Starting out with a PA - Am I on the right track.

[Stub Mandrel]

I'm not sure what the right topic is for this...

 

My brother has given me his band's old PA as it was starting to go downhill in his garage and had become too scruffy to sell. I'm starting up a new band and we will need a PA, and I'm just tidying it up. I've helped out on PAs on the odd occasion for over 40 years, so I 'know enough to be dangerous'.

 

It's a venerable but decent 600+600W stereo amp, a Soundcraft Folio 8+4 mixer and two huge The Box 2x15 cabs. They are only rated 450W RMS, but he says they never missed a beat and his band (like the new one) is very much classic rock and quite loud.

 

I've got a fair stock of other gear including lots of leads, half a dozen decent mikes (SM58, two good clones, a bass drum egg and a condenser pair for drum overhead) and a few cheap mikes. I have ordered extra leads and stands as well as a snare mike. I've also ordered a second hand 6-channel mike mixer for the kit from eBay. I also have a little 8" active monitor, intended as my personal vocal monitor.

 

The new band is a five piece (lead vocal, two guitars) and it looks like four of us will need mikes. I'll expect anyone who wants to sing to get their own mike - that SM58 is MINE I tell you!

 

My brother used to use the whole setup everywhere, but I would rather cut down for smaller gigs. My thoughts are:

 

If we do somewhere really small, just put vocals through the PA, perhaps just using the 6 channel basic mixer. We have decent backline amps and are old enough to be sensible about volume levels.

 

For typical pub gigs just mike up snare, bass drum and vocals. Say six channels but through the proper desk.

 

For bigger club gigs use four vocals plus the SM58 clones to mike up two guitars, DI bass, and snare (or would it be better to put kick) through the 8 channels with full EQ.

The extra mixer gets the kick (or snare), three toms and two overheads and mixes down to stereo that goes into one of the two stereo channels on the main mixer.

Leaves a stereo channel spare, just in case!

 

First questions are:

 

1 Does that sound reasonably sensible. Or should I stick the vocals through the other mixer? Or am I just being over ambitious?

2 Is it better for the kick or the snare to be allocated a full channel?

 

Now the bit causing me angst. The speakers are big and heavy. My thought is to get some decent monitor speakers and use them as PA for the small to medium-sized gigs, then when we go out with the full PA, they become our monitors.

 

So questions are:

 

3 Is it reasonable to expect the same cabs to serve as both vocal (or vocal + kick/snare) PA and as monitors?

4 Powered monitors or another stereo amp and passive cabs?

5 What sort of size monitors? I'm guessing 8" won't do it, 10" will struggle, 12" probably OK, 15" overkill?

6 What sort of monitor power?

 

Sorry this is all so rambling and long... I've spent most of the weekend browsing the net and trying to come up with a strategy!

 

[tauzero]

I'm no PA expert but I think you have a good start. As for monitors, we're using Alto TS308s (8") and they're capable of blowing your head off. Because nobody else wanted to store the RCF ART710s that I had and I wanted something smaller and lighter, they've gone and have been replaced by another pair of Alto 8" speakers (TS408) for FOH. We'll see how those go at the next gig. Currently putting vocals and one of the guitars through that.

[Dan Dare]

The gear you have will certainly be good to start with. In answer to the above:

 

1 Yes. A sub mixer for drums is sensible. I'd suggest mixing the drums down to mono, which will save you a channel on your main mixer as you can route the output from the drum mixer into just one. Stereo drums might matter in a concert hall, but not in a pub/club setting. Ditto the rest of the band. Panning anything right or left In a noisy pub/club will just mean people on one side of the room won't hear properly what's going on at the other side.

2 Definitely use separate channels for snare and kick if you are not sub-mixing the drums. Eq, etc will be very different.

3 Yes, but when using larger cabs as monitors, you will need to roll off a lot of the low end. Too much bass in monitors is mud city and will often cause problems with feedback.

4 Up to you. Powered monitors are more convenient, but used power amps can be had cheaply, so depends on your budget.

5 I use 10s for monitors. They're of reasonable quality (HK Premium Pro), but It isn't just about size. The important quality in monitors is clarity and articulation, not a wide frequency range (see above comment about avoiding running low bass through them).

6 Depends on onstage levels from backline, drums, etc, how efficient/clean sounding your monitors are. I use a 500w a side power amp for four monitor cabs and it's more than ample.

 

Get solid stands for those large heavy FOH cabs. You want something with a wide footprint that can't be knocked over easily.

[Phil Starr]

It's a real shame we have no home for PA issues but I suppose the techie people hang about here so you should get lots of opinions.

 

The first thing is that the weak part of the PA is usually the soft fleshy bit that twiddles the knobs

 

You can easily spend thousands on a PA so I'm not going to suggest a wholesale replacement, I'm kind of assuming you will use what you have first and you will grow your PA rather than welcome the suggestion to bin stuff. The Soundcraft mixer is decent enough for a basic PA. 2x15's are overkill for most PA's now but if they are really old, and a 450W rating suggests they are then you may have limitations, but the BOX speakers are fairly well regarde and you won't know until you try The current 2x15's are rated 700W. Just play some recorded music through them at volume and make a critical appraisal paying attention to the sound of the vocals.

 

How big are the venues you are playing, I've never fully mic a kit for a pub gig, the most I do is mic the kick. The drumkit is usually the loudest sound for most pub bands downing out the rest of the band and bleeding through the vocal mics, the last thing you need to do is amplify your loudest sound. Obviously there comes a stage when the venue is too big for unamplified drums but if this is your first PA I'd expect it to be a while before you reach that stage. Amplified drums rarely sound as good as they sound acoustically. It's really quite a technical job to mic the whole kit and takes a lot of time to set up, a lot of venues won't welcome you taking that time especially if you are in a pub where people are finishing meals before the band comes on. 

 

Monitors are crucial, if you can't hear each other you can't play tight as a band. If anything you need better quality monitors than your PA. Because they are closer to the mics than the PA Mains they are likely to cause most of your feedback problems. A flat response here really helps. Fortunately you don't need them to be particularly loud, you are close and almost any monitor will take you beyond the point where feedback means you have to back off the gain. You don't need extended bass or treble either. In the days when I used monitors I used my RCF ART310's, not exceptional speakers but no sonic nasties, despite being 10's they could reach ear bleeding levels on-stage. Why you would want to make your ears bleed baffles me though!!!

 

That brings me to another aim you ought to be working towards; reducing the sound levels on stage. You can use what you have to give you a vocals plus backline system which people have used since the dawn of rock'n'roll. You really don't need 15" speakers for vocals only though. The problem is having bass and guitars loud enough for the third row back means they a re deafening on stage and will swamp the vocals in the vocal mics which will be picking up more drums and instruments than human voice if you aren't careful. Plus your choice to wear ear plugs or lose some of your hearing. 2x15's were basically built for disco's not for bands but they should handle bass, kick and obviously guitar so I'd be trying to put as much as I could through the PA.

 

So when you are buying I'd always be looking to buy once, to build up the PA you ultimately want. I really wouldn't buy separates now, I'd be looking to replace things with active speakers. I'd also be looking to replace the mixer with a digital mixer as a next step. They are so much more versatile and will unlock all sorts of potential whilst ultimately being easier to use.. Monitors first though in all probability.

 

First step is to set up a technical rehearsal, Hire a decent hall and set up as if you were gigging, Take your time and try and get the best sound possible out of your PA, note your shortcomings and try what solutions you can. I really wouldn't get bogged down in miking the drums at this stage, kick only

 

 

Good luck

[Baloney Balderdash]

I own a The Box 502 PA passive 1 x15" woffer/mids driver + 1.7" high frequency tweeter PA speaker, and I am very impressed by it, outstanding, but at the same time tight and punchy, low end response (much better than most other PA speaker, regardless of price really, but especially at that price point, even most dedicated bass cabs), and overall very well balanced, articulate and clear sound.

 

Just amazing value for the money.

 

I use it as a FRFR cab, and it works exceptionally well for bass.

 

Only downside really is that it weight about a ton.

 

Edited July 26, 2023 by Baloney Balderdash

[Dan Dare]

One other thing I forgot to mention. If your Soundcraft has a low cut option, use it. On everything. A lot of bass in the mix uses up amplifier power and muddies things horribly. 

[Bill Fitzmaurice]

On 23/07/2023 at 20:10, Stub Mandrel said:

 two huge The Box 2x15 cabs.

Old school. Use them for now, but when the time comes to invest you don't want anything of that sort. A pair of 1x10 or 1x12 mains will work far better in the mids and highs, while a pair of 1x15 or 1x18 subs will work better in the lows. In the smaller gigs where you don't need the subs leave them at home. Self powered is the way most are going these days, although the more experienced still prefer passive speakers separately amped.

When you get to this point know that the most popular way to set up is with the mains pole mounted above the subs. It's also the worst way. Subs work best when they’re placed either close together for mutual coupling, or spread very wide to cover large areas. The basic rule is to have them either less than a quarter-wavelength apart or more than two wavelengths apart for their pass band, which for 40 to 100 Hz means less than one meter or more than 15 meters. Boundary loading should be used whenever it’s practical to do so. Having subs next to a wall gets you 6dB of additional sensitivity, and putting them in a corner an extra 12dB. In most cases you’ll have best results aiming the subs towards the wall or corner from about a foot away. The wags will tell you that's all wrong, but that's why they're wags. The mains are pole mounted for proper projection and to prevent feedback, but not above the subs.

[Stub Mandrel]

So much good advice! I will reread it all tomorrow.

 

I like the idea that I make sure everything I get will be a step towards my 'final' PA.

 

Nice thing about the folio is it has a sub 100hz filter on most channels.

 

I hear the rest, and clearly monitors are a priority. If I want the monitors to function as a vocal + kick PA for small gigs (and then use my 10" monitor for vocals) I will need a bit more performance than for pure monitors. Also may need to EQ them for monitor use. Tempted to pair a powered 12" with a matching passive speaker to keep things simple.

 

As Bill notes the ultimate step will be a sub or subs (a sound engineer I know is in the Bill camp and insists you only need one dub even for a tidy sized club), and a pair of powered subs that can stand alone. A club I regularly go to has a sub with built in crossover so everything goes to it, and it sends the mid up to two active speakers.

 

I hope to be playing mid-sized venues not just pubs & small clubs, as the other band I'm in does (the BL's dad has a 4kW pa all singing and dancing with digital control - having seen how often the tablet connection fails worries me a bit although it 'fails safe' so things keep working).

 

I'll re-read all your thoughts tomorrow.  Thanks folks!

[Happy Jack]

7 hours ago, Bill Fitzmaurice said:

When you get to this point know that the most popular way to set up is with the mains pole mounted above the subs. It's also the worst way. Subs work best when they’re placed either close together for mutual coupling, or spread very wide to cover large areas. The basic rule is to have them either less than a quarter-wavelength apart or more than two wavelengths apart for their pass band, which for 40 to 100 Hz means less than one meter or more than 15 meters. Boundary loading should be used whenever it’s practical to do so. Having subs next to a wall gets you 6dB of additional sensitivity, and putting them in a corner an extra 12dB.

 

Bill, my bands play very few gigs where placing our subs 15 meters apart is an option.

 

@Silvia Bluejay and I have accumulated a reasonable amount of PA kit over the years. Our biggest rig uses two Mark Audio subs (each a 2x10 with a 1000W amp), and pole-mounted on top of them either passive GX12s or more recently active Orion 15s by Bishopsound. We're not looking for extra sensitivity ... we have loads of headroom.

 

Question - what 'damage' are we doing to our sound if those subs are just five or six metres apart?

[Phil Starr]

5 hours ago, Stub Mandrel said:

If I want the monitors to function as a vocal + kick PA for small gigs (and then use my 10" monitor for vocals) I will need a bit more performance than for pure monitors. Also may need to EQ them for monitor use. Tempted to pair a powered 12" with a matching passive speaker to keep things simple.

It's a failsafe for any band to be able to use the floor monitors for PA in an emergency. I've known people use matching speakers for both to give versatility but I have to say I have had zero failures of any of my PA. I use my ART310's as PA at some venues and with my duo. I wouldn't go with a mix of active and passive monitors simply because not many people make them so you will be limited in choice to systems designed at a budget. Just about all modern speakers are built with DSP taking care of crossover and speaker protection/amp management and are better for it. If your active cab went down you would have no monitors.

 

If I was designing a system from scratch I would plan to go in-ears though. Using floor monitors means you are accepting poorer sound quality for your audience and sound levels on stage that will permanently damage your hearing unless you wear hearing protection. In-ears will also mean you will have studio quality sound to play to at every venue irrespective of the room acoustics.

 

The tablet dropping out is a problem with the router, many of the main brands like Behringer have a poor built in router and most users take an external router with them and don't get that problem. Yopu can usually use a Cat5 connection if you are worried. I chose the RCF M18 because stuff not working irritates me and the whole point was to reduce the boxes I had to wire in. That has yet to drop out ever.

 

 

[Phil Starr]

25 minutes ago, Happy Jack said:

 

Bill, my bands play very few gigs where placing our subs 15 meters apart is an option.

 

@Silvia Bluejay and I have accumulated a reasonable amount of PA kit over the years. Our biggest rig uses two Mark Audio subs (each a 2x10 with a 1000W amp), and pole-mounted on top of them either passive GX12s or more recently active Orion 15s by Bishopsound. We're not looking for extra sensitivity ... we have loads of headroom.

 

Question - what 'damage' are we doing to our sound if those subs are just five or six metres apart?

Given your video of the other day there's a health and safety reason why I put my tops on the subs if I use them

 

Bill is right that sonically it is not the right thing. Close coupling or using a single sub would be better. If there is a space between the subs then the sound from one will arrive later than the sound from the other. Where the distance is a half wavelength or other multiples you'll get cancellation. the result is a lumpy frequency response in the bass. The frequencies which cancel will vary depending upon the spacing and the acoustics of the room. In practice in a pub I don't think the punters are going to notice. If the punter is much nearer one sub than the other then they are only going to hear that speaker and any adjacent walls are going to give multiple pathways and phase cancellation too so you aren't in an acoustically good situation from the start. Also most subs by definition only work at frequencies where our hearing is poor. It's worth being aware of the problem but when you have half an hour to set up at the Dog and Duck on a 'lively' Sat night I wouldn't lose sleep over it. However if @Silvia Bluejay notices the bass changes in different parts of the room that is what is going on.

Edited July 26, 2023 by Phil Starr

[Silvia Bluejay]

The acoustics in that pub is dreadful. I have had to deal with (and improve, although usually not fix) boomy bass, muddy bass, shrill high frequencies, feedback on the vocals, faux-slapback effect due to the wall behind the speakers, when the speakers have a tendency to leak sound backwards, you name it. It's a lost cause. But it's huge fun (for the band), so we put up with the issues.

[Happy Jack]

12 minutes ago, Phil Starr said:

Given your video of the other day there's a health and safety reason why I put my tops on the subs if I use them

 

Yup. That was the first time in nearly 10 years that we've played the George without taking the MarkAudio sub-based rig. We knew the pub would be half-empty in mid-July so probably fewer than 200 people in front of us, and the rock'n'roll band really doesn't need that much volume.

 

As we drove home from the gig, we were discussing whether we should revert to always taking the big subs simply because they're so much harder for drunks to knock over. 

[Happy Jack]

One thing we could try next time we play there with the covers band (19th August, so probably half-empty again) would be to put the subs together in the centre, and the tops on poles to each side.

 

Both my main bands are 3-piece so having a great lump of 3'-high speakerage in the middle wouldn't be as disconcerting as it might be for a larger band.

[Silvia Bluejay]

It would, however, look 'orrible. 🙄🤷‍♀️

[Downunderwonder]

2 hours ago, Happy Jack said:

Question - what 'damage' are we doing to our sound if those subs are just five or six metres apart?

A big central bass zone and either side your low notes have the bottom drop out where 1/2 wave cancellation of the sub primary waves intersect out of phase. To an extent this is less noticeable indoors with the wall reflections adding in.

 

Putting both subs to one wall gives you control over muddy boom with a little tweak to the EQ. Ok the bass is stronger on one side but it's a nice even dropoff to the other side. Punters with a preference will gravitate one way or the other.

[warwickhunt]

1 hour ago, Happy Jack said:

One thing we could try next time we play there with the covers band (19th August, so probably half-empty again) would be to put the subs together in the centre, and the tops on poles to each side.

 

Both my main bands are 3-piece so having a great lump of 3'-high speakerage in the middle wouldn't be as disconcerting as it might be for a larger band.

 

1 hour ago, Silvia Bluejay said:

It would, however, look 'orrible. 🙄🤷‍♀️

 

Sub()s centre is good in an overly boomy room, we have started taking a sub as we are now all IE with no backline and being a 3 piece we set it in front of the drums, with guitarist one side and me the other.  

[Happy Jack]

Yup, that was pretty much what I was wondering.

[Happy Jack]

30 minutes ago, Downunderwonder said:

A big central bass zone and either side your low notes have the bottom drop out where 1/2 wave cancellation of the sub primary waves intersect out of phase. To an extent this is less noticeable indoors with the wall reflections adding in.

 

Putting both subs to one wall gives you control over muddy boom with a little tweak to the EQ. Ok the bass is stronger on one side but it's a nice even dropoff to the other side. Punters with a preference will gravitate one way or the other.

 

Understood, but if we have a "big central bass zone" then won't the punters equally gravitate according to taste?

 

I get the thing about the side walls, but very few pubs have anything as simple as that. At the George IV for example, on the band's right there are raised seating areas in large alcoves with enormous windows at their backs, on the band's left is a large bar with dozens of people jumping up and down trying to attract the attention of the bar staff. EQ-ing for that space is a nightmare.

 

[Downunderwonder]

36 minutes ago, Happy Jack said:

"big central bass zone

By that I meant a pure and equal response zone. Aka power alley.

 

Either side gets lumpy low bass response, ie uneven notes. A low E may be gutless for one punter and his mate a couple of feet away gets a gutless F.

 

41 minutes ago, Happy Jack said:

George IV

Probably best to side by side them in front of the stage for best effect.

 

The bar staff will appreciate a bit less boom at work even if most of the punters don't notice anything they can put a finger to, aside from the visuals being new.

 

You will be able to run the subs half as hot for the same oomph in the middle. That adds up to a more peaceful venue that drinks more while still giving the dance crowd their jollies.

[Pea Turgh]

I don’t have anything constructive to add, but I’ll post anyway 🤡.

I hate micing up a kit in a pub.  Total overkill. 

 

Also @Stub Mandrel, made me chuckle thinking of you with your featherweight GR bass cab, flanked by two big heavy 2x15’s!

[Happy Jack]

5 minutes ago, Pea Turgh said:

I hate micing up a kit in a pub.  Total overkill. 

 

But mic'ing the kick is a quick'n'easy way to put a smile on the drummer's scowl.

 

You don't actually need to plug the mic in, you understand; just so long as he sees you putting a mic there, he's your friend for the rest of the evening.

 

[Trueno]

22 minutes ago, Happy Jack said:

But mic'ing the kick is a quick'n'easy way to put a smile on the drummer's scowl.

 

You don't actually need to plug the mic in, you understand; just so long as he sees you putting a mic there, he's your friend for the rest of the evening.

 

Oops! Been there, done that!

[Silvia Bluejay]

Oi! Mic the effing kit or I'll down tablets and walk off.

 

Aside from late July to mid-August, there is no way a drummer* can be heard properly by anyone not standing right in front of the band at the George on  a Friday or Saturday night.

 

* Perhaps only our Paul The Drums on a channelling-Keith-Moon night. Certainly not our Mr Dynamics Roy the rock 'n' roll band drummer.

Edited July 26, 2023 by Silvia Bluejay

[Bill Fitzmaurice]

5 hours ago, Happy Jack said:

 

Bill, my bands play very few gigs where placing our subs 15 meters apart is an option.

Then don't. Keep them together.

Quote

A big central bass zone and either side your low notes have the bottom drop out

Although the name 'power alley' makes it seem that way you don't have a big central power zone. You have alternating power zones and null zones across the room. A more accurate description is low frequency comb filtering, as that's what it is.

Quote

Probably best to side by side them in front of the stage for best effect.

That can result in a total cancellation frequency where the distance from the subs to the wall behind the stage is 1/4 wavelength. Side by side or stacked to one side of the stage close to the wall eliminates that possibility. And no, they won't be heard as being to one side. You can't localize long wavelengths. The perceived location of low frequency sources comes from the harmonics produced by the mains.