. The charts are here for you to check and make your own determination, including your own testing and “how it sounds to you”.
I know people love to rant about “if it sounds good” or “use your ears” and so forth. But testing things first eliminates a lot of wasted time — because it reveals problems before you start recording and hear them; or narrows down where a problem might exist so you can adjust your methodology. Engineers spend a lot of time on testing and calibrating equipment. Besides, you will never know if something can sound better unless you keep pushing!
If you choose to compare emulations by different software companies of the same hardware, remember there are nuances within the actual hardware units themselves. None of them will sound exactly alike. But you will also notice different DSP approaches (for example, the type of low pass filtering to eliminate aliasing). It is interesting to compare how the original hardware is interpreted by various programmers. Also, we have to always be aware that the way things appear in tests like this are only a small part of total picture of how a plugin sounds and operates. (Remember, “starting points”.)
The Tests/Charts
Harmonics
Displays total harmonic distortion (THD) and visually shows harmonics and noise, based on a 1000Hz sine wave. I have added a “dimmed” area below about -144 dB, because nothing down there is ever going to be audible. (Please note the frequency chart usually has a range of ±6 dB. Occasionally this is extended if the test shows large variations.)
Freq
The frequency distribution for the plugin, responding to pulsed white noise. This is for the default setting of the plugin. Adding compression or other adjustments may change this. Of course with EQs this would be expected to change, so they have not been included in this test except for special cases demonstrating a technique or interesting result, such as the EQP-1A.
Dynamics
The compression curve. This is measured using the initial setting of the plugin. Of course there are many variations possible with this based on ratio, knee, attack characteristics, etc. This is simply a quick reference to the default settings. There is more in-depth testing and discussion on some of the plugins.
IM
Intermodulation distortion is the interaction between two or more signals at different frequencies. For this test I am using sine waves at 19K Hz and 20K Hz. This is an oversimplification, but generally with these test tones you don’t want to see much happening below 1000K Hz, or a lot of cluttered looking lines anywhere else. For a more technical explanation of IM and interpreting this test you can find a number of sources online. ( I am trying to not get bogged down with anything but sharing test results and let YOU decide how to use them).
Sweep
The most oversimplification possible: If lines hit the top of the chart and bounce back down, then the plugin is aliasing. The more lines and the more defined they are, the more aliasing. Again, do your own research on this as there are various opinions on how this should be considered and how meaningful it is to “real life” use.
Opinion
These are plugins that I have actually used and have been part of a recording or mixing workflow. That doesn’t mean if one isn’t here it’s no good. Although I throw in a few comments or ideas, I am not writing reviews. Please make your own judgements and comparisons. These tests are done using PluginDoctor from DDMF and Voxengo Span with some additional custom sound files. If you like, you can pick these up and start doing your own testing. Or you can save yourself the time and just look here! Also, please visit my Preset Shop — I hope you can find something helpful there as well!
Use your ears. Yes. And all your other God-given senses. Make the music excellent!
~ Robert Conlon