AVR and AV amp chat

petetherock

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Just starting a thread for members to talk about their Audio Video Receivers and Amplifiers.

Some things you should like for in a new amp:
- at least 7.1 capability with built in amps
- latest sound formats:
DD, DTS are basic, you also want Tru-HD and DTS-MA as a standard as well more 3D formats like DTS-X, Dolby Atmos.
These days, not only the video gets upscaled, but you also have upscaling of sound, using tech from Dolby and DTS: Dolby Surround and DTS- Neural X.

You can never have enough power and do note that what they state on the box seldom gets realised in real life. Look at the power consumption for an idea. Eg, if the power drawn from the wall is 700W, and there are 9 channels, even if the amp has an efficiency of 80%, that means you won't see more than 60W per channel when all channels are operating.

However if you live in a domestic setting like a flat and use a subwoofer, this will be enough if you use typical speakers. More power allows you to use less efficient speakers and will give you more dynamism and headroom for the explosive moments.

HDMI inputs and version.

For 3D, you only need HDMI v1.4 but if you want the full function, get the latest version and currently it's HDMI 2.0b. HDMI 2.1 will come, probably in 2019, but there's scant info right now.

You should get an amp with at least four HDMI inputs.

If you do a lot of listening with stereo or legacy gear, make sure the amp has enough RCA inputs for you.

Auto-calibration:
There are many flavors but choose one that is easy to use, especially if you are a beginner. Denon and Marantz use Audyssey, but each company has their own version. Do note that there are different version of this, the highest being XT 32. It's worthwhile getting an amp with this as it also calibrates the bass from the subwoofer. It's very helpful to have this automatic feature, but it does Not take away from usual a SPL meter and measure the individual channels for the best results.

The difference between an amp and a receiver is that the latter has a tuner.

These days many amps also have Internet radio and other gadgets, but remember if the feature count is long for the same money, it means less money was spent on the power section and making the amp sound good.

The larger companies often change models each year, and it's important to see what's new, sometimes buying the higher end model from last year at a discount is a better bet.

As for the DAC and other components used, don't get into a tangle because of it. The implementation is just as important. If sound really matters, a stereo amp will give you far better sound. As a rule of thumb, an AVR will sound as good as a stereo amp costing about a third the price.
So that $1000 amp will be easily bested by a $500 stereo amp.
 

86technie

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Installation

I think majority won't want AVR/AV amp setup mainly due
to the cabling and wall mount.
In market there are hardly any vendors who do setup
for home for a cheap fee.
Adelphi as well as Audio house does installation but can
be pricey.

I only know Prefect install who does AV installation for home
other than them I don't know.
AVR/AV setup maybe more tedious but if compare with soundbar.

Between soundbar and AVR/AV amp

AVR/AV sound is much powerful, directional audio is much accurate,
wider and more fuller surround sound experience. (Depend on setup)
Not to mention AVR/AV got headphone jack (Phono jack) if you
wish to use headphones.

Soundbar don't have such feature so you will need a separate HTS wireless headphone system.
Not to mention AVR switching between sources is much easier since each input there is a toggle button.

Most soundbar you have to route through all the input before reaching the desire input.

AVR with speaker package or choose your AVR and speaker.

Really depends, Courts, Audio house, Harvey Norman, Best denki.
Usually sell AVR with speaker packages which are good for
beginners and budget user.

Promoters for particular brand will try to sell their own brand and not cross sell between brands.

Is Dolby Atmos a must and the best audio format? *Consider your source

TBH I am more of a fan for DTS sound than Dolby.
I know most do not play Blu ray so use media player with software level Dolby Atmos decoding.

However for best experience do try Blu ray disc which are pricey.
Not all Blu ray disc are on Dolby Atmos, some are DTS-X and that doesn't mean it is bad.

Some disc have option for either Dolby Atmos or DTS-X which for me
I will pick DTS-X.
Some Blu ray disc are even unique like those musical ones like Coco.
There is a audio option for DTS-Master Audio High resolution music.
This format is not surround but just 2.0 audio focus at music.

Blu ray does have more feature as well as audio track.
Streaming and etc. movies doesn't have and they are usually compressed
surround sound.

Are there cheap AVR with speaker packages? How much AVR with Atmos capability with speaker will cost.

Consider your sources first, if you don't play Blu ray with comes with Atmos or DTS-X. A cheap AVR like Denon 520BT with speakers will do fine.
Take note not all basic AVR comes with auto room calibration.

Such basic setup usually means the AVR can support DTS-Master Audio or Dolby Truehd Which are decent enough if you have good speakers.
Cost wise usually is below $1k.

Onkyo and Denon are good picks. Pioneer have drop out their basic range AVR with speaker packages.

Atmos/DTS-X wise, for decent setup easily can cost up to $2.5k with the Dolby Atmos enable speaker.
Example is Pioneer VSX-933 with Pioneer Andrew Jone speaker with Dolby Atmos speaker.

This is setup is quite a popular pick since it comes with floorstanding speakers.
For those playing 4K UHD it's best to use floorstanding than small size speakers/bookshelf so it can handle the dynamic range, more sound and etc.

Small speaker setup are not ideal for Atmos playback even though they are cheap.
There is only one Atmos package which is Onkyo HTS-7800.

Good for beginner and budget user who want to embark on Atmos.
However just take note that the speakers are spring clip not binding post.
This is a indication that the HTS-7800 speaker are basic type.

Decent speakers and even AVR usually use binding post than Spring clip.

I just share what I know for general consumers as not many want to invest in a rather high end setup especially the cabling is a concern to many.
 
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Amon86

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No one ever ask this question before are Auro 3D better? or Dolby Atmos better? Both setup were different....most ppl i see used Atmos
 

wwenze

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Mmm... there are lots of things to say but a lot can also be found easily on Google, so I will skip those

One obvious one that needs to be stated however is that HDMI 1.4 supports 4K @ 24Hz to 30Hz (depending on 4096 or 3840), while HDMI 2.0 supports 4K @ 60Hz. Version 2.0 will also support 3D 1080p60 while 1.4 is limited to lower data rates.

For the details of each version, just refer to Wikipedia.
https://en.wikipedia.org/wiki/HDMI#Versions

Power ratings (and THD ratings)
If you noticed why the expensive stereo amps seem to have less power than the AVR cousins, this is the explanation.

Take Marantz for example. From the webpages:
PM6006: $699, 45W 4 ohm / 60W 8 ohm, THD 0.08%
SR6012: $1499, 110W 8 ohm, 20 Hz - 20 kHz, 0.08% 2ch Drive
NR1609: $749, 50W 8 ohm, 20 Hz - 20 kHz, 0.08% 2ch Drive

This is actually a somewhat bad example, since they look kind of reasonably similar, because Marantz decided to be a good guy and include all power ratings at 0.08% THD.

But let's look at NR1609's other rated figures

6 ohm, 1kHz, 1%, 1ch Drive 85 W
6 ohm, 1kHz, 0.7%, 2ch Drive 60 W
8 ohm, 20 Hz - 20kHz, 0.08%, 2ch Drive 50 W
Audio Signal to Noise Ratio 98 dB

And suddenly, 85W is significantly more than 50W.

This gets even more epic with SR6012:

6 ohm, 1 kHz, 10%, 1ch Drive 220 W
6 ohm, 1 kHz. 0.7%, 2ch Drive 150 W
8 ohm, 20 Hz - 20 kHz, 0.08%, 2ch Drive 110 W
Audio Signal to Noise Ratio 102 dB

Basically the key things worth noting are:
- 10% THD
- 6 ohm
- Number of channels drive

So how does the product suddenly get double the power? Simply by giving different conditions. As output power approaches device limits, distortion increases until the point of clipping. But manufacturers continue further, increasing output power even after clipping, until they get the 10% THD value and call it a day. With a lot of sheep thinking max output power is everything, manufacturers usually choose to report output power at 10% THD and etc, allowing them to double the output power compared to reporting at <1%. And the rest of the industry is forced to follow this reporting methodology or get disadvantaged. Fortunately, some companies seem to be trying to reverse that trend.

The problem with power ratings based on 10% THD, is that it does not tell you what is the THD during normal operation (i.e. not at max volume). The good brands will tell you THD @ 1W output, or give you a rating of power @ what THD or THD @ what power. The bad brands will just hide the number. And even if they do show the number, it can't be fully trusted unless a third-party measures it anyway.

In short, not all power and THD ratings are the same, and this is why you may seem to be spending more on certain stereo amp for less power compared to on AVR for more power. However this is not the only reason nor should you blindly believe in it, as there are sellers who just make expensive products that still suck.

Next, 6 ohm - Usually this gives the highest power, because manufacturers optimize their amp for the highest power @ 6 ohm. Because speakers come in 4 ohm and 8 ohm. Ideally, you design an amp that reaches its voltage limit and current limit at the same time when outputting the highest power. This is possible with a fixed load impedance, but not when you have to cater to both 4 ohm and 8 ohm. An amplifier optimized for 8 ohm will have half the output power when driving 4 ohm (current bottleneck), while an amplifier optimized for 4 ohm will have half the output power when driving 8 ohm (voltage bottleneck). So logically, in order the avoid that expensive half-power penalty on the rated power, manufacturers optimize for 6 ohm. Which reduces the penalty to just 33% ~ 25%. But this also means they get this much more extra power if they report at 6 ohm instead of 4 ohm / 8 ohm.

And finally, number of channels driven. Last paragraph we looked at limits due to the output stage, now we look at limits due to the power supply. Put simply, the power supply isn't large enough to supply all channels at the same time without clipping. However the manufacturer assumes (somewhat accurately) that not all channels will demand the same amount of power and at the same time - usually the front channels have higher volume, and when you do surround sound effects and stuff the movie director will purposely accentuate the surround channels.

And that covers the differences in RMS power ratings. I won't go into the at least 3 different definitions of peak power rating, that would deserve their own post and this post is already long as it is so I will end this post here.
 

Amon86

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Mmm... there are lots of things to say but a lot can also be found easily on Google, so I will skip those

One obvious one that needs to be stated however is that HDMI 1.4 supports 4K @ 24Hz to 30Hz (depending on 4096 or 3840), while HDMI 2.0 supports 4K @ 60Hz. Version 2.0 will also support 3D 1080p60 while 1.4 is limited to lower data rates.

For the details of each version, just refer to Wikipedia.
https://en.wikipedia.org/wiki/HDMI#Versions

Power ratings (and THD ratings)
If you noticed why the expensive stereo amps seem to have less power than the AVR cousins, this is the explanation.

Take Marantz for example. From the webpages:
PM6006: $699, 45W 4 ohm / 60W 8 ohm, THD 0.08%
SR6012: $1499, 110W 8 ohm, 20 Hz - 20 kHz, 0.08% 2ch Drive
NR1609: $749, 50W 8 ohm, 20 Hz - 20 kHz, 0.08% 2ch Drive

This is actually a somewhat bad example, since they look kind of reasonably similar, because Marantz decided to be a good guy and include all power ratings at 0.08% THD.

But let's look at NR1609's other rated figures



And suddenly, 85W is significantly more than 50W.

This gets even more epic with SR6012:



Basically the key things worth noting are:
- 10% THD
- 6 ohm
- Number of channels drive

So how does the product suddenly get double the power? Simply by giving different conditions. As output power approaches device limits, distortion increases until the point of clipping. But manufacturers continue further, increasing output power even after clipping, until they get the 10% THD value and call it a day. With a lot of sheep thinking max output power is everything, manufacturers usually choose to report output power at 10% THD and etc, allowing them to double the output power compared to reporting at <1%. And the rest of the industry is forced to follow this reporting methodology or get disadvantaged. Fortunately, some companies seem to be trying to reverse that trend.

The problem with power ratings based on 10% THD, is that it does not tell you what is the THD during normal operation (i.e. not at max volume). The good brands will tell you THD @ 1W output, or give you a rating of power @ what THD or THD @ what power. The bad brands will just hide the number. And even if they do show the number, it can't be fully trusted unless a third-party measures it anyway.

In short, not all power and THD ratings are the same, and this is why you may seem to be spending more on certain stereo amp for less power compared to on AVR for more power. However this is not the only reason nor should you blindly believe in it, as there are sellers who just make expensive products that still suck.

Next, 6 ohm - Usually this gives the highest power, because manufacturers optimize their amp for the highest power @ 6 ohm. Because speakers come in 4 ohm and 8 ohm. Ideally, you design an amp that reaches its voltage limit and current limit at the same time when outputting the highest power. This is possible with a fixed load impedance, but not when you have to cater to both 4 ohm and 8 ohm. An amplifier optimized for 8 ohm will have half the output power when driving 4 ohm (current bottleneck), while an amplifier optimized for 4 ohm will have half the output power when driving 8 ohm (voltage bottleneck). So logically, in order the avoid that expensive half-power penalty on the rated power, manufacturers optimize for 6 ohm. Which reduces the penalty to just 33% ~ 25%. But this also means they get this much more extra power if they report at 6 ohm instead of 4 ohm / 8 ohm.

And finally, number of channels driven. Last paragraph we looked at limits due to the output stage, now we look at limits due to the power supply. Put simply, the power supply isn't large enough to supply all channels at the same time without clipping. However the manufacturer assumes (somewhat accurately) that not all channels will demand the same amount of power and at the same time - usually the front channels have higher volume, and when you do surround sound effects and stuff the movie director will purposely accentuate the surround channels.

And that covers the differences in RMS power ratings. I won't go into the at least 3 different definitions of peak power rating, that would deserve their own post and this post is already long as it is so I will end this post here.

I don't believe in AV amp's watts in term of tech spec for stereo channel in music as they are not consistent watts due to the fact they also need to share with other channels there is fluctuation....that's why there are power amp and mono amp they have more control in term of driving power
 

86technie

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No one ever ask this question before are Auro 3D better? or Dolby Atmos better? Both setup were different....most ppl i see used Atmos

Dolby Atmos still win hands down not in terms of sound but
Dolby Atmos can be found with Mid-range AVR.
Auro 3D wise only for high end AVR and the speaker configuration
is very different than Atmos.

I only heard Auro 3D in Cinema, I am not impressed by it's SQ.
The only good thing is since it uses 11.1 so directional audio
can be heard very clearly.

Like leave zipping past you can hear it as if like 3D environment.
For home wise, Auro supports up to 10.1 which to me isn't suitable
for HDB flats.

Dolby Atmos wise no need for so many speakers, minimal 5.1.2
will do. If you compare with GVmax that one is true Dolby Atmos
setup with 67 overhead speakers.

Atmos may win hands down over Auro but the sound experience
is different between the two. Auro is more towards 3D surround,
Atmos is cinema surround with precision directional audio.

At home is impossible to put 67 speakers, recommend will be still 5.1.2
depending on room size. 7.1.2 is another option but that is for bigger living rooms.

Do also take note that not all Blu ray can output 7.1.2 some is 5.1.2.
Auro 3D Blu ray I have not seen one yet.
 

Amon86

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Dolby Atmos still win hands down not in terms of sound but
Dolby Atmos can be found with Mid-range AVR.
Auro 3D wise only for high end AVR and the speaker configuration
is very different than Atmos.

I only heard Auro 3D in Cinema, I am not impressed by it's SQ.
The only good thing is since it uses 11.1 so directional audio
can be heard very clearly.

Like leave zipping past you can hear it as if like 3D environment.
For home wise, Auro supports up to 10.1 which to me isn't suitable
for HDB flats.

Dolby Atmos wise no need for so many speakers, minimal 5.1.2
will do. If you compare with GVmax that one is true Dolby Atmos
setup with 67 overhead speakers.

Atmos may win hands down over Auro but the sound experience
is different between the two. Auro is more towards 3D surround,
Atmos is cinema surround with precision directional audio.

At home is impossible to put 67 speakers, recommend will be still 5.1.2
depending on room size. 7.1.2 is another option but that is for bigger living rooms.

Do also take note that not all Blu ray can output 7.1.2 some is 5.1.2.
Auro 3D Blu ray I have not seen one yet.

I see...Auro 3D is one of those things i didn't tried before...as for it's config they need to be height speakers mounting on top of LR channel and back due to my living room no false ceiling I can only go by Atmos reflect speakers how great the effect i didn't know but i will be t-loaning a pair to test it out....Auro 3D last time during Marantz SR7010 or SR7011 out...is a feature that must be brought for a few hundreds of dollars as they didn't come with it....nowadays higher end receiver all came with it....but no one is using so kinda strange lol
 

86technie

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I see...Auro 3D is one of those things i didn't tried before...as for it's config they need to be height speakers mounting on top of LR channel and back due to my living room no false ceiling I can only go by Atmos reflect speakers how great the effect i didn't know but i will be t-loaning a pair to test it out....Auro 3D last time during Marantz SR7010 or SR7011 out...is a feature that must be brought for a few hundreds of dollars as they didn't come with it....nowadays higher end receiver all came with it....but no one is using so kinda strange lol

You can try but Auro3D Setup looks tedious. :s22:

https://www.auro-3d.com/wp-content/uploads/documents/Auro-3D-Home-Theater-Setup-Guidelines_lores.pdf
 

86technie

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lol i don't think i got space for that....and must used tons of cabling running above without false ceiling will be quite ugly....

Than your house will be like selling Hi fi speaker with so many
speaker dangling all around. :s13:
 

Amon86

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Than your house will be like selling Hi fi speaker with so many
speaker dangling all around. :s13:

Actually my home got quite alot of speakers liao living room 7.1 all floorstanders,my own room 2.0 bookshelf and my com desktop 2.0 bookshelf as well....last time my mum make noise now she enjoys it

6LCOHzx.jpg
 

wwenze

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You can never have enough power and do note that what they state on the box seldom gets realised in real life. Look at the power consumption for an idea. Eg, if the power drawn from the wall is 700W, and there are 9 channels, even if the amp has an efficiency of 80%, that means you won't see more than 60W per channel when all channels are operating.

However if you live in a domestic setting like a flat and use a subwoofer, this will be enough if you use typical speakers. More power allows you to use less efficient speakers and will give you more dynamism and headroom for the explosive moments.

Let me expand on this...

How much power is sufficient?

This depends on how loud you want to go and how big your listening area is. But first, let's talk loudness - continuous exposure (e.g. workplace) to 85dB is the limit set by OSHA to avoid hearing loss, and some claim 80dB. 80dB is around a vacuum cleaner while 88dB is stated to be that of a blender.

A speaker's sensitivity is the SPL at a specific distance at a specific power e.g. 86dB @ 1m @ 1W is a typical value. Which means if you input 1W of power into a speaker and you stand 1m from the speaker you will get 86dB.

Every doubling of distance reduces SPL by 6dB (i.e. 4 times) i.e. inverse-square law.

86dB sensitivity is usually anechoic / free-space i.e. floating in open space with no walls. Assuming sound travels in all directions, blocking one direction with a wall or a floor will focus all the energy in the remaining direction.

Vol36_Dec08_Boundaries_fig1.png

https://www.prosoundtraining.com/2011/08/29/how-boundaries-affect-loudspeakers/

And finally, the inverse square law mentioned above is only valid if the 2D surface area of the sound consistently expands at the rate of distance^2. With other type of 3D shapes, we fallback to using the surface area i.e. if the sound wave is travelling through a lossless tube then the SPL is equal along the whole length of the tube without losing any SPL as a function of distance. However, since a lot of this is reflected sound (as opposed to direct from speaker) and we don't know whether it will do positive or destructive interference, we can just consider direct sound and assume inverse square law. Just assume the sound that hit your wall get absorbed or something. (Sorry soundbar owners. ;))

Now, assuming that you need 85dB coming from any speaker, and you sit 4m from the front speaker, and we assume no SPL benefit from boundary-loading because the tweeters are super bright and directional and you need all the loading to benefit the bass because you wouldn't have enough bass otherwise,

you would need 16W from the a speaker with 85dB sensitivity (a typical sensitivity value). If you do a 6dB bass boost... for simplicity just multiply it by 4 times again, so 64W.

In other words... compared to sitting at 1m,
If you sit just 0.5m away from your speakers, you need 1/4 times the power
2m = 4 times the power
4m = 16 times the power
Every 3dB = 2 times the power

Due to this exponential / multiplying nature, you can expect a large difference in power requirements between different applications. 1,000W amps for PA are common, some even running on 3-phase supply.

So, we got 16W for that living room hypothetical case above, or 64W after 6dB bass boost. 16W sounds okay, 64W can't be properly handled by NR1609 at a low THD, and even SR6012 may have problem running all channels at the same time. (Although with all channels at the same time the total SPL is also going to be a lot higher)

But remember again that each doubling / halving of power only results in 3dB change, so if you listen at 10dB lower, you need just 1/10 the power.

So how much is enough? Can be 1W, can be 100W.
 
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Amon86

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Marantz/Denon Audyssey MultEq app for $28.98 in IOS

– View the Audyssey MultEQ speaker detection results, to check and modify the configuration, and adjust for any unusual speaker set-ups

– See before and after results of the Audyssey calibration. Easily identify room problems and see what changes the system is making

– Visually edit the Audyssey target curve for each channel pair, to suit individual tastes

– Adjust the overall EQ frequency range of the EQ for each channel pair

– Switch between two high-frequency roll-off target curves

– Enable or disable midrange compensation to make the sound brighter or smoother. Make dialogue even clearer, or tame hard-edged soundtracks

– Save calibration results, ready for instant re-loading should the system require a reset

Anyone using this app already? is it worth the price?
 

wwenze

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Peak power (This focuses on amplifier only, speakers' rated power ratings behave differently i.e. even more bullsh*ttingly)

So I originally didn't plan to write about this. But since "dynamics" was mentioned, I thought I would expand on that, and to appreciate that topic require knowing what "peak power" is, so where we go.

ESP has a good post on power ratings which everybody should read.
http://sound.whsites.net/power.htm

I'm going to ignore stuff that are blatantly made-up, like PMPO, or some value pulled out from thin air which simply violates Ohm's Law. But as I type this post, there are 3 reasons for the existence of "peak power" which I consider legit, and more probably exist.

RMS vs peak

This is the one that probably appears most often on consumer products. Peak will be twice of RMS in this case.

And is also the easiest to understand and most correct. Because this is according to scientific/engineering definition. And is covered in high school physics.

RMS "is the square root of the arithmetic mean of the squares of the values, or the square of the function that defines the continuous waveform" - Wikipedia

For a sine wave, RMS value is sqrt(2) of peak value.

And since power is V^2 / R, the average power of a sine wave would be half of the "highest instantaneous power, which occurs at the peak of the waveform"

So, there, peak power is double of RMS, and nobody can dispute that unless they are nitpicking. It also means that having both peak and RMS ratings is USELESS because one is by definition double of the other, assuming other bottlenecks don't come into play.

Unfortunately a company simply showing both RMS and peak ratings does not guarantee that they didn't simply pull the RMS value from their rear-end and then multiply that by two to get the peak power rating. Such companies can be identified by their output power seemingly violating thermodynamics when compared to their input power or fuse rating, and in some cases the wattage printed on the drivers.

RMS vs program / music / AES

This one appears a lot in pro-audio equipment.

Begin by looking at RMS power first. Give it the loudest single-frequency sine-wave you can reproduce without distortion. This is RMS power. (Actually need not be single-frequency but that makes it easier to understand. Really as long as the power level is constant then it can be considered, regardless of how many frequencies are in there.)

But if you look at the waveform of music, you would find only a few peaks that hit the maximum volume and lots of smaller ones that don't.

Often caused by a power supply (or whatever; an amp is really just a variable-output power supply) that can supply the power for just a short period of time but not enough for longer periods. An example would be a power supply with huge capacitors but small transformers. Although a power supply having insufficient capacitors can also do that - my thread on M50W repair has a waveform which shows clipping every 10th cycle of a 1kHz wave due to reduced capacitance of a bad capacitor. That speaker would have reduced RMS power, but the program / music power would be higher if you count just the first 9 cycle or even just the first cycle.

Notice how the logic is somewhat similar to instantaneous or peak power rating, except the program / music / AES power ratings consider a longer period of time and considers the typical music (or, program) waveform, while the first form of peak power just considers the biggest peak for an infinitely small period of time. Hence, music power ends up somewhere between RMS power and peak power rating. Around 1.5x of RMS rating is logical and common.

Thermal limits

Also appears in pro-audio equipment. Easy to understand - Current passes through semiconductor, semiconductor heats up. If cooling system can handle the heat, good. If cooling system cannot handle the heat, temperature slowly increases, overheat protection kicks in, maximum output power is reduced. This rating is really depending on the manufacturer, and they can give something like 1,000W for 2 hours, and 800W for 24/7. Needless to say, the actual value you get IRL depends.
 

wwenze

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Dynamics and power ratings

To put it frankly, if you have enough clean (low distortion) RMS-rated power for your required SPL, you already have the highest dynamics possible.

It's just mathematics - output sound pressure (of speaker) is a function of input sound pressure (from mic), which was converted and stored in the form of voltage. If your equipment is ideal, that function should be linear i.e. SPLout = SPLin * c where c is a constant which is your gain or volume control. (You can calculate in terms of SPL or voltage, depends on what you're calculating.)

To put it more laymanly, let's say given a piece of music signal, and the amp at that volume setting has a gain of 2. When the input signal is 1V, the output signal is 2V; when the input signal is 2V, the output signal is 4V. This is accurate reproduction.

i.e. if you're aiming for accurate reproduction and you managed to get accurate repduction, this already includes getting the most dynamics.

There are filters/processors that can result in things like: when input signal is 1V, output signal is 2V; when input signal is 2V, output signal is 4.5V or something (greater than 4V). This are called dynamics expanders (or restorers, whatever), or what I like to call "bullsh*t" when used indiscriminately in consumer contexts. These have actual uses when used properly (and goes beyond audio, too), but counterproductive when used wrongly. Let's ignore them for now.

Now, the whole talk and pursue for dynamics came about in the first place, is because real world equipment loses dynamics. I'm not talking about dynamic compression in CDs or etc; ignore them for now too. Back to the layman example above, real world equipment can do something like - input signal is 1V, output signal is 2V, input signal is 2V, output signal is 3.85V...??

Compression of signal shows up as harmonic distortion. If you have enough clean distortion-free power, you won't see it. And this is the point of talking about everything leading to this point - bullsh*tted power ratings are the cause of not having distortion-free power, resulting in statements like "why does this 50W amp have more dynamics than that 50W amp".
 

petetherock

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Before we go overboard with the tech talk - entertaining as it may be, I would like to use this thread to help the typical HWZ members, who aren't on the same level as other more advanced forums like xtremeplace, where there are more season users of AVRs.

We may have members contributing who know a lot, but it's more important to help those who are in need..

The typical member here spends less than 5k on his/her entire HT setup, may have very vague notions on what they want, place aesthetics first, never been to Sim Lim or Adelphi and worse, have no clue about brands.. so let's adopt the KISS principle..

Cheers
 

86technie

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Before we go overboard with the tech talk - entertaining as it may be, I would like to use this thread to help the typical HWZ members, who aren't on the same level as other more advanced forums like xtremeplace, where there are more season users of AVRs.

We may have members contributing who know a lot, but it's more important to help those who are in need..

The typical member here spends less than 5k on his/her entire HT setup, may have very vague notions on what they want, place aesthetics first, never been to Sim Lim or Adelphi and worse, have no clue about brands.. so let's adopt the KISS principle..

Cheers

Agree, not many are really very well verse with technical terms.
Some just want to out there, look for a HTS system based on
factors like pricing, number of speakers, audio format it support
and etc.
 

Amon86

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Actually here in hardwarezone ppl were all into edifier,Swans and lower budget stuff so this thread no one will bother to look at....wwenze mention alot of tech stuff which is long but here no one bothers....got holes to plug in sound came out means good to go....from what i see most ppl here don't play AVR as is troublesome for them run alot of cables they don't know how to do it themselves....they will only look for solution like plug and play things like soundbars and active speakers.....xtremeplace is a place mostly for ppl to sell away their old equipment seldom ppl there will ans question....the best place to get your question ans is AVS forums or headfi
 

vernon_wmk

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XP has a wealth of information together with FAQs. it's probably some folks get tired of repeating themselves.
 
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