Newbie que on "recommended amplifier" rating

I currently have 4 Vienna Acoustics Bachs which, on Vienna's website, have an amplification recommendation of 30-200w. I am currently looking for an amp/pre to replace my very sad Onkyo receiver. I listen to 95%music and 5%home theater, but I really enjoy multichannel SACD and DVD-audio so I am looking for 5 channel amps like theta, simaudio and EAD. I like the pm 2000 for the money but it is rated at 400w into 8ohms and my Bach's are 6ohms so they would be seeing even more than that. In fact, even the theta and sim audio, which are 200w @8ohms would be above the recommended amplification into 6ohms. I want an amp that I can "grow into" (i.e. works with my next set of speakers) as well, not one tailored to Bach's specifically.
My long winded question is: Will these amps damage my speakers and, if not, where do these recommended amplifier ratings come from?
Most speaker damage occurs from using a under-powered amp than too much power. An amp 'clips' when it is driven past it's rated power, that's what damages voice coils. I believe you can never have 'clean' power. Those amps should be fine.

"I believe you can never have 'clean' power."

I think John meant to say " I believe you can never have TOO MUCH "clean" power." If that is the case, i agree wholeheartedly : )

Honestly though, you are more likely to damage a speaker from "underdriving it" ( clipping ) rather than "overdriving it" ( too much power ) unless you are simply CRANKING the volume for a good period of time. Speakers will take a helluva lot of abuse in terms of big power so long as it is not long term i.e. short term "bursts" don't build up a lot of heat whereas long term "cranking" continually cook the drivers.

As such, i would not be afraid to go with a more potent amp than what the manufacturer recommends so long as you use reasonable judgment with the volume control. Besides that, i think that all of the Vienna Acoustics speakers are slightly tougher loads ( from what i recall ), so more power would only be a good thing. Sean
I agree. You can never have too much "clean" power. 1 watt of distortion will do more damage than 200 clean watts. 1 thing you haven't looked at: Even though your speakers are 6 ohm which would increase the amp power (except with tube gear) to probably 1.25 or 1.5 to 1, what about efficiency......
A 94 db speaker will be louder at 45 watts than an 87 db speaker with 200 watts driving it! Here's the math:
3db gain by doubling the power
10db gain gives percieved doubling of volume
ie... 1 watt at 87 db = 2 watts to give you 90db, 4 watts are needed for 93db, 8 watts for 96db, 16 for 99, 32 for 102, 64 for 105, 128 for 108, 256 for 111db-THX requires 110db capability if I'm correct.
The speaker max power handling is basically determined by how much juice the drivers can physically take. One reason for this rating is to warn you in case you decide to, for example, fill an auditorium-size room with very high SPL levels which requires a lot of power. The power level required to reproduce what you want may be in excess of what the speaker can handle. It's your room and the sound levels you want to produce therein that determines how much power you'll need.

For most home listening room environments, about a tenth of a typical SS amp's power can produce more than enough sound levels for most types of listening. Rarely will you need to crank up the volume to the point of 100% of amplifier potential. Even though your speakers may be rated for 200W maximum, a 400W amp can be attenuated down to a fraction of its rating, so it will not harm your speakers. The only time this could be a problem is if the volume knob is unknowingly pegged full when you start a CD. This type of damage is, I think, very rare.

As far as your speakers being 6 ohm and not 8, this can be a little misleading. It's just an "average" impedance. The actual impedance will most likely vary at different frequencies. Better for an amp to see a flat impedance at 6 ohms instead of one of "8 ohms" that fluctuates all over the place between 1 and 8 ohms. Personally, I would not consider it a factor that an amp has a greater power rating than the speakers can handle - I'd never use it.
Most manufacturers recommendations are based upon a standard 8 Ohm rating of solid state amps. While I don't condone this, I'm sure they are just trying to keep it simple. Unless your speaker manufacturer is unique and more specific, you shouldn't have anything to worry about. In fact, you can raise the power by the scale so kindly supplied above, to better meet your needs.
Thanks Sean. Yes that is what I meant to say. If only my co-workers would leave me alone at work, I probably wouldn't lose my train of.


D@mn! It happened again! I probably wouldn't lose my train of thought. YOU CAN NEVER HAVE TOO MUCH CLEAN POWER.
A 400 watt amp is sized perfectly for a 200 watt speaker. Go for it!
I agree with Bob Bundus.

Since we are on this subject, how much power can a pair of Bose 901's handle ? I think that, ever since the Series IV, Bose has stated "unlimited power handling capabilities". Is that because the 24 gauge wiring inside the cabinets limits power transfer or do they have actual light bulbs inside of them to absorb voltages above a certain point ? While this would result in dynamic compression of the speaker, they did this with the earlier versions of 201's, 301's, 601's, etc... Obviously, this was done as a matter of protection and the resultant loss in sound quality was of little concern. I don't know if this "high tech" approach ever made it into the 901's though. Sean

PS... I managed to blow a 901 up way back when, but they were the original version and "only" rated at 270 watts rms. When an amp rated at 350 wpc ( Phase Linear 700B ) swings the meters FULLY off scale, you have to wonder how much power that really is : ) Sean
Sean, even then? I only hope your craze for power is limited to audio. Wait a minute, I remember reading about some of your previous automobiles. Remember... I'm on your side... we're bud's, right? Seriously, did they actually put light bulbs in their speakers? I've heard of diodes being used, but jeesh. I know Bose threatened to sue Thiel over the use of a decimal point. Do you think they'd actually go after GE or Phillips if a blown bulb blew their guarantee?
Sean actually is Tim Allen in real life. You know, Tim 'The Tool Man' Taylor. MORE POWER! urgh urgh urgh.

I was going to ask what is a Bose 901? But I thought some may take me seriously.

Yes, Bose did put light bulbs in their speakers. As voltage levels increase, there is enough energy there to light up the bulbs. The bulbs can be lit full time if the energy level is of a high enough average or only light up momentarily on peaks if the music is basically low level with big dynamic swings. Obviously, the power transfer from amp to drivers is not very linear in this fashion, but i don't think that the manufacturer was really worried about this. The end result is reduced dynamic range i.e. "squashed" peaks AND less warranty claims from blown drivers.

For the record, i found this out when i was 13 years old with a pair of 301's. I was listening to some music at volume ( you would have never guessed, huh ??? ) with the grill's off and i saw something "flashing" out of the ports. I instantly thought that something was arcing or burning up in the speaker, so i ran over and turned the volume down. Being the technical geek that i am ( yes, even back then ), i took the speaker apart to see what was happening. Needless to say, that is when i discovered the light bulbs. I still have the crossovers from those 301's as a reminder of how "junk" can be foisted upon the mass market and made to look desirable. The good thing is, the light bulbs still work and i could use them in an emergency if i had to : ) Sean
Thanks everyone, very informative...I'm going shopping:)