bristoldan Posted January 1, 2009 Share Posted January 1, 2009 This might be really stupid but sound isn't really my area. I work at a School and we've recently had some guys in to service equipment and they've said "o you shouldn't really be doing that" and I'm now completly unsure as to the setup the school has been using for the last five years is safe. They've basicaly been running:4x 250W front house flown speakers off a 900W amp4x Mach 250W (yes, I know their not montior speakers) as monitors, off a 500W amp This has been like this for the last five years and they've yet to have any damage or issues. Is it as simple as you should only run two 250W speakers of a 500W amp? or is the wattage figure just showing how loud the speakers can be? Thanks In Advance,Dan Link to comment Share on other sites More sharing options...
Simon Lewis Posted January 1, 2009 Share Posted January 1, 2009 Dan, The only real problem is that the loudspeakers are probably somewhat underpowered (depending upon the exact ratings for your amps). However, if you never run the amplifiers into clipping (i.e. distortion) then there is nothing wrong with your setup. Simon Link to comment Share on other sites More sharing options...
Charlie Jeal Posted January 1, 2009 Share Posted January 1, 2009 Dan, Were they referring to how the gear is configured or the method used to fly your boxes? If so pictures would help greatly Charlie Link to comment Share on other sites More sharing options...
bristoldan Posted January 1, 2009 Author Share Posted January 1, 2009 Dan, Were they referring to how the gear is configured or the method used to fly your boxes? If so pictures would help greatly Charlie Hi Charlie,I think they were actually refering to the speakers they're using for mointors because they're not actually mointor speakers and they're using four off that amp. Cheers,Dan Link to comment Share on other sites More sharing options...
adamharman Posted January 1, 2009 Share Posted January 1, 2009 Could be to do with the impedance of the boxes.Presumably there are 2 running off each channel of a stereo amp? If they're 4 ohm, that would give a 2 ohm load, which maybe the amps aren't designed to do.Most of the mid/top boxes I've come across are 8 ohm, which would be ok to pair up on any decent amp, but it's a possibility.... Link to comment Share on other sites More sharing options...
Gareth Owen Posted January 1, 2009 Share Posted January 1, 2009 What are the exact make and model of the speakers? Are there any data stickers on there? Info something like "RMS Power 500w, Peak Power 1200w, Impedance 8-Ohms"... Are the speakers wired in parallel or series and how many are connected to each amp channel? What are the makes and models of the amplifier? Do they have load ratings printed anywhere on them? Look for something like " 2x250w@4-Ohms"... It is possible that your service guys think the impedance of the speakers is too low for the amplifiers driving them, which could potentially be unsafe. Link to comment Share on other sites More sharing options...
paulears Posted January 1, 2009 Share Posted January 1, 2009 The key word is 'safe'. If the system is abused, something will fail. This doesn't seem to have happened while you've been using it, suggesting that you are doing it right. Fair enough, you are using 'non' monitor speakers, as monitors. So what! The only real difference is that monitor shaped designs let you put them low and point them up. Yours don't. Not really enough to get worried about - if they do what you want. Do these people just happen to have a very nice systems available that they will sell you at a good price? I bet if you ask them to put their concerns in writing it will be interesting reading. Warning bells are ringing - very loudly. If the system is overheating, ready to catch fire, or has live wires hanging out - the it's not safe. Other than that - don't worry. Link to comment Share on other sites More sharing options...
Dmills Posted January 1, 2009 Share Posted January 1, 2009 Warning bells are ringing - very loudly. I would agree, as long as the concerns don't involve the suspension of the boxes, as the number of times you walk in and find boxes flown via their handles or with lag screws into the top of a chipboard box is not funny. The flying is IME the one likely safety as opposed to reliability issue, but if that has been done right and provided nothing is actually electrically dangerous then it would begin to sound like a sales speech. Having the concerns put in writing would indeed be informative. Regards, Dan. Link to comment Share on other sites More sharing options...
bristoldan Posted January 1, 2009 Author Share Posted January 1, 2009 Cheers for your all your help guys. I couldn’t tell you the make and model of the FOH speakers because their flown quite high up with the full scaf tower needed to get to them, in the same way neither could the service guys. When I’m back in next week I can have a look and see what the info is on the mach speakers. The FOH speakers is wired in mono I believe because there’s a ultra curve box which is suppose to do delay for the second lot of speakers. Two centre at the front of the hall on one channel and two on either side of the hall half way on the other. As for monitors its usually that only two speakers should be used per channel but some people within the drama department, that don’t know what they are doing, like to connect all four together on one channel. Guessing this is where the problem can occur? The 900w amp is a PPX (bit of googleing shows this to be 2 x 450W RMS @ 4Ohm http://www.swlighting.co.uk/products/secon...tc-203/2010.htm) The 500w is a Stage Line (cant seem to find this on google as the one we've got is blue =s) This company have been recommending a lot of 'upgrades' for the system so I won’t be surprised if it was for sales. Cheers,Dan Link to comment Share on other sites More sharing options...
Dmills Posted January 2, 2009 Share Posted January 2, 2009 Well, I could potentially see space to suggest legitimate upgrades there, and making such suggestions is a reasonable salesman sort of thing to do, that is not a surprise. If it is just a case of someone noticing that an amp is driving an excessively low impedance (say all the monitors off one channel), then no problem, it might sound bad, it might even eventually take the amp out, but nothing to be too concerned about seeing as it has been like that for a while and seems to work for you, but if the comment was about say speaker rigging then it needs to be taken a deal more seriously. I would just ask the guys what they had spotted and then take a view on what to do about it and if it was worth fixing. Regards, Dan. Link to comment Share on other sites More sharing options...
david.elsbury Posted January 2, 2009 Share Posted January 2, 2009 For reference, you should be aware of two sorts of "consultants". 1) The legitimate consultant, who has no dealerships, or commercial interest in recommending one product over another. These people are unbiased, and will recommend the best product for the job, rather than the product that they think will make them the most money. 2) The "salesperson consultant" who will recommend products based on what they wish to sell the most of... conveniently, these people will be able to spec, sell, and install the gear for you... You want the first kind, ideally...:blink: Link to comment Share on other sites More sharing options...
Dmills Posted January 2, 2009 Share Posted January 2, 2009 You want the first kind, ideally...The way you can tell which sort you are dealing with is that YOU have to PAY the first kind!The second kind buys you lunch. That said, as long as you know what you are doing, the second kind have their uses, the real danger is when the conslutant of the second type manages to buttonhole an administrator! You really, really want to avoid this situation. Regards, Dan. Link to comment Share on other sites More sharing options...
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