norty303
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Posts posted by norty303
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Don't get too hung up on damping factor as a spec - once it's above a certain value you can pretty much ignore it, and it also varies with frequency and is often embellished as another spec to sell product.
Any halfway decent amp will have enough for your use. It's only really applicable for bass use and even then, you'd only really need to start looking closely at it if running long cables and low impedances.
I would also seriously discourage running an amp at 2R if possible. Only really good amps (read: expensive) do it well, and it seriously reduces the mean time before failure. Handy as a get out of trouble scenario if an amp goes down on a gig but not recommended for everyday use.
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As for the power I would put money on it that the power reading that you got was including IR as the majority of imported lasers do not have IR filters.
What did you measure it with, as you mentioned elsewhere that you haven't got a meter?
I didn't measure it but the person who bought it did!
See the whole saga here...
http://www.photonlexicon.com/forums/showthread.php?t=8278
I sold it as an 'under 60mW' laser head due to not knowing what it was (due to not having a meter as you correctly point out). Turned out it was doing a lot more.
The other 717 I have was quite a bit brighter than that one (it was a later incarnation of the projector) so I'm guessing over 300mW. This would appear to be borne out by the fact that it is only a little dimmer than my new Laserwave head which was measured at 414mW before shipping to me.
I think the evidence is fairly conclusive, even if only by comparison
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GVG stopped selling lasers I believe due to the problems of meeting the EU regulations and the fact they were a simple importer and didn't really understand the specialities of the product.
Your easiest way of getting a new key is to change the keyswitch, the GVG ones that I had didn't last long anyway before breaking.
As for power, I had 2 of the GVG-717 which were rated at 100mW.
However, the lower powered one of the 2 (the dimmer one) has recently been metered at 240mW so the other is around 300mW (generously overpowered!)
These particular modules are by AiXiZ, not sure where yours may be from.
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Or even better, a Drawmer 2120, but they come up far less regularly
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Basically, any decent speaker cabinet will have a few numbers associated with it:
Power rating/handling: This is normally quoted as RMS or Continuous and is the amount of power the speaker can cope with if fed a 'continous' signal e.g. a sine tone without burning up the voice coil. Sometimes it is quoted as Peak power which is generally 2 times RMS rating. As music is not a continuous sine tone, you should aim for an amp of between RMS and Peak values in power output, as the 'averaged' power present in modern music is about 2/3rds the peak value.
Impedance: The speaker will also have an impedance value (ohms). This is the 'nominal' load it presents to the amplifier, and will usually be 8R or in some cases 4R. If you measure an 8R driver across the terminals you'll actually find they're around 5.5R, but for simplicities sake we deal in nominal values. Also bear in mind that impedance changes with frequency and box tuning but thats an order of magniftude more complex than we should go into here. The impedance is important because it dictates how much power the amp provides at that impedance. Some people talk about running amps 'in 8R mode' or 'in 4R mode'. This is a misnomer as amps don't have modes, they simply have a load attached to them and make power that varies according to the load presented. E.g. an amp may be rated to produce 150w at 8R and 250w at 4R. If you connect a 4R rated speaker then it will receive 250w if run at max. If you connect 2x 8R speaker wired in parallel (which makes them a 4R load combined) then they will share 250w equally between them.
Sensitivity: Normally quoted as spl (sound pressure level) at 1W/1m (1 Watt at 1 metre). Basically its a measure of how much noise the speaker will make when fed with 1 watt and measured at 1 metre. Higher is better for outright SPL. It means that to achieve a given output level it needs less power than a speaker with lower sensitivity. In order to produce 3dB (decibels) more output, you need twice the power input.
Taking 2 examples, one speaker with 90dB at 1w/1m sensitivity and a speaker with 100dB at 1W/1m we can see the following:
Speaker 1
1w = 90
2 = 93
4 = 96
8 = 99
16 = 102
32 = 105
64 = 108
128 = 111
256 = 114
512 = 117
1024 = 120
Speaker 2
1w = 100
2 = 103
4 = 106
8 = 109
16 = 112
32 = 115
64 = 118
128 = 121
256 = 124
512 = 127
1024 = 130
So we can see that speaker 2 surpasses speaker 1 in outright SPL with only 128w input power, that speaker 1 requires over 1000w to achieve (if it can handle the power even!) Even then, at high power an effect called power compression comes into play whereby some of the input power is turned into heat rather than sound resulting in less than 3db gain for each doubling of power. You'll also see that speaker 2 goes on to make significantly more noise!
These might seem like extreme examples, however a good number of 'DJ' grade speakers are still in the 90db at 1W/1m range, whilst some moderately priced pro-audio cabs are getting onto the 100db at 1W/1m range. Not only could you save some money on amps by buying more sensitive speakers but they will likely sound nicer as they will be less stressed.
If you are familiar with a company called Funktion 1, they design speakers to have the greatest sensitivity, whilst not neccessarily having massive power handling (their 2x18" bass bins were only 450w rated drivers which is very low compared with some of the 1200w monsters out there now). However with clever design of horns they make the very best of these light cones.
If you want to know more about audio then try out the forum in my signature, there's a huge wealth of info there, including a newbie section that covers most stuff you're interested in.
I am just trying to get my head around this so if i get an amp that outputs 1000watts would this be good enough?If thats 1000w PER SIDE at 4R then yes. I hate describing amps by their total power output for both channels, it's used by manufacturers to make them seem bigger than they are. A 1000w amp you're talkign about is really only 2x500w, which isn't really that big (but ONE THOUSAND sounds sooo much better doesn't it! :) )
As I said, i'd look for something in the 800w per channel at 4R range. Behringer, C-mark, Thomann T.amp, Tapco, etc all do something around that power. Once you get over 500w per side, the odd hundred watts here or there don't make too much difference. If you can find one, a second hand QSC PLX3402 (2 x 1100w at 4R) or 3002 (2 x 900w at 4R) will do the job perfectly, and only weigh 10kg. £400 - £500 should get you a good one, and it'll retain it's value. The 3402 was more popular therefore easier to find.
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Can anyone advise if i have the correct amp for the correct speakers?
Even assuming that connecting your tops and subs together makes them an 4R load, the amp is grossly underpowered for the job. Assuming that peak is 2x RMS on the speaker ratings, you have 800wrms power handling per side and only (at best) 250w to drive it with. If the internal crossovers preserve the 8R load then you only have 150w driving it. This is why it sounds good when the red lights start showing because it's only just really starting to work the drivers.
You could at the very least go to 500w per side and gain significant increase. Personally I'd go for 800w or more per side (at whatever load it is) but you may not have the money for it - although bigger amps are getting cheaper all the time. Try Thomann for a good deal.
Better still, buy an active crossover and 2 amps (or one big one and run tops off one side and subs off the other in mono until funds permit the second amp) and REALLY notice the difference fully active systems can make to the spl and sound
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A basic way of explaining - the sound source is sending a signal that is distorted / making the amp work harder.
Basic and a little misleading.
It is possible to drive an amp to clip/limit without the mixer clipping/distorting, it comes down to a number of factors, including input sensitivity on the amp and any pieces of kit in between that may be attenuating or boosting the signal. It's all related to proper gain structure.
If you have clip limiters on the amp and they are switched on then the peak light usually indicates them activating. If they are not switched on then the peak lights will indicate clipping. Hard limiting can still damage your speakers. The occassional flash should not present too many problems providing your amp isn't rated more than 2x the RMS rating of your speakers.
However, as with most things 'red = bad' so try to avoid the red lights. Unfortunately most rigs start to sound 'on song' with a few red lights flashing on the amps because they are getting decent power, and the temptation is often to keep going up. Thats when damage happens.
A good way to set up your gain structure is so that when red lights come on on the mixer meter, the amps are just starting to peak/clip. That way you know from looking at the mixer what the amps are doing.
To do this, first turn the amp gains all the way down, then play something through the mixer so that it just starts to hit the red lights on the mixer. Then turn the amp gains up slowly until the peak light starts to flash. Some people like to back them off slightly from this point for a small safety margin. Now you know that red lights on the mixer = red lights on the amp. You can still over drive the amp by cranking the EQ/gains so don't be fooled into thinking this is now safe to abuse. you also now have a situation where meddling hands could turn up the amp (as they're likely not in the full position after doing this)
The 'other' way around this is to run with the amps on full (impossible to turn them up further) and use something like a crossover/EQ/system processor in the middle to control the overall gain going to the amps. The benefits of doing it this way is that you can page lock/lock away the controller/EQ to prevent fiddling and still ensure red lights on the mixer = red lights on the amp.
You might also want to check whether your amp has an input sensitivity switch for the inputs. Many do. You can then run the mixer hotter by reducing the input sensitivity of the amp.
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No, unfortunately I'm not Mr Speakerplans. That accolade belongs to Mr Rog Mogale who runs Void Acoustics and designs all their phenomenal cabs. I'm just the admin over there :)
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Glad to hear they're working for him :)
For bass designs DIY is usually the best option until you get into really top end gear (where you then start to pay for the innovation R&D for having the next level of audio systems). That way you can spend the money on the important bit - the driver - rather than fancy boxes and marketing.
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i've heard jamo are a quite good
Someone was lying to you.
Some of their earlier home stuff was ok, but for PA work it's junk.
£60 is about what you should be paying for a reasonable cheap bass driver (12" or 15"), we're talking Celestion Truvox or some Eminence, or maybe Fane but be careful of some of the studio drivers not have much excursion. I'd say the Truvox present best bang for buck at the moment (they also do some very immpressive compression drivers on the cheap). If you want a 'good' driver, you're going to need to spend £80+ each and even then you can get better but into £120+ territory.
Passive crossovers for a 400w rms rated cab will probably set you back £50-£60 pair. Eminence is a good bet here, and some have protection lamps to protect the HF.
If you fancy a DIY project then most manufacturers have plans on their website for their drivers, or one you can take and modify, or check here www.speakerplans.com and check the forum, but be warned, DIY does not neccessarily make it cheap, it just means you can get better speakers for the money you are spending. Building speakers with crap components is just a waste of time and money as they will never really do the job right. As a rough guide, if you can't afford to spend minimum £140 per cab on components (bass driver, compression driver, horn and crossover) then don't build, go and buy something instead.
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8ohms would be the nominal impedance.
You should measure somewhere between 5 and 6 ohms
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I was told by someone who does Martin board repairs that it's a multilayer PCB and when one of the common faults occur, it takes out some of the internal tracks making it unrepairable.
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It's a problem across the whole Ego line unfortunately. I've got some 03's here as spares donors - unfortunately nothing seems to ever break on them apart from the boards!
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I find active gear an even bigger pain than non-powered gear, especially if you've got subs and tops.
4 set of signal cable, 4 sets of power cable instead of 1 main power line and 4 easy to handle speaker cables (or 2 x 4 core cables)
Powered gear is ok in some situations (DJ monitors) but not for others (floor monitors on a busy stage) imho
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Yeah, sorry Andy, must've missed that post. I think i saw the first one about the bridged 1500 and skipped to the end of the thread.
Agree with Andy, the 4k is a great amp if it does what they claim, and the price is looking great.
Oh, and if you think you might ever want to expand your system, stick with 8R cabs. 4R is fine if you ever only intend to have one speaker per channel on the amp. As soon as you want to pair up, 4R cabs become a problem, especially on bass as very few amps that you will want to spend money on will drive bass at 2R.
The only amps that I know of that will drive bass hard and consistently and reliably are in excess of £1k. You're looking at Crown Macro 5k's, Void Infinite 8's, Lab Gruppen. A QSC RMX4050HD will do it also on a budget.
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You'd be better off spending the little bit extra and getting the EP2500 and running one cab off each side in stereo (~450w per cab). You'll barely notice the difference between 450 and what is in reality around 550-600w from the 1500 (you'll see the 4R bridge specs are at 1khz, not full range)
Bridge mode runs amps harder for a given load and so can reduce the mean time before failure.
Always buy the most powerful amp you can afford, it'll sound better on your speakers as it'll be able to be more dynamic.
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And if you go for one of any reasonable power rating (>80mW) then make sure you understand the implications of operating it and what you may have to do from a H&S and licensing perspective regarding paperwork, risk assessments, etc
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So, if the cabs are empty, what is the 'built in' filter you are referring to?
If its the one on the amp, these are 'usually' a high pass filter to cut out damaging low frequencies that the driver/cab combination is unable to produce. Some do have a low pass filter as well, but its not the norm.
If you are looking to put anything over 300w per cab then it may still be more economical to use an active crossover as you could spend £30 to £40 per cab on a passive filter/crossover network.
If you wanted to be able to pass through to some top cabs and have them filtered too then that would be more expensive again.
A cheap 2/3 way analogue crossover from Behringer is only about £80 and gives you much greater control and sound than with passives.
regarding your 'low budget', can you be a bit more specific? for a 15" bassbin I'd be looking to spend ~£80 per driver. Cheaper drivers than this tend to be limited on both power handling, sensitivity and xmax, 3 things that are vital for good bass performance. I was pricing up replacement 12" drivers for someone the other day after he blew some of Maplin's finest, and the difference in performance between a £50 driver and an £80 driver was phenomenal. If loaded right, Celestions new Truvox drivers can present good value for money.
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I'm not sure i understand you.
Are you saying you already have some bass bins with filters already installed? In which case yes, you can use the filters fitted I suppose, as ong as they have the power handling for your intended use.
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I believe the Eminence designer software is a stripped down version of BassBoxPro, quite a capable application. I'm not sure if it supports the incorporation of other manufacturers drivers but you may be limiting your choices if just going for Eminence.
WinISD is also a free application for calculating reflex and bandpass enclosures.
If you need components then I'd go somewhere like Blue Aran or Pro Audio Parts. I'm not a fan of filters in bass bins but if you want the simplicity then Eminence do a range that will probably fit the bill.
Probably best if you first of all find out what size drivers your cabs take and go from there. Dimensions are fairly fixed but ports should be able to be modified if need be.
If you post back with some sort of idea of budget for drivers/components and the box sizes (and ports) then I might be able to give you a shortlist of drivers that would work best and what might be better with some mods.
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What size are the midrange drivers in the satellites? If they are smaller than 12" then I'd guess you could get away with bullets/slots.
Otherwise I'd say you need a 1" or 1.4" compression driver. The other consideration is how much do you want to spend? A pair of moderate compression drivers with horns is going to set you back about £100, and you may then also require passive crossovers (and an L-pad if the rest of the system is really that unsensitive) depending on how they are set up currently. For either option you're going to have to modify the cab.
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God, I'm gonna get shouted down here I think but simply buying some decent kit would help. From looking at the Cube setups on their website the best they appear to achieve is 90db (which I assume is with 1w@1m - although it does say max in some cases.....) That is unbelievably poor and no wonder you're wringing its neck to be heard.
Good sound (that lasts) usually costs a bit, but soon pays off when you're not replacing components every other gig.
I think there are some threads on here about why the sensitivity of a speaker is often a more important number than it's power handling - I suggest a good read.
It sounds like you also might be simply asking too much of the setup you have.
Question, do you use a mic, and do you suffer from feedback often?
edit: I couldn't find a Cube 350 anywhere but did find that virtually all of their mid/top cabs appear to use dome type tweeters. This is your weak point, and they are not generally used in PA applications. A good bullet or slot tweeter (or even a piezo) is far better but compression drivers are really the order of the day these days.
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I'll correct my previous post about the origins of the LW software, if you read this thread you'll see the various versions that existed (again, cracked Mamba version doesn't instill confidence...)
http://www.photonlexicon.com/forums/showth...orld+showeditor
I expect you've got the version that is HE-Laserscan clone. If you need documentation or help might be worth looking for that software rather than the LW version.
edit: BTW if you have the software, do you also have a DAC? If so, there may be a good chance the one you have is compatible with Mamba Black from Medialas. Might be something worth looking into as this is a well supported piece of software and has a user feedback forum on Photonlexicon, and the developer posts there too.
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Hopefully the laser related forum is Photonlexicon, you won't go far wrong there...
Be sure to read the seller review about Laserworld :wink:
I'm not sure its about being the Skytec of lasers, its about their honesty and dealing with customers.... I also have a review of LW there too....
I'm curious about the midi controlled laser, especially when you consider the cable length limits associated with the communication format... not much good when it's rigged up in the roof!
Have you got a link to the laser in question? The Laserworld site has their products listed, along with pics, perhaps you can locate it there for us? Midi is certainly not a control format I've come across b4 for lasers directly.
I've spoken with the laserworld UK distributors today and they tell me the keyboard plugs straight into the back of the laserOut of interest, who is the UK distributor and are they a specialist laser supplier, or are they a disco equipment supplier? I'm questioning just how much they know about lasers and control systems....
*awaits to be proved wrong*
edit - have just been to the Laserworld UK site and seen the controller you are talking about. IF you read the description it actually says ILDA keyboard. I suspect the reason why it's 'overinflated' in price is because they custom build an ILDA interface into the keyboard. It's not simply a midi controller, and it doesn't plug in with a midi cable, it uses a regular 25 pin DB25 cable, you can see it on the pic on the website.
As a stand alone ILDA controller i presents pretty good value for money, although its not clear what control and patterns it gives. For about the same money (maybe a bit less) you could buy Pangolin Flashback 3 DAC and a copy of LivePro. It's basically what the big guys use to control their laser shows, and Pangolin is without doubt the leader in laser control. But if you've joined Photonlexicon you'll feel the Pango love soon enough.... ;)
Looking For A Couple Of Uv Cannons
in Buying Equipment
Posted
Be careful of using UV cannons in a mobile disco setting where they are close to the audience, perhaps rigged overhead on a truss, etc facing intop peoples faces.
They can be very damaging to the eyes at those sort of ranges, only people don't notice it because of the wavelength of light. If you put a 400w whitelight at the same position you'd soon have people complaining.
You can get good sealed 4ft units from Thomann with reflectors which give surprisingly good coverage (better than my cannons at short range) whilst being much safer and cheaper.
http://www.thomann.de/gb/dts_uv-strahler.htm (inc lamp)
Apologies if you knew this already