Grahambythesea Posted June 9, 2022 Share Posted June 9, 2022 For years I’ve used combos. My current amp is a Behringer BX1200 Ultrabass,on this there is an actual lead and plug from the speaker which plugs into the back of the amp. I’d like to run an extension cab and I am thinking of using a Jack splitter to give me two outputs. Would this work? Quote Link to comment Share on other sites More sharing options...
yorks5stringer Posted June 9, 2022 Share Posted June 9, 2022 (edited) Yes, from their blurb: 'The BX1200 features a custom-made 12" aluminum cone speaker that reproduces your sound with incredible power, sensitivity and warmth. Should you need extra clout for larger venues, you’ve got the option of connecting additional speakers and/or power amps. ' https://mediadl.musictribe.com/media/sys_master/h44/h4b/8850001690654.pdf P3 mentions 'connector for external speaker cabinets!' P6 cautions to only '4 ohm cabinet' use only Trouble is there is only 1 output as I guess you have already seen, I'm not sure how a splitter would work with a 4ohm cab ( as the combo speaker is 4 ohm too) but I'm sure someone will be along who does! Edited June 9, 2022 by yorks5stringer Quote Link to comment Share on other sites More sharing options...
BassmanPaul Posted June 9, 2022 Share Posted June 9, 2022 (edited) Really the manual is as clear as mud. I have the feeling that the combo has a 4Ω minimum which is filled by the internal speaker. Then again the manual says 'short circuit proof power amp' so who knows. I would be very wary about connecting a speaker in parallel with the internal diver. That would mean a 2Ω load. Get it wrong and you have a blown amplifier. Incidentally most combo amplifiers develop their maximum power into the internal speaker. Edited June 9, 2022 by BassmanPaul 1 Quote Link to comment Share on other sites More sharing options...
Dan Dare Posted June 9, 2022 Share Posted June 9, 2022 I'd be cautious, as Paul suggests. Behringer have likely fitted a 4 ohm driver to maximise the output (the fact that there is no extension speaker jack suggests this to be the case), so adding another could be risky. If there is a preamp out, run that into a power amp and drive an additional speaker with that, Quote Link to comment Share on other sites More sharing options...
Downunderwonder Posted June 9, 2022 Share Posted June 9, 2022 Sure looks like a pair of speaker outputs on the back of the amp to me. Test the DC resistance of the speaker with a multimeter. If it is around 6 ohms it indicates an 8 ohm speaker. Then you can add another 8 ohm cab. Quote Link to comment Share on other sites More sharing options...
Mottlefeeder Posted June 9, 2022 Share Posted June 9, 2022 37 minutes ago, Downunderwonder said: Sure looks like a pair of speaker outputs on the back of the amp to me. Test the DC resistance of the speaker with a multimeter. If it is around 6 ohms it indicates an 8 ohm speaker. Then you can add another 8 ohm cab. The instruction book says one speaker jack and one headphone jack, which mutes the speaker jack. My interpretation of the handbook is that they allow you to add extra speakers, but only in series with the one supplied. David Quote Link to comment Share on other sites More sharing options...
Downunderwonder Posted June 9, 2022 Share Posted June 9, 2022 16 minutes ago, Mottlefeeder said: The instruction book says one speaker jack and one headphone jack, which mutes the speaker jack. My interpretation of the handbook is that they allow you to add extra speakers, but only in series with the one supplied. David Could well be. I can't read the labels on the jacks in the photo. It would have to be a really poorly matched speaker that could realise any gain from putting another cab in series. The amp would be throttled back to 8 ohm output level. Unless there's a bona fide matching B'ringer extension cab available I wouldn't bother. It's not a good idea to throw any old cab into series as there are unpredictable consequences to adding random loads in series that include giving the amp the heebie jeebies. 2 Quote Link to comment Share on other sites More sharing options...
Bill Fitzmaurice Posted June 9, 2022 Share Posted June 9, 2022 1 hour ago, Downunderwonder said: It would have to be a really poorly matched speaker that could realise any gain from putting another cab in series. The amp would be throttled back to 8 ohm output level. Voltage sensitivity would be a wash. You'd gain 3dB from mutual coupling, but lose 3dB from the doubled impedance. You would still realize as mush as 6dB additional maximum output, but it would all be power derived, if the amp had the power available to give. Quote Unless there's a bona fide matching B'ringer extension cab available I wouldn't bother. It's not a good idea to throw any old cab into series as there are unpredictable consequences to adding random loads in series that include giving the amp the heebie jeebies. True. Even in parallel the results would be unpredictable. Quote Link to comment Share on other sites More sharing options...
yorks5stringer Posted June 9, 2022 Share Posted June 9, 2022 I think the manual I quoted from was for the standalone amp and not the combo, as despite the blurb, the various diagrams showing how you can connect it up only show one cab from the speaker socket. Quote Link to comment Share on other sites More sharing options...
Stofferson Posted June 10, 2022 Share Posted June 10, 2022 https://www.gear4music.com/Guitar-and-Bass/Palmer-CAB-M-Passive-Cabinet-Merger/T2K Cab merger? Quote Link to comment Share on other sites More sharing options...
Phil Starr Posted June 10, 2022 Share Posted June 10, 2022 This is a very simple set up and I suspect a copy of the Hartke Kickback which had the same arrangement. The speaker will almost certainly be 4ohms so you can't add another speaker with a splitter to any real advantage. However if you have other cabs they might be more efficient than the inbuilt one so you could just try unplugging the one in the combo and plugging the other cab in. Certainly in my Hartke that gave extra volume. If you like fiddling there might be the possibility of changing the internal speaker for an 8ohm one and then adding an external 8ohm cab and it might be fun to try but if I just wanted more volume I'd probably not start with what you have but move the combo on and start afresh as that would probably work out easier and cheaper. 1 Quote Link to comment Share on other sites More sharing options...
nekomatic Posted June 10, 2022 Share Posted June 10, 2022 7 hours ago, Stofferson said: https://www.gear4music.com/Guitar-and-Bass/Palmer-CAB-M-Passive-Cabinet-Merger/T2K Cab merger? Yeah but… as noted upthread, the amp probably can’t drive another cab in parallel and it probably won’t work well to connect two different cabs in series. Quote Link to comment Share on other sites More sharing options...
yorks5stringer Posted June 10, 2022 Share Posted June 10, 2022 (edited) 3 hours ago, Phil Starr said: This is a very simple set up and I suspect a copy of the Hartke Kickback which had the same arrangement. The speaker will almost certainly be 4ohms so you can't add another speaker with a splitter to any real advantage. However if you have other cabs they might be more efficient than the inbuilt one so you could just try unplugging the one in the combo and plugging the other cab in. Certainly in my Hartke that gave extra volume. If you like fiddling there might be the possibility of changing the internal speaker for an 8ohm one and then adding an external 8ohm cab and it might be fun to try but if I just wanted more volume I'd probably not start with what you have but move the combo on and start afresh as that would probably work out easier and cheaper. Yes, the spec says the internal speaker is 4ohms. I was thinking due to the model number these were 1200 watts, they are in fact 120 watts! Edited June 10, 2022 by yorks5stringer Quote Link to comment Share on other sites More sharing options...
Stub Mandrel Posted June 10, 2022 Share Posted June 10, 2022 It's straightforward. Internal speaker is 4R. You unplug it and plug in one or more (daisy chained) speakers instead for down to 4R minimum. 1 Quote Link to comment Share on other sites More sharing options...
Grahambythesea Posted June 11, 2022 Author Share Posted June 11, 2022 Thanks for all your wisdom. To summarise- don’t do it! Quote Link to comment Share on other sites More sharing options...
Stub Mandrel Posted June 11, 2022 Share Posted June 11, 2022 13 minutes ago, Grahambythesea said: Thanks for all your wisdom. To summarise- don’t do it! Not at all, a good external 4R stack will be louder and bassier. Quote Link to comment Share on other sites More sharing options...
Downunderwonder Posted June 11, 2022 Share Posted June 11, 2022 Nobody in their right mind is going to disconnect the combo driver and carry it around as an amp for another cab. That's the only way it will assuredly work well. 1 Quote Link to comment Share on other sites More sharing options...
agedhorse Posted June 12, 2022 Share Posted June 12, 2022 5 hours ago, Downunderwonder said: Nobody in their right mind is going to disconnect the combo driver and carry it around as an amp for another cab. That's the only way it will assuredly work well. Agreed, not a 120 watt heavy combo. Quote Link to comment Share on other sites More sharing options...
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