• TalkBass has been independent since 1998. Add your voice.
    Create a free account to reply to discussions, view embedded media, and browse with fewer display ads.
    Join free Log in
    Want zero display ads or expanded classifieds tools? Compare plans.

Just Want To Check...

MrBassman17

MrBassman17

Dec 30, 2011
781
581
74
Brewster, NY
#1
I have a Crown Power Base 1 power amp and will be running it in 'parallel mono' mode into two 8 ohm speakers, wired in series. The specs on the amp say that it is good in that mode from 4 to 2 ohms, so I think I'm good. First time using this mode and want to know if the speakers in series will show 4 ohms. Thanks in advance for the help!
 
#3
Explain how you're running in series. If you're daisy -chaining them you are running parallel. BTW yes two 8ohm cabs in series is 16 ohm, in parallel they are 4.

OP, please give more details about the exact connections. Are you pushing one cab from each side AND connecting them? DON'T DO THAT if so.
 
  • Like
Reactions: MrRubi04 and Inara
#4
basscooker said:
Explain how you're running in series. If you're daisy -chaining them you are running parallel.
Click to expand...
True ... I forget that many people seem to think that daisy-chaining cabs is a series connection, when it's pretty much universally a parallel connection (unless some special non-standard wiring mods have been done).
 
Last edited:
#6
Admittedly I assume it means one mono input and both sides will output. Is that incorrect?
Even if I was thinking incorrectly I'm still curious as to the wording of the first post. I think we may be talking about daisy chaining, which would be fine, but wanted some details from the op just to be sure....
 
  • Like
Reactions: MrRubi04
#7
basscooker said:
Admittedly I assume it means one mono input and both sides will output. Is that incorrect?
Even if I was thinking incorrectly I'm still curious as to the wording of the first post. I think we may be talking about daisy chaining, which would be fine, but wanted some details from the op just to be sure....
Click to expand...
For the Crown amp in question - parallel mono means both positive output terminals are connected to the positive wire; one negative output terminal is the negative to the speaker(s). I am connecting one speaker to the amp, the second speaker to the first - 'daisy chain'. This produced a 16 ohm impedance? The amp specs say :

Stereo mode (both channels driven):
240 watts into 4 ohms.
200 watts into 8 ohms.
Bridge-Mono mode:
455 watts into 8 ohms.
395 watts into 16 ohms.
Parallel-Mono mode:
455 watts into 2 ohms.
400 watts into 4 ohms.

I hope this is clearer for all you who have a better grasp of these things than I do! Thanks again for your help - I certainly don't want to fry this old guy the first time I use it!
 
#10
MrBassman17 said:
For the Crown amp in question - parallel mono means both positive output terminals are connected to the positive wire; one negative output terminal is the negative to the speaker(s). I am connecting one speaker to the amp, the second speaker to the first - 'daisy chain'. This produced a 16 ohm impedance? The amp specs say :

Stereo mode (both channels driven):
240 watts into 4 ohms.
200 watts into 8 ohms.
Bridge-Mono mode:
455 watts into 8 ohms.
395 watts into 16 ohms.
Parallel-Mono mode:
455 watts into 2 ohms.
400 watts into 4 ohms.
Click to expand...
I've never seen parallel mode have more power than stereo mode. Is this correct? Is parallel mode on this amp also bridged?
 
  • Like
Reactions: MrRubi04
#12
if you were using a stereo source in parallel mono the preamp would sum both sides. so both sides of output would be a mono mix. but still running 2 individual amplifiers. so plugging a 8 ohm source into a single output would be a 8 ohm load.
the wattage ratings are a little misleading i think. either way its plenty power and your not running to low of a impedance
 
Last edited:
  • Like
Reactions: morgansterne
#13
Wikipedia explains it
Parallel Mono - twice the current - more power into low impedance
220px-Parallel_amp.gif


Bridged and paralleled amplifiers - Wikipedia

Versus bridged - twice the voltage - more power into high impedance
200px-Bridge_amp.gif


Crown and others did it before and It's coming back to new generation of power amplifiers.
QSC also has excellent documentation on how these configurations work.
 
  • Like
Reactions: johnpbass
#14
If you are showing the amp a 4 ohm load then you need to use parallel mono, if you are showing it a 16ohm load then you want to use bridged mono. Odd that it's 2 ohm stable but doesn't support a 4 ohm bridged mono load, but according to what was posted you above, you need one of those two setups, which will result in basically the same output.
 
Last edited:
#16
I think the source of the confusion is that the connection method doesn't determine the ohms. Those are just power ratings for connection types based on examples of cabinets being used.
Also, my understanding of parallel mono on the old Crown amps is that you're using one input source to drive both channels of the amp as opposed to stereo mode where you need to provide 2 separate input signals. IIRC, some of the old power amps needed a jumper cable to connect the two input channels if you were driving both channels with a single input. I may not be understanding what that amp's Parallel Mono is though.
Those Crown Power Base amps were solid great power amps. I ran a PB 2 for many years for my bass rig!
 
Last edited:
#17
basscooker said:
Explain how you're running in series. If you're daisy -chaining them you are running parallel. BTW yes two 8ohm cabs in series is 16 ohm, in parallel they are 4.

OP, please give more details about the exact connections. Are you pushing one cab from each side AND connecting them? DON'T DO THAT if so.
Click to expand...
"Daisy chain" WRT electricity is a slang term with no fixed or standard definition so there's no way to be sure your audience will interpret it as you do. "Series" and "parallel" are defined.
 
#18
johnpbass said:
I think the source of the confusion is that the connection method doesn't determine the ohms. Those are just power ratings for connection types based on examples of cabinets being used.
Also, my understanding of parallel mono on the old Crown amps is that you're using one input source to drive both channels of the amp as opposed to stereo mode where you need to provide 2 separate input signals. IIRC, some of the old power amps needed a jumper cable to connect the two input channels if you were driving both channels with a single input. I may not be understanding what that amp's Parallel Mono is though.
Click to expand...

From the manual:

"2.2 Mono

Your amplifier's mono modes provide double the

power of Stereo mode in a single channel. In Bridge-

Mono mode, the outputs are wired in series for twice

the output voltage. In Parallel-Mono mode, the outputs

are paralleled for twice the current capacity."

So the connection method does in fact determine the allowable loads in this case. And to those contemplating trying that parallel mono mode wiring on other amps: do not try this at home, with very few exceptions. Smoke is only magic as long as it stays in the box.
Yel_wink.gif
 
  • Like
Reactions: johnpbass

Latest posts

Top Bottom
Back