jwbassman Posted January 30, 2008 Share Posted January 30, 2008 Hey guys... Here we go with an Ohms question for all you clever mathematical folk... I'm currently running a UL112 - 300watts @ 8Ohms from my Alesis RA300 - 300watts RMS @ 8Ohms, which seems to make perfect sense to me, however I'm contemplating a deal to bring a UL310 into the mix, like this... [attachment=5303:rig.jpg] (new rig?) I understand that these cabs are a 5.3 Ohms, so the first question is, if I run the UL310 and the UL112 as a stack, connecting the amp to the 112 and the the 112 to the 310, what's the likely outcome in terms of power output and amp efficiency? Second question is, can I run just the UL310 from my power amp without any issues, if so what will the power output be if I do? Thanks in advance, I'm aware I've still got a lot to learn re the separate amp/cab route John Quote Link to comment Share on other sites More sharing options...
obbm Posted January 30, 2008 Share Posted January 30, 2008 [quote name='jwbassman' post='130995' date='Jan 30 2008, 10:13 PM']Hey guys... Here we go with an Ohms question for all you clever mathematical folk... I'm currently running a UL112 - 300watts @ 8Ohms from my Alesis RA300 - 300watts RMS @ 8Ohms, which seems to make perfect sense to me, however I'm contemplating a deal to bring a UL310 into the mix, like this... [attachment=5303:rig.jpg] (new rig?) I understand that these cabs are a 5.3 Ohms, so the first question is, if I run the UL310 and the UL112 as a stack, connecting the amp to the 112 and the the 112 to the 310, what's the likely outcome in terms of power output and amp efficiency? Second question is, can I run just the UL310 from my power amp without any issues, if so what will the power output be if I do? Thanks in advance, I'm aware I've still got a lot to learn re the separate amp/cab route John[/quote] John Are you running your RA300 in bridged mode? If so then you must not use the UL310 and UL112 together as the combined impedance will be too low at 3.2ohms and the amp will overheat and most certainly expire. Neither can you run the UL310 from the RA300 in bridged mode for the same reason. The lowest impedance that it will handle in bridged mode is 8-ohms. The only way you could run both cabs is to use the two channels of the RA300 separately with one speaker on each and parallel up the inputs so the pre-amp signal goes to both channels. The will be a difference in sond levels as the speaker sensitivities are different and the amp power outputs will be different for the different speakers. 90-watts in 8-ohms and probably 120-watts into the 5.3 ohms. This can be balanced by the amp output controls.. I've been down this road and found that there was no useful purpose in running a 112 with the 310. The 310 is just fine on its own. I used a QSC PLX1602 to drive my UL310 - QSC amps can handle a 4-ohm load in bridged. Quote Link to comment Share on other sites More sharing options...
jwbassman Posted January 31, 2008 Author Share Posted January 31, 2008 Hi Dave, thanks for the warning, I'm glad I asked the question - yes, I run the RA300 bridged so that it matches the UL112 - which was my initial carefully considered solution... Looks like I may need to reconsider my options with regards the 310, or look at a different power amp. The reason I went for the RA300 in the first place was that it was very quiet, I didn't want a amp with a fan because some of the more intimate gigs I do can be pretty quiet affairs (3 or 4 piece jazz gigs for weddings and meals etc), however on the other end of the scale playing with my rock trio is a different matter... My intention was to run either the 310 on it's own or with the 112 but from what you're saying this is neither a desirable or workable solution as things currently stand. I'm clearly going to need to think about this some more, thanks again for you help... Quote Link to comment Share on other sites More sharing options...
obbm Posted January 31, 2008 Share Posted January 31, 2008 [quote name='jwbassman' post='131057' date='Jan 31 2008, 12:15 AM']My intention was to run either the 310 on it's own or with the 112 but from what you're saying this is neither a desirable or workable solution as things currently stand.[/quote] You really won't need another cab with the UL310. There was a guy on TB who tried a pair but gave up as he reckoned that one was more than enough. I use the UL310 on its own or a pair of 112s, which has smaller footprint. I suggest you find an alternative powr amp to go the best out of the UL310. Quote Link to comment Share on other sites More sharing options...
jwbassman Posted January 31, 2008 Author Share Posted January 31, 2008 To be honest Dave I'm starting to wonder if I really need the 310 at all - I know it's a great cab but I seem to be doing fine with my 112 set up, maybe just got a bit carried away I'll have to look into the alternative power amp options and see what the financial implications are... Cheers John Quote Link to comment Share on other sites More sharing options...
obbm Posted January 31, 2008 Share Posted January 31, 2008 [quote name='jwbassman' post='131246' date='Jan 31 2008, 12:21 PM']To be honest Dave I'm starting to wonder if I really need the 310 at all - I know it's a great cab but I seem to be doing fine with my 112 set up, maybe just got a bit carried away I'll have to look into the alternative power amp options and see what the financial implications are... Cheers John[/quote] Well I've used my UL310 once in the past 18-months. I just keep lending it to Paul Geary, however I won't sell it because I never know what's around the corner. If you want a bit more oomph then get another 112. A T112NYC as they have a lot of bottom end aand are 8-ohms. Are you coming to the Bash? Quote Link to comment Share on other sites More sharing options...
jwbassman Posted January 31, 2008 Author Share Posted January 31, 2008 (edited) Hi Dave - it makes sense to have a more powerful rig should the need arise, so know where you're coming from. The beauty of the deal was it was going to be a trade so no cash involved which suited me great, however if I have to shell out for a new power amp it somewhat defeats the object... Does that mean I'd be able to link the cabs together and use my current amp? Yeah, I'm hoping to get to the Bash, if Alan has a spare seat then there's a good chance I'll be there. Edited January 31, 2008 by jwbassman Quote Link to comment Share on other sites More sharing options...
obbm Posted January 31, 2008 Share Posted January 31, 2008 [quote name='jwbassman' post='131426' date='Jan 31 2008, 05:36 PM']Does that mean I'd be able to link the cabs together and use my current amp?[/quote] You are in a Catch 22 situation with that RA300 because you can either have: 300-watts in 8-ohms with the amp bridged, 90-watts 8-ohms per channel 150-watts into 4-ohms per channel. You can't run the 310 in bridged You can run one 112 in bridged. 2 x 112 = 4-ohms so you can't run bridged. You would have to run one on each channel but that would give max power of 90-watts to each speaker. Sorry to say but the limiting factor is the RA300 power amp. I am fortunate in that both the Epi UL502 amp and the Ashdown ABM-500 will both support loads down to 4-ohms so I can use one or two 112s or the UL310 with either. Quote Link to comment Share on other sites More sharing options...
jwbassman Posted January 31, 2008 Author Share Posted January 31, 2008 Cheers Dave and thanks for the idiot's guide, it's a lot clearer to me now I've decided that the UL310 is going back to Mikeh and I'm sticking to 112 for the time being, so if anyone else fancies it drop him a PM, he's a good guy... Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.