"Here are the specifications, (do not ask for more), it's all there... All you need to know is in this shiny booklet."  says the Salesman.

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Audio manufacturing is like an online dating site where everybody tries to shine, and most omit to reveal their flaws and limitations. Flaws are the very thing I WANT to know about!

 

Example: This girl is very nice, very fit, generous, and always loves to laugh. However, she’s just out of prison where she served time for murdering her ex-husband. Did I say she was nice?

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Back to Audio:

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(1) A DAC that claims to have a noise floor of -130 dB is a useless specification. Some even claim 140 dB now. Once connected in a home environment, it will NEVER, EVER materialize. Not even close, as the room is the limiting factor.

The average HiFi enthusiast’s listening level is perhaps 90 dB

The background noise present in one HiFi room is rarely better than 40 dB (reference: a quiet library noise is usually in the range of 40 dB)

90 dB – 40 dB =50 dB of dynamic range possible .

If you listen at 100 dB, which is fairly loud, after removing the noise from your room you get 60 dB of dynamic range at most. (100-40=60)

This is quite far from the DAC capability of 130 dB worth of dynamic range. You will never get the 130dB in your room...

In fact, the average 33 rpm vinyl playback has about 60 dB of dynamic range, which is quite sufficient for average listening levels.

This is why vinyl is still going strong, despite being a grossly obsolete technology.

So, the take is, as long a DAC has 80 dB or more worth of dynamic range, you don’t  benefit from more "quieter DAC".

Whilst likely true on lab measuring equipment, the 130 dB spec’s claim is just plain old marketing.

 

(2) Distortion plots in subwoofers, is an industry “best kept secret” and woofers/subwoofers are always the worst performing component, distortion wise, in an audiophile system. "If you see it move, it already distorts a lot"

Transmission lines and back loaded horns are typically the worst for distortion due to various resonances.  Bass reflex isn’t great either.

Sealed or aperiodic are usually the best available option, but one loses efficiency and has to live with more limited output.

Reaching 20 Hz is useless, if a subwoofer does so at 80% distortion.

In fact, 80% distortion is very common... Hitting 20% distortion is often considered acceptable in "deep bass" applications.

Yet, ask any superstar sub-woofer manufacturer, with their small technically advanced enclosures, finished with five coats of piano finish, for their distortion specification @ ie:100 dB/1meter/20 Hz, and you'll never get a reply, as they attempt to hide this sad reality. In my links section, I recommend a measurement site that shows the full light of the problem.

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(3) Amplifier manufacturers often brag about distortion figure as "quality" of their product. The reality is, no speaker on earth is able to reproduce this extreme purity level.

Yet, they always stay silent about their noise floor figure (at least provide the "C" weighting referenced to 1 watt output, and not against full power output to embellish things.

Of course, once the 130 dB silent DAC mentioned above, is connected to an amplifier capable of only 80-90 dB worth of dynamic range (very common reality), you’ll get a system with a maximum of 80-90 dB as the weakest link in the amplifier is dominating the chain overall noise.

Thankfully, as explained above, if you get 80 dB worth of dynamic range from any amplifier, it is "good enough" for matching your room performance.

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(4) Damping factor of amplifiers is usually quite a useless specification if it’s in a passive speaker system. The internal crossover insertion loss will reduce an amplifier’s damping specified at 1000 to barely 20...

Add an "audiophile" small gauge and fairly long speaker cable, and you're lucky to obtain a damping of 15 by the time the signal reaches the woofer terminal.

The amplifier damping factor specification is not the bottleneck, the passive crossover is! Sure, they stay silent about this, and they try to pull ahead of the company that only has a damping factor of 800...  You will NEVER get that in real life. On the tweeter, the L-pad is often used to reduce sensitivity so it matches the mid-range, while the bass section drops the damping factor to less than 10, in most practical cases.

So, the amplifier you proudly purchased with a DF of "1000" at the amplifier terminal, in the real world, and with passive crossover speaker, you’ll never get. Active is the only way to get real high damping factor figures, AND you have to use very short wires.

A dedicated mono block amplifier, on an active crossover system, physically as close to the speakers as possible, can achieve good damping, and the resulting dynamic improvement.

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(5) The power compression of a loudspeaker is never mentioned in HiFi audio, yet JBL Pro and the "pro world community" always discloses this important parameter.

They do it for both the single speaker component, and their complete loudspeaker system. Yet, these professional, sound reinforcement product have the least amount of power compression, and still, they "admit" 3-6 dB worth of power compression.

They usually do this at 1/10, 1/2 and full power, so you have a predictable view of the power compression you will obtain at various output.

Do you really think a mid-line 10" Scan Speak Discovery woofer, with their tiny 32mm voice coil, can  match the power compression level of the pro equipment company "admits" to have? Not in your wildest dreams. HiFi products have very high levels of power compression, and people are kept in the dark about this.

With everything being equal, choosing 4-ohm speakers will help mitigate the power compression issue, but it’ll also lower overall sensitivity, and require more power from the amplifier. The trade-off then isn't always the best, it has to be carefully considered. Efficiency is your best friend with regards to beating power compression.

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(6) DAC manufacturers almost always brag about total harmonic distortion (THD), as a selling feature, "proving" their current line is better than the previous generation. You probably already guessed that in the DAC world, THD it is usually their main strength. Loudspeakers are the bottleneck for distortion in a sound system, the amount of THD the DAC provides is useless in predicting its sound quality.

Jitter rejection, digital headroom, ground noise immunity when used from a computer via USB connection for a DAC? Absolutely nothing is really said...​

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Basically, caring about amplifier or DAC distorsion is the same as changing socks to run faster.