Seeking advice: interesting charity sound installation

[mark76uk]

Mackies will be much much better than Behringer.

Yes, I wasn't disputing that for a moment! :) It's just those woofers won't do the whole job.

 

If you don't want to use the sub

I'd rather not use a sub. The idea is to avoid complexity, so that any member of staff with a little training can potentially wheel it in and play a CD. Lots of labels, warnings and instructions stuck over everything. Hence, one speakon to plug the trolley in. Sure there will be little complexities, but at least it won't involve lifting and cabling like a sub.

 

then why not go for four SRM450, the price will be almost exactly the same.(Studiospares it works out £7 cheeper)

http://www.studiospares.com/pd_261810_MACK...kers%20pair.htm

They would be nice, but not at £2000 including VAT. Plus trolley, cabling and sockets, a mixer and CDN22, plus the Ultradrive. Runs quite close to £3000 inc VAT.

 

Management have agreed I can spend about £3300 including any VAT (and including lighting!)

 

:) Mark

[mark76uk]

Hello again,

 

Ooops, sorry. I meant to post within original thread.

:) And as if by magic... :)

 

So you guys are saying it's best to replace the long distance speaker cables with balanced line instead (either to amps close by the speakers, or powered speakers.) I'm trying to figure it out in my head and would be grateful for any hints!

 

My main questions at this point are:

 

If I have four speakers around the room, and four sockets around the room where the sound-desk-trolley may be plugged-in to control it all:

 

How do I join all the balanced line signal cables (8 cores for each speaker or amplifier channel) which end up at the amp or powered speaker?

 

Will this joining affect the 'balanced'ness of the cable runs?

 

Can I still use 8pin Speakon connectors between the sound-desk-trolley and the wall?

 

Thanks again!!

/Mark

 

Added possible cabling layout:

http://www.hinwickhall.ac.uk/external/soundandlightforum/ampsnearspeaker.gif

[Chris Hinds]

I figured I could just put the L and R of the stereo into two mono channels. This way, I could pan either side of the stereo to any side of any subgroup.

You *could* do this, but I can forsee doing this resulting in a LOT of nasty routing errors with sound coming from odd places, double bussing happening and other such events, like those two channels ending up reassigned to L+R - result a huge feedback loop that takes out the drivers and everyone's ears in the vicinity.

 

If I put the amps near the ceiling near the speakers, how do I join all the wires coming from the four sound-trolley-plug-in sockets?

The lines from the wall run to a patch bay, where you patch a socket to the amp in the ceiling. Or you could just join them all together, like having an open Y-Split, that's not ideal but it works fine.

I'm not willing to surrender the multiple trolley-plug-in-sockets idea, as it's the solution we need. I think I'd rather suffer the consequences of over-long amp to speaker cables.

If you feel that is the easier option then go with it, you'll lose stuff but you probably won't notice it.

 

I'm not sure I can justify these to myself. In a way, with those small woofers, it's taking us back down the Behringer Truth route (yes, I considered getting a sub for those too!) I may consider getting cheaper powered speakers, such as The Box from Thomann £196.65

It's nothing like the same if you don't mind my saying. One is a speaker designed to be listened to at close range of under two metres, while the other is designed to project sound to a small audience. The speakers and mics make the most impact on how good your system is, so that's where I'd spend my money. However as your budget just took a nose dive from £2700 to £1500 the Mackies are untenable anyway.

 

Does anyone know if they do Feedback Killing and Delay simultaneously? Or only one function at a time?

I would expect them to to both. But don't quote me, I haven't used them.

 

I thought of getting a sub, but it involves extra cables. I'd rather have the bass from the main speakers, up on the wall.

That's kinda expecting them to be jack of all trades master of none. Would you ask one of your servers to handle email, file, print and user authentication while at the same time letting the secretary type letters on it logged on locally? Same thing with a speaker. You're asking it to do the low weight work (the HF and Midrange) and also the real heavyweight shoving of the extended LF, something is going to give when working hard.

 

Is this any better? :) Here's my alternate wiring idea. Balanced line level signals come from each of the four sound-trolley-input-sockets and are fed to two amplifiers, on shelves above each of the 'front' speakers. I guess this is better because it has long runs of line level cable, not speaker cable?

Yeah it's better, because you'll lose less, see comment above on the two options of joining the signal to the amps. You could most likely get away with just the Y-Split idea to be honest. But it's going to be a lot more work. However it's going to be expensive and difficult getting the signals into the system. If the 4 location thing is really non negotiable then I guess I'd put the amps on the trolley and use a speakon. You would need a fancy multipin connector capable of handling 12 pins of connection for the 4 balanced lines, more work. Then the other end you need to get somehow 4 mic lines into one XLR - which is not easy to do.

 

I note other posters have suggested a DSP type system, unfortunately the Behringer DCX is apparently now out of production, and therefore the next cheapest option that can do what you wish will eat over half your budget making DSP unviable.

 

The other though that's occurred to me is could you consider equipment from known 2nd hand suppliers e.g. Pro Audio dealer ex demo gear - that could save you some.

 

Regards

 

Chris

[MarkPAman]

They would be nice, but not at £2000 including VAT. Plus trolley, cabling and sockets, a mixer and CDN22, plus the Ultradrive. Runs quite close to £3000 inc VAT.

 

 

:D Mark

 

Try Boxy Music £1082 + shipping. That's got to give you another £800 for lights! :D Desk & Ultradrive may be cheaper there too, I didn't look.

[mark76uk]

Try Boxy Music £1082 + shipping. That's got to give you another £800 for lights! :D Desk & Ultradrive may be cheaper there too, I didn't look.

Thanks, but it seems more expensive to me £2164 inc VAT + Delivery. You realise I need four? :D

 

/Mark

[MarkPAman]

Try Boxy Music £1082 + shipping. That's got to give you another £800 for lights! :D Desk & Ultradrive may be cheaper there too, I didn't look.

Thanks, but it seems more expensive to me £2164 inc VAT + Delivery. You realise I need four? :D

 

/Mark

Price is per pair (at least their quoted RRP is)

[mark76uk]

Price is per pair (at least their quoted RRP is)

 

I don't see that. It says 'two way', but that means woofer and tweater, doesn't it? Some places sell them seperately.

 

One of the cheapest SRM450s I found are £463 each inc VAT

 

:D

[MarkPAman]

OK it does not say it a pair but the list price they give is £832.32 which is the list price of a pair. I assume then that where it says Our Price £541.01 must also be for a pair. This would be about the same discount as their other Mackie products.

[mark76uk]

OK it does not say it a pair but the list price they give is £832.32 which is the list price of a pair. I assume then that where it says Our Price £541.01 must also be for a pair. This would be about the same discount as their other Mackie products.

Unfortunately not.... :D

 

Your Question : Mackie SRM450

 

Hello,

 

Is £541.01 the price for one or two speakers? I'd like to buy 4.

 

The page says 'Our Reference Number : 19959'

 

Thank you,

Mark

 

 

Our Answer :

 

Dear Mark Major,

 

We received your Question. Thank You for shopping at boxymusic.com !

 

The price is per Unit.

I added a link below so you can place your order.

We invite You to return to the product page to continue shopping :

o Mackie SRM-450

 

Thank You again for shopping at boxymusic.com !

[MarkPAman]

<_< Can't argue with that! Sorry for the bad info! :)

[mark76uk]

:) Can't argue with that! Sorry for the bad info!

 

No problem. I'd have been happy if that was the price for two! <_<

/Mark

[mark76uk]

REVISED PLAN, TAKING ADVICE GIVEN BY THIS FORUM

 

Hello good people of the Blue Room forum. :P I went away, researched and thought about your advice regarding our common room sound installation. I've tried to build those suggestions into the new plan. Please take a look if you can find a moment. Thank you. :)

 

http://www.hinwickhall.ac.uk/external/soundandlightforum/revisedsound.gif

Drawing not to scale, as the plan I based it on seems to be wrong (building dates from the 1600s!!)

 

Changes

Mixer

- No more Behringer mixer.

+ Mixer will be a Yamaha MV12/6 (half price!) in a 10U Mixer/Rack Case.

+ Each of the four subgroup faders (balanced subgroup outputs) will control the level of one speaker, allowing any combination of the four speakers to be used easily.

 

Speakers

- No more Peavey speakers.

+ Yamaha AX15s, 200w/400w/800w@8ohms, 1w@1m=98dB / 126dB max., 60°H/40°V. This narrower dispersion cone will reduce the problem with reflections? I plan to situate them at a height of 2.3metres, and the swivel brackets will tilt them up to 30degrees downward.

+ From reading the web, I've found that Yamaha speakers seem to be well thought of in recent years.

 

Getting sound to the four speakers

- Amplifiers no longer on sound trolley. No more 30metre runs of speaker cable

+ The two stereo amplifiers will be on shelf above one of the speakers. Longest speaker cable run is now 18metres.

+ Amps will be Thomann TA1400 2x450W/8Ohm. Giving us 95dBSPL at 4m with 17dB headroom, according to the Crown Amplifier Calculator.

+ Four balanced lines (one per speaker) will run from the mixer, through a 10m multicore (Cordial CMG8), into any of the four multipin trolley-sockets situated around the room (any socket can be chosen, depending on what orientation the event is to be staged in.)

+ The 4 balanced lines from each of the four multipin trolley-sockets, wired up the wall and across the ceiling, will be cabled using Cordial CMS4 to a panel below the amps. This will have four 3-Pole-4-Throw rotary switches, which the sound operator uses to patch the balanced lines from the appropriate trolley socket to the amplifiers. Obviously, this is done prior to turning on the amps (BIG RED SIGN!)

 

http://www.hinwickhall.ac.uk/external/soundandlightforum/3pole4throw.gif

There will be four of these rotary switches, one per speaker channel.

All the switches should be changed to the number of the trolley-output-socket in use.

 

+ Cordial CLS240 will be used between the amps and speakers (longest run: 18m, shortest run: 11m.)

 

Delay

Purchase of Behringer Sharks, or similar, planned for Phase II (in a year or so.) Before then, will have to live with articulation problems, or only use 2 speakers at a time.

 

Queries

? Assuming half-decent soldering, do you think the cable will remain 'balanced' from mixer to amp?

? Any ideas to replace the rotary switches, or are these fine? Trying to avoid patch cables, as it gives people the chance to get things *seriously* wrong.

? There are a lot of fluorescent lights in the ceiling. Should I expect trouble with those speaker and balanced line cables running among them?

? Any idea what sort of multipin connector I should use for the four trolley sockets? It needs to be tough, and there don't seem to be many around for 12 core signal level jobs.

 

Thanks for any input,

Mark :)

[James]

Queries

? Assuming half-decent soldering, do you think the cable will remain 'balanced' from mixer to amp?

? Any ideas to replace the rotary switches, or are these fine? Trying to avoid patch cables, as it gives people the chance to get things *seriously* wrong.

? There are a lot of fluorescent lights in the ceiling. Should I expect trouble with those speaker and balanced line cables running among them?

? Any idea what sort of multipin connector I should use for the four trolley sockets? It needs to be tough, and there don't seem to be many around for 12 core signal level jobs.

 

Thanks for any input,

Mark :P

 

? Yes

? Don't bother with the switches, If there is only one trolley have all the wall outlets paralleled together

? No, If you are realy worried use starquad.

? 12 balanced cores? On a budget? Use 39 pin socapex. Small, solid and standard connector - not too expensive either.

 

James

[mark76uk]

Thanks for getting back to me, James :P

 

Don't bother with the switches, If there is only one trolley have all the wall outlets paralleled together

Yes, there's only one trolley. Just 'choc-block' four balanced lines (one from each of the four sockets) together to an XLR input for each channel of the amp?

 

No, If you are realy worried use starquad.

Thanks, I'll look into the cost.

 

? 12 balanced cores? On a budget? Use 39 pin socapex. Small, solid and standard connector - not too expensive either.

Seems like about £30 a connector or socket (average.) I was looking at DSUB, but not sure it's a conventional or otherwise good method.

 

/Mark :)

[Chris Hinds]

? Assuming half-decent soldering, do you think the cable will remain 'balanced' from mixer to amp?

? Any ideas to replace the rotary switches, or are these fine? Trying to avoid patch cables, as it gives people the chance to get things *seriously* wrong.

? There are a lot of fluorescent lights in the ceiling. Should I expect trouble with those speaker and balanced line cables running among them?

? Any idea what sort of multipin connector I should use for the four trolley sockets? It needs to be tough, and there don't seem to be many around for 12 core signal level jobs.

 

Hi Mark,

 

Your revised equipment choices look good to me - the amps I can't speak for but I wasn't disappointed in the Yamaha AX speakers I heard, for the price they are very acceptable. The Mixer likewise is a solid unit - the one I know of in an install has been there several years and keeps ticking. A fair number of our lecture theatres on campus have one of these somewhere in the chain.

 

You are also quite correct that the narrower coverage of the cabs will reduce your likely reflections off walls etc.

 

In answer to your questions,

 

1. Yes

2. The switch will eventually fail or get dirty contacts, as James says if you can be certain nobody else will randomly plug something in by mistake then you could parallel all the sockets. Me? I'd be happier with some isolation as in the switch *just in case*

3. I've never had issues with fluorescent light fittings inducing noise.

4. Could use a Socapex connector as James suggests, these 13 Pole CEEP Connectors will likely be cheaper though. I haven't looked up what a soca connector costs though.

 

Edit: Just realised the 19 pin CEEP is a Soca! You could also use the EDAC connectors below which are cheaper but less hardy.

 

Overall I'm a lot happier with this revised layout than either of the initial designs.

 

Regards

 

Chris