soundian Posted December 18, 2003 Report Share Posted December 18, 2003 Originally posted by GraemeC:Shit.....I was just away to say that.....G... What, all of it? Quote Link to comment Share on other sites More sharing options...
Guest lime 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. im finding this all a bit unnecessarily condescending,there wasnt really much need for that, all you needed to say was, 300w is different from 300 w rms , is watts even measured in rms?? its not somethign iv ever come across to be honest. 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 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 You have some bloody nerve claiming Ian is condescending....!! Quote Link to comment Share on other sites More sharing options...
Tav Posted December 18, 2003 Report Share Posted December 18, 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. Cheers Rob, that was the equation I was thinking of using...just wanting to confirm I was thinking right. 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:i dont really understand this statement, rms just divides the peaks by root 2, im probably out of my leauge And I was explaining what rms was. In a slightly condescending manner but I found your next statement condescending so I couldn't resist giving you a taste of your own medicine. Am I doing your physics homework for you? Quote Link to comment Share on other sites More sharing options...
Guest lime Posted December 18, 2003 Report Share Posted December 18, 2003 Originally posted by soundian:And I was explaining what rms was. In a slightly condescending manner but I found your next statement condescending so I couldn't resist giving you a taste of your own medicine. Am I doing your physics homework for you? i know what rms is, if you could do my physics "homework", youd probably have a much larger pay cheque than you do. Quote Link to comment Share on other sites More sharing options...
Guest lime Posted December 18, 2003 Report Share Posted December 18, 2003 Originally posted by GraemeC:You have some bloody nerve claiming Ian is condescending....!! nothing in your quoted statement was condescending, ian said he was being picky, but if your being picky "resistance" is wrong. end. Quote Link to comment Share on other sites More sharing options...
GraemeC Posted December 18, 2003 Report Share Posted December 18, 2003 well heres another equation for you......Lime = arrogant prick. 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:i know what rms is, if you could do my physics "homework", youd probably have a much larger pay cheque than you do. Now that's definitely condescending. On second thoughts, no it's not. How can you be condescending from a position you haven't reached yet. Quote Link to comment Share on other sites More sharing options...
Guest lime Posted December 18, 2003 Report Share Posted December 18, 2003 marry me? Quote Link to comment Share on other sites More sharing options...
Guest lime Posted December 18, 2003 Report Share Posted December 18, 2003 Originally posted by soundian:Now that's definitely condescending. On second thoughts, no it's not. How can you be condescending from a position you haven't reached yet. blah blah blah. Quote Link to comment Share on other sites More sharing options...
j.turgenev Posted December 18, 2003 Report Share Posted December 18, 2003 havent you all got any better to do with your lives for fuck sake? 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 j.turgenev:havent you all got any better to do with your lives for fuck sake? Yes thanks......and you? Quote Link to comment Share on other sites More sharing options...
Guest lime Posted December 18, 2003 Report Share Posted December 18, 2003 yes, what about you? Quote Link to comment Share on other sites More sharing options...
Guest Hairy Scary Mark Posted December 21, 2003 Report Share Posted December 21, 2003 impedance mis-matches shouldnt be a big problem especially concidering i think that is a solid state amp which has few parts that are likely to be damaged.It really dosent matter what the speaker cabinet is rated at within reason alough getting one rated around the same as the head is advisable. just get whatever cabinet sounds good with your head.If you get a battered second hand cabinet replacing the speaker drivers would be advisable. Quote Link to comment Share on other sites More sharing options...
Guest lime Posted December 21, 2003 Report Share Posted December 21, 2003 impedance mis match results in an inefficient power transfer ratio.it really shouldnt be a problem though, heads have different outputs or switches to changed the output impedance of the amp. Quote Link to comment Share on other sites More sharing options...
soundian Posted December 22, 2003 Report Share Posted December 22, 2003 Originally posted by Hairy Scary Mark:impedance mis-matches shouldnt be a big problem especially concidering i think that is a solid state amp which has few parts that are likely to be damaged.It really dosent matter what the speaker cabinet is rated at within reason alough getting one rated around the same as the head is advisable. just get whatever cabinet sounds good with your head.If you get a battered second hand cabinet replacing the speaker drivers would be advisable. Try sticking a 300W 8 ohm rated amp through a 300W 4 ohm cab. Quote Link to comment Share on other sites More sharing options...
Guest lime Posted December 22, 2003 Report Share Posted December 22, 2003 on closer thought, in addition to an inefficient power transfer ratio, an impedance mismatch would result in part of the output signal being reflected back into your amp.now this is bad for a number of reason, i havnt experimented with it and dont know exactly, but im assuming it will damage your amp, unless it's designed to take reflections. Quote Link to comment Share on other sites More sharing options...
Guest RomanChrome Posted December 24, 2003 Report Share Posted December 24, 2003 thank you all for your help. I have a pretty good picture of what I'm going to be getting! Quote Link to comment Share on other sites More sharing options...
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