Room Simulation

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Using the Reverb effect block to simulate early reflections of a room (or amp booth or similar) adds a very realistic touch if you are recording direct.

Here are some more detailed explanations on early reflections and reverb:

Improved early reflections

Lately I've been experimenting in using two reverb blocks in parallel to the dry signal each with GEQ/PEQs to shape the resulting sound. I suppose this simulates cabinet reflections (poor man's approach) given the size of the reverbs; regardless of what it simulates it gives that feeling that sometimes it's missing when when mic'ing a real cab. I tend to keep the size very small to retain that in your face tonality and not a live room type of vibe.

Reverb parallel.png

With the following settings:

  • Mix: 100% (since it's parallel)
  • Level: -18dB to -10dB (depending how dramatic you want to get)
  • Type: Small room in one block, small Hall in the other block
  • Time: 0.10 sec
  • Size: 1.4-2.0 (something really small) = 2.2 feet to 6 feet essentially keeping the room is really "cabinet size". I try to keep these very close if not the same on both blocks. 1.0 is way to small and results in complete metallic ringing.
  • Color: 0-2 (I like to damp the high frequencies, the lower the more damp)
  • Lo-cut: 150Hz-400Hz (Since the size is so small, the reverb will get very boomy at the end, so I cut it)
  • Hi-cut: 10000-15000Hz (adjust to taste, this is rather subtle)
  • Diffusion: 100% (This doesn't matter as will only do early reflections). Input diffusion and time are the same they don't matter here as we are turning off the "reverb" level and leaving only early reflections.
  • Pre-delay: 0ms -0.4ms (I usually keep it at 0ms, but changing to 0.4ms/0.8ms has a lot of impact on the sound due to phasing which may or may not sound better). You may do 0.4 ms on one block and 0 on another or keep them the same.
  • Density: 12 (Lost of density to avoid metallic ringing)
  • Early delay: (No real value here, experiment, this affects the phasing of the early reflections so go through the range to find the most pleasing value). I set this to a different value for each of the reverb blocks.
  • Early level: 0dB (we just care about early reflections for this simulation. Same on both blocks.
  • Reverb level: -40dB (the minimum you can set it at). Same on both blocks
  • Mod: 0% (this don't matter on early reflections).

For the GEQ's that are inline with the Reverb blocks, I tend to bring up the highs, as the reverb will be fairly dark (even with color set to 10). This is of course completely up to taste.

I usually set the bypass mode to Mute out, so that I can compare taking the reverbs in/out of the chain and compare the tonality (I assign reverb 1 and 2 bypass to the same cc).

Old Previous Notes about room reverb

On the Axe-Fx you can use these initial settings to simulate a small space like an "amp booth" for example:

  • Mix: 50% (Adjust to taste)
  • Level: 0-8dB (adjust to balance non bypassed vs. bypassed state)
  • Type: Small room
  • Time: 0.10-.26sec
  • Size: 1.4-20 (any more will sound like too big of a room) - 2.0 = 1m wall, 4.0 = 2m wall
  • Color: 1-5 (adjust to taste again, this is just a starting point).
  • Lo-cut: 100Hz-200Hz (Used to reduce reverb low freq boom)
  • Hi-cut: 80000-13000Hz (if your settings give too much harshness you can tame it with this)
  • Diffusion: 100%
  • Pre-delay: 0ms-0.4ms (This will really change the phasing if you are using Mix < 100%)
  • Density: 9-12 (I find a lot of density really improves the early reflections)
  • Early delay: 13.8%
  • Early level: -8dB (keep the early and reverb level fairly close, but again experiment)
  • Reverb level: -9dB
  • Mod: 0%


In general here are some guidelines for modifying the parameters (but they are not rules, experiment!!). Also see Reverb for an official explanation of what the controls do.

  • Size. This will set up all the pre-delay, early delay time etc. This is the most crucial parameter that you should experiment with to get the sound you want, then you can "fine tune" the other controls once you establish the base sound.
  • Time. Keep this farly, try to avoid any metallic ringing.
  • Color. This is a bit more subtle, but keep it low for a more darker room. Adjust to taste depending on how reflective you want the walls of the virtual space.
  • Lo-cut. Use this to reduce boominess.
  • High-cut. Adjust to taste, depending on how bright you want the space to be.
  • Diffusion: Keep it fairly high if not 100%. As per the name, this will diffuse the early reflections so they are not as direct.
  • Pre-delay: The pre-delay is set by the size parameter. Change this value if your mix is not 100% as this will affect phasing.
  • Early Delay: This is to change the default time set by size (i.e. 0% is the default). Adjust it to match the sound you are looking for. This also affects phasing. If it's too echoey, decrease this (to the negative side). This effectively reduces the room size.
  • Early Level, Reverb Level: May want to keep early level close to the reverb level.