Crown XLS-1000?

needspeed52 said:

Hello,
I'm thinking of getting this pro amp, 230 watts @ 8 ohms, weight 11 lbs. I can get it really cheap, I would like to know if most receivers preamp outs could drive this amp, I don't know my receivers output voltage. One other question, the literature states this amp can bridged or comformed to a mono amp, how does one do this, make a mono amp out of a stereo amp?
Thanks Jeff

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That is an awfully light Amplifier.

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GranteedEV said:

I think the crown drivecores are a great choice. I hope your receiver is decent enough to drive this amp. Its rated sensitivity for full rated power, is 1.4 vRMS - only a really poor preamp output would fail to drive that to full power.

Bridging depends on each individual amp as different amps have different methods. It shouldn't be difficult although I'd be careful with bridging. What is the Z-chart of your speakers?



Yep, it's a class D, temp-controlled fan-cooled design. According to SAC, the fan doesn't kick in unless you REALLY push it to high SPLs. Amazing what is possible today! This kind of performance in the 1970s would weigh over 100lbs at least!

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Jungle Jack said:

Jeff,
Usually there is a switch for Stereo or Mono Operation. That is an awfully light Amplifier. As for the Preamp Voltage of your AVR, what AVR are you using? Not all Pre Amp Sections are created equal. You might be better off with a Behringer as many folks with AVR's have used them with no issues.
Cheers,
JJ

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jackfish said:

The Crown XLS Drivecore amps are Class D with a switching power supply, and have RCA inputs with input voltages and impedances compatible with most home stereo preamps. However, I think the XLS 1000 is rated at 215 wpc into 8 Ohms (1kHz and 0.5 THD). Between bridged mono capability and the robust crossover this is an attractive option for a lot of applications. Bridging is set with the menu on the LCD display.

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needspeed52 said:

Jack, I have just read correct me if I'm wrong, that by connecting a speaker wire from the + side of the first stereo channel of the amp to the + terminal on the speaker and connect another speaker wire from the second stereo channel's - output to the same speaker's - terminal you will have successfuly bridged the stereo amp for mono operation thus increasing power output also doubling the output impedance, if the amp in stereo mode outputs 2 ohms in mono it would be 4 ohms, how will doubling the output impedance affect the speaker it is connected to? Thanks my friend.
Jeff

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jackfish said:

When bridged and connected to a 4 Ohm load the two channels within the Crown XLS 1000 will be operating into 2 Ohms. This amplifier is designed for this. So yes, you could get two Crown XLS 1000 amps and use them as a pair of mono amps producing 1100 watts into 4 Ohms, 1 kHz and 0.5% THD. The speaker is what determines the load the amplifier will "see", so if you have 4 Ohm speakers there is no affect on the speakers other than being supplied the power produced. If you have loudspeakers which dip below 4 Ohms it could be a problem for the amp as impedance would drop below 2 Ohms internally.

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jackfish said:

When bridged and connected to a 4 Ohm load the two channels within the Crown XLS 1000 will be operating into 2 Ohms. This amplifier is designed for this. So yes, you could get two Crown XLS 1000 amps and use them as a pair of mono amps producing 1100 watts into 4 Ohms, 1 kHz and 0.5% THD. The speaker is what determines the load the amplifier will "see", so if you have 4 Ohm speakers there is no affect on the speakers other than being supplied the power produced. If you have loudspeakers which dip below 4 Ohms it could be a problem for the amp as impedance would drop below 2 Ohms internally.

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bsoko2 said:

The Crown XLS is not designed for 2 ohms when bridged. This is per Crown tech support. It will do 2 ohm load when in Stereo mode only.

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jackfish said:

When bridged and connected to a 4 Ohm load the two channels within the Crown XLS 1000 will be operating into 2 Ohms. This amplifier is designed for this. So yes, you could get two Crown XLS 1000 amps and use them as a pair of mono amps producing 1100 watts into 4 Ohms, 1 kHz and 0.5% THD. The speaker is what determines the load the amplifier will "see", so if you have 4 Ohm speakers there is no affect on the speakers other than being supplied the power produced. If you have loudspeakers which dip below 4 Ohms it could be a problem for the amp as impedance would drop below 2 Ohms internally.

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bsoko2 said:

The Crown XLS is not designed for 2 ohms when bridged. This is per Crown tech support. It will do 2 ohm load when in Stereo mode only.

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jackfish said:

Please read carefully. As you have stated the Crown XLS 1000 will operate into a 2 Ohm load in stereo mode. When bridged it will operate into a 4 Ohm load. However, each of the two channels internally are operating into 2 Ohms when the amp is bridged (think of the two channels operating in parallel) and the bridged amp as a single channel is operating into 4 Ohms. If the bridged amp were presented with an 8 Ohm load on that single channel, internally each channel of the amplifier would be operating into 4 Ohms. That's how bridging works. That's why when the amplifier is bridged and impedances from the loudspeaker drops below 4 Ohms it could cause the amplifier into a fault condition as each channel internally would be seeing less than 2 Ohms. Is that now clear? Sorry for the confusion.

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