la bam

Sorry (i know im being a pain - it will sink in i promise), but ive gone into confused mode again.... The QSC manual quotes: https://www.qsc.com/resource-files/productresources/amp/discontinued/rmx/q_amp_rmx_series2ru_usermanual.pdf "Bridged mono mode combines the power of both amp channels into one speaker, resulting in twice the voltage swing, four times the peak power, and approximately three times the sustained power of a single channel. This mode uses Channel 1's input, gain control, input filter, and clip limiter; Channel 2's should not be used. WHEN TO USE IT (OR NOT) Use bridged mono to deliver the power of both channels to a single 8- or 4-ohm load. Set switch positions 6 and 7 to "BRIDGE MONO ON." Use Channel 1's inputs, and connect the speaker as shown." There is also a picture on page 21 of a guitar set up showing everything fine in bridged mode with one cab as long as its >4ohm, which my 6ohm cab would be?

Thanks, I think it's becoming clearer. So, by running in bridge mode, each channel is giving 600w at 3ohm, but overall that's 1200w at 6ohm, which is perfectly safe to run at?

Thanks all. I dont know where i got the information that running in bridged halves/doubles the ohmage the amp runs at, but its a relief to hear just to treat it as one amp. Thanks.

ah, that is perfect.

.

So, if im right, will it run at 6ohm, or x2 lots of 6ohm (as its bridged) so 6/2 = 3ohm? (as im only using x1 cab).

This is where i get confused...... If the QSC spec is 4ohm bridged giving 1400w, then using my 6 ohm cab will draw approx 1000w - is this correct? Completely confused now though for some reason i thought running in bridged mode doubled/halved (depending on how you look at it) the ohmage - so instead of 6ohm in one channel of stereo, it would use 3ohm, as both channels are being used? Any clarity appreciated!

no problem (ive probably not described it properly). Im wondering what ohmage the power amp will be running at, when running in bridged mode, if using a 6ohm cab, and what output in watts that would be giving. Would it be 3ohms (as the amp is bridged)? Rather than 6ohm in normal / stereo mode?

for me - i love it. they really do sound like led zep making new music (albeit in an old style). i cant believe people think theyve no, or even a slight resemblence to led zep - i think theyre EXACTLY like led zep. they vocal style, phrasing, drum sound, guitar playing - its as if theyve done a degree in playing like led zep. good to hear some decent rock for the first time in a while. whether thats a reflection of how good greta van fleet are, or how bad the current scene is, im not sure.

Hi all, With so many different threads on "what would my ohmage be...?" and with a bit of confirmation needed, I thought it might be an idea to have a thread where we could put everything in one thread, also so others can reference and understand. Im sure a lot understand, but also a lot don't. Theres also different set ups, amp set ups and cab configurations. So, i'll start with...... Cab - Markbass 6x10 900w runs at 6ohms. Amp - QSC RMX1450. What will my ohmage be, running this amp in bridged mode? And is there any problem with that?

Luckily never during a gig, but I did have a mag300 break a week or two into buying it new, years ago, so it's always a good idea to have a back up just in case. I have had a cable go on me. First song of first set. Worked perfect in sound check. So I now always have, spare bass, spare tuner, spare cable and spare amp on top of my main amp.

whoa! i didnt even know they were over here on tour?

They ARE different though! A dedicated bass head say off 500w RMS will give all its power out of one output - 500w with a 4Ohm cab, and approx 250w with an 8ohm cab....and thats pretty much that. A dedicated power amp (take the QSC 1450) will work in 2 different ways. It will give its output out of 2 outputs - 500w per channel with a 4 ohm cab, apprx 250w per channel with an 8ohm cab.....thats if you are using a standatrd speakon cable with the amp in stereo mode. So as you can only use one channel (if youre using one cab), thats all you will get - between 250-500w. BUT, flick it to bridged mode, and use a dedicated (wired differently) speakon cable and youll get approx DOUBLE that from one channel - channel A.So youre now at approx 1000w with a 40hm cab and 500w with an 8ohm cab with all that coming from just the one output. Thats how if you think youre using a 2000w power amp with a 200w cab, I actually think youre probably using it in stereo mode at 250-500w output. I might be wrong though, but some people dont understand how power amps work differently from designated bass guitar ones. Hopefully the above shows how you can get approx double the output from the same channel, depending on how you actually set the amp up. In theory, the difference could be huge - using an 8ohm cab in stereo mode the amp would give a max of 250w, using a 4ohm cab in bridged mode could give you 4 times the power at 1000w - all from the same amp. So it isnt just the volume dial of the power amp you have to take into consideration.

sorry, i meant the power amp he was referring to, not the bugera. I use a QSC 1450rmx and regularly adjust its settings and cables to the cab im using at that time. Just explaining that plugging into a power amp, can be a different game to plugging in to a designated bass amp.

That's not right though is it. You need to find out how it's giving out 2000w. Just guessing, but I'd imagine that's bridged at 4ohm. To get that output, you'd need a 4ohm cab and to not only run the amp in bridged mode, (selector switch is/menu) but more than likely need a bridged cable too (different speakon connection). Just plugging a power amp into an 8ohm cab is probably running stereo about 250-350w per side. So if you run from one side into your cab, that's what your getting. Not 2000w.

That's not right though is it. You need to find out how it's giving out 2000w. Just guessing, but I'd imagine that's bridged at 4ohm. To get that output, you'd need a 4ohm cab and to not only run the amp in bridged mode, (selector switch is/menu) but more than likely need a bridged cable too (different speakon connection). Just plugging a power amp into an 8ohm cab is probably running stereo about 250-350w per side. So if you run from one side into your cab, that's what your getting. Not 2000w.

That's hardly 2000w though.

Why buy a big high powered amp and not use it? Just buy a smaller one. I struggle to believe you've run an amp at 2000w into a standard 200w cab. Or if you are, your not running it bridged, and/or are not using a bridged cable. This brings it down from 2000w to around 300w (8ohm running one side) as a guess.

That would defeat the point. And you've no idea how much power youre putting in via your volume dial.

You don't need ridiculous power. If you were getting 1000-2000w rms from behringer - you'd never have a cab to use with it, bar an 8x10. Certainly couldn't use it with your standard 250-300w cab.

Loved my abm600. So much power it was frightening through my 610. All id say is if you do get one, take lots of time to work out what each slider on the eq does, it'll help you get a real grasp of how to get the sound youre after quickly. Also ..... Remember to work out the comical in or out for the pre shape and active/passive button. Oh, and they're beautiful made and finished.

Youre only as good as the combined total sound of your band. What equipment you use to get that total sound will have an effect if used and implemented correctly.

doh! i knew i should have gone for it! Worse - there were x2 mint ashdown ABM 4x10s available with it for an extra £100 ! Ah well, im sure theres some bill somewhere that needs paying instead!

Doh! ive missed it now im afraid. Could have got it in mint condition for £300.

Didn't John use rotosound 77 flats? I bought a set for my p bass and it fairly nails the sound (just not the skill!).