Axiom Home Page Forums General Discussion What's New At Axiom LFR1100 Active

Not pilgrims ... politicians... the law of physics or anything else work only as they declare them to ... at least according to them

That's the lovely benefit of democracy. You have the freedom to choose your own pains.

Off Topic
Actually the people who are hurt the most are the ones who believe ... a lot of people only listen to or only have access to one side of an issue ... so to them it's obvious what is right even if it's not true (or not the whole truth). To them they see the hand waiving a carrot in front of their face while not seeing or understanding that they will lose so much more.

This combined with a broken government is going to be our down fall if not corrected soon. .... a bit depressing ...
Let's get back to audio ...

Perhaps that is better than having so much choice, which people misinterpret as greater freedom, that it becomes a distraction rather than a benefit.

By the way, my last comment applies to audio too. You can tell by my signature how distracted I am.

So back to audio...

What is the actual difference? Between going Active and just Bi Amping?
I get there's an external crossover. Can you adjust the crossover to your own liking? Or is it each set of particular drivers needs to be powered? In their own ranges?

Would using a lower power Amp. or Tube Amp. for the highs be advisable? Similar to Bi Amping.{Tweets use little power}

I've heard some darn impressive results from Active configurations bigger dynamics and body more open.

But aside from having hundreds too thousands of Watt's per speaker. What would really be the most beneficial reasons?

Brendo, the net effects of digital, active cross-overs are about a 3dB improvement in sensitivity, improved imaging, improved soundstage and improved micro and macro dynamics.

The 3dB improvement in sensitivity is a result of the elimination of the traditional analog, passive cross-over. Yes, that's right, half the power you sink into a speaker is turned to heat by the traditional crossover. Put 250W in, 125W of that goes into heating the room as a result of the crossover.

All the other improvements are partly due to much greater control with the spinoroma (family of parametric) curves. The DSP gives the designer a lot of freedom to "flatten this" and "boost that" in a more granular manner. Phase response can also be improved. So can transient response although there is a trade-off there between transient response and frequency response. Then there is also the greater control that an external amp can have over the driver directly with the traditional crossover eliminated.

Your questions about the type of amp and the power required are very good. Axiom I am sure will eventually publish specifications for its driver arrays to make sure that customers can marry them up with their choice of amplification. Or maybe not although that wouldn't be the Ian we know who likes to give customers choice. I suppose Axiom could introduce amps that make the most of their active line and leave the present ADAs to the legacy (analog crossover) speakers. I really believe a new line of amps would make the actives shine even more and that's all I'll say about this publicly. Nothing wrong with the ADAs for the current lines though and in the interim for the actives.

I have no doubt the actives will sound significantly better. I know first hand what havoc analog filters wreak on a design as environmental conditions and part specs (due to tolerances) change. Active filters don't suffer from these limitations. You hear about better crossover parts and all that is true and I've witnessed it on the v4. But, no matter what you do, those parts drift particularly when you're pouring gobs of current into the speaker. If you listen closely, you can hear the effects. That's not your ears objecting to the SPL; that's the speaker objecting as it shifts from its design limits!

Axiom is just starting to scratch the surface with actives. Actives are a geek's haven! Ditto with LFRs.

I'll also add in here that Ian has been obsessed his whole life with eeking the maximum possible performance from his existing driver architecture. No one's told me this - all you have to do is watch what he's been doing and it's pretty darned obvious. That's another reason why he's one of my heroes. I think the actives will open up an entirely new area of research for Axiom. There is stuff happening inside those drivers that actives will naturally expose. I am not saying there's anything wrong with the drivers. I am saying that more knowledge will be gained about how to make them even better. This is the nature of scientific inquiry and the pleasure of finding things out.

That's where my confusion comes in. At some point there's still an external crossover. So wouldn't that need a chassis for the heat? Plus still limit the drivers to their desired ranges?

I also believe that the ADA Amps are Axioms own specific custom design. Around the time I became an Axiom customer 2013/2014 the blog had some in depth articles and some you tube vids. regarding creating their own design and the differences of typical class D and the ADA.

The external crossover handles everything as a digital "preamp" that separates the signals. We are talking less than a volt in terms of power at this point.

A passive crossover is taking the high powered signal from the power amp, which is where it loses the 3 dB.

In the case of the Active Speakers, each woofer/midrange/tweeter is connected to the dedicated amp that already has the response curve for the crossover sent to it from the DSP.

There are no resistors, capacitors, extra wiring nor anything else between the amp and the speakers.

Another benefit: If one is listening to music with powerful deep bass and female vocals - The mids are delivering the vocals, which won't have the amp being taxed by the deep bass.

Headroom will increase, no signal will be lost. It's all good science.

To add to Craig's comments, it is the high currents and voltages and heat liberated from the voice coils that cause part specs on the traditional crossover housed inside the speaker cabinet to drift. When those specs drift, amplitude, phase and transient response are all negatively impacted and the effects are audible.

As Craig said, the voltages and currents in the DSP-based digital filter are a lot lower. The signal voltages the DSP deals with are no larger than about 7 Volts and currents are much less than an Amp...likely one tenth of an amp. Contrast that to over 100 Volts and 40 Amps (sourced from an amp) that an analog crossover has to deal with. On top of that load, the voice coil of an HP driver reaches 200 degrees C. Some of that heat gets excreted through the sphincters, some is radiated off the glorious aluminum dust caps and the remainder is trapped in the cabinet and affects the performance of the crossover components (and the voice coil itself). These nasty effects don't take place inside the DSP box.

The DSP can also bring benefits that Axiom isn't currently exploiting. For example, by monitoring the temperature of the voice coils, the digital filter coefficients can be adjusted to compensate for the rise in resistance of the coils (as much as double) due to temperature.

As for the ADA amps, within the present industry paradigm, they are a very good value particularly for multi-channel.

What about the "active" technology, e.g. Apple's HomePod, that listens to the in-room audio and adjusts output in real time? I wonder if Axiom has experimented with that, and what it could contribute to Axiom sound.

I also still wonder if Axiom has tested the HomePod and can shed light on what Apple has, and hasn't, accomplished with their active tech in such a small package.