Dynamic broadcast mic into a budget 2-in interface, gain at about 3 o'clock to get peaks around -6dBFS on spoken word. The take is fine but there's a constant hiss under everything that becomes obvious once I compress. Cable is balanced XLR, nothing else plugged in, laptop on battery. Is this the mic, the preamp, or something I'm doing?
Don't chase -6 peaks. That's a habit from 16 bit days. At 24 bit you can happily peak at -18 to -12 and still have an enormous signal to noise ratio, and normalising afterwards costs you nothing. Running hot into a weak preamp is what's amplifying its hiss.
The hiss from the preamp, yes, that's fixed by the booster. What you avoid is the extra noise you generate by pushing a cheap preamp to its limit, which is usually the worse of the two.
But if I record at -18 and then bring it up in the mix, doesn't the hiss come up too?
Get closer first. At 15cm instead of 30cm you need 6dB less gain for the same level, and the noise floor drops with it. Broadcast dynamics are designed to be spoken into from very close range and it also gets rid of a lot of room.
Rule out the boring stuff too: try a different XLR cable, and try recording with the laptop's charger unplugged versus plugged in. Cheap chargers put a surprising amount of noise into a bus-powered interface, though yours being on battery already makes that less likely.
@rackmount_rina · 8mo ago · 3 replies
Almost certainly the preamp running out of headroom. That style of dynamic mic has low output and needs somewhere around 60dB of clean gain for speech, which is more than most budget interfaces have on tap without their own noise floor becoming audible. The standard fix is an inline gain booster between the mic and the interface, which gives you 25dB of quiet gain and lets you run your interface preamp at half its current setting. It's the single most common cause of exactly this complaint.
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@listening_lane · 8mo ago
Worth adding that you can test the theory for free: plug in any other mic with higher output, or a line source, and see whether the hiss follows the gain knob. If it does, it's the preamp.
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@flux_and_solder · 8mo ago
3 o'clock is basically maxed on this unit, so that lines up. Ordering one.
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