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Re: Experiment with a Crown XLS1500
Posted: Thu Feb 06, 2014 5:47 pm
by yigba
Bruce Weldy wrote:
Then, if the voltage was achieved by the amp in stereo mode was exactly the same as that in bridge mode the sub would indeed sound louder in bridge mode up until the limiter engaged - after that it will be exactly the same.
That's what I couldn't wrap my head around. Therefore I'll bridge and limit.
Bruce Weldy wrote:As an aside......you did check voltage across both red terminals when testing in bridge mode, right? Not the red and black like in stereo?
Yes.
Re: Experiment with a Crown XLS1500
Posted: Thu Feb 06, 2014 5:54 pm
by yigba
byacey wrote:The input however, will be 6db more sensitive, if that's what you mean.
Which would be the reason why the bridged amp is louder!!!!
Thank you everyone for excusing my ignorance and helping me understand this.
Re: Experiment with a Crown XLS1500
Posted: Thu Feb 06, 2014 10:03 pm
by byacey
Actually the reason for it being louder is because the input stage is now driving two power amplifiers out of phase with each other. This doubles the voltage swing, or from an input sensitivity perspective, a 6db increase in sensitivity.
Re: Experiment with a Crown XLS1500
Posted: Thu Feb 06, 2014 11:21 pm
by Bruce Weldy
byacey wrote:Bruce Weldy wrote:
Then, if the voltage was achieved by the amp in stereo mode was exactly the same as that in bridge mode the sub would indeed sound louder in bridge mode up until the limiter engaged - after that it will be exactly the same.
As an aside......you did check voltage across both red terminals when testing in bridge mode, right? Not the red and black like in stereo?
I don't follow what you are trying to say; 25 V out in bridge mode will sound just as loud as 25V out in stereo mode. The input however, will be 6db more sensitive, if that's what you mean.
Good point on measuring between the + binding posts.
I wasn't talking about voltage in that case. With everything else equal prior to hitting the amp, bridge mode will be louder. Once the limiter kicks in ensuring equal voltage, the volume will be the same.
Re: Experiment with a Crown XLS1500
Posted: Fri Feb 07, 2014 12:05 am
by byacey
That's correct, the sensitivity is increased by about 6db when put in bridge mode.