Live sound question 3!!!and 4!!!!

  • Thread starter Thread starter rockironwebb
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jimmys69 said:
Isn't there a basic rule that says it takes 10 times the power in watts, to get twice the perceived volume? Obviously there are variables that make this only a vague statement.
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I believe that's correct. The bel unit was intended to represent a clearly heard change in level. A 10:1 increase in power yields 10 decibels (1 bel) which is said to be a subjective doubling of level. A doubling of power yields 3dB, which is considered the smallest noticeable change in level in normal circumstances. That said, in mixing sessions I and people I've worked with have noticed differences as small as 0.1dB.
 
So I suppose you could form a general judgment based upon how loud your PA is now in relation to the level of your instruments at rehearsals. From that you could guess as to how much power you need. Keeping in mind that the efficiency of the drivers (speakers) will have a huge affect on the ability to produce the needed volume. If you guys are as loud as some of the bands I have been in, you are going to need easily 1200 watt amp into two 400 watt 15" cabs as mains. Use the CS 400 bridged to power one wedge pointed at the singer with only him sent to it. Throw that into the trash if you plan on playing live and placing mics on the kick drum. Then you need to add a sub and a whole bunch of amp power.

I would first get a power amp with 1000+ and see what your speakers can do when an with clean power. You are going to need the amp eventually anyway. Then decide whether you need to get better speakers. You can always use the ones you have now as side fills. Moving more 'air' by adding more speakers will always result in more volume. It can become a nightmare with feedback tho in a small room. More speakers at lower volume will result in clearer sound in general.

Or just turn the hell down and be good with what you have! Shit, I sound like my mom! LOL!
 
jimmys69 said:
Moving more 'air' by adding more speakers will always result in more volume.
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As long as they're within a quarter wavelength of each other at any frequencies they are expected to reproduce and they are wired correctly. The latter is easy, but the former is not so easy above sub frequencies. Adding mid-high cabs mostly reduces intelligibility.
 
Back to the original statement. I believe the problem is your speakers. I use 2 yorkville y115 cabs for practice and I am running them off of a 100watt PA head thats old as dirt. You can hear everything fine. I promise you. You need to work with speakers with good SPL not wattage. (the sound is clear no flabby distortion) I cut alot of the bass out and push the highs/mids and I play in a metal band I have the speakers on stands elevated and everything is fine and for gigs I've gotten away with using them along with a set of subwoofers with their own private power amp and they had no trouble keeping up with the massive bass. I hope people figure this wattage scam out soon because this class D stuff isn't all its cracked up to be.
 
If you have the correct ohm speakers connected the amp will be plenty loud enough for a rehearsal room. There are a couple of other things to consider, different speakers have different efficiency ratings, as bobbsy said, this means that they put out a different amount of dB for the watts put in. Also if you are running say a 12" speaker and a horn driver the dB will be a lot more than just a speaker as the horn driver has a much greater dB output per watt than just a speaker. The design of the actual speaker box also has a direct bearing on the efficiency of the speaker.

Now the proof, in our rehearsal set up we have 2 fold back wedges, each wedge has 2 x 10" and a piezo bullet horn. The amp is 200 watts a channel at 4 ohms but the wedges are 8 ohms each so we only get about 140 watts a channel. Due to the fact that the wedges are very efficient (they are part of a larger PA and have been on tour and coped very well and actually sound very good) we can very easily hear the vocal above the drums, guitars and bass. However one point is that we only use the fold back for vocal.

Another thing to consider is the room acoustic, a very live room tends to make everything sound loud, thy deadening the room so that the sound does not splash around, and finally turn down the amps and get the drummer to play softer, because at some point you will be at a gig and the manager will come up and say "you guys are too loud, turn it down", so you may as well find a good stage volume that works.

Oh and one last thing, the peavey has a limiter circuit that protects the speakers if you push the amp too hard, make sure this is switched on.

Alan

Alan
 
^^^^^^ Double this. ^^^^^^^

Being in a band is about the best combined sound, not a bunch of people all trying to play louder than the person next to him.
 
Bobbsy said:
^^^^^^ Double this. ^^^^^^^

Being in a band is about the best combined sound, not a bunch of people all trying to play louder than the person next to him.
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Youre right but thats easier said than done...sometimes
 
Lt. Bob said:
first ....the wattage of your speakers is simply to tell you have much power they will handle withoput blowing up. It does NOT tell you anything at all about how loud they will get.

second ...... those amps are only 120 watts into 8 ohms so of those are 8 ohm speakers you're not getting 200 watts a side out of them.

third ...... if you're rehearsing using all those large stage-ready guitar amps and bass rig then you're likely practicing way too loud and in a basement like that it can be hard to get the vocals up enough for a drummer to hear over all of that plus his drums regardless of how much power you may have.

lastly ...... that amp would do ok for a monitor rig or something like that. You also could maybe use it in a tri-amped set-up to drive the horns but it's certainly not enough for gigging as the primary PA amp.
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THERES the answer right there. Who needs a half stack or TWO bass cabinets at a rehearsal???How can you even tell how it sounds? Get some rehearsal sized amps and practice listening to each other play.
 
Thanx for all the advice. If anyone would like to "donate" gear to some poor white boys from Illinois, we'll take it. For now we just work with what we have.
 
rockironwebb said:
Thanx for all the advice. If anyone would like to "donate" gear to some poor white boys from Illinois, we'll take it. For now we just work with what we have.
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well ........ I'm not saying buy gear ..... but you NEED both bass cabs? NO ONE has a practice amp? Those are the ONLY amps you have period?

Those amps don't come with volume knobs on them?

It doesn't matter to me at all, of course. Your band ..... your fun .... your rules.
But if you're playing that kinda gear at anything louder than around '1' .... then there's no hope of hearing your vocals very well in a small room/basement and it's not the CS400s' fault. Basically without spending a bunch 'o' money on PA gear you'll never get it loud enough for you to clearly hear and even then it's gonna be hard.

Been there ...... done that. You can overload a room with sound to the point where nothing will make the voices cut thru ...... you could have 10,000 watts and you still wouldn't hear them very well.
 
And at some volume level the limiting factor will be vocal mic feedback regardless of how many watts you can throw at it.
 
bouldersoundguy said:
And at some volume level the limiting factor will be vocal mic feedback regardless of how many watts you can throw at it.
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that's it. There are limits and the common newbie misconception that it's the amps' fault is usually mistaken.

I have absolutely no doubt whatsoever that I could have a full band rehearsal using that exact amp/speaker combination and would be able to have the vox where they could be heard well enough.
 
Wow, feels like i'm kind of getting reamed. For now the gear we have is what we have to work with. Up until now we have been writing without a singer so the vocal amplification is a new deal for us. I have been able to hear everything that both guitarist and bass player are doing. I do realize that we are not going to be a ble to crank up like we have bee, but we will make it work. I have played the drums for a long time. I have never been involved in using any PA gear whatsoever and had many questions. My guitar player (the one with the 5150) lives in a single wide trailer and has four kids, I don't expect that he can currently spare any money to buy a "practice" amp. He is an awesome rock guitar player. I am recently married and about to buy a home and start a family. Of course we would all love to have better gear, but we don't. I am a pack rat scavenger and have always been quite resourceful. Until I finish school and land a big bucks job in a few years, I will continue to piece together what becomes available. I just want to rock out. Anyway, I appreciate all of the help and advice. We got practice on Sunday, I'll re-post with the results of my mad max set up.
 
rockironwebb said:
Wow, feels like i'm kind of getting reamed.
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Don't take it too hard. People are just giving you the benefit of their experience. It's better to get reamed here than to get it from an audience or the management at a gig.
 
All of us understand about budgets and all that stuff and can certainly appreciate what you're going through in the struggle to get it all audible. But at some point it becomes a physical reality.....the physics of sound are finite there arent any ways around them. In order not to spend any money no one has then it becomes a matter of discovering how to play quieter in order to use what you have to its best ability.

The really amazing thing that happens when you finally are forced to look at these needs is you'll play better together, you'll hear things in the arrangements you havent heard before (even though you think you have) You'll learn to be cohesive at any volume and every soundman on earth will be your lifelong friend and dial you up so sweet at shows......
 
cavedog101 said:
You'll learn to be cohesive at any volume and every soundman on earth will be your lifelong friend and dial you up so sweet at shows
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^^^ This

I've done a number of sound jobs where I've been bagged because the sound was bad. I show them the desk . . . no guitars in it because they are so freaking loud. To achieve a decent mix is close to impossible . . . so I just pray for the band to get a brain or for the night to finish, which ever comes first.
 
Yup, yup, yup. If the overall mix is constrained by one instrument being too loud for the venue, there is nothing you can do to fix things.
 
rockironwebb said:
Wow, feels like i'm kind of getting reamed. .
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no you're not ..... I went back and read thru the thread ..... no one really had anything mean to say to ya' ..... everyone was just telling you their opinions as to why you couldn't get the vox up enough.
If you can't afford other gear then you can't ..... but then it becomes a fact that it's gonna be more difficult to get the vox up enough if you can't manage to control your volume.
And you're mainly talking about getting even more powerful and louder gear (more PA or speakers) which is simply gonna make the problem worse if anything.

Instead of taking insult at well meant advice you should mainly be thinking about how you can control your volume so you CAN hear.
It's not gonna be possible otherwise ...... simply turn down and you should be able to get by.
That's my opinion ...... you have the right to reject that of course and go your own way ....... I don't mind.
But I believe the advice you're getting suggesting that you might be practicing too loud is probably the best.
 
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