Room modes, reflections and low end LOSS

[MaurysMusic]

I been live streaming once a week with a remote music partner. We use very similar gear and his feed is lacking in low end. It just sounds a little bit thin & distant. Could room reflections, comb filtering and etc really be to blame for a blatant loss of low-end information when playing acoustic guitars? Is there a way to test and see if his room is the reason? As far as I could tell from looking at the stereo waveforms, his 2 mics aren’t out of phase… but I’m not sure what’s up.

[Doug Young]

You can measure room response with Room EQ Wizard (free, I think). I'd not expect a difference just in low end thru close-mic'd guitars, but hard to say. Is there a specific episode where this shows up?

[MaurysMusic]

Thanks Doug - we each have a close mic aimed at the 14th fret and a shotgun 2' away aimed at the bridge. Here's a clip that demonstrates it



It can be heard on any recent episode, but sometimes he's playing an OM and I'm playing a dread etc... for an unfair fight, so to speak.

[Doug Young]

Does sound like phase issues to me. You have a nice stereo image, but nearly perfect correlation (in the 0.9-1.0) range. Marshall has a slightly wider stereo image, his voice pulls to the left, and his correlation dips into the 0.4-0.5 range. I'm guessing phase cancellation between his guitar and vocal mics? You say the gear is "similar" but it's not identical, so lots of things could be going on. Any chance Marshall also has his webcam mic active?

eCamm may also be playing games with you, but I don't recall any issues with guest audio back when I was hosting shows using it.

[MaurysMusic]

Wow thanks for this. We both have a rode Ntg-2 shotgun overhead. My other mic is a rode nt5 and his other mic is a different brand of SDC. Extremely similar mic positions. He said he has no other webcam mic active… maybe he’s wrong?

[jim1960]

The Auto-Align plugin from SoundRadix is simple to use and can solve your phase issues. I expect it will go on sale next month.

[rick-slo]

First thing that comes to mind looking at the videos is strumming distance from bridge. You strumming right over the guitar's soundhole and he is strumming much closer to the bridge.

Also his guitar is aiming more towards his right and yours more towards the mike.

Then of course different guitars being played.

That I can see in the video. Harder to speculate on what I can't see though room modes on their own would not thin out the low end uniformally.

[Doug Young]

Originally Posted by jim1960

The Auto-Align plugin from SoundRadix is simple to use and can solve your phase issues. I expect it will go on sale next month.

Won't be helpful in this case, I don't think. Maury's not recording multi-track, they're live-streaming 2 channels via eCamm, which doesn't support VST plugins, (and only takes a mono or stereo audio feed)

[Doug Young]

There could be lots of things going on. Different players, guitars, mics, rooms, mic placement, etc. I'd start by simplifying what you can. For example, turn off the vocal mics and see if you can get a similar sound from just the guitar mics. I'd start with the same mic placement, measuring the distance, angle, etc, but with different mics/players/rooms/guitars, that may not be where you end up. If you can get the guitar mics to sound similar, then add in the vocal mic and see what happens. If it's a phase issue between the guitar and vocal mics, inches can make a big difference.

Another thought, tho. I knew there was something about eCamm that was bugging me. I haven't touched it in more than a year, but when I was using it, eCamm had an audio quality issue with anything but Chrome. For good sound, guests had to use the Chrome browser. Maybe they've fixed that, but it's worth exploring.

[Bob Womack]

I've been working with streaming so long and it is always a challenge. While we are in a race to the top in recording sound quality, most inexpensive streaming services represent a race to the bottom. Some days they are okay and some days the sound quality is just terrible. I never take on an audio issue based on the streaming. I always ask for the person at the other end to record an example of what he is broadcasting, hopefully one I've heard via streaming, and send THAT to me via WeTransfer.

Best,

Bob

[MaurysMusic]

Thank you all for chiming in. Marshall and I did troubleshoot this offline a few times, where he’d record locally to his Mac and Dropbox’d me some tests. We tried one mic and two, and experimented with mic placement. The only variable we didn’t really replace was his SDC but results were worse with an sm57 in its place. It’s just odd.

[MaurysMusic]

Originally Posted by rick-slo

First thing that comes to mind looking at the videos is strumming distance from bridge. You strumming right over the guitar's soundhole and he is strumming much closer to the bridge.

Also his guitar is aiming more towards his right and yours more towards the mike.

Then of course different guitars being played.

That I can see in the video. Harder to speculate on what I can't see though room modes on their own would not thin out the low end uniformally.

We have his mics aimed so that he can have his guitar aimed like that; the off camera mic is adjusted to make up for it… or so we think. Good point about him picking by the bridge, though.

[MaurysMusic]

Originally Posted by Doug Young

There could be lots of things going on. Different players, guitars, mics, rooms, mic placement, etc. I'd start by simplifying what you can. For example, turn off the vocal mics and see if you can get a similar sound from just the guitar mics. I'd start with the same mic placement, measuring the distance, angle, etc, but with different mics/players/rooms/guitars, that may not be where you end up. If you can get the guitar mics to sound similar, then add in the vocal mic and see what happens. If it's a phase issue between the guitar and vocal mics, inches can make a big difference.

Another thought, tho. I knew there was something about eCamm that was bugging me. I haven't touched it in more than a year, but when I was using it, eCamm had an audio quality issue with anything but Chrome. For good sound, guests had to use the Chrome browser. Maybe they've fixed that, but it's worth exploring.

Correct. We have Marshall connecting via chrome and it sounds better than Safari. Marshall’s issues are the same when he records to his computer without streaming.

[KevWind]

Originally Posted by MaurysMusic

Correct. We have Marshall connecting via chrome and it sounds better than Safari. Marshall’s issues are the same when he records to his computer without streaming.

Well very very hard to diagnose not being in the room
That said :
Now I am just listening on my MacBook Pro laptop so the speakers are still marginal
#1 In that clip Right off the bat it sounds like your feed is louder than his so that could be contributing some to a lack of low end .

#2 But in answer to your OP question YES comb filtering and or even low end buildup (can) take both clarity and punch away from low end response as well as clarity and presence. AND strange as it may sound (if you are using a DAW to feed into the streaming service) you might want to put an EQ in high pass filter mode and experiment with setting it from anywhere from 50 hz up to 100 hz , to help clean up the low end which will in fact make it more present .
Which can clean up the recording but may not to much if it is the room causing the issue

Unfortunately there could be multiple elements contributing so as noted hard to make any one suggestion of a fix

[j3ffr0]

Phase problems notwithstanding, I suspect he is sitting in a bad spot in the room…. There are spots in small rooms where frequencies can dip 30db or more relative to the peaks. It could be the low end drop out, but I feel like I hear more room in his recording too.

So additional things to try:
Moving spots in the room a few feet.
Room treatment/bass trapping
Mic closer to/pointing more towards sound hole

Basically move stuff around until it sounds good. Can’t assume a mic placement that looks good IS good because of room variables. Have to place mic/performer, listen, rinse, repeat.