Does DSP belong in State of the Art Systems?

[pjwd]

They do DIFFERENT than passive filters. If you don't have jitter and other digital artifacts under control, and for sure all but the most dedicated designs do not, then you will hear the effect of a digital filters, especially if from a hardware implementation and also if it has its own DA conversion and analog stages. These are often cookbook recipe circuits as the guys are mostly digital engineers. This means these will not sound nearly as good as properly implemented DA solutions. If it is software, well, it still has go into some kind of DA system to get to analog and a computer card will NOT cut it sonically.

Have you heard jitter from a mult dac/ amp system with convolution filters in server .. set up with acourate, audiolense or similar .. sounds remakably pure to me

 

[Holmz]

Your speakers are what they are, dsp or not.

You do have control over speaker position. Some speakers allow you to alter time arrival from different drivers. Some let you fiddle with the cross-over. Field-coil speakers allow alteration of tsp characteristics.

Some box listens to music in your room and adjusts how it sounds. What is the basis of preference of that box?

Phase EQ does allow some opportunity for a better response.

Assuming the drivers distortion is what it is, then at least the one can time and phase align the system a bit easier digitally than mechanically and with solder.

It is at least theoretically possible to also alter the signal to decrease some of the driver distortions.

 

[schlager]

I would agree transparency is on the signal and is revealed by increasing levels of precision in playback
Would this percieved harshness be one of the reasons for a slightly rolled off top end that is present in all the target curves. Linkwitz had a quite an interesting theory on the reason as I recall
Of course the biggest distorters are speakers and room
Phil

You get the slightly rolled off top end (tilted FR) when you take an anechoic flat measurable speaker and place it in a room with furniture and the lot. This tilt is dependent on room size, rate of direct and reflected sound, speaker directivity and listening distance. This tilt is very important, to get the right spectral energy over the frequency bandpass. A good starting point is 0 dB at 20 hz tilting downward to -10 dB at 20 Khz. Even small changes as little as 0.1 dB has an impact on perceived timbre and tonality. It is very unlikely to get this "right", without use of DSP/EQ.

 

[pjwd]

You get the slightly rolled off top end (tilted FR) when you take an anechoic flat measurable speaker and place it in a room with furniture and the lot. This tilt is dependent on room size, rate of direct and reflected sound, speaker directivity and listening distance. This tilt is very important, to get the right spectral energy over the frequency bandpass. A good starting point is 0 dB at 20 hz tilting downward to -10 dB at 20 Khz. Even small changes as little as 0.1 dB has an impact on perceived timbre and tonality. It is very unlikely to get this "right", without use of DSP/EQ.

I probably like the harmon curve a bit more with a bump at the lower end but I am sure it depends on speakers and room. I know the theory of furnishings naturally rolling off top end but that is not what I have measured ( outside and up in the air to get a 6ms gating)
I totally agree on the fine adjustments making a difference esp below 1000 Hz .. it just blows me away what a tiny difference makes. In my case I am just using dsp so I can design an active bottom end with the same transfer function but its virtually impossible to match it.

Phil

 

[Bjorn]

Do you mean whichever topology of loudspeaker driver surface distorts less? For example, electrostatic membrane distorting less than dynamic driver?

The non linear distortion of the transducer itself but also how it performs when mounted in the speaker. For instance will a transducer with lower mass have lower distortion in the highs and possible mids compared to one with higher mass. Or a horn-loaded woofer will have much lower modulation distortion vs the driver in a front firing speaker.

The diffraction of the cabinet also play role and will effect clarity and intelligibility. And the directivity of speaker will also greatly effect "resolution" due to how it causes specular reflections from room surfaces.

But we can't completely disregard frequency response either. Thermal distortion with compression is very common in speakers and leads to a change of the frequency response with as much as several dBs in certain areas. If you have a drop over 1-2 dB in the highs, obviously this will result in lower perceived resolution. This is something that happens over time besides compression happening at short peaks at high levels. It's a result of conductive metal voice coil getting hotter which leads to both linear and nonlinear distortion.

This is worse for a speaker with the passive crossover circuit. The thermal power compression will shift the crossover frequencies with the result of resulting in summation errors between drivers. Another clear benefit for the active electronic crossover, and preferably with all the electronic placed outside and not inside the speaker (since amps will add heat).

 

[Bjorn]

One problem that is poorly understood is how the ear/brain system uses higher ordered harmonics to sense sound pressure; this means that some 'transparent' systems might also sound bright and harsh, since the ear assigns that tonality to higher ordered harmonics, just as those harmonics sculpt the sound of any musical instrument.

I think this is more related to weaknesses in:
1. The speakers
2. The acoustics of the listening room
3. The recording itself (mixing, mastering and recording techniques)

After all, there is already harmonics in the music that was originally played. With number 1 and 2 there's something we can do. With number 3 however, we are left in then hands of someone else and unfortunately many recordings are of low quality. That being said, I find that great systems and good acoustical rooms are much less sensitive to variations in recordings and sounds much less harsh and fatiguing with very poor recordings.

 

[Holmz]

You get the slightly rolled off top end (tilted FR) when you take an anechoic flat measurable speaker and place it in a room with furniture and the lot. This tilt is dependent on room size, rate of direct and reflected sound, speaker directivity and listening distance. This tilt is very important, to get the right spectral energy over the frequency bandpass. A good starting point is 0 dB at 20 hz tilting downward to -10 dB at 20 Khz. Even small changes as little as 0.1 dB has an impact on perceived timbre and tonality. It is very unlikely to get this "right", without use of DSP/EQ.

At low frequencies the room enters into the equation.
But at high frequencies the direct path sound is responsible for the timbre.

So in a bad room, then a nice speaker with good timbre… sounds like a nice speaker in a bad room.
If not we would just buy better rooms.
But our ears can pick out the direct sound, even in the presence of reflections that happen later.

 

[schlager]

But our ears can pick out the direct sound, even in the presence of reflections that happen later.

Late reflections will give more ambiance to the sound. Put in other words, the room will have an imprint on all recording playbacks. We don´t want anechoic rooms, but a well treated room will allow you to, to a much higher degree, to hear the "room" of the recording, without your own room obscuring the "recording room". Late reflection is best solved with acoustic treatment.

Early reflection will smear out the direct sound, confusing the human psycho acoustic hearing mechanism, to hear two sound sources, to close in time, to be separated. Early refection will be from room surface, but also cabinet diffraction.

Though you can´t change the rooms late reflection pattern with DSP, you can to some degree remedy early reflection problems with the best DRC programs.

 

[Bjorn]

Though you can´t change the rooms late reflection pattern with DSP, you can to some degree remedy early reflection problems with the best DRC programs.

This is actually where DSP systems starts to stray from natural and good sound IMO.

 

[schlager]

I know it is a bit controversial, but 1. reflections, can to some degree, be remedied by counter signals generated in DRC software combined with group delay correction, that can be beneficial. The correction will of cause generate new reflections, but it will also be remedied by counter signals, for as long as the filter is running. Something like this.

 

[Bjorn]

I know it is a bit controversial, but 1. reflections, can to some degree, be remedied by counter signals generated in DRC software combined with group delay correction, that can be beneficial. The correction will of cause generate new reflections, but it will also be remedied by counter signals, for as long as the filter is running. Something like this.

View attachment 101594

I know well what yo'ure talking about and heard systems many times that does this. But when you have myriad of reflections arriving at different times, superposition between drivers and speakers it doesn't work without adding artifacts. Plus part of the frequency area is too small in regards to the wavelengths and will either not work for both ears or when head is moved sligthly.

One should EQ what's minimum phase behaviour only IMO.

 

[schlager]

Yeap, as I said it is a bit controversial. And I think you are right, that minimum phase is most "safe" to get in order. On a personal note, the best systems I have heard was with DRC. I have tried to do my own convolution filters in REW combined with Rephase, but I can never beat the result that a well tuned filter from DRC can give me. Maybe my REW and Rephase skills just sucks?

 

[Kingrex]

Phase EQ does allow some opportunity for a better response.

Assuming the drivers distortion is what it is, then at least the one can time and phase align the system a bit easier digitally than mechanically and with solder.

It is at least theoretically possible to also alter the signal to decrease some of the driver distortions.

Thats what i was thinking but Tima is right in the speaker has a sound that won't really change.

Eq can't fill a bass suckout,

I had a DEQX Premate. They could never get it to voice worth anything.

I have a Denon receiver. That works great to make TV in surround play great.

 

[Atmasphere]

Nope. It is a subjective observation that does not exist without human perception. An analogous term for the signal would be "accurate."

I think we can all agree that if we lacked perception we would not buy stereos.

Since we do have perception (and the human ear/brain system uses the same hearing/perceptual rules across the entire population), we really don't have to worry about the fact that we are also human. Its a lowest denominator sort of thing.

As a designer/manufacturer its all too painfully obvious to me that if the circuit can't pass the signal correctly, it will not be perceived as 'transparent'.

Put another way, if we mess up the signal, you personally will not perceive it to be transparent; neither will anyone else. You might take the position that transparency arises out of declaration and you would be correct, but this is not an existential/philosophical discussion as it is technical. Although I do grant that it is also based on opinion which is always based on made up stories.

 

[Kal Rubinson]

As a designer/manufacturer its all too painfully obvious to me that if the circuit can't pass the signal correctly, it will not be perceived as 'transparent'.

OK but that is not a statement that informs us about anything. How do you define "can't pass the signal correctly?" Even if I accept your implied premise that a perfectly correct and accurate signal should be perceived as "transparent," how imperfect does it have to be (and in what way) in order for it to be perceived as "not transparent?" This is critical since it is unlikely that any of us have perfectly correct and accurate systems.

Put another way, if we mess up the signal, you personally will not perceive it to be transparent; neither will anyone else.

I doubt that has been demonstrated.

You might take the position that transparency arises out of declaration and you would be correct, but this is not an existential/philosophical discussion as it is technical. Although I do grant that it is also based on opinion which is always based on made up stories.

I can accept your statement that you may perceive a given setup as "transparent" and regard that as a qualitative assessment and praise. It has no other value for me.

 

[microstrip]

(...) As a designer/manufacturer its all too painfully obvious to me that if the circuit can't pass the signal correctly, it will not be perceived as 'transparent'.

We had a long thread just debating transparency and could not agree on its definition.

Some people need emotion and tears to evaluate it - and I can assure you they were not considering measuring the transparency of the tears to visible light!

 

[Kingrex]

I can sense exactly what Ralph is saying about messing up the signal. I have had my preamp upgraded 3 times. Every time a layer of some impurity in the signal was removed and I was very much surprised at the amount of detail that became audible. And every time I was surprised how much better it got, thinking there could be no way there was more room for improvement.

 

[Atmasphere]

OK but that is not a statement that informs us about anything. How do you define "can't pass the signal correctly?" Even if I accept your implied premise that a perfectly correct and accurate signal should be perceived as "transparent," how imperfect does it have to be (and in what way) in order for it to be perceived as "not transparent?" This is critical since it is unlikely that any of us have perfectly correct and accurate systems.

I doubt that has been demonstrated.

I can accept your statement that you may perceive a given setup as "transparent" and regard that as a qualitative assessment and praise. It has no other value for me.

In your position I can see that this might be mysterious. As any competent designer knows there's nothing mysterious about it at all. If I were to offer you advice (and this based entirely on this brief exchange so could be way off base) I would advise to dump the made-up story that perception is all that difficult or mysterious. None of it is.

Humans all have very similar perceptions and in this regard true 'Golden Ears' are really rare. If we didn't use the same hearing perceptual rules, the science and art of audio would not exist. There is a reason deciBels exist, why bandwidth has to be at least 20-20KHz and so on. I'm not going to go into all the perceptual rules here but there are a lot of them and we all have them in common unless our hearing is damaged/defective.

So this could become a conversation going down some existential rabbit hole which is entirely unnecessary. Your comment about 'I doubt that has been demonstrated.' is false- its been demonstrated many times; everyone on this thread including yourself has been witness to such, unless you have a difficulty distinguishing between that which is being perceived and the perceiver. Or- I grossly misunderstand what you are trying to say.

You might ask how I know this. My response is go read the reviews of our equipment. One thing that is common to all of them is that our equipment has that character of being 'transparent'. I know what transparency is because its my job to know how to design equipment that is just that and to know when I hear it.

(Whether audiophiles like it or not there is science to audio and good measurements are paramount to good performance/good sound. But you have to know what is important! Daniel Recklinghausen said it very well and his words are as true to day as they were ages ago!)

I've advised many time to make recordings yourself so you were present at the musical event and then produce media like LPs or CDs so you can play those recordings on various systems. You'll know right away what you're listening to- how well it plays bass, can you make out the smaller details, that sort of thing.

When the recording equipment fools you into thinking that something you just heard was real and not coming through the headphones or speakers then you know you are on the right track. Microphones, mic preamps and headphones have been there for a really long time. Most of the transparency is lost when the signal is committed to media but even then you can still make a system sound so real that it can on occasion fool you so completely that you are convinced someone broke into your home and is singing/playing along with your stereo before they axe you to death. Its as spooky as it sounds.

 

[Kal Rubinson]

My position about perception is based on data from scientific, including psychoacoustic, studies although I do experience the world through my own perceptions, as do you. There is, afaik, no evidence that non-blind, non-statistical, individual assessements of poorly-defined percepts, such as audio transparency, have global validity and, yet, I am convinced of my own, as are you by yours.

 

[Holmz]

The non linear distortion of the transducer itself but also how it performs when mounted in the speaker. For instance will a transducer with lower mass have lower distortion in the highs and possible mids compared to one with higher mass.
….

How does the mass enter into things?
At a higher frequency the driver is not moving much and the force on the air seems to be the main thing stopping the cone from moving?

Or are we talking subwoofers and woofers?

Even with those I regularly see that they play 20Hz to 1kHz. The SPL should drop with frequency, as the mass increases.
But to hit the higher frequency implies the motor is putting out force.