Does DSP belong in State of the Art Systems?

[pjwd]

Having an all analogue system is like having one watch ... you always know the time
Having a fully dsp system with crossovers in the digital domain is like having a million watches all showing different times .....quite a few will be more accurate than your analogue version...but which ones
Hours of fun and false horizons

Phil

 

[Lagonda]

Having an all analogue system is like having one watch ... you always know the time
Having a fully dsp system with crossovers in the digital domain is like having a million watches all showing different times .....quite a few will be more accurate than your analogue version...but which ones
Hours of fun and false horizons

Phil

A nice Rolex, compared to a million Casio's ! I liked the calculator model !

 

[godofwealth]

I normally drive my Klipsch La Scalas with a variety of SET amplifiers, but this week, the Bay Area is having a “heat dome” with temperatures even in San Francisco hitting 90 degrees! I am running my La Scalas with a Lyngdorf 2170 PWM digital amplifier with RoomPerfect room correction. It works quite well. Not a SET sound, of course, but very transparent and musical given the right recordings. It won’t sugarcoat a bad recording, but with well-recorded material, it is a nice cool running one box HiFi setup (the 2170 has a USB input, and decodes all codecs including DSD).

One advantage of true PWM digital amplifiers like the Lyngdorf is that there is no volume control in the circuit at all (digital or analog). When you reduce the volume, you are adjusting the power supply voltage. The bitstream is converted into a pulse-width modulated signal at a constant level (using the Equibit method), and the sound is kept in the digital realm till the last passive RC network, which converts the very high bitrate PWM bitstream directly into analog. If you want to do digital amplification, this sounds like the way to do it. With RoomPerfect as the cherry on the cake, this really does feel like a true 21st century solution to Hi Fi.

Of course, with my 105 dB efficient La Scalas, my volume setting is like -50 dB (!), but like I said, with PWM digital,
there’s no digital truncation like you get in a normal DAC that throws bits away. I wish Lyngdorf would release a high efficiency model with something IIke 5-10 watts, but that’s not going to happen!

 

[godofwealth]

Just listening to a magnificent choral album by one of my favorite groups, Stile Antico. On well-recorded digital recordings, the Lyngdorf really shines with the La Scalas.

 

[pjwd]

A nice Rolex, compared to a million Casio's ! I liked the calculator model !

I was at a talk by the chief designer at grohe years ago.. he showed two identical watch faces and asked what was the difference ... none to us ..but he said one is a rolex and the other keeps better time .. it was a timex. The talk was about creating brand value where performance and price weren't the key drivers .. there were many other clever points that I forget
Might have some corollation to hifi

 

[Tim Link]

I was at a talk by the chief designer at grohe years ago.. he showed two identical watch faces and asked what was the difference ... none to us ..but he said one is a rolex and the other keeps better time .. it was a timex. The talk was about creating brand value where performance and price weren't the key drivers .. there were many other clever points that I forget
Might have some corollation to hifi

A good correlation would be hifi gear that's heirloom quality in terms of working practically forever with some basic upkeep, so you can pass it on from generation to generation if they're interested. Another correlation would be it's value going up as it gets older, especially if it has all the original packaging and paperwork, and zero blemishes. Another correlation would be it's measured performance being not state of the art, yet nobody cares.

 

[gleeds]

Surely any DSP should be introduced into the digital section of your system to avaid analogue to digital conversion. Doing this job between preamp and power amp or amp and speakers is likely to be most unsatisfactory.

I've used 4 DSP systems so far and not been particularly impressed with any. If good quality speakers are used and room acoustics are not too bad, I believe DSP should not be necessary.

How many of us have rooms that do not exhibit irregular low end response, especially without significant room treatment and placement flexibility? For less than ideal rooms, DSP or other forms of parametric EQ below 300 hz can have a profound effect on the overall performance of your system. I first learned this when Richard Rives Bird dropped one of his PARC units into our system at the Stereophile Show at the New York Hilton circa 2003. The EQ was applied discreetly in our bi-amped system and confined to the bass below 360 hz. In the right application and with the right hand on the dials DSP and other forms of EQ can be an amazingly powerful tool.

If someone wants to experiment with bi-amplification and DSP including discrete DSP channels for low-mid-highs and an excellent sounding DAC/Pre/DSP engine see if you can find a pre-owned DEQX HDP-5. I have used this as the bedrock of several custom high-performance systems we engineered and the results were excellent. The machine is not recommended for audio purists or first time users, in which case cut your teeth on MINIdsp which is silly cheap and incredibly ease to use.

 

[Hear Here]

How many of us have rooms that do not exhibit irregular low end response, especially without significant room treatment and placement flexibility? For less than ideal rooms, DSP or other forms of parametric EQ below 300 hz can have a profound effect on the overall performance of your system. I first learned this when Richard Rives Bird dropped one of his PARC units into our system at the Stereophile Show at the New York Hilton circa 2003. The EQ was applied discreetly in our bi-amped system and confined to the bass below 360 hz. In the right application and with the right hand on the dials DSP and other forms of EQ can be an amazingly powerful tool.

If someone wants to experiment with bi-amplification and DSP including discrete DSP channels for low-mid-highs and an excellent sounding DAC/Pre/DSP engine see if you can find a pre-owned DEQX HDP-5. I have used this as the bedrock of several custom high-performance systems we engineered and the results were excellent. The machine is not recommended for audio purists or first time users, in which case cut your teeth on MINIdsp which is silly cheap and incredibly ease to use.

I'm of the opinion, borne out by careful listening, that EQ DSP that's built into a full range amp will degrade the top end, even though the DSP may not actually ADJUST anything above say 300 Hz. My Dirac is the sub 500 Hz version but any filter will slightly reduce the sparkle / goose-bump factor that I get from my speakers when there's no filter.

I would suggest that most rooms can produce excellent sound, but many owners use the wrong TYPE of speaker for the acoustics of their room. Most will simply but a conventional box speakers and then do little by way of careful placement or attention to room furnishings such as carpet, curtains and soft furnishings - and position of listening chair. If a different type of speaker (horn, electrostatic, omni, etc) is likely to perform better in your particular room, don’t buy a box speaker! If these aspects are carefully attended to, the need (if ever needed) for DSP is hugely reduced.

With "room correction" DSP, it is never the room that's treated, it the signal that feeds the speaker being messed with. This spoils the perfection that the speaker designer has worked hard to achieve and so "room correction" is a totally false and misleading description. Call it Signal Processing and then ask if you want to process the precious signal. For me, this (like tone controls and all other forms of processing) should be avoided if possible.

This type DSP has its place but normally only where multiple speakers need to be set up and this complex job is beyond the skills of the owner. For simple 2-channel audio, DSP is very rarely needed if all alternatives are explored. If the room is so acoustically poor that all other avenues are unsuccessful, then an active speaker system should be considered with DSP applied only to the amp that feeds the bass driver, leaving the top end to reach other drivers unmolested by this unnecessary signal processing.

 

[pjwd]

@gleeds... excellent advice ... I aim always amazed how clean the minidsp sounds below say 180hz .. it seems any ad/da distortion is masked by the inherent distortion of bass

Phil

 

[Bjorn]

I measured the result of Dirac a few times. And even when it was set to only adjust below 500 Hz or 300 Hz, it actually corrected above this. So they might be the reason why one experiences differences higher in frequency. Another potential cause could be pre-ringing.

 

[pjwd]

I measured the result of Dirac a few times. And even when it was set to only adjust below 500 Hz or 300 Hz, it actually corrected above this. So they might be the reason why one experiences differences higher in frequency. Another potential cause could be pre-ringing.

Was that just a taper of the correction .. similar to first order filter. I presume in dirac you can just change the target to remove effect

 

[Bjorn]

Was that just a taper of the correction .. similar to first order filter. I presume in dirac you can just change the target to remove effect

I might to do it again and remeasure. It's a few years ago and I can't find the measurement file at the moment. But I thought it was more than simply right above the limit that was set. It didn't sound good. Correcting what's non minimum phase behaviour will lead to what Richard Heyser described as "phase distortion" and can sound very unatural.

 

[pjwd]

I might to do it again and remeasure. It's a few years ago and I can't find the measurement file at the moment. But I thought it was more than simply right above the limit that was set. It didn't sound good. Correcting what's non minimum phase behaviour will lead to what Richard Heyser described as "phase distortion" and can sound very unatural.

I know! I think I have named measurements logically.. after a year it all looks like gibberish

 

[Kjetil]

My system would not work without DSP. It’s the crossovers in my 4 way system.
It’s rather ignorant to equal DSP to room correction.
Disclaimer: I would not claim that my DSP setup is SOTA. It’s a MiniDSP Flex Eight.
But it time aligns the drivers, pulls down high q room resonances below 300 Hz, and phase corrects the system from appx 100 Hz and up. Forget that with pure analog.

 

[OrigTweaker]

New member here who, as a longtime Meridian user, is accustomed to DSP in quality music reproduction.

My first post: I am surprised that this discussion hasn’t included recognition of the excellent custom room correction filters from Thierry at homeaudiofidelity.com.

 

[audiobomber]

I am surprised that this discussion hasn’t included recognition of the excellent custom room correction filters from Thierry at homeaudiofidelity.com.

Also Mitch Barnett: https://accuratesound.ca/

 

[cjfrbw]

DSP is certainly welcome with the bass below 200 Hz. If you listen to digital sources, I suppose it is to taste with the rest of the spectrum, since digital 'stacking' to achieve equalizations might not be entirely harmless or transparent. However, trying to 'equalize' or 'mystify' with cables and power cords seems awkward by comparison.

With digital sources, the Yamaha Pre/Pro has a program called 'Enhancer' for digitally and dynamically compressed sources. I have no idea what it does technically, it is proprietary, but from listening I surmise it does bass and upper bass equalization, expands the dynamic range of the midrange a bit, and enhances the high frequencies. The Yamaha has a lot of processing power, so this works quite well in my estimation. With full range, low dynamic range compression or low bit compression recordings, it does seem to pump a bit, but otherwise is quite useful, and can be turned on and off with a button.

For vinyl, all is analog, except for the bass equalization with the larger speaker systems and/or surrounds, as seems appropriate to the source.

 

[Multiway]

DSP (Najda - Pre / X/O / DACs system) certainly raised the bar on my 4 way horn system + ribbon tweeters
The ability to time/phase align and test my way forward to choose the right crossovers for the job so easily, would simply not have been possible for me otherwise.
If I decide to swap in a new driver with a different impedance - no problem.
The cost saving in large air cored inductors and capacitors on the bass channels was more than the DSP kit cost!

It is also very easy to use, both setting up and for anyone in the family to use to play music.

I first ran Najda on pass through set up at 48 then 96 then 192KHz to evaluate its sound.
This was with my then passive X/O system.

At 96KHz it imparted no artifacts or audible traits that could have otherwise put me off.
This setting gave more than enough processor power for all the PEQ filters and crossover types I would ever use.

Playing different analogue sources through, sound as you'd expect like different turntables / carts / tonearms.
Just as they would in an analogue system. A cheap TT sounds it. A fantastic one sounds fantastic.

One day I might get another more powerful system $$$$' that can do FIR to explore that realm.

 

[Tuckers]

For my ears, I have not heard a DSP room or speaker correction system (one that measures the room and creates a DSP) that I could live with long term. This includes DSP that makes changes in timing or phase of frequencies. But systems that simply create EQ curves or crossovers can sound good to me. The former examples may sound good for a while, but over weeks or months, their mark on the sound becomes obvious and detrimental. It takes a while for the brain to grok what is going on, but once you hear it you can't unhear it.

Also, I don't listen in just one spot, but all over my open plan space, and all those measurement DSPs sound good only in the sweet spot and fall apart very quickly when you leave it.

I use a single digital parametric EQ for bass through Roon, and that really improves my system. I can hear a bit of detrimental effects of adding additional curves, so have never added more than that. I am sure there is a bit of negative effect from the bass EQ, but this allows me to not use a passive crossover, or put my speaker in a closed cabinet, and those would affect the sound much more negatively.

 

[Kal Rubinson]

DSP is certainly welcome with the bass below 200 Hz. If you listen to digital sources, I suppose it is to taste with the rest of the spectrum, since digital 'stacking' to achieve equalizations might not be entirely harmless or transparent. However, trying to 'equalize' or 'mystify' with cables and power cords seems awkward by comparison.

With digital sources, the Yamaha Pre/Pro has a program called 'Enhancer' for digitally and dynamically compressed sources. I have no idea what it does technically, it is proprietary, but from listening I surmise it does bass and upper bass equalization, expands the dynamic range of the midrange a bit, and enhances the high frequencies. The Yamaha has a lot of processing power, so this works quite well in my estimation. With full range, low dynamic range compression or low bit compression recordings, it does seem to pump a bit, but otherwise is quite useful, and can be turned on and off with a button.

For vinyl, all is analog, except for the bass equalization with the larger speaker systems and/or surrounds, as seems appropriate to the source.

What is " digital 'stacking'?