d&b D12 amps & speaker multicores

[ghance]

I'd be grateful for any advice from d&b users for D12 amp rack configuration & wiring systems with a view to making cross rentals easier!

 

We currently don't have panels on our amp racks, just a set of tails to NL4, EP5, NL8 & socapex that we cable tie into back of rack depending on job. We've also got a small stock of NL8 fans & boxes we use as a stage monitor satellite breakout system for our passive MAX15.

 

Now we got more D12's the racks tend to live as twins & quads & we need to settle on one system or another.. so if there is a common theme between say SFL, Entec, Dobsons & Dimension then we'd follow the party line.

 

(I know J is all triples, but if we hire in J we get amps with the boxes and those 3-way soca fans!?.. meanwhile we've generally found twins & quads a more more useful stock for our small / medium C/Q/Max stock. But I'm happy to consider any sound argument)

 

PS.. anyone know the current trend with d&b & connectors?.. When I went to Nailsworth to hear V there seemed to be a heavy emphasis on NL8 as the new defacto multi-pin.. I appreciate the rock'n'roll boys will probably stick firmly to soca/EP5 and corporate hoes on NL4, so its a bit academic anyways.

 

cheers all.

[ianl]

Well seeing as no one else has replied.....

 

I use nl4 on the q1 and q7 and a nl8 on the dual d12 racks

 

I guess if I had quad racks they would have 2 nl8

 

I chose this because its what I had loads of from previous rigs

 

I thought I was alone in this as all the c or q I've ever hired in has been on EP and multicores on socapex ( with either 3 or 4 ep to a socapex)

[RobertKendall]

We have ours on EP5 apart from our E0s, multi wise it's soca.. no stupid joiners etc, a lot nicer!

[Mark Payne]

I'd be grateful for any advice from d&b users for D12 amp rack configuration & wiring systems with a view to making cross rentals easier!

 

 

Hi G

 

From and SFL perspective:

Our general D12 racks are Quads. We do have 6 way racks for the J as the J soca makes you think in threes but to be honest I think we are canning the 6way racks.

 

The soca config supports sub/top or active mode breakouts to 4 ep5 or 4 nl4 (we have both). With 18 lines in the soca you can only sense drive on two of the Ep5 channels.

The pin out we use was is a legacy from Entec/Dobson et al. It is based on the old skool C4 configs. Would you like me to post it here?

 

Our amp pannels also carry a second soca config which presents all 8 channels of the quad to an alternative "pins 1 only" breakout. we use this for monitor sends (passive) and big q1 hangs or front and side hangs from single soca lines.

 

Oh and now we are adding the third type to the panel as we are now supporting J from these racks.

Also our panels represent all amp outs on NL4.

I can post pics if anyone is interested.

 

Thinking about it we have invested a massive amount of headspace into these racks!

 

Cheers

 

Mark

[david.elsbury]

I wouldn't mind racks, always interested in seeing good rack pics :)

[ghance]

Hi Mark,

 

Yes please.. be great if you would share the panels & pinout. Pic's always helpful too.

 

 

Currently we use a VDC pinout which seems to be different to SFL/Entec/Dobson.. so looking to re-terminate.

 

Cheers

 

.g

[Mark Payne]

Hi Mark,

 

Yes please.. be great if you would share the panels & pinout. Pic's always helpful too.

 

 

Currently we use a VDC pinout which seems to be different to SFL/Entec/Dobson.. so looking to re-terminate.

 

Cheers

 

.g

 

Yes I think this standard became "the standard" so it would make no point doing anything else.

Jonathan used the VDC standard but sacked it of when we supplied him our SFL racks.

 

I have seen others copy our rack format (kind of flattering) but without doing the distro and IO panel work (cost/time/know-how I guess).

 

The team loaded for FOL today so I think nearly all the racks went (I will check tomorrow).

Thats 120 Q1 and 80 Qsub so when I go looking for soca systems to take pics, I am not sure I am going to find much!

 

I will report back later.

 

M

[Yorkie]

is FOL this one? http://www.facebook.com/photo.php?fbid=389250507773744 :o

[Pete McCrea]

Yes that's FOL.

 

You don't want to forget a patch cable for the far projector delay line. Nearly a 1km round trip from stage to the back of the auditorium. Been there, done that back in April when I was working on if for SFL...

[Stuart91]

Nearly a 1km round trip from stage to the back of the auditorium.

 

Here's the solution...

[Mark Payne]

Dear all:

 

Ok so as promised I have taken a bunch of photos and I present the soca pin outs for the defacto standard used by SFL for d&b systems.

 

You will find all of this here on our facbook pages. I cant post pics here it seems:

 

https://www.facebook.com/sflgroup/photos_albums

SFL Amp Rack Secrets

 

I hope this helps. I have annotated the photos with notes so if you click on them you will see the detail.

 

Feel free to email me mark@sflgroup.co.uk if you ever need help and advice with d&b and L-Acoustics systems configs.

 

Peace

 

Mark

[BlueShift]

I'd like to chime in here and extol the virtues of SFL's Quad rack configuration.

 

I'm a freelancer, and I work with a number of production companies, and several who are d&b houses and I think this is probably the best all round implementation of D12 racking I have seen.

 

First off, clearly if you are using mostly J, then 3 way or 6 way racks (or 27 way, as in the case of a recent tour I did... :)) are the way to go, along with d&b's proprietary 15 core Socas (which use pin 19!! for no reason whatsoever, so you can't even use your standard soca if you wanted to...).

 

However, if you are using any other d&b system (Q, Max, M, V, C, etc...) then racks in multiples of 2 are definitely the way to go. Not to mention that d&b seem to be ditching sense drive (because they appear to be ditching EP5s in favour of NL4's) so you don't need 5 core speaker cables for much anymore...

 

Its also worth mentioning that I have been the System Tech for the last couple of years of FoL events for SFL, so have used these Quad racks extensively, in every configuration...

 

The clever thing with these racks is the fact that you have every possible soca outlet available to you, which gives you lots of options with no reconfiguration of the rack needed. CAN bus is also broken out on XLRs, which makes life much easier.

 

With some clever patching of the racks, you can use multiple soca outlets at once for different tasks. In fact, for this recent FoL, I had a quad rack for which I was using 3 soca outlets simultaneously to feed various different groups of speakers.

[gibbothegreat]

Mark,

 

many thanks for that, and that does indeed look like a really ingenious solution: the investment in time and materials would clearly be repaid many times over in ease of use. The only question I would have is about the mains for the rack in d&b configuration: the company I learnt d&b with reckoned on 9 amps full whack for a flat out D12, so four of them could be a stretch for a single 32A supply. Obviously, you're not going to trip breakers, but one thing we've come to swear by is headroom in the mains, and the audible difference it makes. Do you ever double up for those types of gigs where the amps will get driven hard?

[Mark Payne]

Yes, point well made. I discussed very point yesterday this by email with Gareth.

 

We do figure on 8A per D12 (flat out) hence 32A per quad rack. We have no isuues with this. The distros are actually 63a capable with the option to split them into two electrical halves and dual inject two 32a feeds. This is done more for our LA8 l-acoustics systems (16A per amp) which use the same rack infrastructure. We never do this in the D&b configs but we could. You just remove a powercon link plug on the back of the panel and inject a second 32a feed at this point. The use of the 32a type powercon connector here makes this intrinsically safe.

 

Mains stiffness is I agree very important and if you have a weak AC voltage rail then the D12s are going to compensate by current dragging, now all the bets are off. For me this is more about the specing of generators (outdoor) and the lengths/quality and copper crossections in feeder cables and distros.

 

Mark,

 

many thanks for that, and that does indeed look like a really ingenious solution: the investment in time and materials would clearly be repaid many times over in ease of use. The only question I would have is about the mains for the rack in d&b configuration: the company I learnt d&b with reckoned on 9 amps full whack for a flat out D12, so four of them could be a stretch for a single 32A supply. Obviously, you're not going to trip breakers, but one thing we've come to swear by is headroom in the mains, and the audible difference it makes. Do you ever double up for those types of gigs where the amps will get driven hard?

[BlueShift]

I also know what you mean about the mains speccing Gibbo.

 

First off, you are right about it being close on a 32A inlet. So you do have to watch out. At FoL, the amps spend most of their time near to gain reduction, with both channels driven. I metered the mains in the process of checking a dodgy cable and believe I was seeing around 230v. So in those conditions, we had no mains tripping issues. Next time I use the system I'll see if I can meter current draw on the distro and report back, but I suspect that its lower than you'd think.

 

The other issue though, is that If I was running 3 of these racks full tilt, I'd be feeding it from a 63A/3Ø supply, and thats because these lovely switch-mode class D amps present a pretty complex load and therefore can generate a significant amount of neutral current on a three phase system, so although I'd trust 4 * D12 not to trip a 32A MCB, I wouldn't trust 12 of them not to trip the neutral breaker on a 32A/3Ø supply given the right conditions.

 

Certainly on the last large scale D12 job I did where we had 160 odd amps, this was a big consideration in the speccing of the audio gennie and distribution...