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Discussion Starter #1
I purchased a V663 a few months back (the J&R deal).

I've been reading up and deciding on what speakers etc to go with and i've been ''upgrading'' those....though i have yet to purchase any.

So...I've been reading up on speakers being ''less efficient'' and ''more efficient'' etc. and i'm considering upgrading to the Onkyo 805 to obtain more watts per channel and other upgrades that i may not be aware of.
I have also read that it's much cheaper to just add an amp to a system if the reciever is already ''good enough'' at doing the other stuff i want it to do....excluding watts per channel of course.

Here is my 'system' that's in the works currently....and you can tell me what you think.

TV= Samsung 46'' A550
L/C/R= Ascend Sierra-1's (probably)
Surrounds= Ascend CBM-170se
Sub= SVS PB13-Ultra

That's it....that would be my ''10 year system'' if i ever finally get it.

So....Keep the Yamaha 633.....add an amp if i need it?? (do you think i'll need one?)
....Try to sell or return the Yamaha and look into an Onkyo 805??

Thanks a ton guys....you've been more help than you know.
matt
 

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Looking at the specs,.... looks to me like the Yamaha should be up to the task as far as the 170's go. It may struggle with the Sierra's, especially if you listen at or near reference.

Personally I'd give the Yamaha a shot and if it was not up to the task I'd add an amp.
 
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i'm considering upgrading to the Onkyo 805 to obtain more watts per channel
You misunderstand the relative importance of "watts per channel". Running flat out, at "maximum volume", the 130w spec of the Onkyo over the 95w spec of the Yamaha might yield a 1.3dB loudness increase. Most people cannot discern a loudness increase of even 3dB (a doubling of watts).

The Yamaha will do fine in your application.
 

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I also suggest to try the Yamaha ... and if you want more power "get an external amp" :yes:

If you sell the Yamaha and get a new Onkyo, you'll get just 35Watts more and will need to spend a couple of hundreds ... in the other hand, if you add an external amp, you'll get one with at least 200 watts or more for around the same money :bigsmile:
 

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You misunderstand the relative importance of "watts per channel". Running flat out, at "maximum volume", the 130w spec of the Onkyo over the 95w spec of the Yamaha might yield a 1.3dB loudness increase. Most people cannot discern a loudness increase of even 3dB (a doubling of watts).
The Yamaha has less wattage yes but thats not the only thing to keep in mind. It also a far smaller power supply and The DAC's are not as good as the Onkyo. The amplifier section in the Onkyo is also a Push Pull design and can sustain higher peaks than the Yamaha's.
Over all the Yamaha should do fine but getting an external power amplifier will be almost a must if you want to run near Reference.
 

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Discussion Starter #6
knowing that my setup will eventually be L/R/C Sierra's and 170SE surrounds......is there a specific amp that wouldn't crush the pockets...but get the job done, meaning, giving me the extra power that i need??

thanks guys.
as you can see, i'm still learning
 
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is there a specific amp that wouldn't crush the pockets [...] giving me the extra power that i need?
You don't need any additional power. Your speakers @ 86.5dB SPL efficiency will do just fine. If you feel the urge to spend more money get better, more efficient speakers. You'll get way more bang for the buck doing that than buying watts!
 

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You don't need any additional power. Your speakers @ 86.5dB SPL efficiency will do just fine. If you feel the urge to spend more money get better, more efficient speakers. You'll get way more bang for the buck doing that than buying watts!
86db efficiency is not very good at all however very good sounding speakers. The Yamaha will not be able to drive them along with the other channels during movies it will be underpowered (for two channel listening it should be able to do it). The power supply is far to small to maintain the maximum output on all channels.
People forget that the ratings on receivers is done driving two channels at full watts not all 7 simultaneously, very deceiving as the power supplies in most receiver can not keep up. The Onkyo 805, 875 and 905 all have huge power supplies. There are some high end Denons as well as some Pioneer receivers that also employ large PS to accomplish it. Yamaha for some reason doesn't seem to think its necessarily.
 
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86db efficiency is not very good at all however very good sounding speakers. The Yamaha will not be able to drive them along with the other channels during movies it will be underpowered (for two channel listening it should be able to do it).
This is nonsense. I use the 663 with speakers that are roughly the same efficiency and have direct, measured experience of them.

Dolby and THX spec that all channels be capable of average of 85 dB with peaks of up to 105 dB. The LFE channel must be capable of 95 dB average with 115 dB peaks.

This means that the speakers in question (86.5dB sensitivity) can maintain THX/Dolby average loudness of 85dBSPL with about 0.7W per channel and they can generate the 105dB peaks with 71W per channel.
The power supply is far to small to maintain the maximum output on all channels.
This is true of all receivers in this class.
People forget that the ratings on receivers is done driving two channels at full watts not all 7 simultaneously
This is also nonsense. You obviously do not understand the various measurement standards used by Yamaha.

The minimum 95w/ch spec they use is all channels driven, 8Ω, 20Hz-20KHz, 0.06%THD, 500mS.

They also offer other standardized measurement results of the same unit:
  • IHF: 2-channels driven .. 135/165/195/240 W/ch @ 8/6/4/2Ω
  • IEC: 2-channels driven .. 105 W/ch
  • JEITA: 2-channels driven .. 135 W/ch
 

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The minimum 95w/ch spec they use is all channels driven, 8Ω, 20Hz-20KHz, 0.06%THD, 500mS.
You do realize that 500mS is not anywhere near long enough sustained output at those specs. You just stated what I already said it can run at those levels but not for any length of time. Real world numbers, not what Yamaha wants you to believe is what is important. If you want to live with high distortion levels then go for it but you can damage you speakers running it that way.
They also offer other standardized measurement results of the same unit:
  • IHF: 2-channels driven .. 135/165/195/240 W/ch @ 8/6/4/2Ω

  • There is not a receiver in this price range of for that matter for three times as much that can run at 2 Ohms stable and those numbers are in no way real world conditions.

    The OP wanted to know if upgrading to the Onkyo 805 would be a better choice or an external amp paired up to the Yamaha. I say for the price the 805 would be his best choice and would eliminate the need for an external amp. The Onkyo weighs 20lbs more than the Yamaha due to the larger power supply and that makes a huge difference.
 

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Dolby and THX spec that all channels be capable of average of 85 dB with peaks of up to 105 dB. The LFE channel must be capable of 95 dB average with 115 dB peaks.
I don't want this thread to turn into a series of hair splitting arguments but I do want to comment on the above posts and clarify a few things.

THX receivers are held to the standard that they can achieve 105db with appropriate THX speakers used as a system in concert according to their testing methodologies. Non THX receivers are not necessarily held to this standard. Dolby Digital is nothing more than a sound format with a few features such as dynamic compression and LFE trim thrown in. The DD format itself max's out at 105 for the mains and 115 for the sub, however this is a calibrated number. DD knows nothing more than 0db=full output, -20db=20db below full output. It is up to the end user to calibrate the system so that a -20db signal results in 85db at the seating position. In this way DD has no bearing on the output of the amplifier itself.

Other things to remember - speaker sensitivity is measured 1 meter from the speaker. Listening positions are rarely this close. In this test of my system about 6db were lost from 1m to 4m at the seat. 6db=4X more power. Listening rooms are going to vary, so this number could be significantly different from room to room.



Also, clipping is a phenomenon that sets in gradually and is therefore not always audible. While you may have never heard distortion in your system does not necessarily make it true that enough power is present. I'm not doubting your comments, just making a point.

On the receiver power supply issue - this is probably one of the most hotly debated topics on the internet. In reality, the power supplies for both of these receivers are going to be adaquet for vast majority of listening. I like things loud, but rarely watch much above -5, unless I'm showing off:bigsmile:. 86db is a tad low for sensitivity these days, but with normal impedence and normal listening I see no reason the Yammi couldn't handle the load.
 

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Discussion Starter #13
guys, i appreciate all of the input.

something that i don't understand, i guess, is that i see a ton of people on here running amps with their system. but in this thread, when i asked about a specific amp to pair with it, it's almost like i'm being talked out of one. i'm sure i'll get the bug, like 'thxgoon' said, to ''show off every once in a while''....and i just want to make sure that i'm not damaging my speakers when i do that.

how can i make sure that i can listen to them, however i please, without damaging the speakers?

thanks
matt
 

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Hi Matt, I still think an external amp is a good idea in any case simply because it relieves the amp of a large part of its load reducing heat and thus reducing wear.
I have the Onkyo 805 and have an external amp on my mains it gives me more control and allows me to have two third octave EQ between the receiver and the amp to really flatten the response of the mains. some would say overkill but I disagree as my receiver stays nice and cool even at reference levels and I still have lots of headroom.
 

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There's really no way to actually know without doing some pretty involved testing and calculations. Really the best way to know if you are damaging your system is to listen for any kind of distortion and use your head. If you're looking to reproduce 115db all of the time... you are going to need a completely different system. If you are just looking to enjoy movies at spirited levels then the system you have now is fine.

As Tony said, an external amp does have its advantages. I bought mine because on certain favorite demos, my Denon would clip. I bought my external amp, which actually has less power (125 vs 140/ch) and I've never clipped it, even at insane levels, mostly due to the ability of the amp to deliver lots of current which enables it to handle low impedence loads such as my speakers. Your speakers are not as demanding though. There is so much more to amplifiers and speakers than watts, don't get confused, it really is as simple as listening to it. :) Hope that helps.
 

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Discussion Starter #16
thanks for the info guys....keep it coming.

another question.

if i do listen to it....and i do hear clipping at spirited levels.....how do i know how much extra amp to put into it?

again, the system will be.

L/R/C - Ascend Sierra-1 Mains
Surr. - Ascend CBM-170ses
Sub. - SVS PB13-Ultra

reciever is Yamaha RX-V633

thanks guys.
matt
 

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if i do listen to it....and i do hear clipping at spirited levels.....how do i know how much extra amp to put into it?
Generally an amp with 100-200Watts per ch will be plenty as was mentioned before the amp has its own power supply and thus will have much more headroom. Your cost per Watt goes up substantially once you get into the larger 200 and greater watts per channel amps.
 

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I'll avoid the whether to amp or not debate going on and just reply to the OP's question. You can go to Audiogon and get a very nice NAD power amp from 125 - 200 wpc for a very reasonable price. Also for reasons I wont get into here you can pretty much disregard as to whether a 150wpc NAD will be enough. That company is extremely conservative in their power ratings and actually a 100wpc NAD will IMHO outperform a substantially higher power rated receiver and power your Ascends with no trouble at all.
Good luck...
Cheers,
Konky.
 

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Other things to remember - speaker sensitivity is measured 1 meter from the speaker. Listening positions are rarely this close. In this test of my system about 6db were lost from 1m to 4m at the seat. 6db=4X more power. Listening rooms are going to vary, so this number could be significantly different from room to room.
It's also important to note that the sensitivity ratings are measured in anechoic chambers at 1 Meter. In room, you do gain several dB(at least 3-4 dB can be expected in average sized rooms/acoustics) over the anechoic SPL; so be sure to allow for this compensation.

-Chris
 

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As suggested by others, if you want to have a substantial upgrade in power output, another receiver is NOT the answer. External amplifiers are the only feasible route. You could for example, get 3 Behringer EP2500 amplifiers, which output 450 per channel at 8 ohms, or 650 watts at 4 ohms, for under $300 each if you shop around. For well under $1000, you could have a massive power output ability(of course, realize, you need to install a dedicated 20A circuit to get full power from such high powered amplifiers).

-Chris
 
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