Correct input gain level?

SQ SQ General Discussions
1

Hello fellow SQ users!

Our church just bought an SQ-7 and I am wondering about setting the correct input gain on the preamp.
Is it correct to assume that the meter is a peak meter, and not an RMS meter? And, should the preamp be set so that the meter reads to the zero mark at maximum peaks or is it good to drive that preamp?

I am really enjoying Robert Scovill’s “The Lab” videos where he goes in depth about gain staging, and I’m wanting to get this right.

Thanks!

Dave

p.s. - I searched the forums but didn’t find quite what I was looking for.

2

I think you are correct that the meter approximates a PPM, at least for the attack part of its operation. The top of the green LEDs is roughly +4 dBu on analog outputs and -18 dBFS on the AES output, when measured with a steady tone.

When I played a snare drum hit from a live recording, and adjusted levels until I was consistently hitting the top of the green, the analog PPM was reading +4 and the AES meter was also peaking to about -18 dBFS.

If you adjust input gains to light up the top of the green, you’re leaving almost 20 dB of headroom, so the danger of clipping should be nil. Whether that’s the sound you want is another matter.

FWIW, it works fine for me.

Geoff

3

Hi Geoff,

Thanks very much for your in depth reply - and backed up with tests, too - this info is exactly what I was hoping for! Now I know what to aim for at the beginning of the signal chain.

Cheers!

Dave

4

Also no you should not drive the preamps into clipping. It will not sound good!

5

Thanks for the reply, DRC!

Dave