slobluesine Posted April 19, 2009 Share Posted April 19, 2009 Hi Alex, what's the down side of connecting an extra cab with a 20ft cable? i want to split two cabs either side of the stage, will it damage the amp? it's a couple of Aguilar 12's and an LM2, guitar player cant hear my Double Bass and i cant go any louder thx John Link to comment Share on other sites More sharing options...
alexclaber Posted April 19, 2009 Share Posted April 19, 2009 No problems electrically - just use 16 AWG or thicker to avoid resistive losses or changes in response. Note that with separated LF sources you could end up with nulls where the direct and reflected sounds from both cabs all cancel out substantially, so it's rather a cross your fingers and hope situation. Can you stack the cabs vertically, point them at the guitarist, boost the midrange and then find a null that you can place your double bass in to avoid feedback? Alternatively, try reversing the polarity of your pickup to put the upright and the cabs out of phase. Alex Link to comment Share on other sites More sharing options...
slobluesine Posted April 19, 2009 Author Share Posted April 19, 2009 how does it all work with PA rigs then? all PA systems have seperate LF cabs, i've just got a Shadow pup on my DB, std 1/4 jack, how do i rev the phase on that Alex? Link to comment Share on other sites More sharing options...
Mr. Foxen Posted April 19, 2009 Share Posted April 19, 2009 I used 2 8x10s one either side of the drummer ruinnging off the same amp. It made crazy null places, it was cool cause I could get note decayin one spot and hold my bass out for awesome feedback. Link to comment Share on other sites More sharing options...
Alien Posted April 19, 2009 Share Posted April 19, 2009 [quote name='slobluesine' post='466688' date='Apr 19 2009, 12:52 PM']how does it all work with PA rigs then? all PA systems have seperate LF cabs,[/quote] Not if the soundman knows his stuff. You get more output for the same power if all the subs are in one place, and you reduce the comb filter effect, where you get bass hotspots (and coldspots) throughout the venue. A Link to comment Share on other sites More sharing options...
alexclaber Posted April 20, 2009 Share Posted April 20, 2009 [quote name='slobluesine' post='466688' date='Apr 19 2009, 12:52 PM']i've just got a Shadow pup on my DB, std 1/4 jack, how do i rev the phase on that Alex?[/quote] I think you should be able to reverse the polarity with a cable that swaps tip to ring and vice versa. Alternatively if you have Speakons you can swap the polarity of them very easily - maybe make up a second set of cables with reversed polarity so you can swap between to see what works best. Alex Link to comment Share on other sites More sharing options...
alexclaber Posted April 20, 2009 Share Posted April 20, 2009 [quote name='Alien' post='467125' date='Apr 20 2009, 12:13 AM']Not if the soundman knows his stuff. You get more output for the same power if all the subs are in one place, and you reduce the comb filter effect, where you get bass hotspots (and coldspots) throughout the venue.[/quote] Exactly! It's not so bad in smaller venues where the standing waves are significant and not as much output is required from the subs but in larger venues and especially outdoors the separation of sub (unless they're separated by a huge distance) is a very bad thing. Unfortunately hardly any soundmen seem to know this and those that do are often stuck with working a venue that already has the subs in the wrong place and won't move them. Alex Link to comment Share on other sites More sharing options...
slobluesine Posted April 20, 2009 Author Share Posted April 20, 2009 [quote name='alexclaber' post='467300' date='Apr 20 2009, 11:01 AM']I think you should be able to reverse the polarity with a cable that swaps tip to ring and vice versa. Alternatively if you have Speakons you can swap the polarity of them very easily - maybe make up a second set of cables with reversed polarity so you can swap between to see what works best. Alex[/quote] oh, ok, so i just swop the polarity on one of the speakon cables of one of the cabs? that will put that cab out of phase and Bobs my uncle B i could just take a feed into the pa and put the DB into the foldback i spose??? Link to comment Share on other sites More sharing options...
alexclaber Posted April 20, 2009 Share Posted April 20, 2009 [quote name='slobluesine' post='467342' date='Apr 20 2009, 11:51 AM']i could just take a feed into the pa and put the DB into the foldback i spose???[/quote] That would be a much easier solution - get some midrange to your guitarist so he can hear your notes! Alex Link to comment Share on other sites More sharing options...
slobluesine Posted April 20, 2009 Author Share Posted April 20, 2009 gonna try both, that should shut him up hey, so i've got a 20ft speakon cable and i just change the polarity on one end? Link to comment Share on other sites More sharing options...
alexclaber Posted April 20, 2009 Share Posted April 20, 2009 [quote name='slobluesine' post='467512' date='Apr 20 2009, 03:04 PM']gonna try both, that should shut him up hey, so i've got a 20ft speakon cable and i just change the polarity on one end?[/quote] Not sure about just switching the polarity of one cab - unless they're really far apart they'll cancel out each other's bottom. I think you'd need to switch both to see if it helps avoid feedback. What you really want is a variable phase control like you get on a decent active subs and some dedicated acoustic instrument preamps. Alex Link to comment Share on other sites More sharing options...
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