Risk using amp Wattage than speaker rating?


I'd like to upgrade the amp for my Vandersteen 3A Sigs, but am a bit confused on whether or not I need to stay within the band of wattage (100 - 200 into 8 ohms) that is *strongly* recommended in the manual. I've read several articles/blogs/forum posts stating that exceeding the recommend power range for a loudspeaker system should be of a little concern, as long as you don't "push them too hard". What exactly does that mean? How much risk of damaging my speakers would there be if I used a 300 W/ch (into 8 ohms) amp with my speakers? I have a fairly large room, if that makes a difference. I appreciate any advice, as you all seem to be very knowledgeable about audio and have a lot of experience. Thanks, Rob
rtrauthwein
1) How big is your room and 2) from your listening position, how loud (in dB)do you like to listen most of the time?
I have not had any problems exceeding the suggested wattage range. Pushing them hard means playing them loudly with a distorted signal from the power amp or section of an inregrated/receiver. It is the distortion or clipping that blows your speaker. In many cases having an under powered amp is the reason that a speaker blows. The reason for that is that the small output amp strains when trying to get to the desired volume, that straining pushes the amp into clipping and sending a distorted or irregular wave form to the speakers. So the bottom line is not to drive your speakers with distortion, powerful will likely distort at higher volume than a small amp will.
All that said it is of course possible to exceed the speaker's ability to fill the room at the volume you desire. You can blow the drivers simply by sending a more powerful signal than they can deal with. I don't know if your speakers have a very limited maximum output in terms of Db, and thus the stern warning from the manufacturer. A Db meter can be bought at Radio Shack, they are inexpensive. Never the less the most dangerous and most likely problem remains distortion IMO.
Exactly. And when that distortion is being caused by an over driven amp, it's going to be excessive heat that literally "fries" your drivers. Mechans is dead on. Unlimited power eliminates this factor from the scenario. I would definitely not use a classical cd to see how far I could go with my speakers, but buzzing due to over driven speakers versus buzzing due to an over driven amp is way less dangerous. Just turn down the volume and be reasonable.
I second the previous comments. Probably the most common speaker damage scenario is blown tweeters resulting from the distorted signal that would be produced if an underpowered amp is asked to put out more power than it is capable of.

Based on some rough calculations, your speakers should be able to produce an SPL (sound pressure level) of about 100 to 102 db at a listening distance of 4 meters (about 13 feet), when driven by an amplifier rated at 200 watts into 8 ohms. Most listeners would be unlikely to raise the volume level high enough to send more power than that into the speakers. And even if you did, it would probably just be on occasional brief peaks, which would probably not do any harm as long as the amplifier's maximum power capability is not exceeded.

Regards,
-- Al
@Stevecham: 1) very large room. ~16'x24', it opens to the kitchen and the ceiling is vaulted and transitions from about 8' in the kitchen to 18' in the front of the room. primary listening position is ~13 ft from speakers. 2) I'm not sure about the dB level. Normally, listening levels are moderate, but occasionally I like to crank it. I am very protective of my hearing though, so if I begin to experience any discomfort, I always back it off a bit.

@Mechans, @Csontos, @Almarg, thanks for your input. This is the impression that I've gotten from my research so far, but it is always nice to be reassured some more.

-Rob