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"Drivers are custom-made for us by SEAS/Scan Speak/Audax/Accuton..." - really?

I listened to the current version of the Marten Miles - above my budget but I certainly preferred them to the Magico A3 at the end of an Accuphase class A amp I compared them to in the same shop. But then the Martens have a higher sensitivity, so I guess this is hardly a surprise.

I am currently waiting for these to arrive (if I don't run out of patience before and just get a B&W 804 D3 :)):

https://www.marten.se/products/oscar/oscar-trio/

Personally, i don't get on well with B&W speakers, they have a recess midrange which only after a while becomes fairly apparent, then i can't ignore the effect.
 
I never liked the older 800s but I seem to like the current D3 series. To be fair in a direct comparison between the 805 and 804 (both D3) I preferred the 805, even though obviously they don't go as deep as the 804 and I was missing some of the low level information.

But it could be that my ownership of active speakers have ruined passive 3 way speakers for me, which is why the Marten is an interesting proposition as it's a true 2 way design with two bass/mid drivers, not a 2.5 way speaker (or even a 3 way).
 
I had a pair of ProAc Response 2S. According to Stereophile, ProAc had Scanspeak use a heavier magnet than normal for higher power handling. I've heard of other manufacturers specifying different cone materials, voice coil wire composition, surrounds, and/or baskets.
 
I was told by Tony Gee who has designed diy speakers for the last 25 years (Humble) that SEAS have a minimum order quantity of 100units where you can specify a drive unit exactly how you want.
A german diy speaker magazin, Hobby Hifi, had 4 protoype samples made to test the effect of a specific attribute, voice coil former material, by SEAS and then had a batch, 100?, made. So it is possible for small speaker manufactuers to go this way.
I think Tony also mentioned that Scan Speak have a lower minimum order quantity but the parts are considerably more expensive with such small numbers.
 
The Marten speakers are an interesting proposition as they, like a number of other European manufacturers, make extensive use of Acuton drivers. Now these drivers are super stiff and flat within their intended usable range but have significant breakup artefacts outside of that range (at least many/most of their designs do). And yet Marten (and others) use second order crossovers that offer relatively little in terms of out of band damping...
 
The Marten speakers are an interesting proposition as they, like a number of other European manufacturers, make extensive use of Acuton drivers. Now these drivers are super stiff and flat within their intended usable range but have significant breakup artefacts outside of that range (at least many/most of their designs do). And yet Marten (and others) use second order crossovers that offer relatively little in terms of out of band damping...

Yes, I read that too somewhere - maybe those audible artefacts are part of their sonic signature? ("it's not a bug, it's a feature" :))
 
maybe steeper active filters ( 4th or 8th order) could help with acuton cone break up..
anyone knows if these drivers are used with active crossovers?
 
maybe steeper active filters ( 4th or 8th order) could help with acuton cone break up..
anyone knows if these drivers are used with active crossovers?

I generally like Accuton-equipped loudspeakers but still think the best application of them I have heard are in the Gauder Akustik range. As it happens, Dr. Gauder uses crossover slopes of 48dB/octave or more in his designs.
 
thanks for the link, these look interesting..
some models got 60db/octave filters.. that's quite high!! couldnt that be done easier and with more precision in active crossover than passive? or it dosent matter?
 
thanks for the link, these look interesting..
some models got 60db/octave filters.. that's quite high!! couldnt that be done easier and with more precision in active crossover than passive? or it dosent matter?

I'm sure it's easier done using active analogue or digital filters. As for doing 60db/octave filters in a passive XO, no idea how they do that but I can imagine that it does have some disadvantages in other aspects (no free lunch and all that).
 
Steep crossover filters, and notch filters, are best done in the digital domain I think. I’m not inherently pro-digital, not at all. It’s more that I think such filters are more difficult to achieve in the analogue domain without ringing or smearing. Having said that YG seem to do a pretty convincing job of passive crossovers that use very steep crossover slopes...

I’ve also heard a number of Acuton driver equipped speakers and generally liked what they did. However, for the most part they have been two way units and perhaps the out of band distortion has been less easy for me to hear. On the other hand, none of these speakers redefined my expectations so perhaps I was hearing some issues..... just not in an ‘overt’ manner....
 
Steep filters with cones on flat baffles will result in a sharp change in directivity through the crossover region (large driver radiating narrowly and small driver radiating widely). This can produce an airy sound but it is not realistic which requires a smooth change in directivity. The optimum slope tends to lie between 2nd and 4th order regardless of the type of crossover being used. Slopes outside this range are probably best viewed with a degree of caution unless waveguides or multiple drivers are being used to control the directivity. Modern active crossovers can have pretty much any slope desired but something around 2nd to 4th order is normally about optimum in terms of maximising the smoothness of the transition between the drivers and minimising the passband required by the drivers.
 


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