Speaker Analysis for Armchair Critics


Hello everyone,
There’s a very important discipline called "Speaker Analysis" or "Speaker Testing" which though complicated, is brilliantly illustrated in this breakdown of the B&W 685.


http://www.audioexcite.com/?page_id=6070

Speaker analysis is to measure each of the components both separately and as they come together in a complete system. It is a part of creating a new loudspeaker, but it can also be used to analyze an existing speaker, to understand it and perhaps to make it better.  I prefer the term Analysis because it better reflects that the goal is not merely quality assurance, but to build a complete electro acoustical understanding of the system as a whole so changes can be considered, and their final results predicted.


This particular article does just that, and comes up with a couple of suggestions for re-working the crossover to end up with hopefully a better end result. At the very least, it is a significantly different speaker at the end, and achieves a far greater level of change than cables can.


I share this with all of you just as an example of the work that goes into making a loudspeaker from parts, and the tools, and how much of what we hear has to do with choices made in the crossover.


Best,

Erik
erik_squires

Showing 2 responses by xyobgyn

Erik:

Thank you for sharing that link. 

I believe the article is fascinating on several levels.  Thank you for possibly one of the most thought provoking posts (IMO obviously) of the year.

I happen to find pleasure using several older B&W matrix series speakers. 802,804,805 etc In different settings around the home.  I like their sound, I run them with Bryston power, and various sources. It pleases me, not trying to say it’s perfect. (Use what pleases YOUR ears, not here to push an agenda)

B&W btw has web access to see their crossovers for all their models in Service Manuals. On my two way 805 for example there is a far more sophisticated crossover than the two way analyzed in the linked article from Eric.

It would be fascinating to speak “off the record” to the people who made the decisions regarding crossover choices in the model reviewed.  
Would they say:

1) Cost drove the decision?
2) Some version of “Played side by side with competing speakers in typical show rooms, polls of unsophisticated listeners prefer this sound”
3) If we put in a proper crossover, even with inexpensive components, it would sound SO good, people wouldn’t buy the more expensive line of speakers.
4) We think it sounds great this way, why change it?

Personally I find it surprising they use (apparently) very good quality drivers, but hamstring (again, apparently) the crossover. 

I think the least likely explanation is that B&W actually thinks it sounds “better” than with a more appropriate crossover..... so it begs the question why?

The ironic part of this discussion is that B&W are not stupid collectively as a company. Odds are likely that the majority of us in this forum, if charged with making the decision of how to release this particular speakers crossover, might actually AGREE with B&W decision once the true reasons were revealed. 

(ie Porsche knows it’s SUV are a dilution of their core product, but to survive and produce their “good stuff” they essentially have no choice.)
The first B&W Matrix 801, 802 (I still have a set of the latter) included adjustment dials on the back of the module contains midrange and tweeter.

perhaps a nod to the idea that YMMV.

Quite possibly we should have crossovers with some caps and or resistors we could swap easily to adjust the sound to where we want it. 

Makes more sense to me than swapping around fuses, power cords, and cables to tame or enhance the tone.  We are acknowledging here that there is huge variation in how a designer arrives at the sound THEY perceive we will prefer.

why not make it the way we want?