Sound Devices 302 High-Pass Filter Issue

[Renetta Harris]

Help please. I recently purchased a Sound Devices 302 Mixer, but it appears the High-Pass Filters are not working in either the 80 or the 160 setting. I leave near an expressway and I opened the window and recorded 10 seconds with no filter, 10 seconds at the 80 setting and 10 seconds at the 160 setting as the tech and Sound Devices suggested. I tested it using all 3 channels – right and left and it all sounds the same. I even ran a fan and did the same test all over again and it all sounds the same. According to the technician, I should hear a difference. Shouldn’t the hum of the fan or the rumble of the traffic be lower when using the filters? Can anyone tell me what I’m doing wrong? Thanks.

[Allan Black]

Renetta, I'll bet the filters are working fine. You're either using a mic that doesn't record low frequencies, or you're listening on headphones or speakers that won't reproduce them.

Check your mic doesn't have the low cut switched in then ask a deep voiced male friend to speak about a foot away from it while your run the tests again.

Here come the post police we should be in the Audio forum.

Cheers.

[Jim Andrada]

Or play some really low notes on a piano or synth or whatever comes to hand

Said while looking over shoulder to see if the post cops are coming. Seriously, it would be better to post on the Audio forum.

[Renetta Harris]

Thanks for your suggestions. I'm using Seinheiser ME66 microphones - switched opposite the low-cut (I've tried it both ways actually -nothing makes a difference). I've moved this thread to the Audio Forum. Thanks again.