Steve Guttenberg on active speakers

[Purité Audio]

On the Active vs Passive LS50, the former also has phase correction which seems to improve the soundstage to some degree. I haven't heard the two side by side, but disabling phase correction on the active lS50W does have a noticeable effect. The instruments and voices just seems more focused with that feature enabled.

There's also the matter of bass. It was interesting that @Purité Audio 's measurements showed pretty much no difference, even though KEF's specs suggest otherwise.

According to KEF, the LS50 is - 3dB at 79hz while the LS50W is -3dB at 50hz with the default settings. The -6dB point is not as wide a gap at 47hz for the LS50 and and 43 for the LS50W, but that can be extended to 40hz.

I assume you were using the default DSP settings, Keith?

If I remember the LS50W have very rudimentary boundary filters, I would have set those to the appropriate setting, you can’t really expect deeper bass from the same driver in an identical volume enclosure, I thought the bass punchier from the active version and they are very versatile and easy for the whole family to enjoy.
Keith

 

[GrimSurfer]

The thing that bothers me the most about active speakers is the potential for engineering laziness.

Getting a passive speaker to perform well requires work. The cabinet and drivers need to be really well configured for the end result to perform well.

With an active speaker, a manufacturer can use DSP to overcome basic engineering deficiencies in the cabinet or driver. The goal of adequacy trumps that of excellence... at a price point equal to or greater than a really good passive design.

Some might say that this shouldn't matter, and on a certain level they'd be right. But it violates the natural principle of performance through simplicity, which is something we used to value in engineering and industrial design. It places profit ahead of performance to a higher degree than it already (lamentably) is in our society. Finally, it avoids solving what I would call "the driver problem", which has vexed loudspeaker design since the discovery of the moving coil.

I can appreciate how these things may not affect active speakers from companies like HEDD. My sense is that there is ample incentive for many, many consumer brands to use DSP as a crutch for ordinary performance (as kind of appears to be the case, IMHO, with designs like the LS50).

 

[Ron Texas]

If I remember the LS50W have very rudimentary boundary filters, I would have set those to the appropriate setting, you can’t really expect deeper bass from the same driver in an identical volume enclosure, I thought the bass punchier from the active version and they are very versatile and easy for the whole family to enjoy.
Keith

The spec is better with -3db at 63 hz instead of 79. There is probably a shelf filter with a modest boost in the low range. IMO, that is what most are hearing when they say the actives are better. With a sub, it probably doesn't matter. Boundary effects are very audible.

 

[Purité Audio]

The thing that bothers me the most about active speakers is the potential for engineering laziness.

Getting a passive speaker to perform well requires work. The cabinet and drivers need to be really well configured for the end result to perform well.

With an active speaker, a manufacturer can use DSP to overcome basic engineering deficiencies in the cabinet or driver. The goal of adequacy trumps that of excellence... at a price point equal to or greater than a really good passive design.

Some might say that this shouldn't matter, and on a certain level they'd be right. But it violates the natural principle of performance through simplicity, which is something we used to value in engineering and industrial design. It places profit ahead of performance to a higher degree than it already (lamentably) is in our society. Finally, it avoids solving what I would call "the driver problem", which has vexed loudspeaker design since the discovery of the moving coil.

I can appreciate how these things may not affect active speakers from companies like HEDD. My sense is that there is ample incentive for many, many consumer brands to use DSP as a crutch for ordinary performance (as kind of appears to be the case, IMHO, with designs like the LS50).

Bruno has talked about the difficulty in using DSP to correct driver anomalies and ultimately found it simpler and better just to use better drivers, his new enterprise ‘purifi’ have produced a new amp/driver .
Keith

 

[svart-hvitt]

The thing that bothers me the most about active speakers is the potential for engineering laziness.

Getting a passive speaker to perform well requires work. The cabinet and drivers need to be really well configured for the end result to perform well.

With an active speaker, a manufacturer can use DSP to overcome basic engineering deficiencies in the cabinet or driver. The goal of adequacy trumps that of excellence... at a price point equal to or greater than a really good passive design.

Some might say that this shouldn't matter, and on a certain level they'd be right. But it violates the natural principle of performance through simplicity, which is something we used to value in engineering and industrial design. It places profit ahead of performance to a higher degree than it already (lamentably) is in our society. Finally, it avoids solving what I would call "the driver problem", which has vexed loudspeaker design since the discovery of the moving coil.

I can appreciate how these things may not affect active speakers from companies like HEDD. My sense is that there is ample incentive for many, many consumer brands to use DSP as a crutch for ordinary performance (as kind of appears to be the case, IMHO, with designs like the LS50).

Your comment reminds me of this:

«Airplanes are becoming far too complex to fly. Pilots are no longer needed, but rather computer scientists from MIT. I see it all the time in many products. Always seeking to go one unnecessary step further, when often old and simpler is far better. Split second decisions are needed, and the complexity creates danger. All of this for great cost yet very little gain. I don't know about you, but I don't want Albert Einstein to be my pilot. I want great flying professionals that are allowed to easily and quickly take control of a plane!»

 

[sergeauckland]

Bruno has talked about the difficulty in using DSP to correct driver anomalies and ultimately found it simpler and better just to use better drivers, his new enterprise ‘purifi’ have produced a new amp/driver .
Keith

That's pretty much my view. Poor (cheap) drivers tend also to have greater variability, so using DSP to make corrections would be much more difficult to model and hence correct. Doing any correction on a case by case basis is pretty labour-intensive, so likely to be more expensive than just using better drivers.

DSP is very good for correcting frequency response errors, and for creating an operating envelope balancing output level and bass extension, it can also incorporate user controls like tone, volume and balance control. It's not so good for correcting driver or cabinet colorations unless these are consistent, in which case they can be engineered out in design and not need correcting.

S

 

[Ron Texas]

FWIW, B&W has jumped on the lifestyle bandwagon with it's Formation line of wireless speakers.

https://hometheaterhifi.com/blogs/bw-formation-wireless-audio-line-first-look/

I expect other large speaker manufacturers to follow.

 

[GrimSurfer]

Your comment reminds me of this:

«Airplanes are becoming far too complex to fly. Pilots are no longer needed, but rather computer scientists from MIT. I see it all the time in many products. Always seeking to go one unnecessary step further, when often old and simpler is far better. Split second decisions are needed, and the complexity creates danger. All of this for great cost yet very little gain. I don't know about you, but I don't want Albert Einstein to be my pilot. I want great flying professionals that are allowed to easily and quickly take control of a plane!»

Not quite. That would be like taking the listener out of the loop when playing music... a ridiculous notion.

It's more like this:

The conventional aeroplane wing has reached its limit of strength to weight to lift ratio. The solution, therefore, is NOT to add power to increase performance. It is to increase the capabilities of a new generation of wings that perform better, through better materials and technologies that allow the sweep, camber, and aspect ratio to seamlessly change to meet aerodynamic requirements with the same or less power.

That, sir, is an example of dealing with the engineering problem in a truly effective manner.

PS. Issac Newton, not Albert Einstein, has been in the cockpit since Kitty Hawk. He has a way of taking over whenever the engineering casualty lies beyond the pilot's skill to resolve. So you had better hope that the aircraft engineers trying to outsmart him are working through, not around, the problems at hand.

 

[FrantzM]

We are slowly assisting the demise of the Audio Shrine, you know, The tower with preamp, DAC ( in three box with the obligatory Atomic Clock and the reclocker) plus the mono-block amplifers at each side and the fat, huge garden hose speaker cables ... Even for seasoned audiophile it seems more interesting to go wireless. I am thinking about it. Bluetooth audio is transparent and so are DACs costing $20 .... Active speakers is the way forward, The way of the future. If one want to be convinced, just look at the Emotiva PA-1, essentially an Ice Module within an enclosure. No engineering IMO to speak of (except for that of B&O) ... How difficult is to put it in a speaker box or 3 of those in a 3-way? The module of the PA-1 is about $299 at retail...
The future of Hi-Fi is in speakers. For all practical purposes most electronics are beyond what our ears are able to discern... Speakers not so much.. They are not that good for the most part with final output that varies widely depending on the room ...Not there yet ... their interaction with the room remains a point that needs to be addressed consistently. Audio systems that take the room into account are not the norm .. Come to think of it, the best (perhaps most popular in this forum) examples we know of audio systems that are in principle speakers: Kii, Dutch 8C and Beolabs are complete audio systems all you need is a source ... All try to address the room... As for the source? ... Your PC, Your Tablet, Smartphone? USB drive...? A turntable?
Interesting days we're living. Future of Audio is brighter than I had come to think

 

[GrimSurfer]

Bruno has talked about the difficulty in using DSP to correct driver anomalies and ultimately found it simpler and better just to use better drivers, his new enterprise ‘purifi’ have produced a new amp/driver .
Keith

Then why is there so little difference between the KEF LS50 and LS50W? Surely it would have been "simpler and better" to use a cabinet of larger volume and different driver to get significantly better bass extension.

 

[Snarfie]

I would never go back to passive. Active DSP Beolabs FTW!

I went the otherway. Had KRK's, Adam A7X active monitors etc. quite happy with them. Than is installed a NAD C370 with IMF Compact II monitors of almost 40 year old an I got the vibe's (imaging voice where clear not sounding if they have a cold) back that i was missing (after a/b comparison on the C370). Got explenations that KRK's and or Adam speakers are not made for Hifi but for uncolourd sound more. Could be but i sold them asap IMF are still running fine and now JK Accoustics Optima 3 fullrange speakers of 40 years old did replace the active monitors. The fun is back.

 

[Ron Texas]

Then why is there so little difference between the KEF LS50 and LS50W? Surely it would have been "simpler and better" to use a cabinet of larger volume and different driver to get significantly better bass extension.

The intent was to sell into a different market. It just so happened acceptance was good among so called "professional audiophile" reviewers. The wireless does have a built in high pass filter which is often a difficult function to add to a conventional system not hooked up to an AVR.

 

[pozz]

Finally, [DSP use] avoids solving what I would call "the driver problem", which has vexed loudspeaker design since the discovery of the moving coil.

Very true.

 

[andreasmaaan]

DSP doesn't "avoid" solving "the driver problem". An audio reproduction system is just that: a system of components that work together to produce a desired outcome.

The conventional aeroplane wing has reached its limit of strength to weight to lift ratio. The solution, therefore, is NOT to add power to increase performance. It is to increase the capabilities of a new generation of wings that perform better, through better materials and technologies that allow the sweep, camber, and aspect ratio to seamlessly change to meet aerodynamic requirements with the same or less power.

That, sir, is an example of dealing with the engineering problem in a truly effective manner.

This type of thinking misses the mark. Truly effective engineering means finding solutions at every level of the system's functioning, from the minutiae to the level of the whole system. Focusing on a single component of the system is missing the woods for the trees.

Effective engineering means doing whatever can be done to produce better outcomes.

An aeroplane with better wings is good, but an aeroplane with better wings and more power is best.

(I know nothing about aeroplanes FWIW.)

 

[JJB70]

We are slowly assisting the demise of the Audio Shrine, you know, The tower with preamp, DAC ( in three box with the obligatory Atomic Clock and the reclocker) plus the mono-block amplifers at each side and the fat, huge garden hose speaker cables ... Even for seasoned audiophile it seems more interesting to go wireless. I am thinking about it. Bluetooth audio is transparent and so are DACs costing $20 .... Active speakers is the way forward, The way of the future. If one want to be convinced, just look at the Emotiva PA-1, essentially an Ice Module within an enclosure. No engineering IMO to speak of (except for that of B&O) ... How difficult is to put it in a speaker box or 3 of those in a 3-way? The module of the PA-1 is about $299 at retail...
The future of Hi-Fi is in speakers. For all practical purposes most electronics are beyond what our ears are able to discern... Speakers not so much.. They are not that good for the most part with final output that varies widely depending on the room ...Not there yet ... their interaction with the room remains a point that needs to be addressed consistently. Audio systems that take the room into account are not the norm .. Come to think of it, the best (perhaps most popular in this forum) examples we know of audio systems that are in principle speakers: Kii, Dutch 8C and Beolabs are complete audio systems all you need is a source ... All try to address the room... As for the source? ... Your PC, Your Tablet, Smartphone? USB drive...? A turntable?
Interesting days we're living. Future of Audio is brighter than I had come to think

Couldn't agree more! The idea of a pair of speakers and maybe a sub which can pair with my DAP, smartphone or tablet and deliver tip top sound strikes me as ideal. Why do we want all this stuff? Audio gear is a tool, it's there to facilitate enjoyment of music or whatever else you want to listen to. If you can do that without the clutter then why not? I love classic hifi gear and could happily collect it but in terms of an everyday system I think wireless active speakers are the way ahead.

 

[GrimSurfer]

DSP doesn't "avoid" solving "the driver problem". An audio reproduction system is just that: a system of components that work together to produce a desired outcome.



This type of thinking misses the mark. Truly effective engineering means finding solutions at every level of the system's functioning, from the minutiae to the level of the whole system. Focusing on a single component of the system is missing the woods for the trees.

Effective engineering means doing whatever can be done to produce better outcomes.

An aeroplane with better wings is good, but an aeroplane with better wings and more power is best.
(I know nothing about aeroplanes FWIW.)

An airplane that performs better is better. If the wings are the performance bottleneck, fix those. Power is just power.

Effective engineering is NOT doing "whatever" to fix a problem. It is finding an appropriate solution to a specific problem.

It is your kind of thinking that explains why people feel the need for 1kW amps for their home audio systems.

 

[andreasmaaan]

An airplane that performs better is better. If the wings are the performance bottleneck, fix those. Power is just power.

Are you saying that a plane with better wings but worse performance overall is better than a plane with better performance overall?

 

[FrantzM]

An airplane that performs better is better. If the wings are the performance bottleneck, fix those. Power is just power.

Think you're missing his point.

 

[GrimSurfer]

I understand brute force engineeering. It's an approach but not the best one.

 

[GrimSurfer]

Are you saying that a plane with better wings but worse performance overall is better than a plane with better performance overall?

I'm saying that if the wings are the problem, fix those.

If a driver or cabinet is the problem, then fix those. Don't reprogram the DSP to boost power levels to try to make the driver or cabinet do something it isn't configured to do. That's brute force engineering.