Help With PA Needed =)
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Posted on Dec 22, 2008 11:11 pm
Homeoftheben
Member Since: Dec 22, 2008
New here- got a rather not quick question =)
I'm part of a smaller youth group (about 40 people, meeting in a rectangular room that seats about 120=80ft. x 50 ft.), and we really don't know too much in the way of sound. Those of us who play are all fairly decent musicians, however, so we bring some quality instruments to the table (i.e. my HH Sterling..shameless plug, I know). We've been playing through some Tannoys (I'd say maybe 14-15 inchers) and 2 x 18 inch subs (Peaveys) for a while now, running them out of 3 500 watt Peavey amps and 1200 watt SoundTech amp. We've never really liked the sound we get, so this past week we purchased a couple of Peavey 115's for about 350 bucks. Then comes the fun part. We disconnected the Tannoys, hooked the 115s to a 500 watt apiece, and then hooked both subs to the Soundtech. My question comes here- is there something we should buy/set that will help this setup? Should we have run something different, and are we in danger of possibly blowing anything? One of the guys mentioned crossovers- is that something worth buying at a much higher quality, or would the cheaper ones on Ebay be alright for that?
As a second option, we've recently priced a pair of Tapco Thumpers 15's for about 500 bucks, which would also be in our price range (barely). Would these (powered) be a better option for this kind of system? Would this bypass the amps completely?
Thanks for any help/direction you guys can give me! Like I said, we really are just shooting in the dark here =)
Ben
Oh- instrumental setup is as follows:
3 vocals
Acoustic
SM57 on a Marshall 100 watt
Sterling
Caged drum, pieces mic'd with an overhead
Thanks again!
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Noize2uCzar of MidiAdministrator
Since: Apr 04, 2002
Dec 22, 2008 11:19 pm I'll leave this one for Rob Stemple. He is our resident large format PA guy. He will have a better opinion on what you have and how to use it properly.
I will say for large format here I use a pair of Peavey PR15's with a 1000 watt amp and love em. And EQ in the chain is what I use to smooth it out and correct the sound.
But I am guessing since you are running a dedicated pair of subs a crossover is a good idea. But exactly were you would want to cross it with the 115's on the system I'll leave up to Rob to help you with.
Dec 22, 2008 11:41 pm Hey Homeoftheben. I am just taking a moment to review all of the pieces that you have.
One thing I would like to know, what board are you running with your system?
This will help we with some options that are available to you.
Dec 23, 2008 12:02 am Looking over the Specs that you have listed, I feel that what you have should work fine for you. With just a little tweaking.
Who ever suggested to you on running a crossover, was 100% correct. Having a crossover will help clean up some of the sound for you. It will tighten up the sub, and give it a much puncher sound.
One that I like, is a Rane AC23
This is a great little unit. And will bring the subs to life for you. Sending just the low end information to your subs will give you some of the sound that you are looking for.
You are going to have to learn some information, in order to understand how and why the use of a crossover is necessary.
There is an article that I have written on the subject, that is posted here in the help section. Sadly, I have found an error in one of the paragraphs. That I will correct here soon. It has to do with the series/parallel section. I have the wrong answer down on that.
Now, is this all of the pieces that you own that are listed here? Are there anything such as monitors that you left out? If you could list every piece that you have, I can give you a detailed list on setting up your system, that should work very well for you.
Dec 23, 2008 11:44 pm Hi Rob! Thanks for the quick replies, and for being willing to help out so much. I'm currently visiting relatives for the holidays, but I should be back home sometime tomorrow afternoon, and I plan to take my camera over to our youth room to make a sort of montage post for you guys.
--I did happen to find some older pictures: hopefully they can help? From what I can see, the board is a Spirit LX7. I also managed to get a (small) shot of the older Tannoys- in case we just used them wrong and they would outclass the Peaveys? Sorry I can't provide too much info at the moment- I'll do my best to list everything coherently tomorrow evening.
We do run monitors, out of the third Peavey 500 amp. An additional line runs straight from the board to a pair of headphones for the drummer as well.
Thanks again for all the help guys!
Ben
Dec 23, 2008 11:47 pm
Dec 24, 2008 01:10 am Well, you got yourself a nice little set up there. I was nicely surprised that the speaker where flown. Always a great touch.
I will say that the Peaveys will be a better choice for your space. They are wider in the coverage pattern. And if you can fly them like the Tannoys, I think you will get the desired results that you are looking for.
The board that you have is a fine board. The one thing that I will have to look at a little more closely, are the outputs. The Spirit division of Soundcraft has a tendency to use unbalanced outputs. Which may mean that you will have to use some creative wiring to keep everything quite. I'll get back to you on that.
So, a crossover is going to do you good in this space. You only need it in between the Subs and the Peaveys. With the crossover point around 100Hzs. (This means only frequencies from 100, and below, only go to the subs.)You will need one that can delay the Peaveys a small amount. The Rane model that I showed you will do that. Although, I believe now that you should get the lesser model. The AC 22. It's a 2 way instead of a 3 way crossover. (We'll get in to 2 way and 3 way later.)
When you put the Peaveys in the air, you are going to have to splay them a small amount. You want around 30 degrees in between them, with the backs of the speakers touching. This will give you about 110 degrees of coverage in your room. Which should be perfect.
There is one more piece that I think that you should get. That is a few 31 band EQ's. These will help tune your speaker to your room, and help reduce feedback. Which gives you more headroom in your PA.
This one that I am showing, is one of the most expensive models on the market. I am NOT saying this is the one that you should buy. (Although you wouldn't be sorry.) I am only showing this as an example.
The way that the signal flow would go is as follows.
Mixer Main out. (Left, Right) to EQ channels 1 and 2
EQ channels 1 and 2 to crossover Left and Right.
Crossover Left and Right to Main amp for the Peaveys.
Then Crossover Left and Right to the sub amp.
We will get in to much greater detail as we go along. This is just to start you off. And also to show you what is still needed for your system. I will start to look for some pieces at a great price. As I find them, I'll post them here for you.
Hope you have a great holiday. I'll get back soon.
Dec 24, 2008 06:10 am Didn't think you'd be that quick! Thanks again for all this help.
Sounds great about the crossover- I'll get with the other guys and see what kind of money we can come up with for one. As for flying the Peaveys, I might YouTube a video of us doing that one for your enjoyment. Trade advice for entertainment =) Should be home by this afternoon, however, and hopefully have the pics up by the night.
Thanks for the holiday wishes- the same to you too!
Ben
BeerHunterwww.TheLondonProject.caMember
Since: Feb 07, 2005
Dec 24, 2008 03:41 pm Hey, not trying to pull this thread off topic but I just wanted to say... Rob, I have read many of your posts and have very much appreciated your input on every occasion. You are a wealth of information that has benefited us all and I for one have really appreciated your efforts and dedication to help us! I think I can speak for many of us when I say thank you, Lonnie
Dec 24, 2008 04:03 pm Awww, thanks Beerhunter. Ya know, I just wish there was a post group like this when I first started down the dark path of sound engineering.
The misinformation that was given to me was staggering. It took me years to find this out as well. And I hated spouting off this misinformation, and having other engineers look at me like I had two heads.
From the moment that I decided to join the HRC, I really wanted to share in giving people the correct information. And not having them stumble their way through a show. But, ratter giving them useful knowledge that gives them some insight on how their system is behaving.
Dec 24, 2008 06:42 pm First off, I'd like to second BeerHunter's sentiments- you really have been a huge help already. Thanks again.
I made my photo trip as well, and I was a bit embarrassed to find a couple of things: 1) there were 4 Eq's already rack mounted and 2) there's a Peavey 1500 watt amp as well ... if I knew how to make a red face, I'd make one. At least we didn't secretly own a crossover already, right? :)
Without further ado, though, my photo hunt:
Sorry for the sort of randomness- got kind of carried away, didn't want to miss anything =)
I'm texting the guys about the crossover as well- definitely perfect for our price range!
Thanks!
Ben
Dec 24, 2008 06:46 pm Oh! To account for the Peaveys not being there- we've been locking 'em up. At the moment we're just setting them on top of the subs (seen on either side of the last picture, and we rerouted the mains of the board through the stereo cables run to where a second set of monitors used to be on stage).
Dec 24, 2008 07:41 pm Well, we are ahead of the game now! Great! I think that we can soon hit some of the technical details that you are going to need soon.
The way that you have your EQ's labeled I think is fine. Two 31 band EQ's for the mains, and 15 band EQ's for the monitors.
When we institute the crossover, you are going to have to readjust some setting on the EQ's. The EQ's are going to be in front of the crossover. So, you will need to turn the HPF all the way down to 10 hz. You want that information going to the sub.
The one thing that you stated that you have wired in...... Is not my favorite thing to do. That is running the mains back into a monitor. This creates phase issues, and is hard to control the overall EQ. It is best to still use the Aux sends to create a mix for the monitors. Even if you have to put every channel in that monitor. This will keep the phase correct, and will allow you to make adjustments to the FOH sound, without effecting the monitors.
One thing that I should mention, is that you want to run all of the AUX sends going to the monitors in "Pre". When you are in Pre mode, you can move the FOH (Mains) faders all you want without effecting any level going to the monitors. Post means that the Aux send looks to the FOH fader for it's level.
Another thing that I saw that was a little concern. You never want to raise an EQ fader in live sound. That is one of the big No No's when doing live sound. You can easily cause a driver (When you say speaker, it refers to the box. When you say driver, it refers to what the speaker it's self is doing. In this case, it's the LF driver. Low Frequency driver.) to move more then it should. The movement of a driver is called excursion. So, you can cause an over excursion. This causes damage to the driver. And sometimes, the driver's voice coil can leave the magnet air gap all together. How many times have you seen a driver that the center is stuck out, and will not go back in? That is what the cause was.
When you get the crossover, there is a level control on there. Which will allow you to turn the sub up, or turn the tops down. Making it much safer to control the over all sound.
I still have yet to check to see if your board has balanced outputs. If it does, you certainly are going to want to use balanced cables. They will be of the 1/4" variety. Not the Mic cable type. The way to tell if they are balanced or not, is to count the rings on the end. When you pull it out of the board, you should see what looks like a headphone jack. So, two black rings, with three silver rings. That is balanced.
For unbalanced, it will look like a guitar cable. One black ring with two silver. That is not what you want. Unbalanced cables will lead to buzzes and hums that will drive you nuts looking for. And are limited in how long they can be before they cause problems.
So, balanced cables everywhere in the PA. Except if you have a reverb unit. That is one of the few exceptions. Most, not all, do not except balanced signals.
I would also like to see you get the Peaveys above your audience's heads. Having them close to the ground, means you have to run them harder to people to hear them. Which leads to feedback, and a bunch of other things that you do not want. Do you have a box or such to put them on? Just something to get the horns above head height. You won't have to push as hard, and it will sound better anyway.
Dec 25, 2008 02:40 am Just wanted to check in, so it doesn't seem like I go dark in the next few days =)
Another day of traveling for me when I wake up, and chances are I won't be able to make it back here till the 1st. Thanks for all your help though- and I believe (if nothing goes wrong) we should have purchased the crossover by then as well. Here's to us successfully flying those 15's too!
Thanks again for all your help Rob- hope you and yours have a Merry Christmas!
Ben
Dec 25, 2008 10:37 am Good work, Rob, and good luck Ben.
Ditto what BeerHunter wrote above. And just let me add that I appreciate the way you share your knowledge without making people feel stupid and without just trying to pimp yourself.
Kudos...and Happy Holidays!
Dec 25, 2008 10:37 am Deleted By guitar_jim
(Accidentally double-posted!)
Dec 26, 2008 12:54 am Thanks Jim. But, honestly, I never forgot when I was first learning to run sound. And I'll never forget how I felt when I asked very similar questions.
I really have to say that dB and Noize deserve all of the credit for creating the HRC. In there mission statement, it clearly states that rudeness will not be tolerated. I and many others have joined the HRC based mostly on that alone. And also all the incredible engineers here as well.
Kudos to dB and Noize for starting and maintaining the HRC! Thank you guys for doing so!
Noize2uCzar of MidiAdministrator
Since: Apr 04, 2002
Dec 26, 2008 01:54 pm Its funny but the story is the same for me. There were several in my early days, that gave me guidance and let me take control of my own recordings. And one in particular who pushed me into experimenting and not having a fear of something not working the first time.
I owe a lot to those guys, and HRC is simply a way to pay it forward I guess.
monmixrIf 50hz 60 will kill ya.Member
Since: Jan 08, 2009
Jan 08, 2009 01:19 am Your PV 500s are 500 watts into 4 bridged. I would imagine your 115s are 8 ohm boxes. your 1500 will give you 300 watts into 8. You didnt say if you bridged the 500s , Im assuming you did and did correctly. im thinking that would be the best bet for your top boxes. (your kind trying to use a weed eater engine to power a car here.) PV says the 1500 will do 4 ohms bridged, sooo... go with a stereo 2 way crossover, mono subs (there non directional anyway. use the 1500 bridged for your subs and a 500 bridged for each of your tops. that will give you kinda enough power for the front. now for monitors...your pl802 will give you 250 into 8 or 400 into 4 (per channel stereo). I dont know what you have for monitors, but you can throw 2 8 ohm boxes on each side of the soundtech and have 2 monitor mixes. Im my opinion (everyone has one) I might use the 31s on monitors simply because they will give you more problems with feedback then the front and if you set your crossover up decent you should be able to run the front pretty flat anyway. I like the DBX crossover better than the rane, but its all what your used to I suppose. Now, the picture of the Klark dn360. yea... kinda like putting a 1000.00 paint job on a 200.00 car. I would like to comment on turning the HPF down to 10, and why mabey you dont want to do that. the lower the freaquency, the more power it takes to create. your subs cant get anywhere near 10hz, and you really dont have alot of wattage in the cottage to be throwing around, so set it to something like 25 (youll have to beat the crap out of your subs to get anything below 30 out of them realisticly. same with the monitors, if your just running vocals through them, cut everything below 100 or at least 80. if your running other stuff through them then cut everything below lets say 50 (conserve that power) Please remember this is just my opinion, and for 50 engineers, there are 50 ways of doing something.
