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System Synergy, Fact or Fiction

9K views 468 replies 16 participants last post by  Scotth3886 
#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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#2 ·
#28 · (Edited)
That doesn't help, and I'm inclined to agree with you. However, you really can't tell me that the examples I give above will all work similarly! At a certain limited volume range, maybe. However, then there's noise floors and everything else to consider.

Of course, as I mentioned right from the start, if one picks "better" speakers, they have a higher chance that none of this matters.
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.
A few things:

1) High voltages in car applications are typically due simply to signal noise interference. A car's electrical system is noisy! If you've dealt with car installs, I'd bet you remember every single install where you had to diagnose alternator whine. High voltage balanced signals (I used to use Zapco's Symbilink products) are helpful in eliminating that. Fortunately, most car audio amplifiers are more like pro-amps with configuration (gain) to optimize the signal chain. You just need enough voltage out of the pre to rid yourself of noise.

2) I am not sure there are things that science can't measure regarding audio. However, I am sure that things like SPICE exist and that we can drop an amplifier circuit into it and simulate it. I also know there are programs that exist to simulate speakers (subwoofers for sure). I wouldn't be at all surprised if we could connect a SPICE simulated amp to a SPICE simulated crossover to some other simulation that would approximate a speaker's T/S parameters (and box where applicable). Then one could playback a PCM file through the entire simulation chain to read-off the excursion of every speaker at every sample! This would be super sick, and I'm sure it could be done with some level of accuracy should it be desired and someone (anyone want to work with me?) knew the math and had the programming chops to implement it!
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.

https://www.youtube.com/watch?v=aocZo3oeNxw

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.
While I agree there aren't "magical benefits", how do I drive an amplifier to its maximum power without being able to provide the required input voltage? Obviously I can't (without another amplifier in between). So, if you need that power (Speaker A is pretty inefficient, do you dispute that someone may actually need a lot of power for it?) and can't get it, then you need a different pre (or another device to compensate). If you don't call that "synergy" then fine, but that's what I mean here.

Moreover, if all a pre-amp can provide is a max of .9v at best, then it must provide significantly less if, say, it has 120dB of dynamic range. So, a quiet piece being played back at a low level will be providing even less voltage into the amplifier, which will then be providing even less voltage into a speaker, and quite possibly that speaker "barely moves" (which means it may hardly overcome the noise floor of your room or the Fletcher Munson curve of your ear depending on the content). Thus, you may be relegated to using that .9v pre at its max volume all the time. That doesn't sound "synergistic".

Of course, this is all under a presumption that some sort of minimum voltage level must be present (all the way back to the pre) in order for a speaker to "react" in an audible way (and I'd certainly be inclined to believe that how much it must "react" to be audible has something to do with the environment it's in and the listener's ears). Once you reach that minimum voltage, I suppose you're out of the (for lack of a better term, or maybe it is the right term) "noise floor" of the system, then from that point forward I suppose you're good. I wonder if the minimum voltage required changes based on parameters of the speaker itself? Possibly not its inductance, but may it have something to do with the speaker's frequency response and, again, Fletcher Munson curves? So, do we create a situation where upon playing back a quiet piece at a low level, due to the whole system (signal chain, speaker, room, listener), it audibly sounds like we're coming in and out of the "noise floor" in a way that "pumps" oddly?

Having said all that, I certainly realize that all of this can be mitigated by other electronics in the chain (even better by using electronics that are configurable and can be easily mated to various signal chains...like most pro-gear). Certainly I can add gain via another amplifier between my pre and my power amp. Certainly I can add a resistor as well. But, most people won't go to that level of "trouble". If they don't, however, they may end up with a system that has a sub-optimal signal-chain...and I'd call that "lacking synergy".

Moreover, if one simply replaces amplifier A with amplifier C and does nothing else to their signal chain, they may find themselves unable to conduct a viable blind test (which they weren't doing anyway, lol) but may also find themselves unable to spin the volume of the pre-amp to a level that makes both amps sound "the same" (as they should, providing the signal chain allows it and the amp is transparent to begin with).

edit -- this post (I hope) helps show the "audiophiles" why amps (which may otherwise be designed for (and tested as having) transparency) can sound different in different signal chains even when level matched (i.e., there are more variables in the signal chain to control and if you don't things sound different...but maybe not for the reasons you were "taught" by a cottage industry designed to fleece you).
 
#3 ·
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.
 
#4 ·
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.
 
#5 · (Edited)
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.
 
#8 ·
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.
 
#16 · (Edited)
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.
 
#9 ·
#12 · (Edited)
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.



Sent from my iPhone using Tapatalk
 
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#10 ·
#13 ·
it doesnt matter I or anyone else say. science says they sound the same when parameters are used. end of story.
 
#19 ·
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.
 
#20 · (Edited)
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 "
 
#24 ·
I have read many accounts of class d having alot of 3rd level harmonics which the human ear doesnt enjoy. the ear loves 2nd order harmonics tho. so the science is designing new class d with tubes in some cases because tubes are rich in 2nd order harmonics. all this science above my paygrade and I cant explain the best. if everyone is fine with amps sounding same, I dont lose any sleep. Im just trying to share my views however flawed they are to others I guess.
 
#29 ·
I'm sorry I wasn't clear. I wasn't talking about what you are calling synergy but rather what the placebophiles call synergy: "This speaker works best with this speaker wire and this interconnect because it gives you the best imaging" sort of stuff. Their foolishness is the magic they cling too because they hate judging audio by just their ears; they insist on using their eyes too.
 
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#30 ·
these 2 headphone amps sound so different its silly to think they wouldnt. its really enjoyable to be able to swap in/out multiple headphones and listen to different music very quickly and with minimal effort. the red amp is chifi under 100bux and the black amp is the thxaaa789 which many regard as the best in the world for 350bux
 

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#34 ·
My grandparents had a tube amp. Also a horse and buggy.
 
#95 ·
my uncle is really into music. he was also into tube amps.

i asked him the other day if he was still doing the tube amp thing to which he replied “it got too expensive and too tedious. i sold all of that stuff, picked up a nice amp/pre-amp setup and sunk the money into high quality speakers.”

people are into whatever they’re into. it isnt a matter of being old.

to each their own.


Sent from my iPhone using Tapatalk
 
#35 ·
somehow I think both camps/sides can be correct. depending on the parameters or lack there of.
 
#37 ·
I had an awesome opportunity from a professional on this forum to participate in a listening test of 2 different speakers he had eq'd to match almost perfectly he said. he shared the measurements and asked me which I preferred. he wouldnt tell me which speaker was which til this day. I picked the recording with higher 2nd order harmonics in my brain. the 2 speakers were a kef 50 and jbl 4732 or something like that. 2 extremely different speakers that this pro made sound spooky close. I wish I could participate in more of these things, but would like to know if my answers were correct. :)


the synergy topic is that yes, everything is important. have any studies shown speaker measurements in a chamber actually changing due to different amp?
 
#38 · (Edited)
I wish I could participate in more of these things, but would like to know if my answers were correct. :)
I enjoy these tests too. Would you like to participate in a blind test of amps? I'll send you a recording of a file that I'll pass through my AVR you spoke of disparagingly and we'll see if you can detect the degradation my AVR (and recording gear) causes vs. the original, untouched file.
 
#40 ·
transparency is a goal that is worthy. the thxaaa science is pretty new and breaking ground with many owners/reviewers. thus the reason I bought the headphone amp(affordable). https://www.thx.com/mobile/aaa/


benchmark has this science in their amps. also sites like audioscience has this amp measuring better than others in many tests.
 
#44 ·
Well, there's one rub with audiosciencereview -- measuring better doesn't mean the better measuring product is audibly better. One must be able to interpret the measurements and correlate them to human limitations. I think my biggest complaint with a site like this is, they are all about the tech-geekdom that is spec-racing, but I don't perceive them making it obvious where the line is drawn between "technically better and audibly better". Maybe they do in the text, but I'd rather it be right in your face -- here's the THD, here's the level where THD is perceptible by a human (right on the graph). If the THD is under the limit, it "doesn't matter" (unless you're spec racing).

Basically, I'd prefer a "transparency rating". Plus, for things like amplifiers/pre-amplifiers, some notion regarding the current capability of the amplifier/pre-out so I can decide if it'll work with my speakers/amps. Further, for a power-amplifier, the input sensitivity is good to know. Pretty much, the signal chain and all the variables in my original post -- in my opinion, that's all that matters. With that information, you can tell, immediately, how "synergistic" your system will be (you may also want to know the noise-floor of your room so you can determine how much power you'll need to overwhelm your noise-floor).

Finally, my guess is, in most normal (non-extreme like some of my OP examples) conditions, it's a non-issue for most people, most program material, most rooms, most speakers, etc....but most isn't all. Thus, without highly controlled tests, one can certainly see why people that don't control variables hear differences!
 
#46 · (Edited)
I had some technical discussions with nad engineers on my amps and gain settings. the engineer said to turn up my gains which causes the amp to work less(paraphrased). said many think opposite which is wrong.


here is one discussion


I talked to our director of engineering. The C275 is capable of putting out in excess of 1200 watts in bridged mode into low impedances. Your speakers re rated at 350 watts maximum. Here's what I'd like to try:

Move the right amp to the left and the left amp to the right. If the problem stays in the same speaker, then it is very likely the crossover in the speaker has become damaged from excessive heat. If the problem switches to the other speaker, then I'd recommend having that amplifier looked at by a service technician. I have attached the list of our service centers.

Also, do give those amps plenty of breathing room. They run warm when bridged. Also, do not use power protection of any kind. Plug the amps directly into the wall. in fact, try that before you send it out for repair.

Regarding your gains question, it's quite the opposite...turn the gains on the rear of the amps up! By having them down, you are making the amps work harder. Also, do swap the speakers. We need to make sure the crossover in the speaker isn't damaged. If it is really just that one amp, then you should have it serviced.
 
#49 ·
I have and do use foobar2000...I will say no I havent abx, but I think I might have years ago.
 
#50 ·
Please download and install the ABX component for foobar2000 as I describe in the video. Then play around with it for a few days, or however long you need, until you feel comfortable with using it. As initial test files to play around with you could compare, for example, CD vs. vinyl, here:
https://www.avsforum.com/forum/173-2-channel-audio/3094024-lp-vs-cd-blind-test.html
It is pretty easy to tell because only one file has pops and ticks and the other doesn't.

Once you post a completed score sheet from a test, so I can see that it works for you and you know how to do it, I will then work at creating the recording of the Gershwin music passing through my AVR, which will take me at least a day or so to prepare. OK?
 
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#51 ·
P.S., to the more technical in this thread (e.g., @m. zillch, @ClawAndTalon, @A9X-308) please, please, don't let me speak from authority if I'm full of it! A big part of why I have been starting threads like this is to learn if I'm full of bull or not (and to brainstorm, I mean...maybe we really don't know everything)!

I don't expect you to congratulate me and pat me on the back when I'm right, I'm not looking for affirmation. However, if I'm wrong, I want and need to hear it! Spreading more FUD is not my goal here! However, this is not my background, I'm far from an EE -- everything I "know" is intuition and what I think I know from informally educating myself through whatever (non-paid) means possible...mostly Wikipedia and others on this and similar sites.
 
#54 ·
I have foobar 1.4.1 should I upgrade to newest version?
 
#55 ·
Yes, but more importantly they seem to have taken down the add-on component, "ABX Comparator", perhaps for maintenance or an upgrade, I don't know. [They were on v.2 last I checked but maybe there is a v.3 coming soon?]

Unless you can find it on your own this project will need to be put on hold, sorry.:(
 
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