Outdoor sound system (not for movies)

[Mike Blakesley]

What is the difference between QSC RMX1450A and RMX1450? The specs seem to be about the same, at least power-wise. I'm leaning toward a couple of RMX1450 on the Reverb site that were "church owned." They're being sold by a dealer called ChurchGear and are both under $300. That seems pretty good since the asking price for new ones is about $900.

[Marcel Birgelen]

The RMX "a" series are just an updated design, slightly more efficient (according to marketing) and probably a few internal components swapped out for more recent designs, but both virtually identical spec-wise. Since the "a" series are newer, expect them to be less available in second-hand markets and if so, to be somewhat more expensive.

[Mike Blakesley]

OK, I have pulled the trigger on (2) QSC RXM1450 amps, now I just need to figure out a mixer. The audio player in our fireworks firing system has a variety of outputs -- a pair of XLR, a 1/4", and a pair of RCA outs.

I've looked at the Behringer mixer that has been discussed in this thread, but that may be more than we need as far as features -- simplicity would be great.

Since the amps have the XLR inputs it would be fine to have a mixer with XLR outs, but we don't need a ton of channels. Ideas? (I've probably learned as much from this thread as any other on Film-Tech.)

[Tony Bandiera Jr]

Mike, for the price and reliability, you can't beat that mixer I recommended. Sure it has more features that you need NOW, (just as it does in all of my motorsport P.A. systems) but when, not if, they want to do a one-off event with multiple mics and a music track, with the ZMX you're all set. Plus it is rack mounted, and for around $200 you can get a 5RU road case to house (and more importantly, protect) BOTH amps and the mixer. The other benefit? You pre-wire the mixer outs to the amps, and get a "wall mount" XLR panel mounted to the backside rails of the road case for your inputs. I will get pics of my portable rack when I get a break from the racetrack work to post on this thread.

That said, yes you can get some "desktop" mixers at around the same price point, and of course most will have XLR ins/outs. Behringer makes a few, so does Mackey, Peavey (their mixers are not too bad actually, their amps suck like an Electrolux though.), Yamaha, etc. But now you have the mixer "floating loose" and have to connect it to the amps every time. just makes more work (albeit not a huge amount) with every setup.

The choice is all yours, you're the one operating it, so do what you are most comfortable with.

Excellent decision on the amps, they will serve you well and are easily repairable if anything crops up.

[Mike Blakesley]

when, not if, they want to do a one-off event with multiple mics and a music track

What's funny about that is, just today I was contacted by somebody from the Chamber of Commerce wanting to use our sound system to provide "oldies" music for a car show that's coming up.

I do like the idea of having the mixer and the amps in a cabinet, it would make things easier for sure, plus add a level of protection.

Are these the kind of connectors needed to connect from mixer to amps and audio source to mixer?

xlr-euro.jpg

[Marcel Birgelen]

The picture you listed is indeed a balanced Euroblock/Phoenix to XLR lead. If your player also has XLR out, you can use them both for the connection from your player to the mixer and from your mixer to the amp. That way, the entire system will be balanced too, which will not only improve the audio quality, it will also avoid any possible nasty ground loop.

As for the Behringer mixer: It will be hard to find an equally low priced device with the same functionality in 19" rack format. If you're not going to be DJ-ing all night, a rack form factor is optimal, as you can put all the stuff you need in a 19" flightcase, with some wheels under it.

[Tony Bandiera Jr]

What's funny about that is, just today I was contacted by somebody from the Chamber of Commerce wanting to use our sound system to provide "oldies" music for a car show that's coming up.

I do like the idea of having the mixer and the amps in a cabinet, it would make things easier for sure, plus add a level of protection.

Are these the kind of connectors needed to connect from mixer to amps and audio source to mixer?

xlr-euro.jpg

The Europlug shown appears to be the 1mm spacing, which is too big for the mixer. The mixer comes with a full set of connectors, you you would only need to swap the connectors for that cable to work. Plus they have it wired in the wrong order on the euro end, the have minus, plus, shield and the mixer is wired plus, minus, shield.

If you aren't handy with a soldering iron, I can assemble the panel I spoke of for you since you are not terribly far from me here in Idaho. Please be patient on any responses to this thread here (and the pics I mentioned in my last post), as I am super busy with the mx track the next week or so (plus submitting a bid for a new PA system for the car track right next to the mx track I am working at.) Feel free to PM me so we can chat in detail.

Once you see how I have done my portable setup, it will all make sense.

[Mike Blakesley]

OK, I am convinced, I'm going to pull the trigger on that mixer too. We have till July 6 of 2024 to get it all sorted out.

I'm excited to try the whole thing out when we get all the pieces in place.

[Marcel Birgelen]

The Europlug shown appears to be the 1mm spacing, which is too big for the mixer. The mixer comes with a full set of connectors, you you would only need to swap the connectors for that cable to work. Plus they have it wired in the wrong order on the euro end, the have minus, plus, shield and the mixer is wired plus, minus, shield.

Well, never judge a cable by its on-line photo . But if they got the color coding right on the XLR-side, then yeah, + and - seem to be reversed on the terminal block. Unfortunately, no simple wiring diagram has been given on the specs page...

But the Behringer uses green-color-coded Phoenix/Euro terminals if I'm not mistaken? So, if this thing is a standard green Euro/Phoenix-style connector, it should be standard 3.5mm pitch and it should be compatible. But since the pre-built XLR cable comes with tinned leads, it's sufficiently easy to switch them around or use the pre-populated terminals on the mixer itself. The problem with those euro/phoenix connector devices is that you never can be sure they deliver the device with the plugs in place or not. For new devices it's common to have them populated, but especially with used gear, it's common for them to be gone.

@Mike
I've checked the on-line prices of those pre-built cables and well, it's clear you can save a few bucks by rolling them yourself... Also, if I check my local sources, I can buy two with double the length, with higher wire gauge for the same price with the same Neutrik XLR plug, make sure you're not getting ripped off.

[Mike Blakesley]

The problem with those euro/phoenix connector devices is that you never can be sure they deliver the device with the plugs in place or not. For new devices it's common to have them populated,

These amps will be used, but the mixer is new.

If the amps are going to be in a cabinet with the mixer then the longest wires will be the speaker wires. The only other decision to be made is, whether to put an amp with each pair of speakers (shorter speaker wires, but long XLR cable to each amp) or keep the amps at the home base (short XLRs, but longer speaker wires).

[Frank Cox]

If the amps are out with the speakers then you'll have to run power to each point as well. Which could lead to fun with power surges or someone kicking the cord out of the connector.

[John Eickhof]

Since you are going with low impedance 4-16 ohms, you are better off with a rack set up or road cabinet w/ mixer and amps and power line filters etc,, feeds to the speakers would be 10 or 12 awg monster cable or equiv stranded conductor pairs or four conductor, the safety factor in public is the concern there would be no hazardous voltages running along the ground plus way less chance of picking up transient noises on the lines then on a balanced or unbalanced feed, remember Mike, typical speaker runs like at the Roxy are 100 ft or more and work with no problems and are single conductors and no cross talk between channels. not to mention a heck of a lot easier set up and tear down plus flexibility for other venues! road cases are not expensive any more and are nice to store cordage, mikes, etc, Also, if you put speakers on tripods or scaffold be sure to stake em down! a good gust of wind during the performance can be hazardous! ( i know!)

[Mike Blakesley]

John, I plan to move our "home base" away from where it's located in the picture at the top of this thread. (the Blue dot.) It will move up to the edge of the field toward the "white square" box-looking thing, which is where there are electrical outlets. So we will have very short power leads (15 feet tops). The audio player, amps and mixer will all be right there, fairly close to the top-right speaker. Thus we'll have one short speaker lead the rest will be longer. We won't have any power leads running where anyone can mess them up, and of course we "tie off" all the speaker cables at both ends to keep them from getting knocked out.

Luckily the public's access to this area is via a gate at the opposite end from where the fireworks are, so everyone just sort of naturally stays away from the electronics and the fireworks. Some kids will naturally be running around, we just keep an eye on that area as the crowd is gathering and shoo them back out of there.

[Tony Bandiera Jr]

Well, never judge a cable by its on-line photo . But if they got the color coding right on the XLR-side, then yeah, + and - seem to be reversed on the terminal block. Unfortunately, no simple wiring diagram has been given on the specs page...

But the Behringer uses green-color-coded Phoenix/Euro terminals if I'm not mistaken? So, if this thing is a standard green Euro/Phoenix-style connector, it should be standard 3.5mm pitch and it should be compatible. But since the pre-built XLR cable comes with tinned leads, it's sufficiently easy to switch them around or use the pre-populated terminals on the mixer itself. The problem with those euro/phoenix connector devices is that you never can be sure they deliver the device with the plugs in place or not. For new devices it's common to have them populated, but especially with used gear, it's common for them to be gone.

@Mike
I've checked the on-line prices of those pre-built cables and well, it's clear you can save a few bucks by rolling them yourself... Also, if I check my local sources, I can buy two with double the length, with higher wire gauge for the same price with the same Neutrik XLR plug, make sure you're not getting ripped off.

You are correct that the mixer uses the green Euro connectors, but they are a closer pitch than 3.5mm I think I got my numbers backwards when talking about that cable, that looks to be 3.5mm, I think the mixer is actually 1mm or so. I will be doing the photos pf my portable rack later today and will confirm.

The mixer does come with a full set of those connectors. I would suggest to Mike that he wires from the mixer's euroblocks to the amp's screw terminal inputs, no need to make up an XLR cable for that.

[John Eickhof]

Mike, that sounds like a perfect solution! your speakers appear to be fairly high efficiency so they ought to project well, depending on size. i would recommend they be on tripods and at least 4ft off the ground or on small scaffold or platforms, this will help carry the sound past the first line of people otherwise get it set up and see how she goes! and have fun!!