A few basic amplifier questions

[Matt85]

Hey,

I am trying to understand a few things. I haven't really seen any place in the forums that would answer it, so I will just ask.

First off here is my proposed setup:

-Yamaha V663
- Emotiva XPA-5
-Ascend Sierra-1 LRC
-Ascend CBM-170SE x2.
-Epik Castle subwoofer

Now the questions:

I am trying to understand about the rules of adding an amp to my set-up. I have an interesting room layout. A 3000cu ft home theater room with a large opening into a 3000 cu ft dining room/ kitchen. The HT room isnt that large, in regards to length and width, but the 20 ft vaulted ceiling is is what is killin me.

Will a 5 channel amp work with a 7.1 receiver to power 5 speakers?

If I decide to only get a 2 channel amp for the LR Sierras, would this be a bad idea because the speakers may no longer be equalized with each other as they will be amplified differenty?

Also am I right in thinking that if I go with the XPA-5, I would hook up the receiver's pre-outs using RCAs to the amp, then from the amp to the speakers using speaker cable? Given that the V663 is a 7.1, it should have pre-outs for all channels, which would mean that if I decide to go to a full 7.1, and desire amplification, I would simply need to pick up an additional 2 channel amp, (XPA-2). I think I have the logic right, just want to make sure.

Especially interested in what you folks have to say regarding only amplifying certain channels in your multichannel setups.

For the record, I am 99% HT, and 1% music.

Thanks alot!

Matt

 

[MDS]

Will a 5 channel amp work with a 7.1 receiver to power 5 speakers?

Yes and the receiver can power the other two.

If I decide to only get a 2 channel amp for the LR Sierras, would this be a bad idea because the speakers may no longer be equalized with each other as they will be amplified differenty?

You will calibrate the receiver so that each channel is at the same level.

Also am I right in thinking that if I go with the XPA-5, I would hook up the receiver's pre-outs using RCAs to the amp, then from the amp to the speakers using speaker cable? Given that the V663 is a 7.1, it should have pre-outs for all channels, which would mean that if I decide to go to a full 7.1, and desire amplification, I would simply need to pick up an additional 2 channel amp, (XPA-2). I think I have the logic right, just want to make sure.

Correct.

 

[Matt85]

So would there be any use for getting a 2 channel amp if I will have calibrate them down to match the unamplified speakers?

Should I just get an amplifier that can handle all my channels?

 

[PENG]

So would there be any use for getting a 2 channel amp if I will have calibrate them down to match the unamplified speakers?

Should I just get an amplifier that can handle all my channels?

If you set the outputs of each of the 7 channels of the 663 to the same, the 5 external amplifiers and the 2 internal amplifiers will deliver the same output levels to your speakers because power amplifiers response linearly, up to their rated limits. As long as the 663 does not have to operate beyond its rated limit, you will be fine.

Keep in mind though, if you do your calibration properly you will end up setting some of the channels to different levels because from where you sit the SPL generated by each speaker may be different depending on their locations. Regardless, it does not matter whether you have one or two different amplifiers mixed in together with each other and with the 663's internal amplifiers. They will all response to the 663's preamp linearly up to their rated output limit. So don't worry, your 663 is in total control, just enjoy your nice setup.

 

[Seth=L]

The surrounds and center should be able to be powered just fine with the receiver if you decide to just get a 2 channel amplifier to handle the front left and right. Unless your center and surrounds are hard to drive (the ones you have selected are not) then I wouldn't be to concerned about getting a 5 or 7 channel amplifier to power them.

 

[cfrizz]

You have it all figured out correctly.

I think you should get a 5 or 7 channel amplifier and be done with it at one time.

That amp can be used to drive any speakers you have now & in the future & is one less upgrade you will have to worry about.

 

[zumbo]

I like the set-up idea. Very nice indeed. Another option is to bi-amp the mains with four channels of the amp, run the center off the other channel, and power the surrounds with the receiver. Either way, a five-channel external amp is a sweet thing to have.

I use a Yamaha 1400 receiver, with an Adcom five-channel amp. I don't have my mains bi-amped, but I will try it one day. I am a little lazy. I am running the surrounds off the amp(towers at that), but they just flat-out don't need it.

 

[darien87]

So would there be any use for getting a 2 channel amp if I will have calibrate them down to match the unamplified speakers?

Should I just get an amplifier that can handle all my channels?

Getting just one amp would definitely be simpler. But generally, the more channels an amp has, the more expensive it is. So it depends on how much you are willing to spend. The XPA-2 costs the same as the XPA-5.

I happened to get a great deal on a 2-channel Onkyo amp, which I will use for my surrounds when I to 7.1. Look around for a cheap 2-channel amp. Your surrounds won't need as much power as your fronts.

 

[jcPanny]

Receiver and amp.

Matt,
Nice system. The Yamaha is a very capable receiver. You might consider starting with it driving all the speakers. If you need an amp, the emotiva is a good option. The high ceiling will effect the subs ability to pressure the room. The speaker and amp requirements are determined by the speaker's efficiency, speaker distance, and your listening preferences.

 

[Matt85]

Matt,
Nice system. The Yamaha is a very capable receiver. You might consider starting with it driving all the speakers. If you need an amp, the emotiva is a good option. The high ceiling will effect the subs ability to pressure the room. The speaker and amp requirements are determined by the speaker's efficiency, speaker distance, and your listening preferences.

That's what I plan to do actually. See how well my speakers sound with just the Yamaha. If not I think I have a better understanding of what my options are. Appreciate all the help guys.

I should have my system completed before the end of May.

The Epik castle is sure to get me evicted.



Matt

 

[Matt85]

Ok... Just to confirm that I am getting this...

If I had an external 3 channel amp for my Sierras, the difference would be that at louder volume levels, the Sierras would sound clearer and less distorted than they would without amplification. And since the 170SEs are more efficient than the Sierras, by 5db, it's pretty much unnecessary to provide amplification to them.

Is this the right type of thinking?

 

[zumbo]

Ok... Just to confirm that I am getting this...

If I had an external 3 channel amp for my Sierras, the difference would be that at louder volume levels, the Sierras would sound clearer and less distorted than they would without amplification. And since the 170SEs are more efficient than the Sierras, by 5db, it's pretty much unnecessary to provide amplification to them.

Is this the right type of thinking?

Pretty close. It's just the last part. The fact that the 170SEs have a higher sensitivity is not the reason. The fact is, there is just not that much information sent to the rears to give any reason for external amplification. The receiver power will be more than adequate.
There is a very good chance that the receiver will have more than adequate power for all of your speakers.