PA - how much power is enough?

[redbandit599]

Hi all

I'm thinking about changing our PA, we now have a good singer who exposes the limitations of our existing and venerable PA rig. We're also thinking about putting some of the backline through to get a bit more even spread etc. guitars, bit of kick (we've always just run on backline before.)

Anyhow, thinking about active tops and [u]maybe[/u] a sub for those bigger venues where we want to push more through the PA.

I reckon 12's would be good for the tops and a bit smaller than our current passive 15s.

Question is, how much power is enough? I understand the headroom arguments etc. but with active cabs ranging from 300 to 900 watt I don't really want to shell out for more headroom than I'll need.

Think typical pub rock scenario - we play loud enough to rock but not ear-splitting levels. I can't see us moving completely away from a decent backline volume either, so the PA is for more projection and spread rather than doing all the work.

Anyway, you know what I mean. So what do you guys use?

Cheers

PS - lots of love on here for RCF cabs, I note that DB Technologies are the same company etc. - anyone like them too?

[Les]

Mackie srm 450's and Peavey pro subs, All powered, think the tops are 400 ish and the bins are the same.

It's enough for your scenario, pub band, but unlike you we do let the PA do as much of the work as possible.

All bought second hand(at different times) for £580

Les

edit cos' I just read the question properly, I think subs make a worthwhile difference

Edited November 16, 2015 by Les

[Iain]

We run into a pair of Peavey powered 800w speakers - just vox (5 of us), keys and kick. Coped well outdoors without the drummist mic'd up and we had to turn down to his level... If you're running bass-heavy sound through it I'd guess subs/a sub would be handy.

[JTUK]

12" Tops and a sub is just going to be enough to beef up the vox, add a gtr bleed and kick with maybe an o/h in a decent size pub.
I'd suggest 150 people would be the limit size-wize for this P.A depending on the qulaity of your tops.

RCF are ok...the benchmark is QSC in this mid level market, IMO.
You wont be getting rid of any boxes with that size P.A...and a single 12/15 sub wont be man enough on its own to help with the bass much
altho you could run a little line thru it to help...but you'll probably find the effort isn't tangible enough for the bass,

[skidder652003]

we've had passive and powered subs in the past, we don't bother anymore as 99% of our gigs are pubs and 2 tops are fine for vocals. Our backline is more than loud and (hopefully) balanced - ampeg SVT and 410 and marshall 100w and 412, the drummer does go through his own 500w PA to balance out the drums. Subs are great if its not you carrying them to and from your van every gig and when you get home!

[xgsjx]

Like is said, it'depends what you're wanting it for overall. I'd get the best you can afford.

My bro has 2 Radiovox amps running 4 15" Peavey tops & then a separate amp running an unbranded sub that's loaded with 2 18" drivers (it's pretty huge).
Has a tremendous sound.

[mrtcat]

Don't worry about the power rating. Look at SPL for a better idea of how loud they are. 1000 watts through naff drivers in a poorly designed box may give an SPL of 120db at 1m but 200 watts through quality drivers in a well designed enclosure may give 130db at 1m which is a whole lot more volume.

Have a good listen to any speakers you are considering buying. Some sound boxy, some sound harsh and some sing beautifully. Personally I'm not convinced by Mackie SRM 450's because they get very harsh as the volume goes up if you're putting guitars and drums through them. If you can afford it look for tops with a 2inch tweeter as they tend to be a bit smoother at high volume.

Subs are a good way of taking some pressure off the tops but unless the sub can put the signal to the tops with the lows removed or the tops have a way of filtering out the lows you may still end up driving the tops hard.

[mrtcat]

[quote name='JTUK' timestamp='1447701249' post='2909653']
RCF are ok...the benchmark is QSC in this mid level market, IMO.
[/quote]

You see this is where it's subjective. We had QSC KW122s and got shot of them in favour of RCF722s because we found the RCF's sounded so much more natural and the throw on them was noticeably better.

[JTUK]

Wouldn't have a problem with 722's

[colleya]

We bought Alto trusonic speakers a few years ago and they're great. Not in the same class as the top top end stuff but plenty good enough for pub gigs and great value for money.

We have 4 of the 12" active tops and use 2 as monitors, which gives us a bit of redundancy should a top go. Added the active 15" sub last summer for a few bigger gigs and am very pleased with that too. Generally just use it for kick and a back line bleed in bigger venues.

[redbandit599]

Cheers all, helpful as ever! The steer on db ratings certainly makes sense probably over my original question re power rating.

I know that 120db is often cited as 'rock concert' level so having a bit of headroom on top of this makes sense to me, will check those ratings.

I think it's the horns that let our current set up down a bit.

The sub is just a 'potential' add on at this stage, mostly if we do anywhere a bit bigger for the kick. My own backline can be either a 210/212 or both and then it moves plenty of air, so as long as it's balanced I'm 'less' concerned about my own needs. Would like that fat kick drum thump though ;-)

[leftybassman392]

RCF would be my choice too - they used to make the chassis units that went into SRM450's (amongst others) in the days when they were [i]really [/i]good units. Quality over power ratings every time too - your audiences will thank you.

[Truckstop]

I also run a pair of Mackie SRM450's and a single Mackie SWA1501 sub for my band (four piece, three vocals). We put the whole band through. 3 mics on the drums, bass DI'd and guitar combo close mic'd.

We find that because we get enough throw out of the PA we don't need to worry about the rig not pushing enough volume. We play pubs and it's plenty enough for us. Never had the volume control on the back of the Mackies over halfway!

Don't forget to include leads, mics and stands into your budget. I managed to get all the boxes for £850 (including a mixer) but all the other stuff added another £250 on top.

[goblin]

[quote name='mrtcat' timestamp='1447701754' post='2909660']


Subs are a good way of taking some pressure off the tops but unless the sub can put the signal to the tops with the lows removed or the tops have a way of filtering out the lows you may still end up driving the tops hard.
[/quote]

Ah, that's where crossovers / system controllers come in. Admittedly, I'm still mostly a passive user (with active HK Actor subs), and at full capacity I run four EV SX100+ passive tops, and the two HK Subs with a 2Kw Peavey ip2 power amp (it's cheap enough to replace if / when it dies). Generally speaking for pub gigs, you can quite easily get away with just the two tops, and I'll occasionally take a sub along as well if the kick's going to be going through. At all times the amp is racked in with an EV system controller (fancy crossover) and that takes care of everything and tells what signal from the desk to go where.

As others have said, pay more attention to spl than wattage. The SX100s are only 200 watts continuous (800 peak), but the spl is 127db, and they'll take a hell of a lot more than 200 watts continuous if you give a good signal to it, especially if you're running with a sub.

Going completely active but portable, RCF do a cracking array system. I work with a function band that has a pair of them, and though I'm not sure of the exact model, christ it's loud! Doesn't half pack a punch that's for sure!

[TheRev]

We use 2 Yamaha DXR 12 tops and a DSR15 sub for all our pub gigs and any events up to 150 people.
It's plenty loud enough for us with everything going through it, but we're a loud acoustic band with a controlled drummer, so perhaps a full on rock band would need more.

Having said that, I use the same rig with an additional DSR15 sub for a small festival stage and it copes with the rockier stuff without protesting, but only just...

[goblin]

The DXR is a nice system, they're Nexo drivers too as Yamaha own Nexo now. One of the bands I work with played in a stretch tent at Electric Picnic in Ireland, pretty big affair and the rig was a pair of DXR12s and a pair of DXS15s, and the rig coped absolutely fine with us (party band)

[mep]

Our band has a pair of EV ZLX15P active PA speakers. We are a 4 piece, vox, guitar, bass/bv & drums. It was a step up from passive speakers and power amp. The vocals, guitar and bass drum always go through. On very rare occasions myself and the drum overhead need to go through. We play small to medium pubs and this is enough. There is still some volume left on the back of the active speakers. A sub would beef the sound up but for us and the places we play it's not worth the extra expense and equipment.

Edited November 16, 2015 by mep

[Dad3353]

We have about the same line-up as you, with valve half-stacks, and play similar venues with a pair of HK tops (HK_RS152X...) powered mono by one half of a 2 x 300 watt amp. The other half is for a pair of monitors. Vox, a smidgen of kick and o/head, no sub (no need...). We're not mega-loud, but it's a rock/pop repertoire with AC/DC, RATM, Smashing Pumpkins and more just the same. Our key feature is our singer, so we privilege the vox; a modest rig that does the job very well indeed. We do outdoors, too, with that, for garden parties and the like, but for bigger, festival-type scenes we call in PA support, depending on needs.

Edited November 16, 2015 by Dad3353

[Phil Starr]

As everyone has said look at spl levels first, and unlike bass speakers you can usually find these out.

Unless you have a pressing reason not to then I'd go for an active system preferably with some sort of DSP (digital signal processing) built in. With the amp and speaker designed to work together and a computer controlling the output so you can't damage the speakers you are going to squeeze every last drop out of the drive units.

Incidentally this is why you get such variation in wattage ratings, basically a 12" drive unit can only handle around 300W (and not that much in the bottom octave) and produce a sound level of around 127dB. However if you limit the frequencies and only apply power for a few thousandths of a second and then compress all the frequencies that might damage the speaker you can kind of cheat by upping the average power and then trimming the signal all but inaudibly to cover the peaks. The DSP computer does all this automatically but sound engineers have been doing this manually for years. It then pays to fit a 1000W amp to a 300W speaker but the amp will only need to give short bursts at this level. Neither the built in amp or the speaker are really 1000W but that's a bit irrelevant, they go really loud and the DSP stops them blowing or even distorting too much, however badly you treat them. you won't notice a lot of difference between ones rated 300W, 600W or 1000W.

I'm another who would go for RCF especially the ones with the 2" horn drivers. I auditioned most of the major brands a year ago and they really stood out in the way they reproduced middle frequencies and edged it over QSC's IMO. Much better than Yamaha, EV, JBL, Mackie and the like. However any of these can give you a good sound which will be more likely to be limited by the mic's you use and the lack of time, and often skill, a pub band has to set up and get a decent mix.

[redbandit599]

Great stuff, thanks again all.

Phill's explanation of what those DSP's actually do is really useful too. Cheers!

[stuckinthepod]

Alto Active 800w 115 tops and matching bass bins. Plenty for a loud pub gig but we do use it to its full extent in a rock cover setup.

[mingsta]

We've got everything (vox, backing, guitar, bass, edrums) going through a pair of yamaha DXR15s. It's a compromise as we don't have the budget or biceps for tops and subs, but it's been working well for us as a portable full range PA. We played a good sized hall the other week and I was impressed by how much it could kick out while still sounding good.

[r16ktx]

[quote name='mingsta' timestamp='1447882985' post='2911291']
We've got everything (vox, backing, guitar, bass, edrums) going through a pair of yamaha DXR15s. It's a compromise as we don't have the budget or biceps for tops and subs, but it's been working well for us as a portable full range PA. We played a good sized hall the other week and I was impressed by how much it could kick out while still sounding good.
[/quote]
Do you have any back line with these, and if not how do you handle monitoring? Also Yamaha state that the frequency response is 49Hz-20kHz @ -10dB and this handles the bass guitar fine?

[JTUK]

[quote name='r16ktx' timestamp='1448008917' post='2912177']
Do you have any back line with these, and if not how do you handle monitoring? Also Yamaha state that the frequency response is 49Hz-20kHz @ -10dB and this handles the bass guitar fine?
[/quote]

I'd be sceptical of that and certainly not at any real band volume. I think they'd be fine for a little colour and bleed, but not the entire bass without backline help.
You definitely will need backline unless a quiet acoustic band.

You have to be reasonable with expectations..you are asking 2 115's to do a LOT if you put kit and bass and gtr/keys at gigging volume

With good backline which provide most of the instruments sound, these will do ok...in a smallish pub
but at the expense of the vocals...which is not at all ideal at all. IMO.

We use to run 4 DX cabas, tops and subs, and even then the bass would stay out as well as most of the drums.
If nothing else, it was too much to mic for pubs and you gained nothing.at all for you efforts.

We did run a loud backline though, so there was no way the P.A would replace that and we just made sure the Vox
were out front of everything and bleed keys and gtr and a kick, if poss.

[Ghost_Bass]

Couldn't be more impressed with RCF, the ART312III tops have 450W (if i'm not mistaken) and will outperform any Mackies. they're cheap on Thomann also (recently bought one for something like 500€.