|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
24.197.204.198
In Reply to: RE: B&W 801 S2 Fatigue VS. 802 S2 No Fatigue? posted by davidstro@yahoo.com on January 25, 2017 at 05:39:17
Most objectionable, shrill sound comes from the midrange drivers distorting, NOT the tweeters, which produce very little sound. Those Kevlar drivers sound terrible unless their intrinsic ringing is damped or attenuated properly by the crossover.Both the 801 and 802 use electrolytic capacitors in their midrange crossovers. It's possible that these have deteriorated in the 801's more than in your beloved 802's. I found the midrange a bit brash in my 802's until I replaced those caps with decent poly film caps. It may not be necessary to go to that extreme, but you might consider replacing the 'lytic caps with newer and much better quality (still not at all expensive) parts. B&W really skimped on the quality of their xover components in those days, which is a shame for such quality drivers and careful designs.
To diagnose which driver is producing the negative impact, you might try alternately screening the tweeters and then the midranges with a piece of thin cloth attached (tape?) to the sides of the enclosures and stretched over the driver under test. This would certainly reduce any glaring high frequencies and allow you to determine where the problem sound originates.
I think that your estimate of amount of glare is exaggerated. Do you really know what 5 to 7 db sounds like? That much boost at almost any upper frequency would not just sound bright, it would probably immediately drive you from the room.
A complete diagram of every component inside that speaker, including exploded views of the enclosure, the individual drivers, all wiring, and schematics with parts lists is available from B&W, free for the asking. You might need to provide them with serial numbers so they know you really own a pair.
Peace,
Tom E
berate is 8 and benign is 9
Edits: 01/25/17Follow Ups:
You could buy yourself a SPL meter from Radioshack for about $50 and use a tone generator online and see the spiking in FR range.
I agreed that it is most likely ringing from those Kevlar mids. That is a big problem and a design flaw. There's a reason Kevlar, magnesium, aluminum and other exotic materials were quietly phased out. Horrible ringing that needed some big ass notch filters. In the end those filters were expensive and only squelched the sound.
Dump that speaker and move on.
However, the tweeters were made of metal-dome and can be susceptible to ringing issues. This is one of the reasons why B&W designers incorporated the APOC to protect the tweeters from signal overload that can produce ringing as an after effect.I have the 801 Matrix S3 that has been redesign to eliminate these sort of tweeters issues in the past. The tweeters in the S3 are still made of metal dome, however, it's filled with ferrofluid to keep them from overheating of which made the APOC protection circuits errelevant. By removing the APOC circuits they were able to simplify the X-over of the S3.
BTW, I'm using the Krell Evolution equipment to drive them and they sounded holographic, airy, visceral, but yet articulate with no shrillness, harshness or listening fatigue whatsoever.
If a thing's worth doing, it's worth doing well
(Proverb)
Edits: 01/26/17
Excellent advice- Tom E.
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: