Great room isn't it? Did Dennis run sound for you? The dude is so killer! I love that stage too...we play there every 2 months or so.
The thing about live sm, let the soundman handle the lows...but try to come in to it being in control. Or you can do what I do...have your studio/man cave sounds and then have your live sounds that are already controlled. The thing with high passing live tones is...it depends on how your cab reacts. You may not need to high pass as much as you would while recording. And then of course you have to find what frequency to high pass as it's not a one size fits all. So see how your cab reacts and then try to hone in on it. That's the best way in my opinion. Like I mentioned to Sidivan about gain, having studio sounds and live sounds allows you to not only adjust your high pass, but if your cabs sustain really well, you will most likely need less gain live than you will for recording if you do anything direct.
I use 25 watt greenbacks live, so for me, less gain is better so the cabs do the work. In the studio when going direct, I need a little more gain and a little more high passing. I either high pass through the Axe or sometimes just high pass using an eq in Sonar X3 and it does the exact same thing.
Effects: you know, for years I've heard people say "if you can hear effects, you're using too much." I actually hate that statement and don't believe in it at all. The reason being? It depends how clean of a player you are. I've worked my entire life to do everything to the point of being so clean, I can use lots of effects and nothing I do gets buried or masked behind the effects. In my world, if I want to hear a delay on my lead, you're going to hear that delay. The notes will be clean though so it won't really matter. The same with chorus, flange or phaser. As long as you play clean and have a tone that is distinct, use as much effect as you feel you need to get your point across.
One thing you may need to do (which can be extremely helpful) is to eq your effects. If the effect has high pass, low pass or some sort of eq in it, by all means use it. This can really help the effect mold to your tone and it can also help you remove the harsh lows that can come from chorus or flangers as they sweep down into the lower register.
Doing stuff like this in recording is essential to having great mixes because if you do not eq your effects and treat them as an instrument (to an extent) you can really have problems with your sounds that use effects. Nothing worse than a flange or chorus that dips down in the low end area mudding up your tone. Same with reverbs...if they hiss like a snake, you either have too long a tail or you need to cut some of the treble out of the verb to warm it up. We can go on and on with effects....but just remember, like a car, drive as fast as you can safely handle it....use as much effects as you need to where it enhances you, not destroys you.
Hmmm this shhhhh sound sounds like high end hiss to me. Can you post up an mp3 or something showing me what it sounds like? I get 0 noise out of my Axe at the moment and let me tell you, I have some extreme gain patches that make me shake my head because I can't believe the thing is not letting out noise nor is it choking off my tone. I don't know how the heck the gate (press layout and then page right two times) works like it does...but it's truly amazing and better than any Hush unit I have ever owned.
Just about all my presets have the threshold at -90, ratio 2.63, att 30.00, rel 35.02, and everything else at default on that gate. I get no noise at all from it unless I'm wide open on my volume knob...which doesn't bother me because I'm a knob whore. LOL! Years ago, when I had 900 stomp boxes and had to tap dance to shut up my rig, I got into the habit of always shutting off my volume knob. I'm so fast at it, it's become a part of my playing. But because of that, I don't need my gate to kick in when my guitar is wide open. I just want total silence when I'm not playing and subtle silence when the knob is 1/4 to half open. Put it this way, I don't get enough noise to where anyone can hear it and it doesn't bother me at all.
You should be able to dial something in with that gate. Especially if you mess with the threshold, the level and the input imp. So many cool variations to remove shhhhhh, you should be able to nail it easily. It very well could be your boss....they can pick up some noise for sure. I'd definitely try to find out where the source of that is coming from and see what can be done. I'm currently not using anything with my Axe to drive it more. It's actually pretty amazing that I haven't felt the need to add anything to it. It's giving me just about exactly what I need. The only thing I need to do is fix a few of my patches where the effects are not in line with the amp, get my MFC and I'll be good to go.