Multiple Amps and Multiple Speaker Sets

[Guest]

Lurking around various audio forums I notice that many people have multiple amps in the setups.
Without being facetious, why?

Do you use different amps for different purposes depending on the input?
Do you have a different set of speakers connected to each amp, or do you use the same speakers, connecting and reconnecting them as required?
Or, can you connect the same speakers to different amps simultaneously?

 

[americanaudiophile]

There are many reasons to use multiple amps. Sometimes people switch amplifiers because there are trade offs in the sound of each so they use one with certain music another with other music.
Primarily though multiple amplifiers would be used in biamplifed or triamplified system. In a standard system a single amp would handle the full range and the passive crossover inside the speaker would send only the correct range of sound to the speaker ie bass to the woofer, mids and highs to the tweeter/mids. In a biamp system there is no passive crossover so the division of sound is done before the amplifiers with an electronic crossover (this is the same as using a powered subwoofer with a surround system). The amp is connected directly to the individual speaker. That way you can tailor the amount of power and sound of the amp to the range and the type of speaker.
You could have a solid state high power monster on the woofers and a tube or class A low powered amp on the tweeter. Many self powered studio monitors are built like this internally with a separate amp for each driver.
Many speakers are built for biwiring which means that there are four speaker terminals instead of two. That gives you access to the woofer separately. There is still a passive crossover inside but some people like to play with putting different amplifiers or two smaller identical amps instead of one bigger one. This is called vertical amping rather than biamping.
Large pro sound systems are all built for multiamping since it allows a great deal of adjustment. lowers distortion and allows for higher spl levels.

 

[tomc53]

In addition to Bi-amping, multiple amplifers can be used for surround systems and zoning. Suppound sound can utilize as many as 8 channels of amplification, needing multiple discrete amplifiers.
Some audiophiles prefer to use 'monoblock' amplifiers, where a separate unit is used for each channel.
Zoning is a term for supplying sound to multiple rooms or venues, such as background music for a dining room or a patio while a movie is playing in the family room.
And as noted above, diferent amplifiers may be more suitable for different types of music, such as Rock or Classical. In those cases, the listener may also use different speakers, as well, for the character of the music.

 

[thee_prisoner]

In my case I use separate amps because they add more flexibility in my surround sound system(s) and the amps are better quality compared to amps in receivers. Now there are good quality multi amps in one unit that can deliver the power to a 5.0 system and get either a powered sub or a amp to power the sub. Subs can suck up a lot of power!

With receivers, the amps are in them are average at best. They are fine for driving 2.0 but if they have to drive 5.0 and even worse 5.1/7.1, you might(will) have some problems.

In terms of some speakers they require a good amp. A receiver for example except a McIntosh(and other good quality receivers) won't drive certain types of speakers but for low end/regular consumer grade speakers, a decent receiver should be fine for 2.0 and possibly 3.0. Although, if people are buying to mid to high end speakers, they won't be using a receiver to power them anyways.

IF you have a new/used stereo store nearby, it's fun to check out. Usually the sales people are really passionate about audio and let you hang around and listen.

be seeing you, the Prisoner...

 

[Guest]

IF you have a new/used stereo store nearby, it's fun to check out. Usually the sales people are really passionate about audio and let you hang around and listen.

There is one locally and I pop in from time to time. Hundreds of thousands of dollars of used gear. Like Aladdins cave.

 

[thee_prisoner]

Ask if they have trade in. For example my local shop if a buy a 200.00 used amp they let me trade in that amp for 200.00 at a later date and purchase something else. Usually it's about a one to two year trade in value. To build up my system(s)s, I shop garage sales, thrift store and etc and use for trade plus buy used from the shop and trade up.

I was lucky also since my grandfather was a big audio equipment collector(and model train collector) so I received a ton of stuff from him, running form vintage to somewhat new at that time.

Happy hunting, the Prisoner...

 

[Fidgetmaster]

Man don't forget multiple Amps are so useful for true awesome sounding Stereo setup in a room you know. I'm not much of a Solid state Guy at least in power section of Amps though, Much prefer Tubes, the interaction with Tubes and output transformer is really amazing sound wise. Nothing quite like a quad of EL34s or 6550s just roaring away and devastating things haha. Sadly current Produced tubes just are not what they use to be Quality wise. and yes more speakers sound pretty good too haha

 

[tomc53]

I just rrealized that we have not answered your last question --
No, you cannot connect a speaker to two amps simultaneously, except in the special case of bridging.

Bridging is connecting identical amps (usually the left and right of a stereo amp) with a special connection to double (more or less) the powetr to the speaker. It looks something like this:

source -> Left Amp -> + Speaker - <- Right Amp

The amp has a switch to connect the right amp to the source out-of-phase to assist in driving the speaker so that when L has a positive signal, R has a negative signal, thus doubleing the voltage across the speaker. The amplifiers share the impedance, such that for an 8 ohm speaker, each amp sees 4 ohms.