Why the market do not move into external active design?

[dfuller]

Maybe, but that does not obviate integration of single unified design process and execution that incorporates all the steps and apparatus to go from a digital file to amplified room corrected and EQed mechanical audibility.

Sorry, I've read this three times and I can't quite parse what you're saying.

 

[Reed]

If functionally a crossover and a DSP accomplish the same task (filter frequencies for a particular woofer or tweeter), in theory, both should be capable of archiving the same results, right? How comes that on two speakers, all things being equal (LS50 and LS50 Wireless), the active version can get to lower frequencies with more authority? That is something I have experienced with active speakers, so all the conversation about performing better is something I agree with, what I´d like to know a bit better is how and why the magic happens.

Take this as a question from someone whose technical knowledge is quite limited being gentle and none being realistic.

Individual amps for midwoofer and tweeter, eq/dsp to counter roll off in volume at low frequencies (thus the need for powerful class d amp) and a protection circuit that actively monitors the speaker, not just the incoming signal. Look at Kef’s white paper on the LS50 Meta. That is the magic in a well designed powered monitor - they get the most out of the mechanicals.

 

[Vacceo]

Individual amps for midwoofer and tweeter, eq/dsp to counter roll off in volume at low frequencies (thus the need for powerful class d amp) and a protection circuit that actively monitors the speaker, not just the incoming signal. Look at Kef’s white paper on the LS50 Meta. That is the magic in a well designed powered monitor - they get the most out of the mechanicals.

So essentially, engineers are forcing each amp to peak in particular moments corresponding to the delivery of a particular frequency that would have naturally rolled off in a passive speaker while at the same time, the device checks it that push is too much for the capabilities of the speaker.

Is it possible to replicate that with a crossover? I guess not with the same precission, but still possible?

 

[Reed]

So essentially, engineers are forcing each amp to peak in particular moments corresponding to the delivery of a particular frequency that would have naturally rolled off in a passive speaker while at the same time, the device checks it that push is too much for the capabilities of the speaker.

Is it possible to replicate that with a crossover? I guess not with the same precission, but still possible?

Separate amps for woofers and tweeters has/does happen but it’s uncommon. As you said though, without the precision.

 

[nerdoldnerdith]

I feel like a lot of people on this thread are willfully ignoring the negatives of actives.

You have to wire both high voltage AC power and low voltage signal, this is incredibly annoying, and the annoyance scales up as your setup expands. Getting 12 different power cords for a 7.4.1 setup is just absolute insanity. I don't think the power grids of most apartments can handle this.

Now we get to wiring the low voltage signal. Good luck if your processor does not support balanced audio output because there is no way in hell that RCA cable is going to work without issues over a distance of 10 meters. all the noise built up over the distance will be amplified by the amplifiers of the active speaker.

Considering how expensive processors with balanced outputs are when you make active speakers you just alienated 99% of the home cinema market. I doubt anyone is building a 7.4.1 setups with JBL 305 MkII.

It is indeed a pain in the ass. Cleanly wiring up my multichannel Genelec setup with GLM was a multi-day affair. Each monitor had three or four cables connected to it: a power cord, an XLR cable, and two ethernet cables. The final product is a bunch of cables the thickness of a fire hose.

 

[Reed]

This hifiberry up cycling for vintage B&O speakers has been out for years with the company gradually adding more dac/amps to the lineup. I think they’ve been covered here on asr. https://www.hifiberry.com/beocreate What’s nice is they create the crossover and eq for the specific speaker. You buy the kit. An enterprising person could do this for other “worthy” passive speakers and sell it as a service.

 

[maverickronin]

If functionally a crossover and a DSP accomplish the same task (filter frequencies for a particular woofer or tweeter), in theory, both should be capable of archiving the same results, right? How comes that on two speakers, all things being equal (LS50 and LS50 Wireless), the active version can get to lower frequencies with more authority? That is something I have experienced with active speakers, so all the conversation about performing better is something I agree with, what I´d like to know a bit better is how and why the magic happens.

DSP actually lets you do a lot more.

Case in point, active speakers usually "cheat" by boosting the bass past the system's natural roll off and then adding a limiter so you don't unexpectedly damage the woofer. This limits maximum usable SPL in one way or another, either by compressing the bass as the volume of everything else increases or just hard limiting the full bandwidth to preseve tonal balance and make it obvious that you've hit the speaker's limit. That's trade-off not everyone may like, which is why I called it "cheating".

Some models even buffer the incoming digital signal and look ahead at the "future" signal to better estimate excursion and thermal load on the driver in order to deliver higher peak power once it knows it really is just a temporary peak. Then once you've decided latency isn't much of an issue you can use FIR filters to linearize the phase too.

DSP offers a lot of tools which are either impractical or impossible to recreate with passive components. That said, with conventional speaker designs I think DSP is usually just icing on the cake.

 

[dualazmak]

I see people posting about multi-channel audio on this forum.

Yes, I am one of the (few) people posting multichannel multi-driver (multi-way) multi-amplifier fully active L&R stereo audio system with software DSP (XO/EQ) which also enables 0.1 msec precision time-alignments between all of the SP drivers; you would please find details of my latest setup here.

Even though we discussed a lot also here and thereafter about the importance of time-domain tuning, i.e. time alignment, of SP drivers in our audio system, very few people properly know/understand how much it matters...

BTW, I use AWG12 and AWG10 multi-core VCT (Vinyl Cabtyre) cables for connections from alimplifiers to SP drivers, as shared here and here.

 

[Vacceo]

DSP actually lets you do a lot more.

Case in point, active speakers usually "cheat" by boosting the bass past the system's natural roll off and then adding a limiter so you don't unexpectedly damage the woofer. This limits maximum usable SPL in one way or another, either by compressing the bass as the volume of everything else increases or just hard limiting the full bandwidth to preseve tonal balance and make it obvious that you've hit the speaker's limit. That's trade-off not everyone may like, which is why I called it "cheating".

Some models even buffer the incoming digital signal and look ahead at the "future" signal to better estimate excursion and thermal load on the driver in order to deliver higher peak power once it knows it really is just a temporary peak. Then once you've decided latency isn't much of an issue you can use FIR filters to linearize the phase too.

DSP offers a lot of tools which are either impractical or impossible to recreate with passive components. That said, with conventional speaker designs I think DSP is usually just icing on the cake.

Oh, so that's why subwoofer integration gets a bit easier. Sure, room modes are still there, position matters the same, but at least the frequencies are very easy to adjust, because you can know exactly how the response of the speaker will go.

 

[Tangband]

If functionally a crossover and a DSP accomplish the same task (filter frequencies for a particular woofer or tweeter), in theory, both should be capable of archiving the same results, right? How comes that on two speakers, all things being equal (LS50 and LS50 Wireless), the active version can get to lower frequencies with more authority? That is something I have experienced with active speakers, so all the conversation about performing better is something I agree with, what I´d like to know a bit better is how and why the magic happens.

Take this as a question from someone whose technical knowledge is quite limited being gentle and none being realistic.

Active designs have technological advantages in the EMF area - in the bass area where directcoupling between amplifiers to the bass drivers are an advantage . This gives better control of the cones moving air.

Further - In an active dsp system - its easy to make the same speaker go slightly deeper in bass frequencies using eq and shelving where the speakers starts to drop of , typical 5-10 Hz deeper bass can be had without a bigger cabinet . In closed subwoofers even more .

 

[jhaider]

Under discussion is the commercial viability of external active.

Suppose I would want to go active. What would I gain by going external active, instead of having the crossover and power amplification as part of the speakers? And how is this for the manufacturer and the dealer?

You would gain the ability to centralize all of the audio electronics and run a single low-voltage (multicore) cable to each loudspeaker. That is especially useful in immersive installations. @nerdoldnerdith mentions above the fire hose worth of cables required for each of his Genelec speakers. By contrast, if his Genelecs were externally amped (i.e. if one could remove the DSP-amp unit from the back and put it in a rack enclosure) they would only require a 6-core speaker cable, or maybe an 8-core cable to get extra copper for the woofers. Such cables are commonly available from pro audio shops.

Arguably, as @dfuller notes, you would also increase durability, as the electronics will not be subjected to the forces exerted by loudspeaker drive units on the cabinet.

The downsides are IMO all on the resale side, though that could have some impact on brand reputation if people who don't know what they're doing get their hands on individual subcomponents of the integrated system. Look for example at the groundbreaking NHT Xd system, the archetype home audio "external amped active speaker." You see XdS satellites offered for sale on the secondary market regularly, but the XdA controller/amp almost never. Maybe this is not a perfect example - Jack Hidley closed out a bunch of the XdS models to DIYers when NHT discontinued the speaker. But you get the point.

 

[Gringoaudio1]

So essentially, engineers are forcing each amp to peak in particular moments corresponding to the delivery of a particular frequency that would have naturally rolled off in a passive speaker while at the same time, the device checks it that push is too much for the capabilities of the speaker.

Is it possible to replicate that with a crossover? I guess not with the same precission, but still possible?

A Passive crossover is only a subtractive device. The bass response, for instance, is dependent totally on the box and port design and good old fashioned T/S parameters. An active crossover with DSP can or should be able to do EQ and has the capability to boost frequencies. So they are capable of adding bass or any other frequency that the passive speaker is lacking.
People already said all this. Oh well.
Active speakers and all-in-one systems remind me of the downfall of Nakamichi when it left doing SOTA tape machines as that technology faded from the market and they desperately tried to sell something relevant and failed.
Give me my stack of black components please.

 

[abdo123]

DSP actually lets you do a lot more.

Case in point, active speakers usually "cheat" by boosting the bass past the system's natural roll off and then adding a limiter so you don't unexpectedly damage the woofer. This limits maximum usable SPL in one way or another, either by compressing the bass as the volume of everything else increases or just hard limiting the full bandwidth to preseve tonal balance and make it obvious that you've hit the speaker's limit. That's trade-off not everyone may like, which is why I called it "cheating".

Some models even buffer the incoming digital signal and look ahead at the "future" signal to better estimate excursion and thermal load on the driver in order to deliver higher peak power once it knows it really is just a temporary peak. Then once you've decided latency isn't much of an issue you can use FIR filters to linearize the phase too.

DSP offers a lot of tools which are either impractical or impossible to recreate with passive components. That said, with conventional speaker designs I think DSP is usually just icing on the cake.

Also if they high pass the very low bass they may be increasing the linear excursion of the woofer if the stiffness of the cone is the limiting factor (that’s the case most of the time).

 

[Jon AA]

Is it possible to replicate that with a crossover? I guess not with the same precission, but still possible?

Yes. Having a passive crossover does not preclude one from doing the same thing with DSP somewhere else in the system. People do it all the time. Most passive crossovers aren't really doing anything there--you're just stuck with the natural response of that driver in that particular box. My default starting point for a passive speaker is to put a high pass at or just below the tuning frequency of the port (with ported speakers) to protect the driver, then boost that thing until it's flat.

A passive crossover in the system does preclude you from doing other things you can do with active speakers (like making adjustments to the crossover itself, obviously) but getting a good bass response isn't one of them. Too many here seem to think there's some law against using DSP with passive speakers and are making a comparison of "No DSP vs DSP." IMHO, everybody should be using DSP--even those with passive speakers. It would be more informative for people making comparisons to limit those comparisons to the things that can only be done with active speakers (steep crossovers, etc) instead of assuming passive speakers won't have any DSP available at all.

Back to the subject of this thread--something I haven't seen mentioned is building codes. There are many places here and around the world where you simply can't have high powered amplifiers built into your walls. This is one of the big reasons pretty much all in-wall speakers--even really high end active ones from Grimani, Pro Audio Technology, etc--use external amps. Even the subs. And yes, running speaker wire through the walls to 15-20 speakers is much easier than a low level signal and having to worry about providing power to each of them.

 

[Vacceo]

Yes. Having a passive crossover does not preclude one from doing the same thing with DSP somewhere else in the system. People do it all the time. Most passive crossovers aren't really doing anything there--you're just stuck with the natural response of that driver in that particular box. My default starting point for a passive speaker is to put a high pass at or just below the tuning frequency of the port (with ported speakers) to protect the driver, then boost that thing until it's flat.

A passive crossover in the system does preclude you from doing other things you can do with active speakers (like making adjustments to the crossover itself, obviously) but getting a good bass response isn't one of them. Too many here seem to think there's some law against using DSP with passive speakers and are making a comparison of "No DSP vs DSP." IMHO, everybody should be using DSP--even those with passive speakers. It would be more informative for people making comparisons to limit those comparisons to the things that can only be done with active speakers (steep crossovers, etc) instead of assuming passive speakers won't have any DSP available at all.

Back to the subject of this thread--something I haven't seen mentioned is building codes. There are many places here and around the world where you simply can't have high powered amplifiers built into your walls. This is one of the big reasons pretty much all in-wall speakers--even really high end active ones from Grimani, Pro Audio Technology, etc--use external amps. Even the subs. And yes, running speaker wire through the walls to 15-20 speakers is much easier than a low level signal and having to worry about providing power to each of them.

Well, I already use DSP´s on passive speakers, because otherwise, Audyssey would not work on them. The questions were more aimed at having the information to weight how worth is going for a fully active system.