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Discussion Starter #1 (Edited)
So, "synergy" in a system is another audiophile claim that I've heard a number of times. Recently, in the Monoprice HTP-1 thread, its sensitivity control setting has been generating some questions. These questions have led me back to questioning how important "synergy" is. Thus, first I want to speculate a bit (please correct me), then explain some signal chain items, give some examples, then turn it over to y'all to educate us.

Incoming speculation --

You know the age-old argument, "if you spend x on speakers you better spend y on amps and z on your pre-amp (and whatever other stupid number on cables, lol)". So, allow me to contend that I often perceive a trend among "boutique" expensive speakers which is that they tend to be very insensitive and hard to drive (have crappy, poorly engineered, impedance curves). If you take this for granted, then sure, to reach high output levels (or have lots of dynamics) you'll need a powerful amplifier (expensive, at least more than a less powerful amplifier) and (possibly) to drive that amplifier you may need more input voltage. Thus, this moves the goal-post up again to the pre-amp, which now needs beefier line drivers. Thus, if we contend that more expensive speakers require more powerful amplifiers and more powerful amplifiers require more input voltage and more input voltage can only be provided by more expensive pre-amps then...well...looks like the statement "works!"

Of course, if it all starts at the speakers, then this is a "problem" created by a cottage industry of boutique brands. Worse, this cottage industry tends, IMO, to be full of garage-educated "EEs" that often can't design their way around anything using actual math and physics, preferring instead their uneducated school of hard-knocks and unscientific design methods. Unfortunately, though, if I'm right, the cottage industry has created a problem which it then solves by "making" you spend more money -- the reasoning above tells you why you have to and some of us sip it right up and reproduce the dogma!

That said, I have "no idea" (I couldn't care less, honestly) if these "trends" are factual. I speculate only why the "cost synergy" argument could be made. However, it's not really "cost synergy" I'm here to discuss. I'd prefer to look at the actual numbers that mean something -- those things that may actually impact synergy in some meaningful way.

Ok, so now on to our signal chain --

For this example, I'll presume it all starts at the pre-amp (who cares the source, it's digital anyway, haha!). Now, in the Monoprice HTP-1 thread there were statements made regarding the performance degradation that would have been incurred if Monoprice decided to make their product produce an 12v max output vs. the 4v they settled on. Their supposition was that by settling on 4v, they could make it perform better for more people than had they chose 12v. However, since this specification is "up in the air" and "not adjustable" on just about all consumer gear, it's the first piece of our puzzle. It will determine how hard you can drive your amplifier. If it's "too much" then, if we take the Monoprice statements as fact, you may be giving up performance in the lower end of the volume control where you'll be relegated so as not to overdrive your amplifier. If it's "too little" you'll never drive your amplifier to its maximum output (which, if your speakers can't handle it, or you don't want those volume levels, or the music you listen to never demands it, then it won't matter).

Ok, so now the amplifier. Again, way too often consumer amplifiers have no (or little) adjustability (personally, I won't buy an amplifier with fixed settings, but that's me -- there's a reason pro-amps have controls, I can't say the design compromises that are made to include them, though). Regardless, the fixed input sensitivity and gain go hand in hand to determine the maximum voltage the amplifier can output. This voltage, combined with the amp's current capability and your speaker's impedance curve, will determine how "well" the amplifier can drive your speakers. Since these are all fixed, if your amplifier needs, say, 2v to reach 500W on a 8ohm load then if you have a pre-amp with an 8v output you're going to cook it (unless you keep your volume level down on the pre). If your pre-amp can't hit 2v (say it's a cheaper unit whose outputs can't reach above 1v) then you'll never get 500W into an 8ohm load.

And, finally, we reach our speakers; arguably the most important thing you can chose! There's a reason that many modern speakers have high sensitivity and are easier to drive -- science progresses. However, if you should chose a speaker that has low sensitivity or is hard to drive, then you best start looking at your amplifier selection and relating it to your listening habits. The speakers you chose will have the largest impact on your signal chain, IMO. Not just because they have the largest impact on what you hear, but because they set the goal-post that every piece of the equipment must reach if you want to produce the full dynamic range of the music you listen to!

Alright, so some examples -- note: here, I have to take the manufacturer's specs at face value...oh well.

First, let's say we have three pre-amps:

  • Pre-amp A can reach a modest 1v output
  • Pre-amp B a "better" 4v
  • Pre-amp C a whooping 8v.
Now let's pick a few amplifiers (honestly, this was harder than I thought, most amplifiers either don't list specs or list (or I compute) a 29dB gain):

  • Amplifier A; Emotiva XPA-DR1: 2.4v in -> 640W @ 8ohm (about 72v, they list gain as 29dB, every 6dB is a doubling, so can we do 2.4 * 2^(29/6) = 68v, about 72....).
  • Amplifier B; QSC GX-5: 1.2v in -> 500W @ 8ohm (about 63v), they list gain as 34.4dB, using the above that also works out around 63v).
  • Amplifier C; Boulder 3050: this is a BIG amp, it doesn't list the required input voltage, but it lists the gain, we'll have to assume their output power is accurate, so with 26dB gain (which, as you can see from the other amplifiers is NOT a lot, especially for such a big amplifier) to produce its (claimed) 2100W @ 8ohm (about 130v) with 26dB gain, you'll need x * 2^(26/6) = 130; x = 6.4v.
Alrighty! So, now I'd love to pull out some real speakers and specs, but there are a lot of variables that are NOT listed for speakers (point me to a manufacturer provided impedance plot for any boutique speaker...). However, I can at least pick two at some extremes which have been measured by stereophile.

  • Speaker A; MBL 101E Mk.II: 81dB measured sensitivity, 3.3ohm measured minimum impedance, this thing isn't going to be an easy-to-drive speaker nor is it very sensitive ("wonderful" combo, lol). Unfortunately, I don't know how I'd compute in-room SPL with this speaker, it's omni-nature probably makes it fall off less than normal as distance increases. Regardless, it's at enough extreme to make a point.
  • Speaker B; GoldenEar Triton One.R: 91dB measured sensitivity, 3.1ohm measured minimum impedance, also not easy to drive, but it's pretty sensitive, so it'll require less power.
So, let's look at some combinations:

Pre-Amp A -> Amplifier C -> Speaker A -- This is not looking very good is it? This probably won't be able to get the MBLs moving none-the-less get any kind of dynamics out of them. The paltry voltage out of Amplifier C with Pre-Amp A's putrid .9v won't make much dent at, say, 40hz; don't try to play back EDM, lol.

Pre-Amp C -> Amplifer C -> Speaker A -- Much better!

Pre-Amp A -> Amplifier C -> Speaker B -- humm...well, Amplifier C is probably overkill for Speaker B, so...in this case, maybe the .9v limit isn't so bad? Or is it? I mean, Amplifier C can handle a lot of voltage, how well does it behave with .9v? What's its noise floor? If it has such low gain, how well does it handle lower signals? I can't answer any of that, but...this combination doesn't make a lot of sense, IMO.

Pre-Amp B -> Amplifier C -> Speaker B -- if the previous was overkill, this is too, right? But, at least we can put more voltage into the amplifier...we won't need it, though, unless we feel like watching Speaker B launch its cones across the room, lol.

Pre-Amp A -> Amplifier B -> Speaker B -- looks a bit better "matched".

And we can go on and on.

Now, the biggest question is, can all those signal chains be "matched" to provide the same levels of dynamics with some external devices? If so (and I presume so), are these devices hampering the overall signal-chain? Do we end up reducing the dynamic range of both systems to an equivalent level just to equalize our test?

Plus, there are amplifiers like: this Benchmark which can be set to have an 8v input sensitivity for 100W output!?! I don't know what the point of that is (I tried to make that point in the Monoprice thread), but...if it needs 8v to output 100W, what the heck is it going to do with the paltry .9v of pre-amp A into something like Speaker A? Of course, at least this amp is adjustable, so we can set it to a higher gain (which requires 2v) and use pre-amp B happily, but does it have the "heft" to drive Speaker A to "reference" given its "horrid" sensitivity?
 

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the problem is that we cant measure everything. I have used car stereo receivers from 2v outputs to 4v to 5v to 8v....just this simple change in output voltages changes everything when comparing. one thing that is really not known is how feedback/power sent back to an amplifier from the speaker works along with basic clipping which many say happens a whole helluva lot more when playing music than when testing static loads. also if something measures the same does it sound the same? let alone if it measures different obviously it wont perform/sound the same. the sciences dont even know what to measure for alot of what our brain processes. lots of unkowns...but if you are happy, be happy....if striving for better sound...try more gear. audioscience review site does a decent amount of tests but no debate is allowed...so the measurements are what they are and they are very different.
 

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the problem is that we cant measure everything.
So, what is it exactly, that we can't measure?



I have used car stereo receivers from 2v outputs to 4v to 5v to 8v....just this simple change in output voltages changes everything when comparing.
For any representative and valid test, you need to adjust the levels of the DUTs so they are within 0.1dB. Something I've been saying for well over 2 decades.



one thing that is really not known is how feedback/power sent back to an amplifier from the speaker works
Sorry, but that is complete rubbish.



along with basic clipping which many say happens a whole helluva lot more when playing music than when testing static loads
Another point well known and easy to measure for years.



also if something measures the same does it sound the same? let alone if it measures different obviously it wont perform/sound the same.
Again, that comment lacks the basic premise that if the differences are outside of the human detection range that are functionally, and therefore sonically identical. For example, modern, modestly priced DACs will have a THD+N at -120dB or lower. How does any human hear this? Therefore, sonically identical.
 

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So, "synergy" in a system is another audiophile claim that I've heard a number of times.
Generally speaking, it's complete baloney, but there are key words and phrases which make people who believe in magic feel warm and fuzzy and releases their endorphins. You've found one of their big ones.


Running high voltage levels on preamp level signal outputs can sometimes improve SNR and reduce an overall system's background hiss, but that's it, (there are no other "magical" benefits) and if you don't notice any hiss from the get go it is a waste of time.

Designing gear to have an abnormally high output level can actually be bad if you want to integrate to other gear which can't take it: here you shoot yourself in the foot and have to turn it down to a much lower output level than its max, bringing its signal level much closer to the gear's own noise floor, and you actually end up increasing your overall system's background hiss.
 

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Oh my!


 

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So, what is it exactly, that we can't measure?



For any representative and valid test, you need to adjust the levels of the DUTs so they are within 0.1dB. Something I've been saying for well over 2 decades.



Sorry, but that is complete rubbish.



Another point well known and easy to measure for years.



Again, that comment lacks the basic premise that if the differences are outside of the human detection range that are functionally, and therefore sonically identical. For example, modern, modestly priced DACs will have a THD+N at -120dB or lower. How does any human hear this? Therefore, sonically identical.

Good response. That was a regular greatest hits of audiophile baloney. The first sentence, we can’t measure everything like an audible change is page one of the audiophoozel book.


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glad we have a large group of people that dont need to listen to amps as within certain made up parameters they will sound the same. at least we have other reasons to choose one amp over another.
 

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A whole bunch of links but you haven’t really stated a coherent point, nor by extension have you explained how these links would advance that point.

Keep in mind a manufacturer’s company white paper, while typically more in-depth than typical audio press marketing, is still marketing. It’s not subjected to any sort of independent scrutiny. In home audio, especially exotic audio, they are written with the intent to be used as filler for the audio press to review with.

Your last link, TAS, which is total garbage, does this a lot.



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it doesnt matter I or anyone else say. science says they sound the same when parameters are used. end of story.
 

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glad we have a large group of people that dont need to listen to amps as within certain made up parameters they will sound the same.
This repeated claim my camp doesn't use listening tests is baloney. We do, just, oh my gosh, at the same matching volume level and without knowing the identity of the amp so we have to judge the amp by . . . get this . . . the sound alone.
 

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This repeated claim my camp doesn't use listening tests is baloney. We do, just, oh my gosh, at the same matching volume level and without knowing the identity of the amp so we have to judge the amp by . . . get this. . . the sound alone.

Im not adding any parameters. enjoy your gear and music.
 

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Im not adding any parameters. enjoy your gear and music.


glad we have a large group of people that dont need to listen to amps”

https://yourlogicalfallacyis.com/strawman

“as within certain made up parameters they will sound the same”

https://yourlogicalfallacyis.com/personal-incredulity

Do you consider proper controls “made up parameters?” Wow... would you like to know why level matching, simultaneous switching, unsighted are important?


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depends what your testing for? science is wonderful for testing. they made a standard, follow it. great. lets examine distortion/harmonics of an amp, do they need to be measured? can 1 amp have more enjoyable harmonics/distortion than another? I personally cant stand amps with virtually no distortion...it sucks any type of air/soundstage out of the room with my systems. I am also not a subject matter expert on the subject. the engineers that build the stuff obviously have no motivation to improve the sound on new designs.
 

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lets examine distortion/harmonics of an amp, do they need to be measured? can 1 amp have more enjoyable harmonics/distortion than another? I personally cant stand amps with virtually no distortion...it sucks any type of air/soundstage out of the room with my systems
Then why do you own that NAD in your signature which has a impressively* low "
 
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