Acustica Aquamarine (SHMC) Mastering Compressor Question

[MCP_Music]

Hi,

In the Aquamarine manual it says:

It has to be stressed that our compressor must operate with an input signal
of -18dB dBFS; otherwise the signal will be highly compressed and sometimes
damaged even with minimum threshold values. This also occurs in the hardware
world, in fact our first compression test results in a reduction of 70dB with
a threshold values around -20dB. Unless you want an extreme compression and
more importantly, if you want to use this software correctly, just keep this
rule in mind.

I'm a little confused as to what this means exactly. As far as I can tell, running a signal in to the compressor up to 0DBFS doesn't trigger the compressor until I begin to lower the threshold.

Is this telling me that the signal I should be feeding in to the compressor should be peaking at -18DBFS and I should lower the threshold waaaay down until it starts reacting?

Any info would be great.

Cheers!

[Matt Houghton]

I don't have that particular one, but I do have the earlier Murano installed. Remember, the Acustica process isn't just sampling the hardware's gain-reduction behaviour, but also (in this case courtesy of the 'preamp' section) the harmonic distortions imparted by the unit. I think the way this plug-in is configured, the two threshold controls will only affect the gain-reduction behaviour (one for each of the two compressor circuits), whereas the overall level is going to affect how the whole plug-in distorts (as well as gain reduction, in relation to the two threshold settings).

In short, treat it as a single hardware unit configured for 0VU = -18dBFS, and then use the two thresholds and associated compressor controls to achieve the blend of compression you desire.

[MCP_Music]

In short, treat it as a single hardware unit configured for 0VU = -18dBFS, and then use the two thresholds and associated compressor controls to achieve the blend of compression you desire.

Sweet, so I got the first part, thanks for clearing that up Makes sense.

As for the 2nd part, if the input VU meter on the plugin is reading 0, then this would be imparting the same amount of harmonic distortion as if you were feeding -18dbfs in the hardware unit?

And so if I'm feeding a signal in to it that is peaking at 0dbfs, which is what I'm doing, the harmonic distortion emulation side of it will be working in overdrive?

I haven't come from hardware so I'm a little rough around the edges when it comes to db references.

Also, the Aquamarine plugin is a free upgrage to the Murano compressor. Apparently the A3 is an upgrade in every way, though I still wish I could keep the skin from the Murano, jeez that is sexy as all hell.

[MCP_Music]

In short, treat it as a single hardware unit configured for 0VU = -18dBFS, and then use the two thresholds and associated compressor controls to achieve the blend of compression you desire.

I also just now got this reply from the Acustica site asking the same question:

there is an input trim already tuned to -18dB on the gui. It means you can use it like all other plugins frome companies, without gain staging at all at original settings

So the input trim dial on the GUI when set to 0 / Unity is tuned to -18dbfs. So essentially, with the default settings on the compressor when I open it, it will be fine, and imparting the standard (if that's the right word to use) amount of harmonic distortion as the hardware unit.

Am I understanding that correctly?

[Matt Houghton]

Pretty much. Though as far as I can see, the 'preamp' emulation is a separate facility from the gain reduction, as it's separately switchable; and switching it off saves computing resources. So you have to engage this to get the harmonic distortion.