Big RMS power advice.

[Tom]

I know there has been a lot of sub and amp threads but iv been thinking ahead a little but now im stuck. This how it is.

Iv been looking at

8x 600 watts rms 8 ohm (bass bins). 4 per side
4x 600 watts rms 8 ohm (mid tops) 2 per side.

total rms = 7200

Now this is where my brain goes a bit mad. I have a few ideas but i need to know if there safe.

1. 4 bass bins per side running in series so if im right thats 2400 watts rms at 8 ohm, and buy 1 amp that is 3200 watt rms amp bridged in 8 ohm. Per side.

or much safer (i think)

2. 2 bass bins running in parallel. so that would be 1200 watts rms at 4 ohm but not bridged, per channel. This is what i was going to do for the mid-tops.


Which would be the safer opition or if you can think of better then just say.

Also i would use these speaker for DJ use but only use a few of them as i would not need that many unless it was a large gig.


And im sorry for another speaker, amp & bass bin thread. i would ask my old man but he is more intrested in computers than audio.

[TonyB]

4 X 8 Ohm bass bins wired in series would be 24 ohms (in series it get added together)

I would think you would be better off using two amps with two speakers per side and daisy chain the amps.

[Tom]

:Laugh: wow. 24 ohms. lol.


ok. thanks tony. food for the brain. also would it be safe to use parallel and series at the same time???

[TonyB]

:Laugh: wow. 24 ohms. lol.


ok. thanks tony. food for the brain. also would it be safe to use parallel and series at the same time???

(oops, my bad maths! 4 X 8 ohms = 32 ohms not 24 ohms)

Well you could - 2 8 0hms in parallel would give 4 Ohms then connect the pairs in series to give 8 Ohms but that wouldn't make the best use of the amps 4 ohm rating and you wouldn't have the redundancy if one amp failed.

[Excalibur]

Using series wiring would be a nightmare to wire up, and a recipe for getting one wrong, and blowing the lot up!:eek: My suggestion would be two pairs of speakers per amp, max output with max safety ie 4ohms. Amps for this power seem to be available from £250 to £850, so no probs there. Other setups are posible, but this gets my vote.

[Andy Westcott]

I agree with Excalibur, and that arrangement also leaves you with an operational system should one amp go down.

Purely out of interest, why the four bins per side? Do you really need that kind of power handling?

[Tom]

live sound pa.

but im still deciding on how much gear i need. the company who sell the speakers now make 800 watts rms at 8 ohm bass bins but they have 18" drivers. so maby even go for 6 bass bins and 4 tops per side.

so in total it would be 14400 watts, but it wont be that much straight away. im looking at the speakers now as later on i dont wish to change them. just keep buying more. plus i think the tops can be in a line array arrangement aswell which is handy.

[Excalibur]

live sound pa.

but im still deciding on how much gear i need. the company who sell the speakers now make 800 watts rms at 8 ohm bass bins but they have 18" drivers. so maby even go for 6 bass bins and 4 tops per side.

so in total it would be 14400 watts, but it wont be that much straight away. im looking at the speakers now as later on i dont wish to change them. just keep buying more. plus i think the tops can be in a line array arrangement aswell which is handy.

800W Speakers will need a bigger amp. If you keep all components equal, then every item is interchangeable, which is how I have ended up with my present systems. All speakers are 350w, full range can double as subs ( in fact I think they will outperform the subs!) both amps same size, do you see my point?

My feeling is that an ideal starting point for your system would be two pairs 600w subs, one pair full range, two amps, and off you go. If you wished, you could swap one pair of subs for full range , in case you wanted a big full range system for a gig, and you could use full range as subs if needed. Either way gives you a viable system. I could be wrong, but I wonder if you will need as big a system as you seem to think? Also, it's going to be interesting to see you fit it into a Corsa!;) :D :D

[bluishbob]

Wow, are you sure you need all of that power? I mean i work for ablike that does most of the big sound in my area, his kit is maybe 6k, and he has never used all of the power, he advertises as 'any venue'.

Why would yolu want 14k?

[Tom]

Wow, are you sure you need all of that power? I mean i work for ablike that does most of the big sound in my area, his kit is maybe 6k, and he has never used all of the power, he advertises as 'any venue'.

Why would yolu want 14k?

when doing outdoor gigs the sound has nothing to bounce off so you need a larger pa system to move the air (from speaker to ear).

for indoor gigs then i wont need all of this. i reakon that most of the gigs i would only need a total of 4-6 subs and 2-4 mid-tops.

[Tom]

Also, it's going to be interesting to see you fit it into a Corsa!;) :D :D

ill give it a go. :p. lol.

bit off topic but got an apointment at the bank to sort out some buisness stuff and im going to mention a small for a newish van.

anyway. back on topic.

as i am upgrading my dj sound system first i might use that for any live pa as hopefully soon it will be all DB technologies and sholuld be 2.2k.

[bluishbob]

still 14k is a huge amount, even for outdoor gigs. If you spend the money on high quality 'long throw' cabs, would that not be better than just going for high wattage? (not critisizing, just interested in what people think)

[Tom]

still 14k is a huge amount, even for outdoor gigs. If you spend the money on high quality 'long throw' cabs, would that not be better than just going for high wattage? (not critisizing, just interested in what people think)

i would rather have one make of speakers instead of pic 'n' mix. you can still get a lot of bass out of reflex cabs plus there smaller and lighter than moving aroung horn loaded speakers that are a lot bigger. would like to fit this in a large van, not a lorry.

[Andy Westcott]

Yes - with this kind of SPL requirement, maybe look at a stack of bass horns; You may be able (depending on design) to squeeze another 6dB out of the same wattage that way - that's the same as putting four times the wattage through conventional ported designs.

[bluishbob]

yes, absolutely, horn loaded cabs can be a pain to transport. But i don't mean horn loaded, i mean reflex, but long throw cabs.

The guy i work for uses them. His are Martin i think, the mids are 2x15inch, 1500 watts but 'long throw' and the bass end is 2000watt reflex cabs. We have some regular pa cabs on top of that for the top end. Its half the wattage that you are talking about, but the amp ratings have been carefully worked out, and it outperforms any similar systems.

Surely by the time you start talking in tens of thausands of watts, you should be looking at these kind of speakers, not just stacking up lots of regular pa cabs.

[TonyB]

when doing outdoor gigs the sound has nothing to bounce off so you need a larger pa system to move the air (from speaker to ear).

for indoor gigs then i wont need all of this. i reakon that most of the gigs i would only need a total of 4-6 subs and 2-4 mid-tops.

From my experience being outside or in a marquee doesn't make a lot of difference to volume level. I done quite a few marquee gigs and one outside gig last year and used the same set up as I use indoors. 400w a channel and it sounds just as loud outdoors as it does indoors.

[Tom]

just to let you know that i did do sound tech at college so i do know a bit about what i am saying. well not everything. and that was not aimed at anyone. just saying.

well have a look for yourself. now they may not be branded makes but i have heard these at the showroom and i was really impressed by the sound, tone and power of these speaker. they really do kick anc punch.

tops - 8 ohm, 600 watts rms, -3db 45-20khz, 127db max spl

http://www.studiospares.com/pd_248400_STU%20Auditorium%20212b%20single.htm



bass bin (no specs on the site but i have the new catalogue) - 8 ohm, 800 watts rms, 38-200hz, 132db max spl

http://www.studiospares.com/pd_248780_STUAuditorium%20118SB%2018%208ohm%20Subw oofer.htm


now im expecting people say dont buy them and all that. you really have to hear them to see to know what i mean about these speakers. there just fantastic for the price.

[super-hero]

If you are looking to hire out your sound system, have a look at second hand Martin or Turbosound. People will happily pay for a name they have heard of.

Plus due to the quality of these speakers you will need less of them to produce the same sound level. So less to set, less to store and less to go wrong.

Remember wattage isn't everything. My big system is about 12Kw rms and I am lucky if a quarter of it goes out twice a year. My smallest system is out every week and has paid for itself 10x over.

[Tom]

If you are looking to hire out your sound system, have a look at second hand Martin or Turbosound. People will happily pay for a name they have heard of.



its only going to be wet hire. you want me my gear then you get me as well. as most people say there gear is everything to them.

[super-hero]

I dont blame you, You can never trust anyone with your gear.

Dont forget to workout the cost of amplifiers to run your sysem. Good amps dont come cheap.

[Tom]

was looking at crown amps. this is going to cost me a bomb but crown was the first brand that came to mind. still searching. found the mixer i wish to get. thats £1000 straight away. then i need a 30-50m, 32-8 snake which could cost upto £500. thats why im buying everything now then in a year i should have most of the gear to do a full band pa but to a max of about 400 people with my dj speakers till i buy the big setup.

[A1DL]

its only going to be wet hire. you want me my gear then you get me as well. as most people say there gear is everything to them.

Super Hero has a very valid point. Irrespective of whether wet hire or dry hire, if you want your PA out working for you and paying for itself, you really do need known boxes from respected brands.

If you're doing PA for mates bands as a hobby, you'll get away with a pile of Peavey and the like, but if you want to get into serious engineered hire, look at what boxes your local PA hire companies are using... if it's Rock & Roll it will be Turbosound, Martin Audio, Funktion One, Void, L'Acoustics, Meyer, JBL Vertec, etc. If it's conferences and award dinners it will be d&b Audiotechnik, d&b Audiotechnik and d&b Audiotechnik.

This will also give you the advantage of being able to hire in extra boxes for big events, and working with other PA companies when THEY need more boxes.

HTH

Tony

[A1DL]

was looking at crown amps. this is going to cost me a bomb but crown was the first brand that came to mind. still searching. found the mixer i wish to get. thats £1000 straight away. then i need a 30-50m, 32-8 snake which could cost upto £500. thats why im buying everything now then in a year i should have most of the gear to do a full band pa but to a max of about 400 people with my dj speakers till i buy the big setup.

(1) what desk are you looking at, Tom?

(2) get a 50m, snake they don't cost much more than a 30m, and if you get a 30m it will be 2m too short. Honest, been there, it's guaranteed ;)

[Tom]

(1) what desk are you looking at, Tom?

(2) get a 50m, snake they don't cost much more than a 30m, and if you get a 30m it will be 2m too short. Honest, been there, it's guaranteed ;)

i was looking at soundcraft


24 channel - http://www.dv247.com/invt/30144/

32 channel - http://www.dv247.com/invt/30480/

[Tom]

If you're doing PA for mates bands as a hobby, you'll get away with a pile of Peavey and the like, but if you want to get into serious engineered hire, look at what boxes your local PA hire companies are using... if it's Rock & Roll it will be Turbosound, Martin Audio, Funktion One, Void, L'Acoustics, Meyer, JBL Vertec, etc. If it's conferences and award dinners it will be d&b Audiotechnik, d&b Audiotechnik and d&b Audiotechnik.


HTH

Tony

i see what you are saying but tbh i dont have that kind of mo ney to spend. i would need to save up for a while before i can do any work. i have a few things like drum mics, 8 channel DI (rackmount) and an effects processor but thats some of the cheap stuff.