Tonematch Mixers / Compressor

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T1 This information is applicable to the T1 ToneMatch® audio engine
T4S This information is applicable to the T4S ToneMatch® mixer
T8S This information is applicable to the T8S ToneMatch® mixer

screen shot of T1™ Comp/Gate settings

If you are new to Compressors, Limiters and Noise Gates you might find this background reading helpful.

The Truth About Compressors and Limiters

Notes from pages 22 and 23 of the T1 ToneMatch® Audio Engine Owners Guide.

Using compressor/gate functions

The Comp/Gate function provides access to gate, compression, limiter, de-esser and kick drum presets with adjustable parameters. Note: To bypass the Comp/Gate settings, press the Type button. Press it again to activate.

1. Rotate the Type button to access the list of Comp/Gate effects and highlight your choice:

  • Compressor 1: Light
Compressor featuring a preset low-compression ratio with variable threshold and gain parameters. Works well as a general-purpose compressor for most instruments and microphones that require minimal level control.
  • Compressor 2: Medium
Compressor featuring a preset moderate compression ratio with variable threshold and gain parameters. Works well with basses, guitars, keyboards, and vocals requiring subtle level control.
  • Compressor 3: Heavy
Compressor featuring a preset high compression ratio with variable threshold and gain parameters. Works well with loud instruments – like horns and drums, as well as strong vocals that require more aggressive level control.
  • Limiter
Hard limiter featuring a preset ratio (8:1) with variable threshold and gain parameters. Works well with very loud instruments, such as drums, to prevent signal peaks from overloading the channel.
  • De-Esser
Side-chained compressor featuring a preset compression ratio with variable threshold and gain parameters. Designed to reduce sibilance on vocals.
  • Noise Gate
Noise gate with a fast preset attack time, variable threshold, and variable speed (release time). Well-suited for eliminating unwanted noise from microphones and instruments.
  • KickGate 1: Regular
Gate featuring a preset attack time, and variable threshold and tightness (release time) parameters. This is a Bose® proprietary technology designed specifically for kick drums. This robust gate provides maximum gain before feedback, making your kick drum as loud as possible through an L1™ system.
  • KickGate 2: Fast
Same as KickGate 1 – but adjusted for faster tempos. Select this setting if you are using a double bass drum pedal.

2. Press the Select button to select your choice, or press the Cancel button to exit the list with no change.

3. For Comp1-3, Limiter, De-Ess:

  1. Rotate the Thresh button to adjust the input threshold (trigger) level from -50dB to 0dB.
  2. Rotate the Gain button to adjust the gain from 0dB to 30.0dB. The gain bar above the button shows the amount of gain reduction. This display helps in setting the threshold.

For Gate:

  1. Rotate the Thresh button to adjust the input threshold (trigger) level from -90dB to -30dB.
  2. Rotate the Speed button to set the gate closing speed to any value from 0 (fastest) to 100% (slowest).

For Kick1-2:

  1. Rotate the Thresh button to adjust the input threshold (trigger) level from -20dB to 0dB.

Nick-at-Bose talks about where to start

What are the recommended compression settings for the tone match?

Right now I'm using medium compression but need understanding what threshold does.


This is a great question. I'll start out by saying compression is a huge topic and there isn't necessary a best setting, though there can definitely be wrong settings.

Sometimes, maybe often times, the best setting is Bypassed.

"Threshold" is a setting that is entirely dependent on the source material. A more negative number will result in more compression. The closer the Threshold number is to 0 (which is the top of the scale in digital terms), the less compression there will be.

The top meter on the screen shows how much gain reduction is occurring. Roughly, each hash mark is about 2 dB of reduction. (No metering would indicate no compression, which means the signal is below the Threshold setting.)

Here's where I would start:

  • Use the Light Compression setting
  • Leave the Gain at 3.0 dB
  • Set the Threshold so that on the louder parts of the performance, the meter at the top of the screen is hitting between the 1st and 3rd hash marks (starting at the right side of the screen). This would then mean that for the softer and mid-volume parts, there may be no compression happening at all. That's perfectly fine and probably desired.

Source: Nick-at-Bose

MikeZ-at-Bose talks about the Compressor settings

MikeZ-at-Bose talks about the Compressor settings in the T1 ToneMatch Audio Engine[2]

Light is about 2:1, fast attack and release.

Medium is about 3.5:1, fast attack and release.

Heavy is about 6:1, fast attack and release.

All have 'soft knee' transitions.

Hope this is helpful. When tuning the compressors I relied much more by ear to determine the settings than by numerical values.

A couple of comments on the settings.

When doing general compression like is done in the T1, I found fairly fast attack and release times to be the most versatile. Slower times need more fine tuning and are more prone to artifacts when used heavily.

The threshold is the most important control on any compressor, in my opinion. Careful adjustment of this is super important. You need to make sure you are compressing the parts of the instrument that you want to compress (peaks, 20% of the time, 100% of the time etc.)

Can I use more than one compressor function

Can you add more than one effect on a given channel under the "comp/gate" channel parameter on the rotary dial?

The is one compressor per channel, and it can do only one function at a time (compressor, limiter, noise gate, de-esser, kickgate). For most signal sources, this should not be a limitation as most of the applications where you would use these effects are mutually exclusive.

The other effects (Mod, Delay) and Reverb operate the same way. You can only choose one function within the family of the effect.

Related Reading

The Truth About Compressors and Limiters