Topic: Help HPF my Omni recordings

[jagraham]

I've been recording with my omnis a lot recently.  Some of them are OK as is but the ones from larger venues with more boom need some help.  I am comfortable with HPF but I want to keep it to a minimum.  I believe that my recordings need very little tinkering but I want these acceptable to listen to on a variety of playback systems, for myself and others.  Listed below are the recording situations and setups.  If anyone has the patience, please listen to the samples and let me know what your opinion is on how much HPF I should add.  I was thinking 6db rolloff in all cases @ < 100 Hz cutoff frequency, using Audacity1.3.11b.  Am I on the right track with that?  This is one of those things where there are many opinions and strategies, so any help or insight is appreciated.  Keep in mind the samples are dithered down pretty low.  If anyone else has similar recordings and would like input, I would be glad to add mine if you post similar samples on this thread.

The first set of samples are the headliners at a country show.  The venue was Carrington Pavilion, Danville, VA.  Source: CA-CAFS(mounted on ears) > STC-9000 > DR-05.  Location: ~20' back from stacks, in line with left stack, back of first section of the "bowl" area of the amphitheater.  IMO, the recording of GA needs less HPF than the other 2.  It was the last act of the night and the sound may have been dialed in better.

[jagraham]

Same source for these.  CA-CAFS(mounted on ears) > STC-9000 > DR-05.  The venue is the same, but this is the small stage setup on one side of the lawn.  I was ~10' away from the right stack on these.  IMO, they don't really need any adjustment at all.  However, I would be grateful if someone could suggest how to make them better.

[page]

regarding the JT source; I wanted to do something akin to 3db/oct but audacity doesn't allow that (it's basically just EQ). So one trick is to duplicate the channel, and run the 6db version on just one pair, and then mix the two together to taste. I wanted to start my rolloff around 150hz, maybe 175 when I did that.

[jagraham]

These are from Martin's Downtown, Roanoke, VA.  Source was CA-14s(omnis/ORTF) > STC-9000 > DR-05, Location: in line with right stack, ~8' high, ~12' back.  the act was the "original wailers" and the opener was lazy man dub band.  This one needs some of the boom taken out.  Volume is a little low on these because peaks weren't removed yet, so crank it up.

[jagraham]

regarding the JT source; I wanted to do something akin to 3db/oct but audacity doesn't allow that (it's basically just EQ). So one trick is to duplicate the channel, and run the 6db version on just one pair, and then mix the two together to taste. I wanted to start my rolloff around 150hz, maybe 175 when I did that.

Thanks for the input.  I am a little confused though.  Are you saying I need more cutoff and less rolloff?  Doing one channel makes sense to get less HPF, but wouldn't that degrade the overall signal in the end if one channel if affected and the other not?  Would it not be the same to just add a little more rolloff and less cutoff?  Those are noob questions but I think many of us are a little behind on this process in particular.

[jagraham]

This is a show where I got busted that I posted about recently.  The first part of the opener (LT) is from center, ~16' back from stage, outside amphitheatre, source was CA-14s(Omnis/HRTF) > STC-9000 > DR-05.  LT2 is the same source, but after I got busted and behind porta-johns at the side of the venue.  Pretty worthless but recorded for posterity.  Honestly that 10 minutes is probably worse than any "zoomie" material out there.  Doubt there's much to save that but suggestions are welcome.  The headliner (CM) was ~32' back, ~10' ROC, CA-14s(Omnis/split on shoulder) > MM-CBM-1 > DR-05.  I think CM needs no editing but LT might need a little HPF.

[jagraham]

heres Megadeth @ The National, Richmond, VA.  Source: CA-CAFS(ear mount) > STC-9000 > DR-05.  Location: ~20' back from stacks, almost in line with left stack, ~6' FOB, ~10' LOC.  First sample is start of show, second is of the last song.  I think it got better throughout but the double bass drums are particularly boomy at the start.

[jagraham]

I've got more but I'll keep it at this for now.  Again, if anyone has similar questions of their own I'd be glad to offer my input.

[page]

regarding the JT source; I wanted to do something akin to 3db/oct but audacity doesn't allow that (it's basically just EQ). So one trick is to duplicate the channel, and run the 6db version on just one pair, and then mix the two together to taste. I wanted to start my rolloff around 150hz, maybe 175 when I did that.

Thanks for the input.  I am a little confused though.  Are you saying I need more cutoff and less rolloff?  Doing one channel makes sense to get less HPF, but wouldn't that degrade the overall signal in the end if one channel if affected and the other not?  Would it not be the same to just add a little more rolloff and less cutoff?

dupe both channels (it came into audacity as a stereo pair "set" and I misspoke), my bad. So you end up with 4 channels, 2 have HPF, 2 dont. Run a mix/render when you're happy with the levels and resulting sound. The reasoning for this is to tweak the roll off per octave.

Second, no, the severity of rolloff is sort of independent to it's cutoff. If you have bass bloat in the meat of the bass or the kick drum (typically 80-100hz) then starting your cutoff which is only 3db down at 100hz doesn't do anything, but it will decimate any resonance you have at 50hz regardless of whether that's appropriate or not.

The sample I played with I wanted to whack the 80-100hz band a lot, but there was significant junk under that so a HPF if controlled well enough works. If you don't have that junk underneath it, then it can sound sort of hollow if you wipe it out. The more I got better at HPF tweaking, the more I found I just wanted to EQ (or even compress) certain bands instead of HPF.

[Gutbucket]

The more I got better at HPF tweaking, the more I found I just wanted to EQ (or even compress) certain bands instead of HPF.

That's all I came to add. HPF almost always seems too blunt a tool for correcting music for me. Works well for loping off subsonics, bottom HVAC rumble and festival subwoofer bleed but I prefer EQ for dealing with frequency balance.  As page says, compression can sometimes help bass quality issues, but that's another rabbit hole, Alice.

[Gutbucket]

Just listened to the samples and the main issue I hear isn't too much low frequency energy, but rather almost no material over 4kHz.

[page]

Just listened to the samples and the main issue I hear isn't too much low frequency energy, but rather almost no material over 4kHz.

I think Jason did that so he could get file sizes small enough to attach to TS.com (which has a 500k limit)

[alpine85]

I opened a bunch of these up in Sound Forge, and noticed right away that they are 8kHz/16-bit files.  It's going to be hard to judge any kind of EQ issues when the high end is rolled off at around 4kHz.   They all sounded a little muffled, but I'm sure that has a LOT to do with it. 

Other than that, I don't think the low frequencies are that out of whack with the low mids, and mids.   I think you're on the right track with the 3db/octave rolloff starting at maybe 100-120. 

Looking at a spectrum analysis, your highest peaks vary from around 40-100, depending on the file (not unusual, but they seem a little excessive in some of the samples).

There does seem to be some subsonic stuff going on under 20 Hz that might be contributing to the muddiness, but the rolloff would take care of alot of that. 

[Gutbucket]

Ahh, didn't notice the 8kHz sampling rate file format.. That makes sense, my bad.

[jagraham]

Thanks for the input on these.  I'm trying some different settings with HPF now.  Will report later my results.