What DSP Can/Can't DO

[BKr0n]

Loudspeaker Enclosure Design Guidelines

ESP - Loudspeaker Enclosure Design Guidelines. Learn about different enclosure types and how to design an for minimum resonances. We also look at diffraction and time alignment, and discuss the ideal ratios between height, width and depth.

sound-au.com

Speakers. Lots of ways to build them. Lots of physics involved. The advent of DSP simplifies a lot of aspects, but its not a magic bullet. So, for clarity, from the most basic to the most complex aspects, what can DSP do, and what can't it do?

 

[Chrispy]

I think you need to narrow it down as to what your point is

 

[Holmz]

Loudspeaker Enclosure Design Guidelines

ESP - Loudspeaker Enclosure Design Guidelines. Learn about different enclosure types and how to design an for minimum resonances. We also look at diffraction and time alignment, and discuss the ideal ratios between height, width and depth.

sound-au.com

Speakers. Lots of ways to build them. Lots of physics involved. The advent of DSP simplifies a lot of aspects, but its not a magic bullet. So, for clarity, from the most basic to the most complex aspects, what can DSP do, and what can't it do?

Your posts seem to follow Quixotic or Saviour-complex themes.

What is this one intended to help with?

Speakers. Lots of ways to build them. Lots of physics involved. The advent of DSP simplifies a lot of aspects, but its not a magic bullet. So, for clarity, from the most basic to the most complex aspects, what can DSP do,

Most circuit filtering, and both causal and acousal.

and what can't it do?

Amplify the signal, and provide a lot of gain and current.

 

[alex-z]

If we are talking about traditional DSP, it does exactly what the name implies, digitally processes the signal. It changes nothing about the mechanical or electrical behaviour of the speaker, or the acoustic behaviour of your room.

Active aka feedback controlled DSP has more capability, such as that found in Dirac Live ART. You can cause the signals from two different sources to act constructively or destructively as needed. This is not a replacement for good speakers or good room acoustics, if you lack dynamic range or have multiple seating positions then DSP inherently has less potential.

 

[theREALdotnet]

what can DSP do, and what can't it do?

I don’t think DSP can fix issues with the beaming or directivity of speaker drivers or correct cabinet resonances and diffraction, but it can fix frequency response and time alignment, and can take care of crossing over between drivers.

DSP allowed me to add another subwoofer to my DLBC setup on the cheap recently. Once-expensive subwoofers (large drivers, well-made cabinets) with dead plate amps are legion for they are many. I got one of those very cheaply, gutted the plate amp and hooked it up to a Nobsound G2 amp. DSP (DLBC in my case) takes care of the rest.

 

[solderdude]

DSP can also allow for better XO (replacing passive XO's) but requires more electronics (amps/DACs)
DSP can fix tonal issues and add or change some spatial effects.
DSP can extend the frequency response (often at the cost of max. SPL)
DSP can correct phase, timing and impulseresponse errors.
DSP can correct speakers much better than passive EQ (in XO) ever could.
Also DSP can be used to integrate subwoofers more seemlessly.

It cannot change directivity of a speaker or completely correct room issues (maybe except for at one narrow listening spot).

As tonality is the biggest contributor in how sound quality is perceived (and can be set using microphone measurements) room errors and tonal aspects of speakers are much easier to correct on site DSP certainly has advantages and can perform 'miracles' ... just not all miracles.

 

[kemmler3D]

DSP can do anything that can be done to a waveform, in the time or frequency domains... you can turn any sound into any other sound, with enough CPU and determination. As others have mentioned, it can't physically change your speaker or room. That's about the size of it.

 

[BKr0n]

I don’t think DSP can fix issues with the beaming or directivity of speaker drivers or correct cabinet resonances and diffraction, but it can fix frequency response and time alignment, and can take care of crossing over between drivers.

DSP allowed me to add another subwoofer to my DLBC setup on the cheap recently. Once-expensive subwoofers (large drivers, well-made cabinets) with dead plate amps are legion for they are many. I got one of those very cheaply, gutted the plate amp and hooked it up to a Nobsound G2 amp. DSP (DLBC in my case) takes care of the rest.

If we are talking about traditional DSP, it does exactly what the name implies, digitally processes the signal. It changes nothing about the mechanical or electrical behaviour of the speaker, or the acoustic behaviour of your room.

Active aka feedback controlled DSP has more capability, such as that found in Dirac Live ART. You can cause the signals from two different sources to act constructively or destructively as needed. This is not a replacement for good speakers or good room acoustics, if you lack dynamic range or have multiple seating positions then DSP inherently has less potential.

@Chrispy pretty much this. After reading the loudspeaker cookbook, one thing that stuck out to me was how the physical shape of the speaker can change directivity and response. I also know that physical properties can change the response of certain frequencies, but DSP can also do this like in the case of baffle step compensation or a linkwitz transform. I guess I'm just trying to see where the line is and to what degree DSP correction or manipulation can account for before physics starts to take over.

 

[kemmler3D]

@Chrispy pretty much this. After reading the loudspeaker cookbook, one thing that stuck out to me was how the physical shape of the speaker can change directivity and response. I also know that physical properties can change the response of certain frequencies, but DSP can also do this like in the case of baffle step compensation or a linkwitz transform. I guess I'm just trying to see where the line is and to what degree DSP correction or manipulation can account for before physics starts to take over.

AFAIK in practical terms when it comes to building a speaker, DSP can (fairly) easily:

• Correct any problem with on-axis frequency/phase response
• Be used for arbitrary crossover slopes as needed

What you can't do easily is reduce distortion at a given level, or do anything to the off-axis response other than move the crossover around. You can't get rid of diffraction or port noise or cabinet resonances.

 

[Keith_W]

It cannot change directivity of a speaker or completely correct room issues (maybe except for at one narrow listening spot) or better integrate SW.

I agree with all your points, but not sure if I agree with "can not better integrate SW" (I presume you mean subwoofers). To me, DSP is the best way to integrate a subwoofer. Could I ask you to clarify your response? Was it a typo?

 

[solderdude]

corrected...