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Ohms FAQ
- Thread starter IvanMike
- Start date
so volume is more based on sensetivity than wattage? If so what is considerred high and low sensetivity
volume is based on bothbigBbass451 said:
however, if cabinet A is 8 ohms and has a sensitivity of 100 dB and cabinet B is 8 ohms and has a sensitivity of 103 dB, cabinet A will need twice the wattage to be as loud as cabinet B. For bass, i would look for a sensitivity of 100 dB or higher. Probably 103 or more if it's going to be your only cabinet and you're going to play loud.
I am just venturing into stereo pre-power amp territory lately, so had a question about this too.
Have a QSC 1602, in stereo mode Each side puts out 500 watt's at 4 ohms, 300 at 8 ohms . Since each side has it's own total imp rating(I think??) would it be safe to run a single 8ohm cab on one side and a single 4 ohm cab on another? Or would this result in a total load of 2.67 as mentioned above?
I know in non-stereo head units it would but just wanted to verify with the experts.
Thanks.
Have a QSC 1602, in stereo mode Each side puts out 500 watt's at 4 ohms, 300 at 8 ohms . Since each side has it's own total imp rating(I think??) would it be safe to run a single 8ohm cab on one side and a single 4 ohm cab on another? Or would this result in a total load of 2.67 as mentioned above?
I know in non-stereo head units it would but just wanted to verify with the experts.
Thanks.
the two sides of a stereo power amp are independent unless bridged. in your scenario one side would see 4 ohms and the other 8 ohms
And this isn't a sticky yet why?
I posted then deleted a question after searching and finding this thread. It was about looking for a head for my 4 ohm 2x10 since I'ld like the option of adding a 1x15 in the future. Since all the 15's I looked at are 8 ohm, I didn't know what output wattage/ impedance rating to consider when looking for a head.
So if I got this straight, if the 2x10 is 350w @ 4 ohms, I'ld want to stick to a head with an output of no more than 350w @ 2 ohms, guessing I may add an 8 ohm 1x15. Or would I want to rewire the 4 ohm 2x10 so it's an 8 ohm cab (wire the speakers in series rather than parallel)? That way, I can look for a head that puts out 350w @ 4 ohms and be safe. Does that make sense?
I posted then deleted a question after searching and finding this thread. It was about looking for a head for my 4 ohm 2x10 since I'ld like the option of adding a 1x15 in the future. Since all the 15's I looked at are 8 ohm, I didn't know what output wattage/ impedance rating to consider when looking for a head.
So if I got this straight, if the 2x10 is 350w @ 4 ohms, I'ld want to stick to a head with an output of no more than 350w @ 2 ohms, guessing I may add an 8 ohm 1x15. Or would I want to rewire the 4 ohm 2x10 so it's an 8 ohm cab (wire the speakers in series rather than parallel)? That way, I can look for a head that puts out 350w @ 4 ohms and be safe. Does that make sense?
first off your 210 is a 4 ohm cabinet that can HANDLE 350 watts. When choosing a head you should check out what power levels it puts out at 4 ohms.RyanHelms said:
if you want to stick with that 4 ohm 2x10 AND want to add a 1x15 in the future you need to get a head that will power a 2 ohm load so you can add another cabinet , or get a stereo head so you can run the 210 off of one side and the 1x15 off of the other.
as far as rewiring your cabinet, it more than likley is 2 eight ohm ten inch speakers wired in parallel for a net impedance of 4 ohms. Wiring it in series would give you a 16 ohm cabinet, which would be very quiet.
bump cause these questions keep coming up
could a mod sticky this?
if not i think i'm gonna delete it and get the cash by selling it as an article to bass player (i've been published in BP before)
could a mod sticky this?
if not i think i'm gonna delete it and get the cash by selling it as an article to bass player (i've been published in BP before)
IvanMike said:
Dude, good post but I think your math is a little off.
3 16ohm speakers = 1/(1/16+1/16+1/16) or 1/(3/16) NOT 3/16.
1/(3/16) = 1/.1875 = 5.333...
Maybe an example will help. I plan on hooking up two 250 Watt RMS cabs rated at 8ohms each. My head puts out 500 watts @ 4 ohms.
2 cabs @ 8ohms gives me...
1/(1/8+1/8) = 1/(2/8) = 1/(1/4) = 4 Ohms resistance
Which means, that with the two cabs, I've matched what the minimum amount of resistance with my head. I think that's pretty clear.
Two 250 watt cabs together in parallel, the total wattage possible that they can handle is 500 watts. So you can say that my two cabs now are a single 2x10 cab that handles 500 watts @ 4 ohms. Is my math right?
gotcha, i had an error in the expression but the net result is right (ie., 3 16 ohm speaker wired parallel in a cab has a net result of 5.33)hdiddy said:
and if you are talking about 2 1x10 8 ohm cabinets wired in parallel, yes you have in effect a 4 ohm "2x10" that can handle 500 watts.
deepestend
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- Feb 21, 2003
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So, let me try... I have a power amp that in bridged mono puts out 400 watts at 8ohms or 500 watts at 4 ohms.
I have a 4x10 that is 8ohms and can handle 400watts
I'm thinking of getting a 1x15 that is 8ohms and canhandle 300watts... so the max that setup can handle is 700 watts (300 plus 400), which should be fine with my amp putting out 500 watts at 4ohms.
Right?
I have a 4x10 that is 8ohms and can handle 400watts
I'm thinking of getting a 1x15 that is 8ohms and canhandle 300watts... so the max that setup can handle is 700 watts (300 plus 400), which should be fine with my amp putting out 500 watts at 4ohms.
Right?
This is a brillant thread. How does sensitivity work. I see drivers rated between 93-97, yet some cabinet designs such as bill fitzmaurice claim efficiencies of 106. Is there a way to increase the efficiency of a given cab?
okay i have read this entire thread and the other one linked, i THINK i know the answer to this but i really would feel much better if someone set me straight.
i have a head thats 200w at 4 ohms (i know, i know) and 100w at 8. i've got an 8ohm 115. i thought that i was safer than if i had a 4 ohm 115 when i bought it, but is this not the case? would i be better off if i bought an additional 8 ohm cab?
and also if it is a problem running what i do play loud, what would happen? would there be damage to the head or cab? and also, is it possible for there to be a problem even if i dont hear it distort?
i have a head thats 200w at 4 ohms (i know, i know) and 100w at 8. i've got an 8ohm 115. i thought that i was safer than if i had a 4 ohm 115 when i bought it, but is this not the case? would i be better off if i bought an additional 8 ohm cab?
and also if it is a problem running what i do play loud, what would happen? would there be damage to the head or cab? and also, is it possible for there to be a problem even if i dont hear it distort?
most bass cabinets have sensitivities between 100 dB - 106 dB. Generally those with higher sensitivities have multiple drivers (like a 6x10).brooklynbassguy said:
changing drivers in a given cabinet might give you a small increase in sensitivity but unless the cabinet is matched to the new drivers it's probably not going to sound anywhere as good as it did with the original drivers it was intended for - so that would be a vote for don't bother
bill's cabinets are a different design than most bass cabinets. i have zero experience with them so i can't say anything about the efficiency of his cabs or how they sound.
