Getting a crown amp for home theater 2 main tower speaker.?

An amp is capable of a peak voltage but with certain current limitations. Those voltage and current limitations are described by citing the power into 8, and 4, and maybe 2 Ohms. There is no switch. An amp will have less distortion into 8 ohms or higher, but you can get a couple dB louder into a lower impedance. Unless your amp is less than 10 Watts, you don't need more power. Your speakers are more important and the power is not the critical spec. Be sure you listened to each speaker and chose the one that sounded best to you. Hopefully that means clear and natural sounding.

Amp For Home Theater

Simple answer: If your speakers are 8 ohms and you plan to keep them, buy an amp that is most efficient when driving 8 ohm speakers. The crown amp is probably designed for use in cars as it claims to deliver 775 watts into 2 ohms. This amp is almost certainly well overrated power-wise and the watts rating is probably a "max " rating which means that it can deliver only a short burst of power at that wattage - its continuous aka RMS rating is probably much less.

No there isn't a switch. This amp is most efficient with a 2 ohm load, and it can drive 8 ohm speakers safely but with greatly reduced power. If you use this amp you are likely to be disappointed with the sound.

Amp For Home Theater

STOP!!

Your car has a speed limit at which it will be destroyed if it hits a wall. There are more important things to consider.

Your tower speakers have a upper limit of 300 watts. But this is a upper limit and there are more important things to consider.

So you do not need to find an amp that matches the crash into a wall upper limit of a speaker.

In truth over the course of a movie each speaker will receive an average of ... 15-20 watts of power.

You are probably fine with a name brand av receiver that can honestly output about 100 watts per channel.

Crown amplifiers are class D pro stage amps. They use fairly large internal fans to dispel heat, and so can undoubtedly run loads that would overheat similar builds, but when they heat, and the fans start to run, you will not enjoy the noise. they are rated at a rather high THD, though acceptable for rock. Their stereo amps can be bridged to mono operation, which for class D usually means when bridged, for 8 ohm loads only, However, Crown s site is not shy about providing the gory details on their products, and your answer will be there, not here. They do not contain pre- amps, They are power stage amps only. Considering their use in bands, I would not be very surprised to find that used amps have received tonnage of abuse. Although made in China, so are many well thought of brands, such as Outlaw, and quite frankly a majority of alternatives these days, regardless of who is doing the engineering. They do include built in variable, tune-able filters, software for which which can be gotten from Crown. However, they are not made for home use particularly, perhaps better for karaoke and eh, band gigs. A lot of them do get sold to run big subs, so forth, in some homes. They are well warranted, but you again, should check their site.

If you're dead set on running a separate amp for your front speakers, then you need to run identical amps to ALL the speakers, or you won't have a "home theater" anymore. You'll have a home STEREO with limited surround sound capabilities. Surround sound receivers nowadays put equal power to all 5 (or 7) channels for a good reason, because the THX standard (as well as DTS) demands a certain dynamic range to all the speakers. So if you're dead set on separate amplification, either spend the money on a proper 5 or 7 channel amp, run multiple identical amps, or do the easy (and probably correct for you) thing and get a receiver that's a bit more in the "upper range" of products. If power is an issue, you probably are running a cheaper receiver. It would make more sense to upgrade it, or, as I said, run a 5 or 7 channel amp.

Any given voltage across 4 ohms results in twice as much current as the same voltage across 8 ohms. Most amplifiers cannot maintain the same voltage when impedance is halved however so they cannot double their power into half the impedance. If it could it would be 600 into 4 and 1200 into 2 ohms assuming it can do 300 into 8 ohms. So no, there should not be a switch, it's just inherent that the amplifier will be capable of more power into lower impedance up to a point. Because the crown only increases from 525 watts to 775 watts going from 4 to 2 ohms it is clearly reaching its limits at 2 ohms.

There are amplifiers out there that can double their power when impedance is halved all the way down to 1 ohm but these are generally very expensive. Amplifiers like Krell mono blocks are an example.

mk

Don't even waste your money on Crown - it's China trash hiding behind a once trusted brand.

If you choose to ignore my strong advice (having sent many to the landfill), the amp does not switch when used in stereo mode. The only switch would be to change from stereo to mono bridged mode. You absolutely MUST know what you are doing when dealing with a pro audio amp, especially a disposable one like a Crown.

The problem I see with Crown amps are that many have a built in fan in commercial use its not too much of a problem but in home use often the noise of the fan is audible during quiet passages of a movie...Many amplifiers used in quality AV receivers are actually capable of pushing 4 ohm loads but the problem is heat build up so they only rate the amp at 6 ohm loads due to the fact that the receiver does not have adequate heat dispersion for 4 ohm loads...Crown is able to push further down due to the fan providing greater heat dispersion....