Trell
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More speakers, less watts?
- Thread starter RichardL
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Audyssey does not designate or suggest large or small speakers, filter levels, or crossovers. It is the AVR software that marks them after calibration.
Audyssey always recommends small speakers for your bass management when using one or more SW.
I also don't understand that the sound "gets muddy" at high volume from the heat, at least I haven't experienced it.
fieldcar
Addicted to Fun and Learning
The sound gets muddy due to heat?
Yep. The denon's throw off some substantial heat. This is considered common knowledge IMO, and there was even a part of Amir's X3700H review where he takes thermal readings with a thermal camera. It's probably the power supply stage causing the distortion. Inadequate power supplies and transformers are a common design deficiency in pretty much all AVR's. Transformer's react to heavy loads and high thermal environments with lower output voltage on their secondary windings, and that's putting it very simply. Then, on the second half the of the issue, you most likely have SMPS issues. If too much power is pulled you get switch mode ripple and harmonics introduced into the amplification stage, and then you just have a mess. If your filtering caps are inadequate due to "size restrictions" of, oh, say a compact AVR, then you'll also run out of filtered DC and see more artifacts in your supply power.
To learn more, here is a good article worth reading. Check the second page for the majority of information on power supplies. I'm sure there are better article's out there, but I didn't want to spend too much time digging.
https://www.audioholics.com/audio-a...or-switch-1/amplifier-and-power-supply-basics
It appears Audyssey has addressed this on their site. Bass Management and LFE: NOT the same thing! – Ask Audyssey (zendesk.com)
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Trell
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Many words, but you've still have to shown that your claim is even reasonable: "Once the receiver gets hot after a minute of loud music, sound gets muddy."
I'm not the poster you quoted but at least with respect to small/large speakers and crossovers he is correct, and that is from Chris Kyriakakis of Audyessey (now bought out). You can Google that for yourself.
No, I am not an engineer, although I could be, I am very happy with my profession.
But this is not said by me, Audyssey says it repeatedly in her articles and forums. Audyssey sets the level at which the loudspeaker loses efficiency in the room, it is the AVR that sets the "size" of the loudspeaker and so on. You can read it in multiple posts and forums.
Another thing is that the Infinity Aircom, or a similar one, is very useful, I think so too. I simply do not agree with some of your statements, after all this is a discussion forum.
Trell
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What Audyssey does is to report back to the AVR when it thinks that bass volume has dropped of "too much" during a measurement (what you write as "the loudspeaker loses efficiency in the room"), and based upon that the AVR makes a decision to show this is a small/large speaker with a crossover.
Otherwise just ignore his post.
Fans are good insurance, especially if driving at high levels (do you use the Eco settings at all?). Can't imagine following Denon's (not Audyssey's) "large" speaker (i.e. do not use bass management) recommendation when using a sub. Even Audyssey recommends starting at 80....I cross my 590s crossed at 100....but have sufficient subwoofage and without localization....
The avr detects an f3 of 40hz or lower generally when suggesting no bass management.
I'll go by my general experience with such....do you find you need max power in all channels simultaneously with movies? I'd rather ask the mastering/mixing guys, tho.
well it depends on how much ‘power’ there is and how sensitive are the speakers ofcourse.
but in general there are always instances where all speakers are working simultaneously.
Sure, working at same time but at same level of power consumption?
ps With less efficient surrounds or at long distances, that could eat up some of the power difference with typically lower levels for surrounds, too. It makes me wonder when stereo amps came out were there complaints that the 2ch rating wasn't as good as the 1ch rating?
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Yeah that doesn't really work like that, though I used to kind of think so. Because first off
and secondly, after giving an explanation like in @beagleman's owner's manual, someone else corrected me and said that while a highpass crossover might reduce the average power somewhat, a side effect of the filter is to require more voltage swing, so actually the amp can clip just as easily (more or less, obviously it depends on a lot of specifics). The poster attached a measurement showing that.
By the way, on a vaguely related tangent, this https://www.aes.org/e-lib/browse.cfm?elib=4864 shows that unlike what you would intuitively think, steeper crossovers do not reduce power transmission more (except at the highest frequencies). The reason is that while the cutoff is steeper in the stop-band, it is actually less in the pass-band. The logarithmic nature of the filters means those more or less even out.
I'll see your tugboat, and raise you a power amplifier!
Here's how it works:
- The power amplifier (outboard or built-in) sees in input voltage and, well, amplifies it.
- From Ohm's Law V=IR rearranges to current I=V/R. So a current flows into the load, more current if the "ohms" are less. Speakers are NOT resistors but never mind that for now.
- As you turn up the volume, the output from the preamp section gets bigger, so the voltage at the power amp speaker terminals gets bigger, and more current flows.
- But at some point the power supply cannot supply enough current, and you get clipping. This depends on the power supply, and the actual speaker load at the moment, and how many channels are how loud if it's a multi-channel amp, yadda yadda yadda.
Tested with resistors, every single AVR I have ever seen tested "drooped" its maximum power as you drive more and more speakers with a steady tone. Usually to like maybe 2/3 or 3/4 or something like that. I have no reason to think this would be different with actual speaker loads, in fact it could be worse again depending yadda yadda yadda
Fortunately, AVRs have enough power for most people to play pretty darn loud, and they all have pretty much the same power within a decibel or two (a tiny bump in volume). If it's not enough, then you need like 300+ watts into FOUR ohms (even if your speakers are 8, because again speakers are not resistors, not even close)
How do you know that? Please understand, I'm not picking on you, but this is one of those "everyone knows" conventional wisdoms that I see get touted in magazines and all over but have NEVER seen any DATA presented. And my experience in various cinematic happenings has been that some scenes sure seem loud as hell in every existing channel and bleeing into adjacent universes.
Seriously, has anyone ever measured this? I nominate the Terminator 2 scene where a semi is smashing into a lot of buildings. Or when The Mummy awakens. Etc. And in a different case, Insane Clown Posse's DVD-Audio of The Wraith: Shangri-La has "as much bass as possible in every channel" as one of the duo said in an interview regarding their instructions to their sound mixer. But maybe those things don't really peak in all channels exactly at once; I'd just like to KNOW.
Oh yes yes YES-yesterday on top of the AVR-X3600H jamming out was it Steven Wilson, the fan kicked up to full for a while. The Focal 936 it runs measure as current hungry beasts; not as sure about the CC900 and SR900.
As others have stated and the review shows, the power is somewhat reduced as more channels are added, but surround channels typically need less power than the main/center, and there's rarely the need for full output from all channels.
Also note that if you have high requirements for power, filling them with an AVR is very expensive, since only the higher end AVRs have significant amounts of power, while a lower end AVR may cover all your feature needs except power. So rather than look for an AVR that has enough power, buy one that have all the features you need, and then add a power amp for your main channels. Then all the power in your AVR is dedicated to the remaining channels, which most likely will be plenty. Cheaper and better than buying a top end AVR.
Also note that if you have high requirements for power, filling them with an AVR is very expensive, since only the higher end AVRs have significant amounts of power, while a lower end AVR may cover all your feature needs except power. So rather than look for an AVR that has enough power, buy one that have all the features you need, and then add a power amp for your main channels. Then all the power in your AVR is dedicated to the remaining channels, which most likely will be plenty. Cheaper and better than buying a top end AVR.
Mr Wolf
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I say this simply because I've spent a considerable amount of time researching how movie soundtracks are mixed and this is what I learned.
I discovered that, in any Dolby reference mix (old or new), the theoretical maximum is the equivalent of four speaker channels (3 front + 1 surround) being driven to 20dB peaks and the LFE channel to 30dB peaks. For broadcast/home releases (e.g. Blu-ray), these peaks are often lowered a few dB to reduce dynamic range.
In the original Dolby Surround format there was a single surround channel, albeit played through numerous speakers. The extra surround channels found in later surround formats has simply changed where the surround sound effect comes from, it hasn't increased overall loudness for the listener. Not only is this logical but it also makes sense when you consider health and safety issues here for hearing as this level of maximum possible output (circa. 119db) is already at or close to the physical pain threshold.
If you only want measurements as "data", the only ones I managed to find published on the web was in this research paper which, due to only a few movie samples, unfortunately isn't much by way of statistical evidence but at least it is consistent with what I found elsewhere.
https://assets.ctfassets.net/4zjnzn055a4v/3h5YQiJIQaPDQB84DTfeuU/5186470a8c23744369d4990c776b9ceb/sound_pressure_capacity_requirements_for_monitoring_makivirta_2015.pdf
beagleman
Major Contributor
I get what you are saying, but Deep bass, as compared to upper or midbass simply requires more power.
I assume we are talking movies here. The really loud deep bass is at very high levels in many movies. And while yes ANY frequency can require a lot of power when played back at very loud levels, taking away just the 80-100 hz range AND BELOW, removes that bass which is on the film at abnormally loud levels.
Put it this way. I have seen really loud deep bass cause incandescent lights on the same circuit dim when the loud notes or sounds "Hit". That does not happen, with other sounds, or not nearly to the degree.
Well intuitively I would agree, since at very low frequencies speakers are generally inefficient unless absolutely huge. However that is a different thing from what I was re-quoting.
- Clipping is not really "running out of power" - it is actually running out of voltage swing when the power supply cannot supply enough current (at least usually).
- The highpass filtering causes additional peak voltage swing.
- So removing the bass reduces some voltage swing, the highpass filters put it back, and your AVRs clips just as easily.
- Of course that depends on umpteen factors, but the point is cutting out the bass does not necessarily give more peak headroom at all. Long term power maybe, however it's the peaks that we don't want to clip.
Very interesting though as you say not conclusive (their film choices aren't very loud). Their Figure 2 is what I would like to do on some loud samples, looking just at peaks. I wonder how they made that...maybe I can email and ask. Though my question is more like "how can I do that myself on a Mac?!?"
