Do You REALLY Need a Fethead / Cloudlifter?

Another question arose in my discord server and I figured I would address it here because I’m sure other people have the same question. Is a Fethead or Cloudlifter really necessary? Does it really improve the noise floor? Let’s address that in this article with some sound tests.

TESTING PARAMETERS

I have done my best to level match channels using a pink noise generator. I use an SM7b, a Mogami Gold XLR cable, and the Focusrite 18i20 (same preamps as the 2i2 2nd gen). This first test is spoken word to give you an idea of the levels. I was hitting between -15dB and -10dB the majority of the time. No post processing was done to any of these audio samples.

Here is nothing more than the the room tone with the microphone plugged in, first without the fethead, and then with the fethead.

Lastly I replaced the microphone with a dummy XLR plug with a 150-ohm resistor to emulate the noise a standard dynamic mic would generate, without having to worry about the room tone affecting the measurement. I boosted both channels audio by +48dB to make the noise floor more noticeable and easier to compare.

FINDINGS

During the room tone test (audio sample #2), when you ignore the sound of the room, you can tell that there is slightly less hiss in recording. Then when we listen to the dummy xlr test (audio sample #3), it becomes much more apparent. There is a drop in loudness of the white noise when we switch from direct to including the fethead. The difference that I measured was approximately 4.2dB quieter when utilizing the fethead.

DO YOU REALLY NEED ONE?

It depends. If you’re buying the fethead or cloudlifter to lower your noise floor, you will have to determine if 4dB of noise is worth $100 - $150. I should also point out that the 18i20 has an Equivalent Input Noise of -128dBA, so if the EIN of your interface is lower, for example -130dBA, the benefit would be less noticeable (about a 2dB improvement of the noisefloor), but if your interface’s EIN is -125dBA, you could expect an even more noticeable improvement (around 7dB improvement of the noise floor).

On the other hand if your interface simply does not provide sufficient gain to drive your microphone, then it may be worth it to pick up one of these mic activators. However, I would remind you that it is good practice to record so you’re hitting between -18dB and -12dB in order to allow sufficient headroom to avoid clipping if your sound source gets loud.