4 Strings Posted April 24, 2012 Share Posted April 24, 2012 I'm making up a pair of Speakon cables for a nice new amp and my nice new(ish) speakers. Its a 900W amp (although I frankly am a little cynical about that). Will there be any difference at all between the two cable sizes? Will the 1.5mm2 be well within its limitations or will I be pushing its limits (whatever that may be)? Cheers Quote Link to comment Share on other sites More sharing options...
LiamPodmore Posted April 24, 2012 Share Posted April 24, 2012 Most cables i see are 2.5mm[sup]2 [/sup]so my best guess would be to go for that, but i'm not really too knowledgeable on that so someone smarter might have a different opnion. Liam Quote Link to comment Share on other sites More sharing options...
obbm Posted April 24, 2012 Share Posted April 24, 2012 4-sq.mm. is optimum. Quote Link to comment Share on other sites More sharing options...
Matt P Posted April 24, 2012 Share Posted April 24, 2012 obbm speaks sense, 4mm would be best for that kind of output, i'm using some 1.5 at the moment for quiet practing but come payday i'll be ordering some of obbm's monster 4mm ones. The manual for my amp actually states 1.5 as the absolute minimum and suggests that 4mm would be best. Matt Quote Link to comment Share on other sites More sharing options...
EdwardHimself Posted April 24, 2012 Share Posted April 24, 2012 [quote name='Matt P' timestamp='1335279180' post='1628504'] obbm speaks sense, 4mm would be best for that kind of output, i'm using some 1.5 at the moment for quiet practing but come payday i'll be ordering some of obbm's monster 4mm ones. The manual for my amp actually states 1.5 as the absolute minimum and suggests that 4mm would be best. Matt [/quote] +1. With an amp really the bigger is the better. Quote Link to comment Share on other sites More sharing options...
4 Strings Posted April 24, 2012 Author Share Posted April 24, 2012 I wondered about bigger the better and I can see that bell wire would be inadequate but is there actually a benefit from 2.5 (or 4 for that matter) over 1.5mm2? For house wiring 1.5mm is used for lighting circuits with a 5A fuse (= 5 x 240 = 1200W) so perhaps for peaky current and accurate transmitting of a signal this is too near the mark for a 900W amp. Quote Link to comment Share on other sites More sharing options...
obbm Posted April 24, 2012 Share Posted April 24, 2012 (edited) [quote name='4 Strings' timestamp='1335286980' post='1628701'] I wondered about bigger the better and I can see that bell wire would be inadequate but is there actually a benefit from 2.5 (or 4 for that matter) over 1.5mm2? For house wiring 1.5mm is used for lighting circuits with a 5A fuse (= 5 x 240 = 1200W) so perhaps for peaky current and accurate transmitting of a signal this is too near the mark for a 900W amp. [/quote] You are dealing with multi-frequency audio not a pure 50Hz sine wave. It's not only volts and current that have to be considered. As for 4-sq.mm. cable, canvas the opinion of those who are using it. Edited April 24, 2012 by obbm Quote Link to comment Share on other sites More sharing options...
neepheid Posted April 24, 2012 Share Posted April 24, 2012 Go for the anaconda, I can't comment on the electrical requirements but it's certainly reassuringly chunky. Quote Link to comment Share on other sites More sharing options...
4 Strings Posted April 25, 2012 Author Share Posted April 25, 2012 (edited) Presumably it doesn't need to be screened cable either. This type of thing any good? http://www.ebay.co.uk/itm/Fisual-S-Flex-Studio-Grade-Speaker-Cable-2-x-4mm-/150561811752?pt=UK_Computing_CablesConnectors_RL&hash=item230e2eed28#ht_1756wt_1031 Edited April 25, 2012 by 4 Strings Quote Link to comment Share on other sites More sharing options...
paul_5 Posted April 25, 2012 Share Posted April 25, 2012 Damnit, I've been using 2.5 out of my 1000W ampeg power amp into my Hartke cab. Now I have cable GAS! somebody tell me this is just 'bad science' and I don't need to upgrade my cable. Please... Quote Link to comment Share on other sites More sharing options...
4 Strings Posted April 25, 2012 Author Share Posted April 25, 2012 Does your bass sound ok? Does the cable stay cool? Do you think 1.5mm would also be fine? Do you rarely, if ever, use all 1000W? If yes to these then your cable is great, you can relax. I'm trying to avoid an embarrassing over specification. Quote Link to comment Share on other sites More sharing options...
paul_5 Posted April 25, 2012 Share Posted April 25, 2012 true dat, but I've got the 'what if' going on in the back of my mind. Cable is supposed to have a 'skin effect' whereby the high frequencies travel on the outside of the conductor, so having a greater diameter would mean (if any of this is even half true) improved top end sparkle and presence. Sounds fine at the moment though. Quote Link to comment Share on other sites More sharing options...
flyfisher Posted April 25, 2012 Share Posted April 25, 2012 I've never heard of the skin effect having any significant effect at audio frequencies, though it's certainly important at radio frequencies. Some background here: http://en.wikipedia.org/wiki/Speaker_wire [i]"Regardless of marketing claims, there is negligible harm done by skin effect in typical inexpensive speaker cables. The increase in resistance for signals at 20,000 Hz is under 3%, in the range of a few milliohms for the common home stereo system; an insignificant and inaudible degree of attenuation.[/i]" Quote Link to comment Share on other sites More sharing options...
Phil Starr Posted April 25, 2012 Share Posted April 25, 2012 Well 900W into 8ohms is just over 10A. Since it is music and not a continuous current the 1.5 cable will handle this easily. If it is a short cable, less than 2m say then the resistance will be negligable and it will be fine, for longer runs use 2.5mm, which will also be fine for short leads as well. Quote Link to comment Share on other sites More sharing options...
obbm Posted April 26, 2012 Share Posted April 26, 2012 What no-one has mentioned is the amplifier's damping factor, i.e. the amps ability to control the loudspeaker motion and produce cleaner and clearer tone at all frequencies. There is a good explanation at [url="http://www.crownaudio.com/pdf/amps/damping_factor.pdf"]http://www.crownaudio.com/pdf/amps/damping_factor.pdf[/url] Cable resistance has a significant effect on this. Typically 1.5-sq.mm. cable has 3 times the resistance of 4-sq.mm., 2.5-sqmm. is almost double. Quote Link to comment Share on other sites More sharing options...
4 Strings Posted April 26, 2012 Author Share Posted April 26, 2012 But if the resistance is negligible (the leads will be only 1m long) isn't 3 x negligible = still negligible? (I ordered 2m of that 4mm cable in the link btw to make 2 cables, on your advice OBBM, it was a couple of pounds and you'll know more than I) Quote Link to comment Share on other sites More sharing options...
4 Strings Posted April 28, 2012 Author Share Posted April 28, 2012 Ok, I think I have the answer to my own question. Just tried to use 4mm cable with a Neutrik. Had to shave the outer insulation and the conductors have to be carefully dressed to just squeeze into the connectors. Took nearly 20 minutes of fiddling. A 2.5mm cable goes in nice and snug. Surely the 4mm is too big for a Neutrik, surely Neutriks are made to handle more than the output of a bass amp (even the unlikely event of using the full 900W output of my untypical amp its going to be into more than one cab and so will be split between more than one cable) and so surely a 2.5mm is going to be more than ample. The cable looks like it's going to power a motor for a train. Quote Link to comment Share on other sites More sharing options...
Bottle Posted April 30, 2012 Share Posted April 30, 2012 [quote name='4 Strings' timestamp='1335607341' post='1633607'] Ok, I think I have the answer to my own question. Just tried to use 4mm cable with a Neutrik. Had to shave the outer insulation and the conductors have to be carefully dressed to just squeeze into the connectors. Took nearly 20 minutes of fiddling. A 2.5mm cable goes in nice and snug. Surely the 4mm is too big for a Neutrik, surely Neutriks are made to handle more than the output of a bass amp (even the unlikely event of using the full 900W output of my untypical amp its going to be into more than one cab and so will be split between more than one cable) and so surely a 2.5mm is going to be more than ample. The cable looks like it's going to power a motor for a train. [/quote] I had the same issue using Canford MCS-HD cable (4mm[sup]2[/sup]), even worse with the 4-core variant for bi-amped applications (check out my for-sale thread on cables ) I used pukka Neutrik connectors (not the cheap Chinese knock-offs) and I had no end of bother. You're right about the 2.5mm[sup]2[/sup] though, went in a treat, so I would say OK for very short runs or low power amps, but worth the extra effort to go to 4mm[sup]2[/sup] for longer runs or more powerful amps (say, >250w) And Canford, bless 'em, also stock MCS-XD which is 6mm[sup]2[/sup], so I'm buggered if I know how that would fit in the standard connectors Ian Quote Link to comment Share on other sites More sharing options...
4 Strings Posted April 30, 2012 Author Share Posted April 30, 2012 Its fine to say 'I would say' etc, and here I am with two elephantine speaker cables believing that the science surely shows its over kill and that there is no difference in using 2.5 or 4mm cable. No doubt diminishing returns are being applied so 6mm seems rather more pointless. I used a single 1.5mm for a gig on Friday (before I had time to spend making up the 4mm pair) and I have rarely been able to play so loud in a huge hall with no pa support, 900W amp - albeit delivering nothing like 900W. Nothing got remotely above room temperature and I have no doubt any sonic differences would have been totally inaudible either in the mix or in isolation. I'm really happy to be convinced otherwise! (I'd note that the flex taking power into the amp is 1.5mm, but I accept this isn't handling a complex audio signal.) Quote Link to comment Share on other sites More sharing options...
Count Bassy Posted April 30, 2012 Share Posted April 30, 2012 [quote name='4 Strings' timestamp='1335274659' post='1628418'] I'm making up a pair of Speakon cables for a nice new amp and my nice new(ish) speakers. Its a 900W amp (although I frankly am a little cynical about that). Will there be any difference at all between the two cable sizes? Will the 1.5mm2 be well within its limitations or will I be pushing its limits (whatever that may be)? Cheers [/quote] Is that Wattage RMS, and into how many ohms, and what is the length of the proposed cable? Quote Link to comment Share on other sites More sharing options...
4 Strings Posted April 30, 2012 Author Share Posted April 30, 2012 Yes, apparently, 900W RMS (presumably with all volume and tone controls set to max). Into a single speaker of 8Ω (and so not actually 900W but more like 600W or less) or into two speakers of 8Ω each (and so 450W). One is 500mm, the other 1500mm. The long one will only be used with two speakers. Quote Link to comment Share on other sites More sharing options...
deepbass5 Posted April 30, 2012 Share Posted April 30, 2012 (edited) Just thought it is worth saying about the internal cab cable, and then the two to the cone probably no more than 0.5mm. so don't get too hung up But like you guys I made my own 4mm cables up. Speakons from Maplins and the low oxygen cable from Richersounds. 4mm is the largest you can get into a speakon terminal. best to tin it with solder first to avoid any of those strands making a mess of things. [attachment=106603:cable.JPG] Edited April 30, 2012 by deepbass5 Quote Link to comment Share on other sites More sharing options...
4 Strings Posted April 30, 2012 Author Share Posted April 30, 2012 [quote name='deepbass5' timestamp='1335826840' post='1636781'] Just thought it is worth saying about the internal cab cable, and then the two to the cone probably no more than 0.5mm. so don't get too hung up >>Too true! 4mm is the largest you can get into a speakon terminal. >>You can say that again! [/quote] Quote Link to comment Share on other sites More sharing options...
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