Please help me understand how much power I really need

[stewart715]

I have spots for 10 speakers (5 zones with 2 speakers in each) and I am replacing them with new ones. I'm not sure what yet, but I have been looking at these:

Polk Audio RC80i 2-Way In-Ceiling Speakers

These are 8 ohm speakers rated for:

50 watts peak power handling
130 watts RMS

For an amplifier...

Do I need something like this, which is 65 watts RMS per channel:
DMA-1275 High Efficiency Mulit-Channel Amplifier[/url]

Or something less powerful like this (40 watts RMS per channel):
DMA-1240 High Efficiency Multi-Channel Amplifier

OR should I go with a couple stereo amplifiers instead of the 12 channel one and use a speaker selector.

I'm just trying to figure out a gauge for how much power I will need when shopping for speakers.


I'm pretty confused as to what numbers to look at and if I need to match the power or if being under is sufficient (and if so, how under is sufficient).

If anyone could bluntly explain this to me it would be appreciated.

 

[ImcLoud]

I have spots for 10 speakers (5 zones with 2 speakers in each) and I am replacing them with new ones. I'm not sure what yet, but I have been looking at these:

Polk Audio RC80i 2-Way In-Ceiling Speakers

These are 8 ohm speakers rated for:

50 watts peak power handling
130 watts RMS

For an amplifier...

Do I need something like this, which is 65 watts RMS per channel:
DMA-1275 High Efficiency Mulit-Channel Amplifier[/url]

Or something less powerful like this (40 watts RMS per channel):
DMA-1240 High Efficiency Multi-Channel Amplifier

OR should I go with a couple stereo amplifiers instead of the 12 channel one and use a speaker selector.

I'm just trying to figure out a gauge for how much power I will need when shopping for speakers.


I'm pretty confused as to what numbers to look at and if I need to match the power or if being under is sufficient (and if so, how under is sufficient).

If anyone could bluntly explain this to me it would be appreciated.

SNELL OH-T7 Full-range 6.5-inch coax “Direct Power†waveguide Each | Accessories4less these are a steal. not sure what size holes you have rite now...

As far as how much power- I run 6 zones of 2 off of a upa200 which is 250watts total and it never even gets a workout, honestly I would be surrised if we use half of its power, but we mostly use it for ambiance background music or when my wife is cleaning......

To figure out how much power you need, first pick a speaker, then look up the sens rating, and then choose your listening level, and you listening distance, then plug it all in the calculator...
Amplifier Power Required Calculator

So if you use them Snell speakers which have a 1w @1m sens of 88db, and want to listen at 85db 12 feet away {call it 4m}, you need about 16watts {with 3db of headroom}... I like to double them figure or go for 6db headroom...
I would take the largest room and use the measurements from it...

Now as far as multi channel amps, there are some guys that like them , but I had some bad luck with them and since I went to a monoprice selector box and emotiva 2 channel amp I havent had one problem, smooth as silk...

The dayton apa150 amps are also a good lower price choice, but for your system I would go with the UPA500 and 2 selector boxes, this will give you 80w per channel {with an extra channel for a mono sub maybe } Or if you want more power a pair of upa200's... Just make sure what ever you get is 4 ohm stable....

 

[stewart715]

Thanks alot, I think I'm beginning to understand, although that calculator doesn't seem to be working for me.

I've been looking at those Snell speakers -- have you or anyone used that website? Are they reliable?

 

[zieglj01]

I've been looking at those Snell speakers -- have you or anyone used that website? Are they reliable?

AC4L is a very good company > they have been around
for a while, and have good customer sevice. A lot of us
buy from them. I reccomend them.

 

[stewart715]

Cool thanks...


So, since the UPA-200 outputs 2 channels @ 125W...

Could I just use the Zone 2 Amp Assignments on my Denon AVR-3312CI (they are rated for 125 watts per channel)? Is that essentially the same thing?

 

[ImcLoud]

Cool thanks...


So, since the UPA-200 outputs 2 channels @ 125W...

Could I just use the Zone 2 Amp Assignments on my Denon AVR-3312CI (they are rated for 125 watts per channel)? Is that essentially the same thing?

I wouldnt, I dont think your avr will appreciate swinging down to 4 ohms... Plus then you can not listen to music through the house and play TV in the living room...

If your avr doesnt have preout zone 2, then you can always get a pure i20 and plug that into the amps inputs, I assuming you are using Ipod for multi room source?

 

[stewart715]

Oh, those snells are 4 ohm speakers? I have preamps for zone 2 and 3.

 

[ImcLoud]

They are 8 ohm, but when you wire 12 8 ohms speakers together like that you will end up with a /10th ohm load lol or end up with no power per speaker, the selector box helps you with that, but it can swing as low as 4 ohms, so as a rule of thumb you want a 4 ohm capable amplifier...

 

[markw]

Personally, I think you would be better off with that 12 channel amp. That way, each speaker has its own amp, you won't need to worry about klunky switches and impedance matching and, conversely, each amp won't need to be that powerful.

Tat DMA 1275 seems ideal, even if overpowered for your purposes, and if you can find one for a reasonable price, I'd jump on it.

But, YMMV

 

[zieglj01]

Personally, I think you would be better off with that 12 channel amp. That way, each speaker has its own amp, you won't need to worry about klunky switches and impedance matching and, conversely, each amp won't need to be that powerful.

Tat DMA 1275 seems ideal, even if overpowered for your purposes, and if you can find one for a reasonable price, I'd jump on it.

I like the looks and options of that amp.

 

[stewart715]

At first I thought for the price, that was the way to go (and I still think I might get it). However, I'm leaning towards just getting one of these for each zone:

mini-X a-100 | 50W x 2 | Emotiva Audio | High-end audio components for audiophiles and videophiles, spanning 2-channel music systems, as well as 5.1 and 7.1 home theaters. Products include multichannel amplifiers, stereo amplifiers, and monoblock amp

Any reason not to?

 

[zieglj01]

At first I thought for the price, that was the way to go (and I still think I might get it). However, I'm leaning towards just getting one of these for each zone:
mini-X a-100 | 50W x 2 | Emotiva Audio | High-end audio components for audiophiles and videophiles, spanning 2-channel music systems, as well as 5.1 and 7.1 home theaters. Products include multichannel amplifiers, stereo amplifiers, and monoblock amp
Any reason not to?

So you like the idea, of having more equipment around the house?

 

[stewart715]

So you like the idea, of having more equipment around the house.

Haha I just think it's a better, more reliable product. And it would be cheaper since I only need 5 channels and not all 6. Also they look cool.

Outside all of that, no harm in doing that right?