Placement of "full range" subs!

[Jenny_Innie]

i'm thinking of getting a couple of those Barefaced FR800 powered PA speakers to use as "sort of subs" for our PA.

I wonder what y'all think of where I should place them.

We have a Mackie PA. We use two of the DLM12 powered speakers on poles for FOH vocals and another two as foldback monitors. Sometimes only for vocals, sometimes we also put the kick drum and an overhead drum mic through there too. Use the Dl1608 digital desk with them.

Works just fine, but has its limitations as, if you put bass and guitar through the FOH too, you start to lose headroom for the vocals - you have to push things and feedback can creep in.

We were going to get a couple of subs until I started to hear good things about these FR800 speakers. A band I know used a couple for a gig and they impressed.

We wouldn't be using these as "subs" in the truest sense, as they are full range and are cable of more than just the low notes I gather - but they will add some sub-like stuff I suspect.

The world and his wife seems to put subs up front with the FOH tops - which I have been reading isn't the greatest idea. I see some "experts" saying that you should put them at the back.

We would be putting them at the back and putting mainly the vocals out of the FOH tops and then the bass, guitar, kick and drum overhead mic out of the FR800s at the back. When I say "at the back" the pub and club "stages" we play are usually not more than a few yards in depth. There are six aux outs from the desk which will allow us to run, in effect, four main outs - the two usual ones to the FOH tops and two more to the FR800 devices.

Doing it this way would even give us the opportunity of going DI and not having a bass or even guitar cab on stage (power trio format).

Will this work - and would we have to worry about any sort of feedback from the drum mics and the FR800 placement at the back?

(PS: I'm not the greatest sound engineer - so go easy on me).

Edited October 6, 2015 by Jenny_Innie

[Dad3353]

The concept has been successfully tried in the past ...

[url="http://imgur.com/T38ziLD"][/url]

... on a somewhat larger scale. It's sound enough, if you've a good control over the levels and frequencies going into the rear cabs. I'd assume that, with the aux sends from the console, you can associate a graphic eq..? This would allow 'ringing out' the cabs to reduce any unwanted Larsen. As long as you're not looking to get concrete-breaking sound pressure from such a back-line, and limit the vocals going to it, I'd say it's an excellent set-up. Maybe a good idea to try it out with a couple of dummy runs before taking any irreversible decisions, and a competent sound engi would be useful, at least at first for getting the basic settings right. It's certainly not the easiest of options, though, as the tuning can change quite a lot between venues. It has a great advantage in that it limits considerably the ultimate decibel level; no bad thing. This type of set-up comes into the category of 'When it is good, it is very, very good; when it is bad, it is rotten'.
Hope this helps.

[colgraff]

I THINK this will work but am by no means an expert. I once depped with a band for a couple of gigs and they didn't use amps at all but had a PA arrangement that is more or less what you describe. The sound was lovely and clear on stage, too.

[chevy-stu]

I used to use a HK Lucas 2000 PA for a few years for pub/club gigs/wedding etc.. and the drummer was always whinging he couldn't hear the kick drum, so for a while used to put the powered 18" sub at the back next to him, and the 12" tops at the front as usual.
It worked well, needed to heavily gate the kick drum to stop feedback, but the sub needed to be a certain volume to work for a decent low end balance out front level, which was then too overpowering on stage, so we went back to having it upfront with the tops. Vocal low end feed back was never an issue but the sub only worked below about 120hz, and the mic had low pass 100z filters so guessing this cured that.

[Lw.]

Have you talked this through with the guitarist? I don't know many guitarists that would be happy being DI'd and from my perspective I wouldn't be particularly happy only getting monitoring from the PA when the guitars have their own on-stage amps for monitoring.

I suppose it depends on your amps but I've always preferred the sound of mic'd up bass through PA to DI'd bass through PA.

Plus bass-stacks look cool [i]and[/i] give you something to rest your drink on :-)

[Dad3353]

[quote name='Lw.' timestamp='1444149902' post='2880693']...something to rest your drink on :-)
[/quote]

Not in [i]our [/i]band, they don't..!

[ironside1966]

From what I gather about the Barefaced FR800,s can replace a full Mackie rig so if that is true, and I have no reason to doubt it, my advice would be to keep things simple and just use the FR800 out front. just use the Mackie's for monitors. That way there is less to go wrong, less to understand and it should work out fine.
While it is true that putting a bass cab near wall in corners can reinforce the bass frequencies there are far more good reasons and advantages to keeping them out front. I could explain but it would get boring very quickly.

[ubit]

[quote name='ironside1966' timestamp='1444153634' post='2880723']
From what I gather about the Barefaced FR800,s can replace a full Mackie rig so if that is true, and I have no reason to doubt it, my advice would be to keep things simple and just use the FR800 out front. just use the Mackie's for monitors. That way there is less to go wrong, less to understand and it should work out fine.
While it is true that putting a bass cab near wall in corners can reinforce the bass frequencies there are far more good reasons and advantages to keeping them out front. I could explain but it would get boring very quickly.
[/quote]


I concur!

[Jenny_Innie]

[quote name='ironside1966' timestamp='1444153634' post='2880723']
....... While it is true that putting a bass cab near wall in corners can reinforce the bass frequencies there are far more good reasons and advantages to keeping them out front. I could explain but it would get boring very quickly.......
[/quote]

No, it's alright. I don't know this stuff - so if you can be bothered, please do spill the beans!

[ironside1966]

· More prone to feed back.
· Timing and phase issues.
· less control , you can control what comes out of a speaker with EQ but it's harder to control what's bouncing off a wall
· Little or no separation of out front and stage sound.

[Guest bassman7755]

[quote name='ironside1966' timestamp='1444153634' post='2880723']
From what I gather about the Barefaced FR800,s can replace a full Mackie rig so if that is true, and I have no reason to doubt it, my advice would be to keep things simple and just use the FR800 out front. just use the Mackie's for monitors. That way there is less to go wrong, less to understand and it should work out fine.
[/quote]

Thats definitely worth a try. If you do end up needing both the makies and the FRs then Id put the FRs at the front, as a full range cab at the back can cause feedback problems with mics. Yes it would be more efficient to put them at the back (ideally both in one corner) but with so much power on tap I doubt you would need that extra efficiency.

[ironside1966]

Phase - take the drum kit for example, you have the live kit sound, the sound from speaker at the back and the sound picked up from the vocal mic's, all coming from different distances so they arrive at your ear at different times. a positive wave meets a negative wave you get phase cancelation.

[JPJ]

Personally, I wouldn't want any of the FoH component coming from behind the band for the reasons set out above i.e. mic spill / feedback etc. Like most, we are 'forced' to run our subs under the tops as the tops are pole mounted in the bins. Even though they are split left and right, I still run the bins in mono and only the tops in stereo. We use a Behringer X-Air XR18, and I have a pseudo crossover set up with a low cut on the main L/R and a high cut on an aux bus at the same frequency.
If I had my choice and space/transport wasn't a factor then I would have the tops on stands and the two bins side-by-side in the centre of the stage. I get to run our rig this way in one venue that has wall mounts for your tops and I think it just sounds more 'together' like this and its easier to get that 'chest thumping' bass drum without drowning out the vocals.

[Dad3353]

If I've read this correctly, the rear cabs won't be carrying much (if any...) of the vocals, and would be in effect being used as replacement back-line for the 'normal' instrument rigs. In this sense, I don't see Larsen as being a major issue, any more than using a 'normal' bass rig. A bass drum won't feed back either, if the levels are kept within reason, and a notch should deal with the overheads, which could also join the vocals in the tops. If we're talking sound reinforcement for the drums, rather than stadium-filling, I can imagine a fair few advantages (no bass/guitar rigs to hump about, a clear stage and a clear sound for all...). There are pro's and con's with every set-up; this has its share, of course. It's nevertheless entirely 'do-able'; just quite different from the 'normal' set-up. The limiting factor, to me, would be the decibel level. This would not be suitable for 'thunderdome' hammering. When done sensibly, though, the results are impressive. The quality of the rear units would be a factor; I'm assuming that the cabs chosen are pretty well vice-free, with smooth characteristics throughout their range. Delicate at first, perhaps, but worth trying out, I'd say. I'd not commit to such a system without 'real-life' trials, though. Maybe Alex will chip in with some counsel..?

[Bill Fitzmaurice]

Subs in the back, or off to the side but still close to the back wall, is what you want. But only subs, running no higher than 100Hz, not full range cabs.

[mrtcat]

However many subs you use, keep them together unless you have enough space to get them a good 60ft apart. As said above, subs at the back against the wall always and tops at the front.

[ironside1966]

I get the impression they will be used has fill range cabs for Bass. Kick and Drum o\heads.
I personally don't see the point in putting the subs at the back any way unless your system is lacking in the bass department, the sub rumble would get in the way of a decent on stage sound. worked with PA s along time, never done or seen it done that way with a band or anything louder than a Duo.

[Bill Fitzmaurice]

[quote name='ironside1966' timestamp='1444164850' post='2880888']
I personally don't see the point in putting the subs at the back
[/quote]The reasons for not placing subs out front is the resulting cancellation notch from Allison Effect, and the loss of boundary loading. It's true that the vast majority of users don't wall load their subs, and they split them left/right under the mains. Those are the two most often seen errors in subwoofer placement, by users who don't know what Allison Effect, boundary loading and the power alley are. I wouldn't put them on stage, I'd put them to one side or the other. As for the rumble, since the output of subs is omni-directional it won't matter much to the band if the subs are in front of or behind them. That's also why off to one side or the other will work equally as well as directly behind.

[ironside1966]

[quote name='Bill Fitzmaurice' timestamp='1444170300' post='2880929']
The reasons for not placing subs out front is the resulting cancellation notch from Allison Effect, and the loss of boundary loading. It's true that the vast majority of users don't wall load their subs, and they split them left/right under the mains. Those are the two most often seen errors in subwoofer placement, by users who don't know what Allison Effect, boundary loading and the power alley are. I wouldn't put them on stage, I'd put them to one side or the other. As for the rumble, since the output of subs is omni-directional it won't matter much to the band if the subs are in front of or behind them. That's also why off to one side or the other will work equally as well as directly behind.
[/quote]

I get the reason and understand the logic, most engineers understand about boundary loading. I just don't see the point if you have a big enough system.

I would not call not having subs at the back a error after all most people don't work that way no including the big boys.

A lot of subs, are much quieter from behind. I have been out of full time engineering a long time but I still get called for occasional job, the last one was with a DbAudio rig I think it was the C4 system but I could be wrong. There was very little sound on stage coming from the 8 boxers a side even though it was belting out front.

[Bill Fitzmaurice]

The point is that the average club band doesn't have a big enough system. They need to get the most possible out of the least amount of gear. That very much takes cardioid sub arrays and freestanding subs off the table.

[Dad3353]

[quote name='Bill Fitzmaurice' timestamp='1444183867' post='2880966']...That very much takes cardioid sub arrays and freestanding subs off the table.
[/quote]

There'd be more space if they took the tables away.

[Phil Starr]

[quote]
I'm thinking of getting a couple of those Barefaced FR800 powered PA speakers to use as "sort of subs" for our PA.[/quote]

I think this works out at well over £2000, for that you have a range of options. I don't doubt that these are great but you ought to look at other speakers. The FR800 is just a PA speaker though I'm sure it is probably a very good one. If Barefaced is what you want then you could use the LF800 as a "sort of sub" . In the end though the Barefaced are just good PA speakers and there are other high end alternatives. If you did buy them then using them in place of the Mackies would be the best way to use them as someone else has suggested


[quote]
if you put bass and guitar through the FOH you start to lose headroom for the vocals - you have to push things and feedback can creep in.

We wouldn't be using these as "subs" in the truest sense, as they are full range and are cable of more than just the low notes I gather - but they will add some sub-like stuff I suspect.[/quote]

The reason subs give you more headroom is that you are splitting the signal and this has two effects. One is that with say, 40% of the power going to the subs and 60% to the tops both have an easier time of it. The second is that with no need to make any treble you can use a speaker designed only for deep bass. Without the deep bass the excursion of the tops is reduced and with it distortion. The point is that it only works if you stop bass going to the tops and the treble going to the subs.

[quote]
We would be putting them at the back and putting mainly the vocals out of the FOH tops and then the bass, guitar, kick and drum overhead mic out of the FR800s at the back. When I say "at the back" the pub and club "stages" we play are usually not more than a few yards in depth. There are six aux outs from the desk which will allow us to run, in effect, four main outs - the two usual ones to the FOH tops and two more to the FR800 devices.

Doing it this way would even give us the opportunity of going DI and not having a bass or even guitar cab on stage (power trio format).[/quote]

This is where it gets confusing. You are basically using the FR800's for bass and drums, this means the main thing you will have changed is that you will have more drum sounds on stage. Is this what you want to achieve? It will mean a messier vocal sound because the vocal mic will pick up any sound that reaches it, you'll have a lot of drums coming through the vocal mic. If you do persuade the guitarist to use a DI system then that creates some additional problem.

I think you need to make a decision. Are you trying to sort out the PA overload problem so you can put the drums through the PA successfully, are you trying to get a better bass stack or are you aiming to replace the backline with stage monitors? Each one will have a different solution giving you three different purchases you might make. I've tried putting drums through the bass stack by the way, it's horrible; you lose a lot of what you hear of the bass and the sound you hear is dominated by drums, you'll hear less of the vox and guitar and with the drums coming from your stack instead of to one side you lose information.



[quote]I wonder what y'all think of where I should place them.

The world and his wife seems to put subs up front with the FOH tops - which I have been reading isn't the greatest idea. I see some "experts" saying that you should put them at the back.

Will this work - and would we have to worry about any sort of feedback from the drum mics and the FR800 placement at the back?[/quote]




You [b]will [/b]increase feedback problems. Amplifying drums and having them coming from the back line means at least a 3dB increase in the on stage sound level and guitar and vox will have to turn up too to re-balance the on stage sound levels so. Probably you'll end up with an extra 6dB on stage. Apart from the long term damage to your hearing ( this is 4x the power damaging your ears) I doubt if you have 6dB of headroom before feedback in the average pub space. The battle is to keep as much sound as possible off stage, not to add to it.

You could easily spend half your money on a couple of 'proper' subs and the other half on a new bass stack rather than £2000+ on what you are suggesting and this would sound better. Alternatively you could simply replace the Mackies with the FR800's as has been suggested.

Edited October 7, 2015 by Phil Starr

[Alec]

Again, if you're considering dropping that kind of money, you're in danger of regretting what you get!

If you're happy with your tops, then add conventional subs. Small pubs/clubs? Try adding just a single sub, which may well be ample. You don't need stereo subs - the only reason you need 2 (or more) subs is for additional level.

Important in small venues, and without large transport, is size & weight. Having a sub under a top loses you no floor space - in fact can even be more compact than a speaker stand.

In a small venue, I might have no more than the kick micd up and through the PA - good mic choice & careful EQ can work wonders on getting the best out of this. The rest of the kit may well be doing more than enough by itself.

You could consider getting rid of backline, but most people *really* struggle with this. Honestly, don't bother.

Don't confuse "full range" speakers with what a sub can achieve. I've never met a 15" cab that can hold a candle to a decent sub plus 10"/12" top.

[Guest bassman7755]

[quote name='Alec' timestamp='1444212306' post='2881097']
Don't confuse "full range" speakers with what a sub can achieve. I've never met a 15" cab that can hold a candle to a decent sub plus 10"/12" top.
[/quote]

Not much around in terms of lightweight (lightweight being < 15kg by my standards) subs though as I found out when sourcing subs for my last bands PA. I ended up using 2 barefaced compacts as subs with pretty decent (if not spectacular) results. I would expect the PF800 to out perform anything including dedicated subs in its size/weight range.

[Jenny_Innie]

We've had a bit of a dry run for this. We're a power trio, guitar/vocals, bass/vocals, drums. Other Jenny, our drummer, is a fantastic jazz trained player. Powerful at times and nicely subtle at others. But we've had comments from some audiences that they can't hear her. So, we put an SM57 inside the bass drum and hung XY condensers over the kit - and we put it all through the two FOH Mackies. Better, but it messed with the vocals a bit.

So, next time out, we did the same, but put the kick (and my bass) through my Barefaced 2x10 and 1x15 stack and sent the overheads in stereo with the vocals through the FOH. Bingo. We listened back to the recording from a Zoom Q3HD out front and it was much better than previously. To do that, we had to DI my bass and then take an aux out with the bass and pipe it in to the rear of my TC RH750 head. We've since experimented with putting a bit of the overheads through the rear too, to good effect.

One of our mates was out from with the iPad wireless mixer (very cool those) and was able to adjust everything ...... other than the guitar.

Good thing is that we get to hear something close to what the audience hears.

So, rather than use kit that's not designed for that (i.e. my bass head and stack) we figured that we can get a couple of the FR800 units which are supposed to be used in such ways.

Kat (our geetarist) figures she might consider using her HD500 straight into the desk (and into the FR800s) if we do this. At just over 120 lbs, she struggles with her Deville 2x12.

So that's where I'm coming from with this. Seems to make sense, but extra advice helps.