Hajo's Headphone Enhancer

Advanced configuration of the sound engine in Hajo's Headphone Enhancer

I've received a few recurring requests from power users that want to customize their headphone experience further. On this page, I try to answer those request in a FAQ format.

• I'm using a very powerful external DAC and the bass boost is too much.
• I want a stronger LFE channel for 5.1 movies.
• When I use my USB or Firewire DAC, and I hear distortions or clipping noise.
• It sounds like the front speakers are to my left and right side, not in front of me.
• It sounds like the front speakers are too close to the center speaker.
• I would like to have more cinema-like acoustics.
• My left/right ear is a bit less sensitive. How do I compensate?

How do I open the configuration window?

Click the menubar icon in the top right corner of your screen and then select "Sound Engine" -> "Gain, Clipping & Custom Sound Configuration ...".

You should now see a window like this:

I'm using a very powerful external DAC and the bass boost is too much.

1. open the configuration window.

2. Click "Switch to Custom Sound Engine".

3. You can now adjust the amount of bass boost with the slider.

I want a stronger LFE channel for 5.1 movies.

1. open the configuration window.

2. In the "Input Channel Gains" row, adjust the value for the LFE box. I usually use 5 for explosion-heavy blockbuster movies on my Sennheiser HD 280 pro. The default value is 1.

When I use my USB or Firewire DAC, and I hear distortions or clipping noise.

Some USB/Firewire DACs seem to have problems with floating-point values outside of the -1 to +1 range. The solution is that my headphone enhancer delivers a digital floating point signal with a low amplitude to your external DAC and then you re-amplify the signal with your DACs hardware amplifier. This creates additional headroom for the digital audio signal to prevent clipping.

1. open the configuration window.

2. In the Output Gains boxes, enter a value less than 1. For example I use 0,2 for my Firewire interface. That means I now have 1.0 / 0.2 = 5x the normal headroom before clipping becomes audible.

3. To check if the digital signal is now completely inside the -1 to +1 range, you can tick "Clip output signal". When that box is ticked, then my app will clip the signal before delivering it to your DAC, so you can use this checkbox to determine if your audio interface behaves weirdly for values outside of the -1 to +1 range.

BTW, the picture shows the exact same settings that I personally use with my external Firewire audio interface.

It sounds like the front speakers are to my left and right side, not in front of me.

This impression is caused if the simulated inter-ear-delays are longer than they are for your natural hearing.

1. open the configuration window.

2. Click "Switch to Custom Sound Engine".

3. Move the head width slider a tick or two to the left.

It sounds like the front speakers are too close to the center speaker.

This impression is caused if the simulated inter-ear-delays are shorter than they are for your natural hearing.

1. open the configuration window.

2. Click "Switch to Custom Sound Engine".

3. Move the head width slider a tick or two to the right.

I would like to have more cinema-like acoustics.

The electronic dancefloor music that I (the author) usually listen to already contains plenty of reverb baked in, so I designed my sound engine to produce a very clear signal with the fewest possible amount of room reflections. However if you are watching a blockbuster movie, you might want to trade clarity in exchange for a more spacious surround experience.

1. open the configuration window.

2. Click "Switch to Custom Sound Engine".

3. You can now adjust the amount of "clarity" with the slider. Move it all the way to the left to simulate a spacious room with reverb. Move it all the way to the right to simulate a anechoic chamber (the default).

BTW, you can also click the menubar icon and then select "Sound Engine" -> "Comparison Listening ..." to compare all of the standard built-in sound engines. I also included two NEW AUDIO TECHNOLOGY virtualization engines that are optimized for movie watching.

My left/right ear is a bit less sensitive. How do I compensate?

1. open the configuration window.

2. In the "Output Gains" row, put different values into the L and R box. The default values are 1 for both boxes. If your right ear hears a bit less, put 1 into the R box and 0,7 into the L box. That will reduce the left channel amplitude to 70%, thereby making the right channel more loud in comparison.