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Posted By: jefft serial crossover on M22ti - 02/24/03 12:46 AM
Has anyone taken a look at this?
http://www.acoustic-reality.com/ar-sxo.htm

They claim to be the newest and best cross-over scheme. I've read a review online where someone recommended this modification to the M22ti.

Can someone explain the difference, and if this would be a significant improvement?
Posted By: sushi Re: serial crossover on M22ti - 02/24/03 01:33 AM
Well, after skimming through the web site, I do not understand why this crossover design is even patentable. It is just a classical first-order filter. Is this serial configuration really new to loudspeaker crossover design??? Maybe Ian can kick in here.

At any rate, I believe that, in the broader scope of general analog filter designs, serial arrangements are absolutely nothing new. I would rather be afraid that, in this design, the woofer's impedance characteristics may directly affect the tweeter performance, and vice versa.

If I were you, I would never even think about modifying the M22ti's crossover design, which I trust has been very carefully optimized for the specific drivers and enclosure used. This is of course unless you just want to play around with your M22s, without necessarily expecting any improvements in sound quality, and without minding the possibility of trashing the driver(s). If I were to try this crossover, I would rather go for a DIY from scratch.

By the way, I believe that Axiom uses as high as forth-order (24-dB/octave) crossover design in M22s and most other models, in order to mask the drivers' roll-off characteristics as much as possible... am I correct?

Cheers!
Posted By: Oak244 Re: serial crossover on M22ti - 02/24/03 04:53 AM
I too read this from the same guy I am sure. I have tried e-mailing hom for more information, but have yet to hear anything. His review of the speakers with his new crossovers sounded great! That is if it really works. My second question would be however, If you change the M22ti's crossover, then do I have to change my M2i, and QS8 crossovers to match? Seeing how they all have the same drivers, I assume they have similar crossovers, and by changing one, it would seem my once balanced staging would now not be, unless I modify all the speakers which I am not to intrested in doing! Any thoughts?
Posted By: sushi Re: serial crossover on M22ti - 02/24/03 06:24 AM
Just to reiterate my previous point...

You will surely alter the timbre balance of the M22s by modifying the crossover (if not, why bother?). Accordingly, you may well have to change the timbre balance of your other speakers as well. Otherwise, they may not mix well with each other anymore.

But my concern is the following: How do you plan to optimize the new crossovers? Will you simply take the chance and copy one poster's parameters, which may or may not be really optimal for the Axiom drivers, and may or may not be suitable at all for your room, taste and other conditions? There will be at least 3-4 independent parameters to be optimized: crossover frequency, high-pass and low-pass slopes, and of course the woofer/tweeter balance. If you decrease the slope (order) of the filters from the M22's original setting (which I believe is 24dB/octave), you will likely introduce a whole mess of complications, since the drivers will now have to work also for signals in broader "shoulder" frequencies. M22's drivers may or may not behave well in these frequencies. Do you plan to depend entirely on your own ears in optimizing the crossover? Or are you prepared to invest in a minimum suite of measurement equipment, such as a measurement mic and a spectral analyzer at the very least? At any rate, what will you have as the "reference" speakers, to which you can compare and judge the sound of the modified M22s (hopefully for the better)?

You get my point by now... Of course your speakers are yours; you are fully entitled to do whatever you want to do with them. But I would be very careful unless you are sure you will immensely enjoy these whole mess of techy/geeky endeavor (believe me... I was exactly like that in my youth; but now I have long found that I enjoy listening to music more than tweaking my equipment... ha-ha).

Oh, by the way, more recently I have also found myself enjoying this forum, while casually listening to my usual music with my Wi-Fi networked laptop on my lap. LOL

Cheers!
Posted By: sushi Re: serial crossover on M22ti - 02/24/03 08:04 PM
Found that Ian had said back in June, '01 that the crossovers in the Millennium line are in fact 18db/octave (still pretty steep). I here stand corrected, assuming that it has not been changed since then.

Also, he has expressed his confidence in the crossover design and quality. It is nice to have these words direct from the president and chief engineer of the manufacturer!

Cheers!
Posted By: JohnK Re: serial crossover on M22ti - 02/24/03 08:57 PM
Don't screw with the M22(Shakespeare).
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