46 replies to this topic

[osmodiar]

It recently came to my attention in another thread, that what receiver manufacturers quote as the rated power times available channels,  (eg 140w x 7ch),  is (atleast in some cases) actually the power that can be delivered with only ONE channel running at once into 4ohm,  not 8ohm across all 7 or even 5.. which is what the majority of people would be running surely.

I'm well aware of the difference between peak output, and RMS power - but this just seems like another level of consumer trickery all over again.  I mean who is going to buy a 7 channel receiver, and run one 4ohm speaker off it??

In the case of the pioneer 1019 it was only delivering 30w into 5 channels before the distortion rating rose above 1% and sharply thereafter.

I'm starting to understand why i've seen a few members on this board talking about using a receiver only for processing, and running pre-outs into proper power amplifiers.  Seemed like overkill to me, or something just for people with big speakers requiring huge currents until i found out that nasty little industry secret.

So ok, in my case i don't really want to go the pre-out option because it's going to cost too much, but trying to find out what actual power various receivers can deliver into 5 channels before the signal begins to degrade is proving to be a bit tricky.  

In the pioneers case it was a review that happened to test for that exact trait,  but that particular review site doesn't seem to always run that test in their reviews, and doesn't have reviews for most of the models i'm considering.

I managed to find a mention of Marantz aiming to provide 70% of the rated power output for one channel, into 5 for all their amps, which seems pretty decent in comparison to the 1019's 30 from 120.. but i haven't so far found any mention of Denon or Onkyo and whether or not their amps such as the 1910 / 608 provide decent power headroom when used in under normal 5 channel conditions.

One thing i'm not totally clear on is how much headroom i actually want to make sure i've got for the speaker system i plan to build.  It will be a 5 channel setup atleast initially,  with JV-60 fronts that i already have (An old jaycar kit - 2x6.25" vifa woofers and a tweeter in each tall ported enclosure),  this centre speaker: http://www.theloudsp...re-Speaker.html and these for rears: http://www.theloudsp.....8Gen-II).html

I figure they are fairly large speakers compared to say a satellite system, and they are going in a relatively large living room so i'm thinking i will want around 70watt RMS across 5 channels to satisfy the notion of having some headroom.. but that's basically a guess and even then it looks like amps in my ~1K budget are going to struggle with that.. ?    I have no idea however of how the onkyo 608 for example will do in this situation..

[bassett]

Unfortunately it's all about marketing a product , and to hell with the bottom line.  So they dream up all these fancy spec's  to confuse or impress Jo Public,
If they advertised an amp, any amp with having an output of 10 or 20 watts, no one would buy the thing.  But sadly this is the reality in a lot of cases.

The easiest rule of thumb, is to ask the magic question,  "What is the driven output per channel"   Then pick the thing up, The heaver it is, the better it is.
Most of these excuses for amps have a switch-mode power supply that would fit in a match box.

As for what wattage output you need, 60 or 70 watts, per channel,  will drive most  8 ohm loads, and while  the volume produced won't make your ears bleed, it will be surfactant  for your lounge room and the neighbors.  But the bigger the output wattage, the less distortion you will get.

[Gior]

bassett, on May 26 2010, 02:57 PM, said:

Unfortunately it's all about marketing a product , and to hell with the bottom line.  So they dream up all these fancy spec's  to confuse or impress Jo Public,
If they advertised an amp, any amp with having an output of 10 or 20 watts, no one would buy the thing.  But sadly this is the reality in a lot of cases.

The easiest rule of thumb, is to ask the magic question,  "What is the driven output per channel"   Then pick the thing up, The heaver it is, the better it is.
Most of these excuses for amps have a switch-mode power supply that would fit in a match box.

As for what wattage output you need, 60 or 70 watts, per channel,  will drive most  8 ohm loads, and while  the volume produced won't make your ears bleed, it will be surfactant  for your lounge room and the neighbors.  But the bigger the output wattage, the less distortion you will get.

This post is inaccurate on so many fronts I don't think I'll even get started with the correct explanations here. The correct information is easily googled.

[K1LL3M]

osmodiar, on May 26 2010, 12:39 PM, said:

I don't really want to go the pre-out option because it's going to cost too much

Not really


The Denon power draw is around 460w, so theoretically about 92w x 5, then allowing say 10% draw for other components, its still not to far off its rated 90w for all channels. If you factor in 7 ch it becomes less again but then will you need 90w at the same time on every channel, doubtful.

I don't think for general use you would have a problem driving the speakers just using the amps in the AVR. (that's not to say there would be no benefit from the power amp)

Edited by K1LL3M, 26 May 2010 - 03:24 PM.

[osmodiar]

interesting, that power amp looks pretty decent for the money..   do you save much on the receiver by just buying a dedicated processor, and do they have as many features? i've never looked into them but i guess i shouldn't just rule it out straight up.

I was starting to think of just aiming a bit higher up on the receiver front,  like the VSX-LX52.  Presumably at that level the rms to 5 channels is going to be decent, and looks like I can get one for ~$1300 with warranty from interstate.   More than i really wanted to spend (by about $500) but probably less than a pre-amp setup and would surely do the job pretty well.  (?)

Really don't want to spend more than that..   it's always the way, the more research you do the more you inevitably end up spending  

[K1LL3M]

osmodiar, on May 26 2010, 03:37 PM, said:

interesting, that power amp looks pretty decent for the money..   do you save much on the receiver by just buying a dedicated processor, and do they have as many features? i've never looked into them but i guess i shouldn't just rule it out straight up.

I was starting to think of just aiming a bit higher up on the receiver front,  like the VSX-LX52.  Presumably at that level the rms to 5 channels is going to be decent, and looks like I can get one for ~$1300 with warranty from interstate.   More than i really wanted to spend (by about $500) but probably less than a pre-amp setup and would surely do the job pretty well.  (?)

Pre is usually a speciality audio item, and they tend to cost to suit.

Most of the added cost in higher model avrs comes in the better power ratings/amps, so when going the budget power, what your buying is the features of the AVR to go with the Power amp.

If your happy to get the VSX, go fo it and if you want to add power later, it has pre's so you can.

osmodiar, on May 26 2010, 03:37 PM, said:

Really don't want to spend more than that..   it's always the way, the more research you do the more you inevitably end up spending  

Once you start looking, you realise what your missing - ignorance is bliss

Edited by K1LL3M, 26 May 2010 - 03:51 PM.

[jliang70]

K1LL3M, on May 26 2010, 04:23 PM, said:

Not really


The Denon power draw is around 460w, so theoretically about 92w x 5, then allowing say 10% draw for other components, its still not to far off its rated 90w for all channels. If you factor in 7 ch it becomes less again but then will you need 90w at the same time on every channel, doubtful.

I don't think for general use you would have a problem driving the speakers just using the amps in the AVR. (that's not to say there would be no benefit from the power amp)

It is actually less than 92 w.  If the power draw is 460W and most avr have  class A/B amp onboard which usually have efficiency of about 70% which give you about 322w.  Over 5 channel you get around 64.5w and over 7 channel is about 46w.

[myrantz]

If not getting a power amp, one trick you may want to try is set the speakers to small, and offload more to the sub. say 120hz, 150hz, or 250hz...

Might work, but YMMV.

[:)]

K1LL3M, on May 26 2010, 03:23 PM, said:

Not really


The Denon power draw is around 460w, so theoretically about 92w x 5, then allowing say 10% draw for other components, its still not to far off its rated 90w for all channels. If you factor in 7 ch it becomes less again but then will you need 90w at the same time on every channel, doubtful.

I don't think for general use you would have a problem driving the speakers just using the amps in the AVR. (that's not to say there would be no benefit from the power amp)

also to add to jlangs post, you need to factor in headroom for dynamic range, no point the amp running flat out to keep up and then a big dynamics moment comes along in the movie and it basically then flatlines and runs out of puff with nothing else up the sleeve. Its why the brands with more conservative ratings eg rotel, nad, HK, cambridge etc have a power consumption at 1.5 to as much as 2 times their all channels driven wattage claims. Its only the japanese brands eg denon & marantz, yamaha, onkyo/integra and even worse pioneer that tend to completely overstate their wattage claims.

and certainly speakers in question will matter too, but in my experience with even budget range speakers a power amp can bring benefit for clarity and dynamics and most importantly not having to crank it to high volumes to enjoy.

with the japanese brands as you spend up you definitely get better and better build in power amps, and with the denons for instance better processing, dacs, audyssey etc as well as you go up the tree. definitely a case of get what you pay for in this kind of thing

ps as far as how much power do I need, check the sticky in the 2ch section will give you some clues with some simple calcs

[K1LL3M]

:), on May 26 2010, 08:04 PM, said:

also to add to jlangs post, you need to factor in headroom for dynamic range, no point the amp running flat out to keep up and then a big dynamics moment comes along in the movie and it basically then flatlines and runs out of puff with nothing else up the sleeve. Its why the brands with more conservative ratings eg rotel, nad, HK, cambridge etc have a power consumption at 1.5 to as much as 2 times their all channels driven wattage claims. Its only the japanese brands eg denon & marantz, yamaha, onkyo/integra and even worse pioneer that tend to completely overstate their wattage claims.

and certainly speakers in question will matter too, but in my experience with even budget range speakers a power amp can bring benefit for clarity and dynamics and most importantly not having to crank it to high volumes to enjoy.

with the japanese brands as you spend up you definitely get better and better build in power amps, and with the denons for instance better processing, dacs, audyssey etc as well as you go up the tree. definitely a case of get what you pay for in this kind of thing

ps as far as how much power do I need, check the sticky in the 2ch section will give you some clues with some simple calcs

Gee, I feel like I need to defend my post that was "theoretical generalisation" of AVRs performance/power. I will just leave it with an affirmation that I don't disagree with you guys, but don't forget the caps & the OPs desire for sub 1k budget.

In saying that I still say the OP will be fine using just the amps in the AVR and doesn't HAVE to purchase a power amp to be happy, while remaining within his preferred budget limitations.

[Gior]

K1LL3M, on May 26 2010, 09:41 PM, said:

Gee, I feel like I need to defend my post that was "theoretical generalisation" of AVRs performance/power. I will just leave it with an affirmation that I don't disagree with you guys, but don't forget the caps & the OPs desire for sub 1k budget.

In saying that I still say the OP will be fine using just the amps in the AVR and doesn't HAVE to purchase a power amp to be happy, while remaining within his preferred budget limitations.

I do think that the amps in most AVRs these days do (A) fine job (UNLESS) the speakers are grossly inefficient (or have crazy impedance variations especially going into the sub 4ohm territory). Only crazy people start thinking about the NEED to run bigger amps...


Edit: Noted I missed a bit of info - been too busy with the DEQX ..check Al's post for his vehement disagreement to the original post. He'll still disagree with the edited post I'm sure though

Edited by Gior, 26 May 2010 - 11:59 PM.

[:)]

Gior, on May 26 2010, 10:06 PM, said:

I do think that the amps in most AVRs these days do fine job if the speakers are grossly inefficient. Only crazy people start thinking about the NEED to run bigger amps...

couldnt dissagree more quite frankly.

but at the end of it a lot comes down to what k1ll3M said "doesn't HAVE to purchase a power amp to be happy, while remaining within his preferred budget limitations." and thats not for anyone to argue, something only the OP can decide. At the end of it dont have to purchase anything to be happy. some people are quite happy enough with just the speakers in their flat panels, others with htib boxes and some with powered computer speaker. While others to be happy will purchase all manner of other options in all sorts of price ranges. I'm not here to judge but do believe theres benefit to be had with a power amp, and something couldnt be more pertinent given the under nourished amp stage in most $1k avrs as the OP has discovered.

[Gior]

:), on May 26 2010, 10:19 PM, said:

couldnt dissagree more quite frankly.

but at the end of it a lot comes down to what k1ll3M said "doesn't HAVE to purchase a power amp to be happy, while remaining within his preferred budget limitations." and thats not for anyone to argue, something only the OP can decide. At the end of it dont have to purchase anything to be happy. some people are quite happy enough with just the speakers in their flat panels, others with htib boxes and some with powered computer speaker. While others to be happy will purchase all manner of other options in all sorts of price ranges. I'm not here to judge but do believe theres benefit to be had with a power amp, and something couldnt be more pertinent given the under nourished amp stage in most $1k avrs as the OP has discovered.

I really like my 1k avr lol Then again, I have offloaded all my bass like what treblid has suggested into a DD18...

Al I edited my post as on actually reading it, I disagreed with it too lol...I was typing a bit too quick in between fiddling with the DEQX I think and left out some info that I thought I had written into it.

Edited by Gior, 27 May 2010 - 12:00 AM.

[sol381]

Most of the time wattage is just a number. unless your receiver has simultaneous continuous power or all channels driven then you are not going to get the rated power.  i have a nad t753 which is rated at 70w but produces around 93w with all channels driven. It is way more than i need . I cant even get the volume anywhere near half way without the wife screaming to turn it down. Also as someone mentioned about weight. Mine is like a bag of concrete weighs about 2okg. Ive seen some rated at 120w and weigh only 11 or 12 kg. its a pretty sure sign you are not going to get what you think in terms of power.

Also power is somewhat overrated. I hear people say that a certain receiver only has 100w whereas another has 120. to hear the difference between the two you would have to have ears like a dog. To double the volume of a 100w amp you need to create 10 times the power and get a 1000w. Even if you doubled the wattage to 200w you would only gain about 3db which is inaudible.

Another thing to note is that higher power is not all about loudness. Higher power generally means you can play clearer and louder at lower volumes. Too much is made of power and to rate one amp against the other on terms of wattage is futile.

Im sure the majority of members here use receivers for their home theatre and id be surprised if any, like me , can get the volume to half way without their ears bleeding. Just get the best machine you can afford, try and make sure that the wattage is with all channels driven and dont get too caught up on numbers.

[K1LL3M]

sol381, on May 27 2010, 07:02 AM, said:

Im sure the majority of members here use receivers for their home theatre and id be surprised if any, like me , can get the volume to half way without their ears bleeding.

Maybe you need to seek medical attention for that ear condition

The sweet spot of amps I feel is usually between 1/2 and 3/4, no sign of ear bleeding here.

If its too loud, your too old

[myrantz]

K1LL3M, on May 27 2010, 06:30 AM, said:

If its too loud, your too old

  I want that for a bumper sticker!

Edit: Oh, I just remembered.. Craig&kim linked to a pretty good PDF describing manufacturer specs, explaining what they are, and what they should be..

Well worth a read I think. If only I can find it again...

Edited by treblid, 27 May 2010 - 10:22 AM.

[:)]

sol381, on May 27 2010, 07:02 AM, said:

Most of the time wattage is just a number. unless your receiver has simultaneous continuous power or all channels driven then you are not going to get the rated power.  i have a nad t753 which is rated at 70w but produces around 93w with all channels driven. It is way more than i need . I cant even get the volume anywhere near half way without the wife screaming to turn it down. Also as someone mentioned about weight. Mine is like a bag of concrete weighs about 2okg. Ive seen some rated at 120w and weigh only 11 or 12 kg. its a pretty sure sign you are not going to get what you think in terms of power.

Also power is somewhat overrated. I hear people say that a certain receiver only has 100w whereas another has 120. to hear the difference between the two you would have to have ears like a dog. To double the volume of a 100w amp you need to create 10 times the power and get a 1000w. Even if you doubled the wattage to 200w you would only gain about 3db which is inaudible.

Another thing to note is that higher power is not all about loudness. Higher power generally means you can play clearer and louder at lower volumes. Too much is made of power and to rate one amp against the other on terms of wattage is futile.

Im sure the majority of members here use receivers for their home theatre and id be surprised if any, like me , can get the volume to half way without their ears bleeding. Just get the best machine you can afford, try and make sure that the wattage is with all channels driven and dont get too caught up on numbers.

hi sol, I think you make soem good points there, the nad t753 in my opinion would be chalk and cheese for power under the hood to the artificially higher rated $1k avrs being talked about here. and yeah the nads biggest strenght which has always been the strength with the nads is in the amp. I have no doubt at all like other nad products the 70wpc all channels driven is a honest figure and well supported by a very decent power supply hence the 20kg weight of the thing !.

I used to own a similar $2k price range and vintage avr myself only a few years ago in a hk630 was also only rated at 70wpc all channels driven but with a very decent power supply and 1000w consumption. SPLs not an issue but adding power amp defintiely did take to another level for a cleaner sound. even utilising my 2ch mono blocs to drive the mains takign their load of the avr added nicely for the end result.

And yeah I too agree its not necessarily about loudness and spls. its about a cleaner sound and dynamics and particualrly performance at lower levels below reference whcih is more important to me.

and your right to the numbers are a mine field because no two manufactuers measure the same, and a lot of it clearly bull dust ! so best not get to caught up in the numbers

[:)]

K1LL3M, on May 27 2010, 08:30 AM, said:

Maybe you need to seek medical attention for that ear condition

The sweet spot of amps I feel is usually between 1/2 and 3/4, no sign of ear bleeding here.

If its too loud, your too old

hehe its a hard one to talk about with av amps as they work off reference. is it 1/2 to 3/4 upto reference ?

for hifi amps I do know, they certainly pretty much max out and in full flight at 12 o'clock or 50% mark typically. any more cranking typically doesnt get much more gain. mine I run at 20 to, 1/4 to postiion upto ten to, very rarely upto 5 to or 12 o'clock hehe with my way of describing volume level probably indicates I am too old ! hehe

treblid, on May 27 2010, 10:19 AM, said:

  I want that for a bumper sticker!

Edit: Oh, I just remembered.. Craig&kim linked to a pretty good PDF describing manufacturer specs, explaining what they are, and what they should be..

Well worth a read I think. If only I can find it again...

hehe would make a nice bumper sticker indeed !

if you do find the pdf do post treb, its the kind of thing is good to link to from the htfaq

[sol381]

my ears are perfect mate.. Maybe its time for you to upgrade your amp to a more efficient one. The nad volume is measured in -db, not sure why but  the lowest level is -73 and the highest is +6. i play movies at -50. any higher and the walls shake and dogs run for cover.

K1LL3M, on May 27 2010, 08:30 AM, said:

Maybe you need to seek medical attention for that ear condition

The sweet spot of amps I feel is usually between 1/2 and 3/4, no sign of ear bleeding here.

If its too loud, your too old

[myrantz]

:), on May 27 2010, 08:30 AM, said:

hehe its a hard one to talk about with av amps as they work off reference. is it 1/2 to 3/4 upto reference ?

for hifi amps I do know, they certainly pretty much max out and in full flight at 12 o'clock or 50% mark typically. any more cranking typically doesnt get much more gain. mine I run at 20 to, 1/4 to postiion upto ten to, very rarely upto 5 to or 12 o'clock hehe with my way of describing volume level probably indicates I am too old ! hehe

I'm in the old camp too..

Oh. That also reminds me.. With some room treatments, I find I didn't need to dial up as much. My guess is standing waves and reflections somehow make it sound less good, and hence the higher volume in the hope of overcoming 'em.

The room plays an important part too... Unfortunately I learnt that too late.

:), on May 27 2010, 08:30 AM, said:

hehe would make a nice bumper sticker indeed !

if you do find the pdf do post treb, its the kind of thing is good to link to from the htfaq

here. File is Audio Specifications. I find that pretty useful (although I prob undersatnd only 2% of it.. hahaha)

sol381, on May 27 2010, 08:47 AM, said:

not sure why but  the lowest level is -73 and the highest is +6.

-0dB is "reference". i.e. apparently that's what they want you to hear from where you sit... I think -0dB is supposed to be 75dB? Go on.. I dare ya. . I think at reference some scenes will prob go in excess of 130dB or something... Maybe more.

Edited by treblid, 27 May 2010 - 10:57 AM.

[Beleg Cúthalion]

reading this thread has been quite interesting. i still laugh evertime i see a Sony HTiB set advertising a power output of 1600/1700W!

But just for my understanding, is the below statement fairly true / agreed with, to calculate the total output roughly?

most avr have class A/B amp onboard which usually have efficiency of about 70%

SO take the power draw (often 400-500W), multiply by 70% and divide by the number of channels being driven?

Edited by Dwain, 27 May 2010 - 11:12 AM.

[osmodiar]

:), on May 27 2010, 09:53 AM, said:

its not necessarily about loudness and spls. its about a cleaner sound and dynamics and particualrly performance at lower levels below reference whcih is more important to me.

Yeah i follow the principle of headroom power for cleaner sound, not max loudness.  I'm definitely not looking to build an 'ear bleeding' system lol.. just going to have some hefty speakers in a fairly big room and don't want to end up under powering them due to 'creative' manufacturer specs.

The more i read about emotiva gear the more appealing it becomes,  i'm starting to think of it like this - the UMC-1 is within my receiver budget.. and the UPA-5 looks like a great amp that will last for a decade probably and is priced so much more reasonably than anything i could buy locally, so although the combination is way over budget it's certainly seems like good value, and clearly it's going to give me the best result anywhere near my price range.

So at this stage i'll keep my options open & keep looking around at receivers which state proper output specs because it would be good to get started under budget, but thanks to you guys on this forum i have a much better understanding of how to do this properly if i want to spend a little more.  

[Chill]

Well there is Watts and there are Watts

Having just added a MF A1 (38 W) into my system for 2CH reasons (thanks again Al) - I notice a clear improvement for HT duities and no problems with volume on big bang crash stuff

now my AV receiver is a Yama 3900 so in 5 ch mode it delivered significantly more than 38 W !

speakers are mid in sensitivity (89db)

if you used speakers such as Kiplish (94 to 98 db) - then number of watts is almost of no importance at all !



as perviously mentioned the difference in max volume between say 80 W and 160 w (the range of most amps) is almost imposable to dectect - you want loud get more effeciant speakers  

Edited by Chill, 27 May 2010 - 02:11 PM.

[K1LL3M]

The Emotiva XPA-5 and UMC-1 I think will provide you with much more than any stand alone sub $1k AVR and probably most sub AUD $5k AVRs. If you can street the budget for those I cant imagine you will be disappointed.

Like any will tell you (ask lensman for instance )Once you start down this road, it becomes quite slippery, but good fun. Have you checked out the Submersive or MAL-X GB yet

:), on May 27 2010, 10:30 AM, said:

hehe its a hard one to talk about with av amps as they work off reference. is it 1/2 to 3/4 upto reference ?


for hifi amps I do know, they certainly pretty much max out and in full flight at 12 o'clock or 50% mark typically. any more cranking typically doesnt get much more gain. mine I run at 20 to, 1/4 to postiion upto ten to, very rarely upto 5 to or 12 o'clock hehe with my way of describing volume level probably indicates I am too old ! hehe

Reference takes all the fun out. My AVR dials down the mains connected to the power amp by about 9db just so I can have "reference"

What's the point in listening to a movie at -50 below reference, may as well turn it off and enjoy the silence.

The 1/2 to 3/4 comment was semi-serious. On a hifi type setup the max output of a good amp is around 3/4 on the dial (you remember those things that have a start and an end point, with a little marker to show where they are). This is from my own audio journey that like most of us was likely inherited at a young age. I know some it stems from being unable to turn the volume up any further without distortion (usually at some else's place). Sometimes it just needs to go to 11 dam it!!

The rest (and possibly even some of this post) was kinda tongue-in-cheek.

C'mon guys, "Turn that sh!t up"*


*Lyics from Testeagles "Turn that sh!t up" and Rage Against The Machine, "Guerrilla Radio"

[dantan]

Chill, on May 27 2010, 12:10 PM, said:

as perviously mentioned the difference in max volume between say 80 W and 160 w (the range of most amps) is almost imposable to dectect - you want loud get more effeciant speakers  

Absolutely right; for more volume, get more efficient/sensitive loudspeakers. For better sound quality, get better source material, source component, and amplification with good current and power capabilities.

Dan.