"humm" with moderate breathing on land Aqualung 2nd

[EskilJ]

I just serviced my regulators, the second stages are Aqualung legend unadjustable=titan LX supreme.
They are very similar to apeks xtx.
They have no issue under water, but while breathing in moderately on land, 1½ of my 4 2nd stages make a humming action/sound. The whole membrane system resonates a bit.
I've double-checked the adjustments, lever heigth and opening effort is right. The membranes look like from the same generation.
In the service manual, it is stated that you should confirm that it doesn't make any humming (stuttering is the wording), if it does, check the troubleshooting table - but it is not mentioned there..
As mentioned, it doesn't happen in the water, so maybe I'm just over-caughtious.

 

[M-Cameron]

did they do that before the service?

peronally every regulator ive used has hummed when breathing dry.

 

[fmerkel]

Not terribly unusual. If it's OK in water I wouldn't worry too much about it.

 

[EskilJ]

Thanks!

 

[divin'dog]

I have an Aqualung Legend... It hums/honks when dry but underwater, it is fine. I did read somewhere that the humming/honnking is due to too much pressure biting down on the mouthpiece. I tried not biting down. Guess what? No humming/honking... At least for me. Don't understand it but it worked. YMMV.

 

[Oitzu]

Most 2nd stages hum/stutter/honk when dry/out of water.
All my 4 aq titan lx 2nd stages do that.

 

[buddhasummer]

It's normal. Some of mine do, some do not, some worse than others. It has zero affect underwater it's just diaphragms resonating.