Guest RomanChrome Posted December 15, 2003 Report Share Posted December 15, 2003 I just got a new Behringer amp and wondered what would be a good sized stack to be used so that I get the most potential from amp and stack. I'm thinking 350 or 400 Watt stack but am I wrong? Quote Link to comment Share on other sites More sharing options...
chris h Posted December 15, 2003 Report Share Posted December 15, 2003 Originally posted by RomanChrome:I just got a new Behringer amp and wondered what would be a good sized stack to be used so that I get the most potential from amp and stack. I'm thinking 350 or 400 Watt stack but am I wrong? I don't think stacks (by which i think you mean speaker cabinets, as you already have an amp?) are measured in terms of wattage. the amp has a wattage, the cabinet will be measured in terms of size and number of speakers, e.g. 4 x 12. crikey. I think a guy called craig might be along in a moment to clarify the situation. Quote Link to comment Share on other sites More sharing options...
GraemeC Posted December 15, 2003 Report Share Posted December 15, 2003 Originally posted by RomanChrome:I just got a new Behringer amp and wondered what would be a good sized stack to be used so that I get the most potential from amp and stack. I'm thinking 350 or 400 Watt stack but am I wrong? Its all down to the output wattage of the amp.....There is no point in trying to drive 400 watts of speakers with a 100 watt amp.It also depends on what sound you are looking for, some people like to cover the whole tonal spectrum combining 10" and 15" speakers sometimes with HF horns thrown in for good measure, or you could go for an all 10" setup or 15's or even 12's which are less fashionable these days but sound great.G... Quote Link to comment Share on other sites More sharing options...
soundian Posted December 15, 2003 Report Share Posted December 15, 2003 Sorry I'm not Craig. Will I do anyway. Cabs are rated in watts but most people forget the other important factor: resistance. A cab with a 300W 4 ohm output will deliver less than 300W into an 8 ohm cab. And if you want to get really picky (and I would advise this, especially for bass) is the output rms or peak. If the output on the amp is rms, you need 30% more power handling in the cab to handle peaks. Therefore a 300W rms 4 ohm output would require a 400W 4 ohm cab. Quote Link to comment Share on other sites More sharing options...
craig deadenstereo Posted December 15, 2003 Report Share Posted December 15, 2003 I'm assuming it's a ULTRABASS BX3000T as that seems to be the only head they make. That puts 300 Watts into 4 Ohm according to the manufacturer's specs. So get a cab with the same specs as soundian said.This thread should really be in the Musician's Corner forum.Craig Quote Link to comment Share on other sites More sharing options...
GraemeC Posted December 15, 2003 Report Share Posted December 15, 2003 Originally posted by soundian:Sorry I'm not Craig. Will I do anyway. Cabs are rated in watts but most people forget the other important factor: resistance. A cab with a 300W 4 ohm output will deliver less than 300W into an 8 ohm cab. And if you want to get really picky (and I would advise this, especially for bass) is the output rms or peak. If the output on the amp is rms, you need 30% more power handling in the cab to handle peaks. Therefore a 300W rms 4 ohm output would require a 400W 4 ohm cab. Eh ian....I think you meant "an amp" with 300w output....And I have always worked with a 50% saftey margin (with valve amps) cos rms figures aint always very accurate.G... Quote Link to comment Share on other sites More sharing options...
soundian Posted December 15, 2003 Report Share Posted December 15, 2003 Originally posted by GraemeC:Eh ian....I think you meant "an amp" with 300w output....And I have always worked with a 50% saftey margin (with valve amps) cos rms figures aint always very accurate.G... Whoops, well spotted G. I don't think I mentioned it but that would be the minimum. Allowing for the possibility of clipped waveforms and the current trend for bass distorion 50% would be a figure I'd be happier with myself in a professional situation. Rms figure don't take into account the extra power you can get from clipping it. Quote Link to comment Share on other sites More sharing options...
Guest RomanChrome Posted December 15, 2003 Report Share Posted December 15, 2003 Yeah it is the BX3000T. So a 400 watt 4 ohm bass cabinet would suffice? Quote Link to comment Share on other sites More sharing options...
Spoonie Posted December 15, 2003 Report Share Posted December 15, 2003 get a 10 watt 1ohm cab. this would be silly, but you might somehow be able tomake it go on fire which can only be a good thing!only jesting, i'd follow ian and G, they know what they're on about and i'm an idiot!spoonie X Quote Link to comment Share on other sites More sharing options...
Guest RomanChrome Posted December 15, 2003 Report Share Posted December 15, 2003 I would do but I find it hard to know what they are talking about with their, very much more, knowledge on instuments and accessories. Quote Link to comment Share on other sites More sharing options...
soundian Posted December 15, 2003 Report Share Posted December 15, 2003 Originally posted by RomanChrome:Yeah it is the BX3000T. So a 400 watt 4 ohm bass cabinet would suffice? I think that would be fine. I doubt you'll ever need to use it full whack. Unless you fancy the sound engineer stabbing you with a rusty micstand. Quote Link to comment Share on other sites More sharing options...
Spoonie Posted December 15, 2003 Report Share Posted December 15, 2003 they do lay it on pretty heavy, only because they know so much but they're both easy to talk to and they'll guide you through whatever it is you need. try PMing them and see how you get on. also, never ask me for any advice on electrical things! i have absolutely no idea about amps, i just turn up and plug in to whatever hole's available. it's a technique which has served me well in all areas of my life so far!spoonie X Quote Link to comment Share on other sites More sharing options...
GraemeC Posted December 15, 2003 Report Share Posted December 15, 2003 Originally posted by Spoonie:they do lay it on pretty heavy, only because they know so much but they're both easy to talk to and they'll guide you through whatever it is you need. try PMing them and see how you get on. also, never ask me for any advice on electrical things! i have absolutely no idea about amps, i just turn up and plug in to whatever hole's available. it's a technique which has served me well in all areas of my life so far!spoonie X Spoonie....you rascal!!400w 4ohm 4x10cab would do the trick...nice tight sound with good bottom end (oooherrr)Or same but 1x15 if you like your sound a bit more rich and bassy.Or if you have plenty of cash and a van a 1x15 + 2x10 setup would be really nice remembering to make sure the ohms match the amp.G... Quote Link to comment Share on other sites More sharing options...
Spoonie Posted December 15, 2003 Report Share Posted December 15, 2003 and there we have our answer! poetic sir, poetic!spoonie X Quote Link to comment Share on other sites More sharing options...
Tav Posted December 15, 2003 Report Share Posted December 15, 2003 So if your putting out 300W @ 4Ohm then you want both cabs to be 4Ohm aswell? In otherwords you don't have to worry about adding values? Quote Link to comment Share on other sites More sharing options...
GraemeC Posted December 15, 2003 Report Share Posted December 15, 2003 Originally posted by Tav:So if your putting out 300W @ 4Ohm then you want both cabs to be 4Ohm as well? In otherwords you don't have to worry about adding values? well you actually increase the Resistance and, I'm not sure what the equation is but, as rule of thumb if you have say...two marshall 16ohm cabs you would set your marshall amp at 8ohms....On the other hand trannie amps are quite happy to run at anything between 2ohms - 16ohms with no adjustment from the user, but as Ian pointed out they will have their sweet spot where they run most efficiently, probably about 4 ohms so two 8 ohm cabinets are the way to go.....Is that about right Ian?G... Quote Link to comment Share on other sites More sharing options...
Frosty Jack Posted December 15, 2003 Report Share Posted December 15, 2003 Originally posted by GraemeC:two marshall 16ohm cabs you would set your marshall amp at 8ohms.... this should of course read -"two marshall 16 ohm cabs you would set your marshall amp at 8 ohms...."pesky smilies...*suddenly feels out of his depth*Um.. yeah...I like quite light sticks... Quote Link to comment Share on other sites More sharing options...
Rob Karloff Posted December 16, 2003 Report Share Posted December 16, 2003 The Maths :1/Rt = 1/R1 + 1/R21/Rt = 1/8 + 1/81/Rt = 2/81/Rt = 1/4 (simplified from above)By cross multiplication, 4 = Rt.If you're wiring in serial, then you simply add up all the resistivities together to get the total ohmage. Quote Link to comment Share on other sites More sharing options...
soundian Posted December 16, 2003 Report Share Posted December 16, 2003 Originally posted by Rob Karloff:The Maths :1/Rt = 1/R1 + 1/R21/Rt = 1/8 + 1/81/Rt = 2/81/Rt = 1/4 (simplified from above)By cross multiplication, 4 = Rt.If you're wiring in serial, then you simply add up all the resistivities together to get the total ohmage. Jeez, that even gave me a headache and I know what it means. Quote Link to comment Share on other sites More sharing options...
Rob Karloff Posted December 16, 2003 Report Share Posted December 16, 2003 Originally posted by soundian:Jeez, that even gave me a headache and I know what it means.Sure that's not the JD....? Quote Link to comment Share on other sites More sharing options...
Guest lime Posted December 17, 2003 Report Share Posted December 17, 2003 Originally posted by soundian:Sorry I'm not Craig. Will I do anyway. Cabs are rated in watts but most people forget the other important factor: resistance. A cab with a 300W 4 ohm output will deliver less than 300W into an 8 ohm cab. And if you want to get really picky (and I would advise this, especially for bass) is the output rms or peak. If the output on the amp is rms, you need 30% more power handling in the cab to handle peaks. Therefore a 300W rms 4 ohm output would require a 400W 4 ohm cab. impedence, actually." If the output on the amp is rms, you need 30% more power handling in the cab to handle peaks."i dont really understand this statement, rms just divides the peaks by root 2, im probably out of my leauge Quote Link to comment Share on other sites More sharing options...
Guest lime Posted December 17, 2003 Report Share Posted December 17, 2003 Originally posted by soundian:Jeez, that even gave me a headache and I know what it means.anyone whos done standard grade physics knows what it means. Quote Link to comment Share on other sites More sharing options...
soundian Posted December 18, 2003 Report Share Posted December 18, 2003 Originally posted by lime:impedence, actually." If the output on the amp is rms, you need 30% more power handling in the cab to handle peaks."i dont really understand this statement, rms just divides the peaks by root 2, im probably out of my leauge IMPEDANCE actually! Amplifiers have a finite gain limit, when you try to amplify above that limit the top of the waveform gets chopped off (clipped). Your peak/clip lights on equipment will come on when you get close to this limit as a warning. RMS is based on sinusoidal waves (the type you get out of your mains socket, normally produced by a rotating coil in a magnetic field). The average output of a sinusoidal wave is 1/ root 2. (basic trig and calculus) Any 'o' grade physics student could tell you that. The 'peaks' I'm talking about are when you overload the pre-amp to such a level that it 'clips'(cutting off the top end of the signal). These can deliver significantly more power than un-clipped waves. Hence the safety factor. To put it simply, if an amp is rated 300W peak, that's your max. power and a 300 cab should handle it. 300W rms on the other hand is a convenient shorthand for average and a 300W cab wouldn't be able to handle the peaks. Capisce. Quote Link to comment Share on other sites More sharing options...
soundian Posted December 18, 2003 Report Share Posted December 18, 2003 Originally posted by lime:anyone whos done standard grade physics knows what it means. Not everyone has though, and some haven't done it in a while. I'm sure I wouldn't remember it if I didn't use it on a regular basis. Quote Link to comment Share on other sites More sharing options...
GraemeC Posted December 18, 2003 Report Share Posted December 18, 2003 Originally posted by soundian:IMPEDANCE actually! Amplifiers have a finite gain limit, when you try to amplify above that limit the top of the waveform gets chopped off (clipped). Your peak/clip lights on equipment will come on when you get close to this limit as a warning. RMS is based on sinusoidal waves (the type you get out of your mains socket, normally produced by a rotating coil in a magnetic field). The average output of a sinusoidal wave is 1/ root 2. (basic trig and calculus) Any 'o' grade physics student could tell you that. The 'peaks' I'm talking about are when you overload the pre-amp to such a level that it 'clips'(cutting off the top end of the signal). These can deliver significantly more power than un-clipped waves. Hence the safety factor. To put it simply, if an amp is rated 300W peak, that's your max. power and a 300 cab should handle it. 300W rms on the other hand is a convenient shorthand for average and a 300W cab wouldn't be able to handle the peaks. Capisce. Shit.....I was just away to say that.....G... Quote Link to comment Share on other sites More sharing options...
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