Need help to get to know more about home theater basics

duckwingman
duckwingman Posts: 2
edited May 2012 in Troubleshooting
what exactly is watts per channel? it says 90 watts per channel but does it divide off to each speaker if you have a
5.1 making it 18 watts to each speaker or what?
- 90/5=18
also i have speakers that are rated for 100 watts per channel...http://reviews.cnet.com/surround-speaker-systems/energy-take-classic-5/4505-7868_7-33310963.html?tag=contentMain;contentBody;1r.... but what watt per channel
will I need to safely power the speakers.
Also do I need a 4 ohm receiver if i want to upgrade speakers in the future. And how do you know if the speakers/rec
-eiver will be loud? Hope you can help, thanks
Post edited by duckwingman on

Comments

  • mcnarus
    mcnarus Posts: 20
    edited May 2012
    The short answer is, it's complicated.

    Watts per channel is a reflection of the power supposedly available to each speaker. So if it's a 5.1 receiver, it can deliver 90 watts to each speaker—under the conditions in which the spec was measured. That last part is important. You certainly don't use an amp the way the FTC requires that it be measured. But it is at least a reflection of the amp's power, and somewhat comparable from amp to amp.

    The good news is that you almost never need anywhere near the amount of power you have. Generally, your amp chugs along putting out a watt or so of power into each channel, and only gets stressed when there's a sudden loud burst.

    As for safely driving speakers, by far the greatest threat to speakers is user stupidity. Speakers often list minimum and maximum recommended amplifier power, and you can use that as a guide, esp. on the low end. But I wouldn't worry if your amp is more powerful than the recommended maximum. Just don't turn it up to far too fast.

    A receiver that's rated at 4 ohms will give you more flexibility in choosing speakers down the line. But there are plenty of good 8 ohm speakers out there. And you might well upgrade the receiver first.

    Loudness is a function of everything: amplifier power, speaker sensitivity, room size, personal tastes. The best way to find out is to try a system out and see if it's satisfactory for you. But remember that there isn't that much difference between amps. A 100-watt amp can play only 3 dB louder than a 50-watt amp. If you want something that sounds twice as loud as a 50-watt amp, you need 500 watts.
  • teekay0007
    teekay0007 Posts: 2,289
    edited May 2012
    Welcome to Club Polk!

    Here's a link to a Home Theater Handbook written by Anthony Chiarella and Matthew Polk: http://www.polkaudio.com/education/hthandbook.php

    It's a bit dated, but will still give you all the basics to get you started.

    Watts Per Channel, or WPC, is the amount of power the receiver or amplifier should deliver to each channel. In a 5.1 receiver, it SHOULD deliver 90 Watts to each of the 5 channels (speakers) - total of 5 x 90 = 450 Watts total output. However, different manufacturers tend to use different measuring techniques and the numbers are usually inflated. You need to read the receiver's/amp's specifications listing. Most often, the spec's will list the power ratings "with two channels driven" and the actual numbers to each of five are considerably lower. The ".1" part of the 5.1 means that the receiver has a pre-amp output to connect to one powered (built-in amplifier) subwoofer. Similarly, if it were a 7.2 receiver, it would drive 7 speakers and have two subwoofer pre-amp outputs.

    With a quality brand receiver that's rated for 90 WPC you should have plenty of power for speakers that are rated for 100 WPC. Whether it's clean (distortion-free) power or not is another story. Cheap receivers often give overinflated power ratings and the power provided is far from clean, which can damage your speakers.

    Also, it's a RARE (and usually very expensive) receiver that can adequately drive 4 Ohm speakers in a home theater setup. Some reasonably-priced ones - must be rated for use with a 4 Ohm load - can drive a 4 Ohm, 2-channel setup pretty well. If you think you might upgrade to 4 Ohm speakers in the future, it's best to get a good receiver equipped with pre-outs on it. These pre-outs connect to power amplifiers that will then boost the signal and drive the 4 Ohm speakers MUCH better. In the meantime, you would just use the speaker output terminals on the receiver to drive your 8 Ohm speakers.

    Hope this helps.
  • duckwingman
    duckwingman Posts: 2
    edited May 2012
    Thank you so much you guys helped a bunch. You deserve a thumbs up:cheesygrin:
  • kidglove13
    kidglove13 Posts: 207
    edited May 2012
    The Energy subwoofer speaker system you referenced is a decent starting point from a good canadian speaker company, that is if they are still making the speakers in Canada and should make for a pretty easy setup with decent sound
    Like others have said you will not run into 4 ohm home theater speakers unless you are spending big bucks
    I would start with a good mid-level Yamaha or Denon AVR with HDMI and go from there.
    I think that an AVR from either one of those companies will make you happy.
    You can always upgrade as time goes on, I believe in keeping it simple, especially if this is your first step into real home theater.
    You never did say what TV you are going to use with the system?