The Audio Path In Consumer-Grade Products

[AcuDefTechGuy]

2.83v is 1 watt only if the load is 8 ohm.

If the SNR is measured at 1W, you don't need to worry about the voltage and ohm.

In this case their are pros and cons in using 2.83v and 1 watt. As long as you compare apple to apple either way is fine.

Now we can move on from this thread.

 

[PENG]

AH SNR measurements from past reviews tabulated and attached. Not that if in dB, it's unweighted, dBA means A weighted.

 

[<eargiant]

You have some misconception here, let me try to clarify (since Irv didn't do it..).

- JA's 128.5 dB is dynamic range at clipping power of 100W, so in that case Dynamic range = SNR measured at clipping power of 100W, presumable A weighted.

- SNR, if measured at 1W would be lower, as Irv pointed out long ago.

- DR, by definition, will be typically higher than SNR, if SNR is measured at 1W output, weighted or not.

- Some cheap AVRs may be able to achieve 109 dBA, but again most likely at rated power output, not at 1W output.

Bingo! Give the man a prize!

I've been trying to make the first point as early as post #14 and as late as post #226. At least when you say it they believe it. I would have assumed that someone like ACDT Guy who was so quick to jump in as early as post #4 with the bluster, yelling and lighting up of the forum like a Christmas tree (or like a brain that has been scientifically proven to light-up in an EEG scan when it perceives ultra high frequency musical signals that the listener did not think they heard. ) would actually understand what he was talking about.

I wanted to discuss analog volume pots next but quite frankly, like Irv I've lost the energy and desire to continue with this discussion...

 

[<eargiant]

Great chart.

Definitely shows that the lowly Denon's & Yamaha's can have Unweighted SNR's that are better than the Benchmark and the so-called high-end separates.

Too bad the Denon PAO-A1 amp (Unweighted SNR 94dB) is like 140 LBS, which is way over my weight limit.

Are you that dense? It "definitely shows" nothing. Still comparing apples and oranges... stop misleading the other forum members.

You should have taken my advice when I told you in post #14 that "I suspect you'll stop humiliating yourself by posting nonsense like this." Too bad you didn't listen.

The Benchmark was measured by JA and those were all measured by Gene. If Gene measures the Benchmark then you can talk.

Do you honestly think my Yamaha A-S801 is going to measure better or even close to the AHB2 if Gene tests the Benchmark? Too bad JA hasn't measured the Yamaha, I'd like to see how it compares on his bench.

A forum like this should be discussing the engineering marvels that are the DAC3 & AHB2. These units are intriguing and in many respects are on the cutting edge. The AHB2 is unlike anything out there that I know of. So many unique and interesting design choices and attributes to speak of. All you can do is knock the research & engineering that has made them a reality by continually comparing them to a $300 unit. If every scientist and engineer thought like you, there'd be no progress because, well- what we have is good enough so who cares.

What a shame.

 

[PENG]

Great chart.

Definitely shows that the lowly Denon's & Yamaha's can have Unweighted SNR's that are better than the Benchmark and the so-called high-end separates.

Too bad the Denon PAO-A1 amp (Unweighted SNR 94dB) is like 140 LBS, which is way over my weight limit.

I wouldn't want to draw conclusions by comparing test results directly, unless the measurements were done by the same lab using the same methodology, and preferably by the same person. Even comparing results from Gene's test bench, you have to read the fine print carefully, because he did not do everything exactly the same way on every DUT.

 

[PENG]

Are you that dense?
What a shame.

Remember Newton's 3rd law?

 

[killdozzer]

There's always another stranger sneaking glances
Some trigger-happy fool willing to take chances
Some old whore from San Pedro'll make advances
Advances on your spirit and your soul.

~ Bob Dylan

 

[lovinthehd]

There's always another stranger sneaking glances
Some trigger-happy fool willing to take chances
Some old whore from San Pedro'll make advances
Advances on your spirit and your soul.

~ Bob Dylan

Didn't know Bob was acquainted with the whores in San Pedro....quite a drive from his Malibu pad.

 

[killdozzer]

Didn't know Bob was acquainted with the whores in San Pedro....quite a drive from his Malibu pad.

I opted for a full passage to do right by the song. Second verse is the one I got reminded of by this and many similar threads. It's just one after another, I see all of you fend of these useless attacks... I mean there are so many (thousands) of forums that completely prefer this "me, me, me" approach, this "personal experience is the holy grail" way, I fail to see where does this need to confront AH people comes from. It really looks like majority feeling somehow threatened by the tiniest minority. In my country it is absolutely impossible to find one single forum that would prefer the "No Bullshit Audio" approach. And still, the very fact that you don't believe that money makes cables makes them label you ignorant, not truly into music, gullible about science (yes, they think we put too much trust into measuring), although they represent the vast majority.

P.S.: I trust Bob when he sings. Maybe he had some experience with old whores while on a setting of Pat Garret & Billy the Kid.

 

[Goliath]

A forum like this should be discussing the engineering marvels that are the DAC3 & AHB2. These units are intriguing and in many respects are on the cutting edge. The AHB2 is unlike anything out there that I know of. So many unique and interesting design choices and attributes to speak of. All you can do is knock the research & engineering that has made them a reality by continually comparing them to a $300 unit. If every scientist and engineer thought like you, there'd be no progress because, well- what we have is good enough so who cares.

They certainly are cutting edge, but you can have a unit that measures far worse (like perhaps 10 times worse) and it would still exceed human hearing thresholds and not by a little.

Every year (or every few months it seems) a new DAC is launched. Technical performance will improve and will keep on improving and this will not stop. That's all that can improve. Technical performance. Ideal audible performance - ie no sonic signature - has been around for decades.

Progress is great if it leads to improved audible performance. Or ... if it leads to a better price/performance ratio. Anything else is just a numbers game.

 

[<eargiant]

Hi guys- Blissfully listening to music again tonight and 4 unrelated questions came to mind. Discussion and constructive debate is good, so here they are:

• Have all (any?) of you heard the difference in sound presentation that simply reducing the gain on a pre-amp makes to the sound signature of the same amp & speakers at an equivalent SPL?

• What is the most important specification?

• Is it possible for two different amp/pre-amp combos to measure perfectly within the audible range on the bench yet when they are taxed with real world music listening at various SPLs one falls short due to design limitations such as insufficient filter capacitance, insufficient output transistors, etc.?

• Are any of you skilled at designing, reading or repairing audio circuits and at the same time in the business of audio engineering?

If you choose to respond, please answer all questions and please don't chomp at the bit, I'm here for an interesting conversation not an adversarial confrontation.

Thanks

 

[Swerd]

Have all (any?) of you heard the difference in sound presentation that simply reducing the gain on a pre-amp makes to the sound signature of the same amp & speakers at an equivalent SPL?

I’m not clear on what you’re asking here. How is reducing the gain different from reducing the volume? I can see how reducing the volume might make an amp/speaker combination sound different at lower SPL, but you're asking a different question. Please clarify.

What is the most important specification?

A loudspeaker’s ability to disperse sound off-axis in a smooth manner (flat frequency response curve), is related to a speaker’s ability to cast a realistic sounding image. So flat frequency response, both on-axis and off-axis, is key in my opinion.

Is it possible for two different amp/pre-amp combos to measure perfectly within the audible range on the bench yet when they are taxed with real world music listening at various SPLs one falls short due to design limitations such as insufficient filter capacitance, insufficient output transistors, etc.?

Not without the real music first taxing the amp/speaker combination. You would have to first rule out that possibility before being able to conclude that something else, such as a pre-amp, is causing the ‘falls short’ effect.

I see where you’re going. Because hearing an example of what interests you, over the internet, is unlikely, I’d settle for having this explained better. You can probably see where I'm coming from… that among the top 10 things that make audible differences in home audio, loud speakers are (at least) #1 through #7 .

Are any of you skilled at designing, reading or repairing audio circuits and at the same time in the business of audio engineering?

No to both questions.

 

[M Code]

The ability of a loudspeaker to deliver a uniform frequency response off-axis is closely related to the loudspeaker's x-over design. A point often overlooked by loudspeaker designers is that when designing a multi-driver system they tend to use too-high of a x-over frequency... When a dynamic driver reaches it highest frequency capability it will start to beam and the dispersion pattern begins to contract...
By implementing a lower x-over point before the driver starts to beam, the entire system will have a smoother frequency response as the audio signal is handed off from 1 driver to the next..

Just my $0.02...

 

[Swerd]

The ability of a loudspeaker to deliver a uniform frequency response off-axis is closely related to the loudspeaker's x-over design.

Yes, exactly! Thanks for spelling that out.

A point often overlooked by loudspeaker designers is that when designing a multi-driver system they tend to use too-high of a x-over frequency... When a dynamic driver reaches it highest frequency capability it will start to beam and the dispersion pattern begins to contract...
By implementing a lower x-over point before the driver starts to beam, the entire system will have a smoother frequency response as the audio signal is handed off from 1 driver to the next..

Another way to spell that is B and W.

 

[killdozzer]

• Have all (any?) of you heard the difference in sound presentation that simply reducing the gain on a pre-amp makes to the sound signature of the same amp & speakers at an equivalent SPL?

If by this you're thinking of anything close to what gain does in musician's amp, then yes. I did notice that no matter if the volume or SPL is the same, that even in home audio adding gain at preamp stage, changes the all around sound. Given that your preamp has the gain knob.

I don't know the answers to other questions and I'm not an audio engineer.

 

[PENG]

If by this you're thinking of anything close to what gain does in musician's amp, then yes. I did notice that no matter if the volume or SPL is the same, that even in home audio adding gain at preamp stage, changes the all around sound. Given that your preamp has the gain knob.

I don't know the answers to other questions and I'm not an audio engineer.

Could you define what "musician's amp" mean, such as, is it still an amp that is design to simply amplify the input linearly without intended distortions?

 

[<eargiant]

I’m not clear on what you’re asking here. How is reducing the gain different from reducing the volume? I can see how reducing the volume might make an amp/speaker combination sound different at lower SPL, but you're asking a different question. Please clarify.

Gain and volume are often confused. While related, they are not the same, so reducing one is not the same as reducing the other. For me, in most cases, a lower gain/higher volume is preferable to higher gain/ lower volume. Just that difference can make the same speakers sound, react and convey the musical signal differently. The presentation you hear will not be the same.

Hopefully we can dig deeper into this topic.

A loudspeaker’s ability to disperse sound off-axis in a smooth manner (flat frequency response curve), is related to a speaker’s ability to cast a realistic sounding image. So flat frequency response, both on-axis and off-axis, is key in my opinion.

I was referring to pre-amp/amp specifications only (or integrated units to make it easier). I should have been clearer.

Not without the real music first taxing the amp/speaker combination. You would have to first rule out that possibility before being able to conclude that something else, such as a pre-amp, is causing the ‘falls short’ effect.

I'm not sure I follow you here but it seems like you're saying Yes since some enthusiasts are not going to get the amp on their speakers until after they've looked at the specs for the pre-amp/amp and in most cases they'll only choose one of the amps they were comparing specs on. I think the "first" for some comes in the reading measurements part.

If by this you're thinking of anything close to what gain does in musician's amp, then yes. I did notice that no matter if the volume or SPL is the same, that even in home audio adding gain at preamp stage, changes the all around sound. Given that your preamp has the gain knob.

I don't know the answers to other questions and I'm not an audio engineer.

That's it, we're on the right track.

Could you define what "musician's amp" mean, such as, is it still an amp that is design to simply amplify the input linearly without intended distortions?

Just to be clear, unlike a guitar amp (which I think killdozzer was refering to- only because they commonly have both controls) when I speak of the higher gain setting I'm thinking of a signal that is not clipping. No distortion is being introduced.

Just two clean unclipped signals. One at a higher gain and one at a lower gain setting.

 

[killdozzer]

Could you define what "musician's amp" mean, such as, is it still an amp that is design to simply amplify the input linearly without intended distortions?

I mean guitar amp or bass guitar amp. Adding or subtracting gain can change the sound. If an home audio preamp has the gain knob, it also changes the sound when you toggle it. Usually less, though.

 

[lovinthehd]

I mean guitar amp or bass guitar amp. Adding or subtracting gain can change the sound. If an home audio preamp has the gain knob, it also changes the sound when you toggle it. Usually less, though.

What home audio pre-amp do you have that has a gain knob?

 

[ski2xblack]

Gain and volume are often confused. While related, they are not the same, so reducing one is not the same as reducing the other. For me, in most cases, a lower gain/higher volume is preferable to higher gain/ lower volume. Just that difference can make the same speakers sound, react and convey the musical signal differently. The presentation you hear will not be the same.

Hopefully we can dig deeper into this topic...

Just to be clear, unlike a guitar amp (which I think killdozzer was refering to- only because they commonly have both controls) when I speak of the higher gain setting I'm thinking of a signal that is not clipping. No distortion is being introduced.

Just two clean unclipped signals. One at a higher gain and one at a lower gain setting.

Gain staging is not some unknown mystery. For the sake of maximizing the s/n and reducing distortion, you want your line level and/or pre amp stages to run hot as possible while maintaining enough headroom to avoiding clipping, and subsequently using only as much gain from the amp as needed to achieve desired listening levels. Proper gain structure will ensure plenty of headroom and should keep any residual noise buried well below audible levels.