some questions about stage amplification/live sound

[ack1961]

I just don't understand live sound as well as I should, I'm sure you guys can straighten me out.

When you go to a show and you see a wall of cabinets, just how much of the overall sound is actually the bass/head/cab and how much of it is the PA System?
If a sound guy has your cabinet mic'd to run through the house PA, the audience is actually hearing the qualities of the PA System, not the instrument/head/cabinet, right?  Sound guy usually says "leave your amp at n level, and I'll boost the gains through the board".

What would it matter then if I just brought a small combo amp, if they're just going to mic the speaker and raise the gain to optimal levels for the house anyway, right?  I mean, I have small SWR combo that has great tone, and I can pick it up with one hand.

If my assumptions are even close to correct, then why would anyone lug a high end head and pair of 8x10's to a gig?  A more relative question is: why spend the money on amp/cab when the sound guy is pumping it through the PA System anyway.  I know that there's a lot of tonal qualities tied to the bass itself, pedals,amp/cab, but how much of those tonal qualities are then brought to the capabilities of the PA System?

See, I'm trying to help my son's band out as much as possible without being obtrusive to the music they choose to play or write. I'm trying to spend money as wisely as possible in an effort to help them get started.
They've played a few small gigs, and have more on the horizon.  So far, it looks like spending money on a huge backline doesn't make any sense at all.  A small (400W or so) PA System (for bars, coffee shops, etc) appears liek a better place to spend some amplification cash.

I may need to be set straight by you guys, so have at it.

Ack

[TBird1958]

Well,
I think there's always good reason to have a good versetile bass rig appropriate for the music  because the band will likely find itself playing in situation where there is little or no house PA (very common for my cover band) and the bass amp will then need to be able to comfortably do the job. In my case that's a GK1001RBII and 2 4x10 cabs, we run the rest of the band out the PA and tweak the mix at sound check. So the band owns a PA that's good for bar situations but for anything past that we rely on the venue.......You don't want to be involved with roading at that crap   
When we play larger venues and the bass goes out the house PA my amp serves more as my onstage monitor, and as you say the soundman has overall control over my FOH sound and how I sit in the mix. When I'm in that situation I usually just want to hear myself onstage and let the soundguy do his thing...........hard as it is to trust them 


   

[rockinrayduke]

Mark summed it up. Same way in my band. I use a SWR Goliath III cab with a GK 1001RBII for most gigs. When we run it through the PA at bigger gigs I just get a good comfortable stage level.

[rahock]

If you're going to be running a PA that's in the neighborhood of 400 watts aimed at the audience, I would think about a couple of decent monitors too.
A couple of JBL EON PB-1 powered speakers can be had for about $250 a piece and they make excellent monitors at 180 watts each and you can always add more if the PA grows. At 400 watts of PA , I would keep the PA for vocal mics and maybe a bass drum. If you start to mic instruments too, you're going to suck up your power and muddy your vocals.
A baseline for instrument amplification would be a bass amp in the neighborhood of 180-300 watts with maybe a  1 15" cab, 2 10" or possibly a 2 12" cab.
Guitar amps would match up well with 60 watts or so and a single 12". This is a pretty loose sketch, as all watts and all amps are not created equal, nor are all volume controls.
I'm very familiar with the working a small to medium size room with a PA in the 400 watt neighborhood. Again , not all PAs at 400 watts are created equal either. But if you are aiming that 400 watts(or a bit more) at the audience  through some well matched speakers and you have a couple hundred watts more dedicated to monitors you can fill the room pretty well.
Rick

[rockinrayduke]

Now for a while at an old house gig I just used a Sansamp and ran it through the PA into a decent foldback. Sounded good and no hassles with amps or cabs. If our PA was larger I'd do that now.

[rahock]

In some of the Detroit casinos I've heard they have a no amp policy. You just bring in your little pod/preamp and they take care of the rest.
If they've got a strong PA and capable monitors, I wouldn't have a problem with that. You really have to count on the PA, your electronics and the sound man.
The guitar player who told me about this is a real strong blues /southern rock  player. Initially he bucked the policy, because he didn't think he could get a tubey Fender sound that would satisfy him. He picked up a pod (Line 6 I think) and lived happily ever after.
Rick

[leftybass]

I can't remember the last gig we played where the bass signal wasn't sent to the PA, I can't imagine what that gig would've been. I use a 100watt Ampeg combo, volume's usually around 5, anything above that is too loud, and we play large theatres and auditoriums. See below.

[Highlander]

Again, as Mark said, it really depends on the circumstances, when I played more metal back in the late 70's/early 80's I used to run my Hiwatt thru a couple of Sound City 412's, or a Marshall 412 and a 15 pa bin, but by the late 80's I only ever used a single Marshall 412, but that was mostly bar gigs...

If the hat fit's... at least if the hat's too big, you can still wear it... if it's too small, though...

[godofthunder]

 For me I have to be loud enough to get feed back from my bass that is my threshold. I like a big rig, it shakes the stage and lets you know your alive. Sound men groan when I load in but after sound check they get it, always get compliments on how the bass/band sounds. The guitar player with the 50w half stack is the volume problem . Btw the cab that is up high I never plug in it's pointed right at my head  Nice to have a back up when I blow a driver.

[godofthunder]

 In reading your thread more closely, I would advise you and your son not to do what I do. At least half my sound comes from my amps, Vintage British Tube stuff, for the most part not the way things are done today but it works for me. I could do it the easy way with a Line 6 POD or one of their modeling combo amps, just not fun in my book. All your son really needs is a good 100-300 watt combo with 1x15 or what ever speaker combination he likes. me I'd go with your head of choice and cabs instead of a combo but that's just me. Hope that helps.