The problem of Subs in Pubs.

[Phil Starr]

2 hours ago, warwickhunt said:

So placing the sub front left/right of the stage with a 10" mounted on a pole above (getting no reinforcement/lift from being placed next to a wall or corner) is preferrable to positioning a sub elsewhere near a wall/corner?  I realise it is a single sub so I don't need to worry about length of wave et al but I thought the consensus was that a sub benefits from placement next to a boundary.  BTW this is NOT for my acoustic duo, this is purely for a 4 piece band inc kick/snare mic'd.

That wasn't really the question I was answering. I thought you were saying you have two lovely 10" speakers already and would it be enough to add a single 12" sub for a four piece band with bass and drums through the PA? Or put another way should you buy a sub or do you have to buy two bigger PA speakers? I think the sub would do it for small and medium venues. You might need a bigger sub, two 12" subs or a very good 12" one though if you play bigger venues. Speaker size alone is only one  factor.

 

If you decide to go for the sub I'm absolutely not telling you to set up the same way at every venue. I actually don't think there is a concensus about this. There's no way I'd personally walk into every room and plonk the sub down in the corner or against the back wall next to the kit. The placement depends upon the venue. I'm really saying that whatever you do will have to be a compromise. What is true is that placing the sub on the floor gives you reinforcement, placing it next to a wall a bit more and in the corner most of all. That much isn't about concensus, it's about physics. If your problem at a particular venue is that you don't have enough bass from the subs then put it next to a wall or in a corner and you'll get as much bass as you would adding a second or third sub. If you are playing a small venue or a really boomy room move it away from the walls. You need to know you have options about sub placement. The plus about corner placement if lots of bass to play with. It isn't all plus though. Placing a sub centre stage is going to give your audience the most even spread of sound and the most natural experience. The trouble with this is that you can only really do this successfully if you are on a raised stage, you can't really put a sub in front of your singer/frontperson. Placing it on one side means people on that side will get too much bass and the people on the other side too little (assuming people in the middle get the balance just right). On the plus side sub placement is less critical than what you do with the tops because of the omnidirectional radiation of lw frequencies from speakers. In a smaller venue with a narrow stage it's going to be convenient to put the sub under one of the tops. That might be next to a wall or not. If the room is small you'll have plenty of volume to play with and on a narrow sate no-one is too far from the sub so they will all hear enough bass.

 

The other problem you mentioned is bass feedback with a sub. You might not get feedback at most venues. If you do get it at the sound check then look at the placement of the sub, can you move it away from the drums? If not will moving it away from the wall reduce the bass reaching the drums? If not can you remove the offending frequencies, perhaps by using an HPF in the mixer. Maybe the drums are sitting in a bass trap and moving them a couple of feet will help.

 

If all this sounds problematic then it shouldn't be, once you've got used to your new system you'll set up and have no problems. If you decided to buy a couple of bigger PA speakers to handle the drums you might have the same problems.

[warwickhunt]

6 minutes ago, Phil Starr said:

That wasn't really the question I was answering. I thought you were saying you have two lovely 10" speakers already and would it be enough to add a single 12" sub for a four piece band with bass and drums through the PA? Or put another way should you buy a sub or do you have to buy two bigger PA speakers? I think the sub would do it for small and medium venues. You might need a bigger sub, two 12" subs or a very good 12" one though if you play bigger venues. Speaker size alone is only one  factor.

 

If you decide to go for the sub I'm absolutely not telling you to set up the same way at every venue. I actually don't think there is a concensus about this. There's no way I'd personally walk into every room and plonk the sub down in the corner or against the back wall next to the kit. The placement depends upon the venue. I'm really saying that whatever you do will have to be a compromise. What is true is that placing the sub on the floor gives you reinforcement, placing it next to a wall a bit more and in the corner most of all. That much isn't about concensus, it's about physics. If your problem at a particular venue is that you don't have enough bass from the subs then put it next to a wall or in a corner and you'll get as much bass as you would adding a second or third sub. If you are playing a small venue or a really boomy room move it away from the walls. You need to know you have options about sub placement. The plus about corner placement if lots of bass to play with. It isn't all plus though. Placing a sub centre stage is going to give your audience the most even spread of sound and the most natural experience. The trouble with this is that you can only really do this successfully if you are on a raised stage, you can't really put a sub in front of your singer/frontperson. Placing it on one side means people on that side will get too much bass and the people on the other side too little (assuming people in the middle get the balance just right). On the plus side sub placement is less critical than what you do with the tops because of the omnidirectional radiation of lw frequencies from speakers. In a smaller venue with a narrow stage it's going to be convenient to put the sub under one of the tops. That might be next to a wall or not. If the room is small you'll have plenty of volume to play with and on a narrow sate no-one is too far from the sub so they will all hear enough bass.

 

The other problem you mentioned is bass feedback with a sub. You might not get feedback at most venues. If you do get it at the sound check then look at the placement of the sub, can you move it away from the drums? If not will moving it away from the wall reduce the bass reaching the drums? If not can you remove the offending frequencies, perhaps by using an HPF in the mixer. Maybe the drums are sitting in a bass trap and moving them a couple of feet will help.

 

If all this sounds problematic then it shouldn't be, once you've got used to your new system you'll set up and have no problems. If you decided to buy a couple of bigger PA speakers to handle the drums you might have the same problems.

 

That's cool, I'm not poking a stick and expecting a 'correct' answer.   

 

Everything you've said is about in line with what I'd do as/when we get a sub to add to the QSC K10s.  We are looking at a good 12" as opposed to an OK 15" (RCF QSC... maybe FBT) but constrained by the physical size and weight as ultimately someone has to load / unload it at home (bodies to help at a gig).

 

I've read enough around subs to get the gist when adding them to an existing system but the overarching info seems to revolve around placing subs at/near rear walls or rear corners, which is just not going to cut it in ANY scenario that I'm likely to encounter.  The only options are really; A). centre of front edge of a stage/performance area, B). under a mid/top speaker or C). at a side wall (to take advantage of a boundary)... but the side wall is looking less and less like a viable option so it is A or B.    I just have to ensure the distance to a wall isn't of a distance (iirc approx 7-8ft) which is going to cause a dip in a particular frequency that would rob us of the benefit of the sub.  

 

The joys of live sound.  

 

 

[okusman]

As above i use 2 QSC K10s and single RCF 12 sub.

Its always enough for pubs and clubs. 
We still use backline for bass and drums.

The separation is the key for me. The K10s working from 80 Htz upwards takes a load of dynamic energy (probably wrong term) away and they sound ‘attractive’ to my ear. Loud, but not taxing.

All the usual space restrictions and apply, so the sub is under one of the K10s. I set the mix, it doesn’t honestly change much from gig to gig and the set the Sub attenuator to suit the room.

it works for me. In the same way I adjust the sub 150hz levels on my bass guitar amp, to suit the room. 
It works for me.

Edited June 10 by okusman

[northstreet]

Ok probably a very silly question. If we use a small (say 12" sub), is there any reason why it couldn't go under the bass cab? Probably ok in terms of placement ie not under a PA speaker, towards the back of the stage (so usually near a wall) and it's not taking up additional space. Or am I missing something obvious?

[SamIAm]

Surely a big problem is getting a sub in through the door ...

 

Sam x

[Bill Fitzmaurice]

1 hour ago, northstreet said:

Ok probably a very silly question. If we use a small (say 12" sub), is there any reason why it couldn't go under the bass cab? Probably ok in terms of placement ie not under a PA speaker, towards the back of the stage (so usually near a wall) and it's not taking up additional space. Or am I missing something obvious?

It will be distracting. Remember than your bass cab drives the stage, the PA drives the room, so to do that the sub would have to be considerably louder than your bass cab. That's OK when it's few meters off to the side, but not right behind you. As for a 12" sub, there are some loaded with premium drivers that are up to the task, but by and large you're better off with a 15 or 18. The very term 'compact subwoofer' is an oxymoron.

[Al Krow]

9 hours ago, Bill Fitzmaurice said:

It will be distracting. Remember than your bass cab drives the stage, the PA drives the room, so to do that the sub would have to be considerably louder than your bass cab. That's OK when it's few meters off to the side, but not right behind you. As for a 12" sub, there are some loaded with premium drivers that are up to the task, but by and large you're better off with a 15 or 18. The very term 'compact subwoofer' is an oxymoron.

 

Finally someone making sense on speaker cone sizes. So they do matter and make a difference. Hallelujah.

[Bill Fitzmaurice]

In and of themselves cone sizes don't make a difference in low frequency output, that's determined by the cone displacement, Thiele/Small parameter Vd. There are twelves that have displacement equal to or better than some fifteens or even some eighteens. But as I noted those are premium twelves, which are only found in premium priced subs. They also require a lot of power to make use of that Vd, which also means higher cost. In the price ranges that most bands can afford, especially those who play pub gigs, fifteens and eighteens will have higher Vd than twelves. They also have larger cabinets, which also contributes to lower response and higher low frequency output. So as is always the case you can't consider just one factor, in this case the cone size. You have to consider all of the factors which when combined give the final result.

[Al Krow]

6 hours ago, Bill Fitzmaurice said:

In and of themselves cone sizes don't make a difference in low frequency output, that's determined by the cone displacement, Thiele/Small parameter Vd. There are twelves that have displacement equal to or better than some fifteens or even some eighteens. But as I noted those are premium twelves, which are only found in premium priced subs. They also require a lot of power to make use of that Vd, which also means higher cost. In the price ranges that most bands can afford, especially those who play pub gigs, fifteens and eighteens will have higher Vd than twelves. They also have larger cabinets, which also contributes to lower response and higher low frequency output. So as is always the case you can't consider just one factor, in this case the cone size. You have to consider all of the factors which when combined give the final result.

 

Sure, and I agree with all of that, Bill. But would a 2 x 10" speaker set up ever make sense for a sub vs a 1 x 15"?

[Downunderwonder]

Depends on your tens and the cabinet. Bill used to offer a 210 option on a  folded horn that would beat the hell out of most 15 regular subs. Also twice the size.

 

A compact 12 sub could add a little thump to a vocal PA.

 

If deployed under the bass cabinet you risk having bass coming out of the bass cabinet out of phase with the PA bass signal which could get ugly for the bass cabinet.

 

It would take quite a bit of wiring and processing to make the best of it.

[Bill Fitzmaurice]

2 hours ago, Al Krow said:

 

Sure, and I agree with all of that, Bill. But would a 2 x 10" speaker set up ever make sense for a sub vs a 1 x 15"?

It depends on the drivers. You can find 2x10 that has as much Vd as 1x15 with equivalent frequency response. The primary reason against that is said two tens would cost more than said fifteen. With electric bass cabs the 2x10 would have the advantage of wider dispersion provided they were vertically aligned. With subs dispersion isn't a concern, they all have 360 degree dispersion.

[Al Krow]

2 hours ago, Bill Fitzmaurice said:

It depends on the drivers. You can find 2x10 that has as much Vd as 1x15 with equivalent frequency response. The primary reason against that is said two tens would cost more than said fifteen. With electric bass cabs the 2x10 would have the advantage of wider dispersion provided they were vertically aligned. With subs dispersion isn't a concern, they all have 360 degree dispersion.

 

Thanks Bill. So I think you're saying lower cost and lack of need of wider dispersion makes the 15" the obvious choice over 2 x 10" for a sub?

 

Would you expect the size / weight of the two set ups to differ for same power output, other things being equal?

Edited June 16 by Al Krow

[Bill Fitzmaurice]

That's correct. The cabs would probably be about the same size. The only reason for the 210 would be if a very small frontal area was desired. In that case the two drivers could be mounted push-pull, with one on the front and one on the back, or if you prefer one on either side. The name push-pull is a misnomer, as it infers that one cone is moving out while the other is moving in, which isn't the case, as they'd cancel each other out. But someone applied the name at some point and it stuck.

[tauzero]

Is there any reason that subs weigh a ton? Is a genuinely lightweight sub possible?

[Bill Fitzmaurice]

The ones I design don't weigh a ton, because I employ well braced 12mm plywood construction. Commercial cabs tend to use minimally braced, if braced at all, 18mm or heavier material. That's because bracing is a labor intensive process, which adds to cost.

[Al Krow]

6 hours ago, Bill Fitzmaurice said:

The ones I design don't weigh a ton, because I employ well braced 12mm plywood construction. Commercial cabs tend to use minimally braced, if braced at all, 18mm or heavier material. That's because bracing is a labor intensive process, which adds to cost.

 

What's the weight of your subs, Bill? Feels like there's a gap in the market / interesting commercial opportunity for a high quality relatively lightweight sub, certainly over here in the UK? In the same way that Alex Claber made a big name with his Barefaced cabs.

Bass Direct in Warwick could be an ideal UK distributor if this sounds interesting, as they regularly import from the USA.

 

Edited June 17 by Al Krow

[warwickhunt]

1 hour ago, Al Krow said:

 

What's the weight of your subs, Bill? Feels like there's a gap in the market / interesting commercial opportunity for a high quality relatively lightweight sub, certainly over here in the UK? In the same way that Alex Claber made a big name with his Barefaced cabs.

Bass Direct in Warwick could be an ideal UK distributor if this sounds interesting, as they regularly import from the USA.

 

 

Bill designs cabs and sells those designs, it would need someone in the UK to do the building... and distribution. 

[Al Krow]

1 hour ago, warwickhunt said:

 

Bill designs cabs and sells those designs, it would need someone in the UK to do the building... and distribution. 

 

@Phil Starr @Chienmortbb gents, any takers?! 😊

[Bill Fitzmaurice]

There is one already, though room for more. https://billfitzmaurice.info/Builders.html

 

[jrixn1]

2 hours ago, Al Krow said:

 

Feels like there's a gap in the market / interesting commercial opportunity for a high quality relatively lightweight sub, certainly over here in the UK? In the same way that Alex Claber made a big name with his Barefaced cabs.

 

They made a 24kg 18" sub: https://web.archive.org/web/20180204074646/https://barefacedbass.com/product-range/LF1400-Subwoofer.htm
It was discontinued, as was the FR800 top.

[Phil Starr]

I was going to say this but then thought 'that looks like a can of worms'

 

there is absolutely no reason that you couldn't make a lightweight Barefaced style sub, the forces are slightly greater with the amount of air shifted but with a limited frequency range resonances easier to deal with if anything. As Bill has pointed out it is just a matter of bracing appropriately. Magnets need to be bigger on subs and big ceramic magnets weigh a lot but Neo is available at a cost. Make the magnet big enough and you can cut down on the need for a big cab too, again at a cost.

 

For a pub band the amount of bass you 'need' is actually fairly modest, it's all do-able as some of the stick systems show

 

[Downunderwonder]

Bill's subs are folded horns. Think brass tuba but made from plywood and one dimensional expansion instead of two.

 

Like the brass tuba a vast amount of low frequency is generated from a relatively small engine compared to what the engine can do into free air.

 

The driver is inside a spring chamber so it deliberately resonates but in a controlled manner in the passband.

 

Woe if you try to make a frequency that is too low. It behaves the same as a regular ported sub would with the same driver. Uncontrolled flapping but not very audible back around multiple horn folds so no warning.

 

[Bill Fitzmaurice]

3 hours ago, Downunderwonder said:

Bill's subs are folded horns.

Most, but not all. The Simplexx subs are ported boxes, but still employ well braced 12mm construction.

Quote

Woe if you try to make a frequency that is too low. It behaves the same as a regular ported sub would with the same driver. Uncontrolled flapping but not very audible back around multiple horn folds so no warning.

That's the scenario if precautions aren't taken, so we do, using DSP to high pass and limit the signal from the amp.