How much power really needed

[BC Dave]

I know that when it comes to power in a home theater system, you can't have too much, and if we could all afford it we'd have separate 200 watt five-channel amps weighing 60 pounds.

However, if you have a powered sub and you set all your speakers to small, wouldn't a receiver basically be loafing along by not having to reproduce bass below 100 or 80 hertz, even at relatively high volumes? Or is 80 hertz still quite taxing on a receiver's power supply?

Also, isn't it fairly rare that a receiver would be called upon to deliver full power to five channels simultaneously? Thanks in advance.

[markw]

I can't argue with anything you've said. True, deep bass sucks up most power. By channeling the bass to a dedicated powered sub you drastically decrease the demands on the mains amp.

Generally, I prefer to run full range mains, set to "large", but even with this the sub takes over most of the hard, low stuff. By running small mains you do decrease the demands somewhat but even running large, the LFE takes a good amount of wotk off the mains.

The key is running speakers as "large" is that they know their limits and simply don't even bother to try to do the lows. Nothing like a speaker fart to ruin a good experience. If that happens, it's time to go back to the "small" settings.

FWIW, I use my system for mainly music so the large setting is nice. It's rare that the sub is ever called upon but it's nice for when I do want it. ... Like the Herford recordings of Bach's Organ works on Philips.

Also true that it's rare that all channels are called upon for max power simultaneously, but it does happen on some occasions.

You show good insight and logic for a "newbie" here. Welcome.

[spacedeckman]

I wouldn't be very interested, though in a 200x6 amp that only weighed 60 lbs. 200x2, maybe. I've got a Parasound Halo for another weekend, then it has to go back home until I save the money to get one. That one is 250x2 and comes in around 70 lbs. Very well done piece, I may add. It is incredibly powerful, and makes my little bookshelf speakers do positively evil things.

On a normal day, I'm very happy with my 35 watts, and used to be very happy with 20. Most of your listening is done at a fraction of a watt, and even a watt is pretty dang loud with any normal speakers. My usual "big" solid state amp is 70 watts....ooohhhh!!!, and does quite well for itself too. My rule for the day is to buy quality over quanitity and you will be a happy listener.

[uncooked]

what do you mean average is only a fraction of a watt? can you explain this to me. i have a 80 x 6 yamaha, and a 100 x 5 panny. and when i crank them its loud, but not even close to ear popping loud. the yamaha and the panny go to the same volume i would say but the yammy stays very clear at high volumes. i registered my yamaha system in with a db meter from radio shack and, cranked it was off the scale on the highest setting, like 110 - 130 db +

BUT to me its not really THAT loud. i wish i had more power. i think the yamaha 1400, or 2400 would be perfect for me.

my average listening level is like 1/4 on the amps volume, how can that be only a fraction of a watt? wouldnt it be like 20 - 30?

thanks for the info who ever responds, and straightens me out :)

[Geoffcin]

I know that when it comes to power in a home theater system, you can't have too much, and if we could all afford it we'd have separate 200 watt five-channel amps weighing 60 pounds.

However, if you have a powered sub and you set all your speakers to small, wouldn't a receiver basically be loafing along by not having to reproduce bass below 100 or 80 hertz, even at relatively high volumes? Or is 80 hertz still quite taxing on a receiver's power supply?

Also, isn't it fairly rare that a receiver would be called upon to deliver full power to five channels simultaneously? Thanks in advance.

You have hit the nail on the head when it comes to HT, and receiver power. In home theater, it actually IS pretty common for a reciever to be called upon to deliver high power to at least the front three speakers at once. Every time there's an explosion, gunshot, or other effect, the power requierments can easily exceed the receivers ability to diliver the current, if only for a moment. I would say that most of the mid-range receivers are not up to the challenge without a self powered sub. Fortunately on most movies a lot of the low frequency energy is directed into the LFE (.1) channel. So even if you set your speakers to LARGE, and DO NOT cross them over @ 80 or 100hz, they will not overtax the receivers amp IF you have a powered sub also. I recommend that if you have full range speakers that you should leave the receivers settings to LARGE.

Another solution is to go with self powered speakers. My HT mains, the Cambridge Soundworks T500, have a 300 watt amp built in to power the woofer, and they also serve as my HT subs.

Of course the most expensive, and overall best solution is a high current multi-channel amp.

[spacedeckman]

Your volume control works LOGRITHMICLY. The first part is tapered to increase slowly, then increases more rapidly. The volume control on the Yamaha works linearly (like is shows in dB on the display) but the display bar works logrithmicly.

It takes 10x the power to double your output, and doubling your output will only increase the sound output slightly. Trying to look at your volume control to guage output wattage doesn't work.

The Yamaha sounds better when cranked up a bit because it has an amplifier built to better handle real world loads. The Panasonic has a much poorer amplifier and power supply, and is built to look good on paper to an inexperienced consumer. The new Panasonic 25 is rated at 100x5or6 at 6 ohms (worth a 20-25% up in watts, not power, on the rating) at 1kHz (decrease number by 20-25% again to get closer to full bandwidth rating) with 1% THD. Think about this for a second. The real problems from a distortion point of view come from the frequency extremes. The 1kHz rating ignores the extremes, showing a real problem from a design standpoint. Although the unit is marketed as a 100 watt receiver, it is really more like a very weak 50-60 watt receiver (not that 50-60 watts is necessarily "weak", but this amplifier isn't designed to do much real world stuff). Specifications don't usually tell you much, but over the past couple of years they have really started to tell a story on entry level products. To the trained eye, it says in big neon letters "This is a poorly designed piece of crap, purchase at your own risk". It is also a real reminder of how powerful numbers are at marketing electronics. We have become numbers numb, not thinking about what they mean, but buying products because the numbers are bigger and the price is lower.

Stick around and you will learn a lot from some of these guys who have been around the block a couple of times. You will find out that what you thought was important probably isn't, and what you thought didn't matter was incredibly important. Glad to see there are some thinkers out there getting into this hobby.

BTW: Yes, running your speaker setting on small and using a sub will allow you to play louder with less strain on the receiver. It will also allow the receiver to play more cleanly at lower volumes since it doesn't have to deal with the power demands of bass.

Going to a 1400 or 2400 will not really let you play louder, but they will go louder without sounding strained. They will also sound less strained at lower volumes, fill out the bottom end a bit, and generally sound a bit better. This, of course if you have good speakers.

The forum needs new blood like you...stick around.

[uncooked]

yea i plan to stay with the site, i'am completely addicted to home theatre stuff. i dont know why. just something about it that is insanely addicting. like i dont like music ALOT. dont get me wrong i like music, but i like the stuff that plays it even more. if that makes sense. anything that plays loud and clear gets my attention.

does it ever end? im 15, and i have 5.1 in my room, 6.1 in my basement. and a good stereo on the main floor. and i dont even feel close to satisfied........ it just seems to never end, theres always better things out there.

thanks for your post explaining the volume.

[This Guy]

wow, I thought I was the only 15 year old here. We got two HT's in our house, too both being 5.1. My dad hooks me up with most of my speakers cause he made speakers a long time ago for bands he would work with (he was a mixer). You should see the designs they used in the late 70's to mid 80's, hell my sub is one of them. A huge 6 ft. spiral bass horn, goes down to 35 hertz and 120 + dB at a meter with around 100 watts.

-Joey

[uncooked]

lol, that sounds awsome 6 ft, that thing is massive. i want something like that, im saving up for a big sub now. i want something that will shake my neighbours houses as well as mine. im sure they can hear it, but not feel it. i did a test a while back. i cranked my room sytem and then walked outside and just started walking. i was surprised, i could actually hear it down the street, which is quite far.

what i want is a sytem for quality sound, and then another for just power. like an old stereo with like 250 + watts a channel. its just that there fairly pricey. well for me anyway. i had to buy all my own stuff becuase my parents arent really that into it. my mom doesnt even watch our 61" tv becuase she says it hurts her eyes........... my dad is a little bit more into it but he can't tell the difference between a 5.1 soundtrack and prologic 2 or neo 6. sometimes i go down into the basement to the main system and he is down there with friends with a music dvd showing it off. and i walk in and its on stereo, or PII, or neo 6 like i said, then i pop it into dolby. and he says what was the point of that?

or my sister, who uses it sometimes, goes out and rents a vhs........ then i get all pissed off at her becuase there the same price as a dvd, but she seriously just doesnt understand. it gets frustrating in the audio world around here :)

[This Guy]

haha, I'm in a much better position then you are. My brothers all like this stuff, although not nearly as much as me. They help me buy new components when in need, they always got money. If you want a loud ass stereo, build yourself some very efficient speakers. Building more efficient speakers is much cheaper then buying a powerful amp. Again, my sub only needs about 100 watts to be heard from over a block away, with the all the windows closed except an air conditioner. haha when I go down stairs and have the music playing, the ceilings fans are ratteling so loud, it seems like they will fall down. And I'm not sure if this happened because of my music playing, or just the house being old, but the crack in my ceiling has been getting bigger ever since I movied in with this beast. haha alright im done bragging. Get yourself some bass horns and you'll love it.

-Joey