Sibob Posted July 3, 2011 Share Posted July 3, 2011 Just realised....If I wanted to get another barefaced....and a RH 450/750.....I couldn't!? One input in each cab.....one output on the head?! Oooops, anyone found a fix for this horrendous lack of compatibility? Si Quote Link to comment Share on other sites More sharing options...
Prime_BASS Posted July 3, 2011 Share Posted July 3, 2011 Found this on talk bass... [url="http://www.talkbass.com/forum/f15/neutrick-speakon-y-splitter-adapter-751612/"]Speakon Y splitter![/url] Also I'm sure Alex would be more than helpful on the matter, asking him to add a second input to daisy chain? Worst he can say is no, or give advice on Y splitters. Quote Link to comment Share on other sites More sharing options...
Sibob Posted July 3, 2011 Author Share Posted July 3, 2011 I did think it would be a case of asking Alex to add another input (if its that easy), but essentially, its late, and I was just thinking out loud really.......consider the thread rhetorical I think....I'm quite tired :-P But yes, seems to be a minor flaw with the stock combination of these products Si Quote Link to comment Share on other sites More sharing options...
alexclaber Posted July 4, 2011 Share Posted July 4, 2011 We recently started putting dual speakons on all our 8 ohm cabs because of this. Previously second speakons were an optional extra for those buying their second Barefaced cab. However it's incredibly easy to turn two speakon leads into a single Y-lead with nothing but a screwdriver and 10 minutes of your time. Quote Link to comment Share on other sites More sharing options...
Sibob Posted July 4, 2011 Author Share Posted July 4, 2011 [quote name='alexclaber' post='1291769' date='Jul 4 2011, 08:19 AM']We recently started putting dual speakons on all our 8 ohm cabs because of this. Previously second speakons were an optional extra for those buying their second Barefaced cab. However it's incredibly easy to turn two speakon leads into a single Y-lead with nothing but a screwdriver and 10 minutes of your time.[/quote] Cheers Alex, nice to know the combination is possible....always thinking of expansion Si Quote Link to comment Share on other sites More sharing options...
Prime_BASS Posted July 5, 2011 Share Posted July 5, 2011 My work here is done Quote Link to comment Share on other sites More sharing options...
RichF Posted July 5, 2011 Share Posted July 5, 2011 (edited) Hello. What does using a y splitter mean for load when connected to 2 8 ohm cabs? There is no end to my ignorance but will that mean 4 ohm?! Edited July 5, 2011 by RichF Quote Link to comment Share on other sites More sharing options...
clauster Posted July 5, 2011 Share Posted July 5, 2011 Yes Quote Link to comment Share on other sites More sharing options...
Prime_BASS Posted July 5, 2011 Share Posted July 5, 2011 [quote name='clauster' post='1293037' date='Jul 5 2011, 07:42 AM']Yes[/quote] I wouldn't ask why though, I'm sure it's complicated. Quote Link to comment Share on other sites More sharing options...
RichF Posted July 5, 2011 Share Posted July 5, 2011 [quote name='clauster' post='1293037' date='Jul 5 2011, 07:42 AM']Yes[/quote] why? Quote Link to comment Share on other sites More sharing options...
andyonbass Posted July 6, 2011 Share Posted July 6, 2011 You could try a [url="http://www.canford.co.uk/Products/49-394_CANFORD-NL4-LOUDSPEAKER-SPLITTER"]Speakon Splitter[/url] which will work but is a bit pricey imo, but what I've done is connect 2 leads into a single speakon, no soldering involved and only takes a few minutes as stated above. Quote Link to comment Share on other sites More sharing options...
ShergoldSnickers Posted July 6, 2011 Share Posted July 6, 2011 (edited) [quote name='RichF' post='1293865' date='Jul 5 2011, 08:13 PM']why?[/quote] Oh go on then, I'll have a go. I heard this one a few years ago. Imagine blowing a balloon up. One that doesn't instantly burst when a hole is put in it. As you are blowing it up, someone comes along and puts a decent hole in it. Air is now escaping and you have to do more work to keep the balloon inflated. This is an analogy to the amp delivering current to a speaker cabinet. The amp has to work to move the speaker cones. OK, so the nice person that put the first hole in, now puts a second in. You now have to work even harder to keep the balloon inflated. There is less resistance to you blowing into the balloon as more air escapes. Likewise, add a second cab, there is less resistance to the current passing from the amp, as it now has twice as many places to flow. This halves the impedance from 8 ohms to 4 in your case. Make the hole in the balloon big enough and you will run out of breath and become hot and sweaty trying to keep the balloon inflated. Add too many cabs to an amp and the current flies out, overheating the amp. All amps will have a minimum impedance value that shouldn't be broken by adding too many cabs. Most amps are happy working to 4 ohms impedance, and some down to 2 ohms. Edited July 6, 2011 by ShergoldSnickers Quote Link to comment Share on other sites More sharing options...
Jigster Posted July 6, 2011 Share Posted July 6, 2011 *applause* Quote Link to comment Share on other sites More sharing options...
aldude Posted July 6, 2011 Share Posted July 6, 2011 Or, according to the rules/laws/whatever of electronics, To work out the total resistance R of two parallel cabs of resistance R1 and R2, use the formula: 1/R = 1/R1 + 1/R2 This is the same as: R = 1/(1/R1 + 1/R2) So if we have two 8 ohm cabs, both R1 and R2 are 8. So: R = 1/(1/8 + 1/8) = 1/(1/4) = 4 ohms! This will work for other ohm values of cabs, e.g. 16, 8, 6, 4, etc. Also will work for 3 or more cabs, just add a +1/R3 in there. /geek mode off Quote Link to comment Share on other sites More sharing options...
Sibob Posted July 6, 2011 Author Share Posted July 6, 2011 All you really need to know is 2x8ohm cabs= 4ohms, and 2x4ohm cabs = 2ohms Match that with the minimum impedance of your amp to know what you can use. Most amp websites will let you know the output into 8ohms and output to 4ohms....the 4ohm output (or 2 if it goes that low) will always be the advertised power. That's why products like the Ashdown Little Giant 1000 were frowned upon slightly....it was only 1000watts into 2ohms, the 8ohm output was a pretty standard 300w or something. Si Quote Link to comment Share on other sites More sharing options...
RichF Posted July 6, 2011 Share Posted July 6, 2011 thanks I was only kidding! However to be fair I was sort of seriously enquiring whether a splitter out of a single speakon into 2 8 ohm cab was in any way different from a single speakon out to an 8 ohm cab daisy chained to another. I had concepts like series and parallel in mind. Based on balloons and maths (2x8ohm cabs= 4ohms) I am now supposed to know that however you connect 2 8 ohm cabs to an amp you get a 4 ohm load? So, crucially, I dont need to worry about finding a 2 output amp to power my single speakon BF cabs. Quote Link to comment Share on other sites More sharing options...
ShergoldSnickers Posted July 7, 2011 Share Posted July 7, 2011 [quote name='RichF' post='1295467' date='Jul 6 2011, 11:58 PM']thanks I was only kidding![/quote] Oh well, it gave me a chance to air what I thought was a decent analogy. Any excuse. Quote Link to comment Share on other sites More sharing options...
aldude Posted July 7, 2011 Share Posted July 7, 2011 [quote name='RichF' post='1295467' date='Jul 6 2011, 11:58 PM']thanks I was only kidding! However to be fair I was sort of seriously enquiring whether a splitter out of a single speakon into 2 8 ohm cab was in any way different from a single speakon out to an 8 ohm cab daisy chained to another. I had concepts like series and parallel in mind. Based on balloons and maths (2x8ohm cabs= 4ohms) I am now supposed to know that however you connect 2 8 ohm cabs to an amp you get a 4 ohm load? So, crucially, I dont need to worry about finding a 2 output amp to power my single speakon BF cabs.[/quote] When you daisy chain cabs, even though it looks like they're connected in series they are actually connected in parallel Quote Link to comment Share on other sites More sharing options...
alexclaber Posted July 7, 2011 Share Posted July 7, 2011 [quote name='aldude' post='1295641' date='Jul 7 2011, 08:47 AM']When you daisy chain cabs, even though it looks like they're connected in series they are actually connected in parallel [/quote] Exactly! What looks like just one wire going between the cabs is actually two, so you're running one wire between the amp's and all the cabs' positive terminals, and another wire between the amp's and all the cabs' negative terminals, so: amp positive -> (cab 1 positive & cab 2 positive & cab 3 positive etc), amp negative -> (cab 1 negative & cab 2 negative & cab 3 negative etc) If you were connecting things up in series then you'd go: amp positive -> cab 1 positive, cab 1 negative -> cab 2 positive, cab 2 negative -> cab 3 positive, cab 3 negative -> amp negative So here you see that with the parallel approach you're applying the amp's full voltage (aka potential difference) across all three cabs. Whilst with the series approach you're only getting 1/3 of the voltage across each cab (with three cabs). In other words with parallel cabs voltage is the same across all three, whilst with series cabs current is the same through all three. (Ignoring the fact that resistance and impedance are actually different but things will get rather complicated if we have to start including phase, so this is a simplified explanation): Power = Voltage * Current Current = Voltage / Resistance Therefore Power = (Voltage * Voltage) / Resistance And also Voltage = SQRT (Power * Resistance). So if we have a 500W into 4 ohm amp. Max Voltage (i.e. when it's putting out 500W) = SQRT (500 * 4) = 44.7V So if you connect two 8 ohm cabs to this 500W @ 4 ohms amp, either daisy-chained or with one cab to one speaker out, the other cab to the other speaker out, so they're in parallel. Power per cab = (44.7 * 44.7)/8 = 250W If you make up a special series lead and connect two 8 ohm cabs in series then the voltage across each cab is halved: Power per cab = (22.35 * 22.35)/8 = 62W Understanding (solidstate, not valve) amps gets a lot easier when you start thinking about the amp putting out volts, not watts. It is a voltage amplifier - it amplifies the current too but only in response to the load, and that's why there's a minimum impedance - because once the impedance drops too low then the amplifier can't put out enough current to keep up. Quote Link to comment Share on other sites More sharing options...
gafbass02 Posted July 7, 2011 Share Posted July 7, 2011 I liked the balloons. Quote Link to comment Share on other sites More sharing options...
Kiwi Posted July 7, 2011 Share Posted July 7, 2011 Me too. [i]"Garcon! More f***ing balloons, I'm hungry."[/i] Quote Link to comment Share on other sites More sharing options...
charic Posted July 7, 2011 Share Posted July 7, 2011 Balloons worked nicely Quote Link to comment Share on other sites More sharing options...
ShergoldSnickers Posted July 7, 2011 Share Posted July 7, 2011 [quote name='Crazykiwi' post='1295828' date='Jul 7 2011, 12:04 PM']Me too. [i]"Garcon! More f***ing balloons, I'm hungry."[/i][/quote] Good analogy for slapping. Just a little too much and it suddenly makes you sick. Quote Link to comment Share on other sites More sharing options...
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