DSP is bad!

[boxerfan88]

Some of us (me included) are deep into DSP tech. Is what he says mostly hogwash? Or there’s some merit in what he says?

Digital Room Correction Destroys Timing and Drains the Life Out of Music, Warns Hi-Fi Engineer

His perspective challenges the idea that DSP is the smartest way to handle imperfect rooms.

www.headphonesty.com

Music consists of impulses and transient attacks, not sustained sine waves. He insists that preserving timing relationships between these impulses matters more…

 

[TurtlePaul]

He must have never measured what passive crossovers and real-world listening rooms do to the time domain response of a transient impulse...

 

[DVDdoug]

I'm not going to read it, but the whole idea is that it can IMPROVE the sound (when used properly). Pro studios use it. Other audio pros too.

Of course It's not a cure-all.

...Just scanning through it looks like they guy doesn't have a clue. Ane he's old (like me ) so he probably doesn't have golden ears.

 

[PatentLawyer]

DSP is good!!

 

[RPoitou]

Some of us (me included) are deep into DSP tech. Is what he says mostly hogwash? Or there’s some merit in what he says?

Digital Room Correction Destroys Timing and Drains the Life Out of Music, Warns Hi-Fi Engineer

His perspective challenges the idea that DSP is the smartest way to handle imperfect rooms.

www.headphonesty.com

I'm very sympathetic to his way of looking at the problem - to my ears the less electronics (especially digital) in the signal path and the less drivers a speaker has the better!

 

[Keith_W]

DSP is good!!

 

[uriy-ch]

Or there’s some merit in what he says?

As I understand it, he's saying that phase-shifting the signal with passive crossover filters affects the sound.

If you have a microphone and a DSP (or a computer with the necessary software), you shouldn't have any problem listening to the linear phase yourself.

FIR can phase-align any speaker system.

In this case, it's best to listen to the results yourself.

 

[Chris A]

It's like conversing with the devil (or a politician): he's mixing truths with falsehoods. Much of what he is saying is related to those that are not very careful at using DSP (i.e., those that tend to "push the button and stand back"). So his comments about trying to correct room modes (...you can't...because they're non-minimum-phase reflections), correcting for passive crossover-induced phase growth of the lower frequency drivers, and just plainly bad "automatic EQ" (a.k.a., "room correction software") that makes a mess of the transition frequencies around 80-400 Hz, etc., all of these subjects are related to lack of attention to detail and poor understanding of what is happening by the user.

One phrase that jumped out at me:

Gauder contends that inserting an A/D → DSP → D/A stage adds jitter, processing delay, and rounding errors that blunt transients and sap immediacy from the signal.

This has repeatedly been shown to be urban myth based mainly on poor understanding by users of automatic EQ software/firmware, and the software manufacturers hiding the resulting information-what they are actually doing--from the user. As long as the transfer function of the loudspeakers' acoustic output is as good or better than what the loudspeaker provides by itself (i.e., their minimum phase performance without all-pass phase growth due to crossover network filters), you're money ahead--every time.

So if I had to sum up what I read, I'd say that the users of DSP need to dig in a lot more on what they are doing, but also use DSP tools that they can control themselves and know what is occurring: 100% transparency.

Chris

 

[skankhobag]

“Bottom line, in Gauder’s view: digital room correction is an effect, not a solution, and it risks stripping the emotional energy from music.”

Well, skimming through what the cat had to say, he’s about 33% (maybe less) correct. Most of what he claims is highly dubious to just plain wrong.

Digital room correction is a partial solution that needs to be teamed with acoustic room treatment to be fully effective.

If you were to only do one, room treatment will be more effective, but incorporated with DSP and a proper sub/sat system, the results will be transformative from listening to a pair of any pair of loudspeakers in a regular living room.

 

[Somafunk]

Oh look, another clickbait headline from headphonesty to drive hits,

 

[levimax]

DSP is a tool which can be used or abused.

Reading some of jj's work on room correction I tried using "ERB Smoothing" on the measurements before I created the correction filters in REW, previously I had used "Var smoothing". Of course this resulted in a much lighter and smoother correction filter which measured much less smooth than either the manual filters I created using Var smoothing in REW or what ever filters DIRAC DLBC cooks up. DIRAC by far measured the "smoothest" in room response but I preferred the "ERB smoothed" correction filters.

While it is now possible for almost anyone to get a MIC and make measurements of their system before and after correction I am not sure that is a great thing as it pushes companies like DIRAC and DIY filter makes to try to hammer their in room response as flat as possible which while it may look nice on the measurement graph may be suboptimal to listen to. Human's ability to "hear through the room" as well as humans hearing limitations, both of which are taken into account to some extent by ERB smoothing, needs to be considered when creating DSP filters as more is not always better.

 

[jcarys]

The headline of the thread should be "DSP is not perfect", which is of course true. However, in a home setting it's better than a non-DSP setup 95%+ of the time. If you have a very high budget and an adaptable room for playback, then you could achieve just about everything needed without DSP. The problem is that's not true for most of us.

 

[KSTR]

Mr Gauder.... grumpy old man who is completely out of his element when talking about DRC.

While it's true that DRC can go wrong when used without knowledge or care it is not enough for blanket statements. In the hand of experts, like fellow countryman Dr. Uli Brüggemann (of Acourate), it is a tool doing exactly what Gauder didn't get right, fixing the time response. Maybe he should arrange a test run with Uli to finally get convinced.

"To pursue that goal, Gauder designs crossovers to aim for phase-coherent behavior across the band. He says he does this the old-school way, like with pencil, paper, and algebra, to solve a set of 48 coupled equations to arrive at target component values, box volume, and other parameters before building prototypes."

IHMO, a clear statement of living in the past. Having decades of experience notwithstanding, no serious loudspeaker designer today gets their job done without using sophisticated CAE tools for design and evaluation/emulation... well, unless you have endless time and can live with preliminary results and maybe get away with a number of tedious and costly physical iteration cycles.
On the same page, no-one serious about their listening at home gets away without properly done DRC... once you've witnessed what it can do there is no way back, even in acoustically well-treated rooms, nice symmetry throughout etc etc.

 

[KSTR]

The headline of the thread should be "DSP is not perfect",

Actually it should read "DRC is not perfect". DSP, digital signal processing, is just a concept and does not have attributes of an implementation, like being perfect or not.

 

[HalSF]

The amount of audio FUD content devoted to raising alarm about stuff that supposedly degrades hi-fi purity of essence, while drawing tribal battle lines trying to force everybody to choose up sides, is regrettable.

 

[jcarys]

Oops, yes I meant DRC, still finishing my coffee...

 

[bmc0]

From your other post here, I assert that you should probably stop looking at that site and stop posting their clickbait here.

It's true that it's easy to do the wrong thing with digital room correction and that there are limitations as to what can be properly corrected. Floyd Toole has talked about this quite a bit. Many of the other claims in the article are hogwash.

Not that it necessarily matters, but the author is evidently unfamiliar with the well-known MLSSA measurement system: "Gauder uses a Melissa measurement system [...]".

 

[Davey]

Boxer engines are hogwash. Way too complicated.

 

[Petrushka]

Boxer engines are hogwash. Way too complicated.

I like the growl.

 

[G|force]

Boxer engines are hogwash. Way too complicated.

Depending on the firing order I like the thumpety thumpety thumpety.