B&W matrix modifications?
Mike
would like to here about what you have done, and what the sonic
outcome was. Any feedback on any matrix speaker welcomed, but
especially interested in 803sII/804 crossover mods. Thanks.
philip ganderton
Yes, I have modified a set of Matrix 801-III and the new Nautilus 801s.
In both cases I gutted the speakers, removing the VandenHul wire,
replacing with silver/teflon wiring of various guages for each driver
(of course this was a waste since all wire sounds the same, but hey, I
love deluding myself 8--) I then removed the OEM crossovers (internal
in M801, underside of aluminum base plinth in N801) and constructed
external crossovers using simple upgrade concepts: large awg aircore
inductors, groups of cascading high grade capacitors and high quality
resistors, star grounding and hard-wiring element-element connections.
(Of course all this is BS since all components sound the same too, and
even if they didn't who am I to think that B&W wouldn't put sufficiently
good components in their crossovers?) I then hardwired the speakers to
the crossovers making the speakers essentially un-movable and
un-sellable (yet someone paid more for my M801s with the external
crossovers over a brand new pair of M801s--what a fool. And to imagine
he thought he heard something in my speakers that he'd never heard in
any stock speaker!) With the old M801s I also mass-loaded them with
150lbs of lead, creating a pair of M801s that weighed, with crossovers
over 700lbs. I didn't need to mass load the N801s as they are
substantial enough stock.
In each case these modifications involved considerable effort and
expense and I would not recommend they be done with faint heart. The
outcome appears to be greater detail, more transparency and openness,
and ease of reproduction. The "voice" and personality of the speakers
did not seem to change, yet they sounded more musical. Noise floor
seemed to diminish and bass was deeper and tighter.
I hesitate to recommend anything to you, but it is my opinion that all
B&W matrix speakers will benefit sonically from these type of
modifications. While the internal wiring mod is certainly debatable,
the stock crossovers use compromised components and mass loading the
speakers seems to remove significant cabinet resonances (that are
noticable when you remove the mass!!)
It must be noted that I believe crossovers to be the one big area where
manufacturers "short-change" buyers, except in the most expensive
speakers (gross generalization) They are little though of, and rarely
exposed to customer inspection, and never compared against alternatives
("ah, can I A-B that speaker with a different crossover?") Seems like a
great opportunity for the engineer to compromise and to make the
accountants happy.
Your experience may vary, and I hope so!
cheers,
philip ganderton
John Busenitz
I am very much for modifying loudspeakers, because doing so can
help one learn about what is involved in speaker design, and how
changing certain things can change the performance of the speaker.
However, this is something that needs to be done with some common
sense; blindly modifying a loudspeaker can result in unchanged or
even worse results. So while I encourage logical modification, I
see a few problems with the following.
>Yes, I have modified a set of Matrix 801-III and the new Nautilus 801s.
>In both cases I gutted the speakers, removing the VandenHul wire,
>replacing with silver/teflon wiring of various guages for each driver
>(of course this was a waste since all wire sounds the same, but hey, I
>love deluding myself 8--)
I'm not going to make this into a cable audibility argument. But
how on earth do you think changing a few feet of cable is going
to do anything, when there is an order of magnitude more unfancy,
non-audiophile "approved", small guage non-silver wire in the voice
coils of the drivers? Or did you change that, too? ;-)
>I then removed the OEM crossovers (internal
>in M801, underside of aluminum base plinth in N801) and constructed
>external crossovers using simple upgrade concepts:
Perhaps "simple" enough to result in little, if any, improvement,
or even a drop in performance.
> large awg aircore inductors,
While air-core inductors have the advantage of not saturating, they
do have a different series resistance than ferrite-core inductors.
So you've just changed the transfer function of the crossover. This
isn't a good thing to do, IMHO, unless you track the changes and
compensate for them. Why do you think that automatically using air-
core inductors is inherently better, anyway? Were the original inductors
saturating?
>groups of cascading high grade capacitors and high quality
>resistors, star grounding and hard-wiring element-element connections.
Did you use silver solder?
>(Of course all this is BS since all components sound the same too, and
>even if they didn't who am I to think that B&W wouldn't put sufficiently
>good components in their crossovers?)
Who says that all components sound the same? Anyway, I think there
is probably improvement to be had in modifying crossovers, so that
their response with your specific drivers is flatter. But in your
case, you just blindly "upgraded" random components, without quantifying
the changes in performance, right?
>I then hardwired the speakers to
>the crossovers making the speakers essentially un-movable and
>un-sellable
Unless you have a soldering iron?
>(yet someone paid more for my M801s with the external
>crossovers over a brand new pair of M801s--what a fool. And to imagine
>he thought he heard something in my speakers that he'd never heard in
>any stock speaker!)
The power of suggestion and the placebo effect are very powerful!
>With the old M801s I also mass-loaded them with
>150lbs of lead, creating a pair of M801s that weighed, with crossovers
>over 700lbs. I didn't need to mass load the N801s as they are
>substantial enough stock.
>
>In each case these modifications involved considerable effort and
>expense and I would not recommend they be done with faint heart. The
>outcome appears to be greater detail, more transparency and openness,
>and ease of reproduction. The "voice" and personality of the speakers
>did not seem to change, yet they sounded more musical. Noise floor
>seemed to diminish and bass was deeper and tighter.
How did you determine these improvements were real? I am especially
curious about the claim of noise-floor reduction, because the noise-
floor is usually determined by the electronic components, and any
increase in resolution of the loudspeaker would seem to me to make
that noise floor, if anything, easier to hear.
>I hesitate to recommend anything to you, but it is my opinion that all
>B&W matrix speakers will benefit sonically from these type of
>modifications. While the internal wiring mod is certainly debatable,
>the stock crossovers use compromised components and mass loading the
>speakers seems to remove significant cabinet resonances (that are
>noticable when you remove the mass!!)
How have you determined that the components are compromised? Did
you measure nonlinearities within their operating ranges? Or did you
just assume that they were compromised, since they weren't made by
the current special-audiophile "esoteric" component maker of the day?
>It must be noted that I believe crossovers to be the one big area where
>manufacturers "short-change" buyers, except in the most expensive
>speakers (gross generalization).
Probably. But with a speaker like the 801, I have trouble with the
implication that the engineer, who has successfully engineered many
more loudspeakers than the amateur hobbyist, cannot design a crossover
properly.
>They are little though of, and rarely
>exposed to customer inspection, and never compared against alternatives
>("ah, can I A-B that speaker with a different crossover?") Seems like a
>great opportunity for the engineer to compromise and to make the
>accountants happy.
Yes, but not as much in something like the 801 as in less expensive
speakers.
>Your experience may vary, and I hope so!
Thanks for posting your experiences. My goal is not to denigrate
them, but rather to raise questions. I think that speaker
modification can definitely be beneficial, but in the right
directions. Loudspeaker manufacturers have to skimp on cabinets, be
cause the weight is directly related to shipping cost, and the
complexity proportional to assembly cost.
Furthermore, the use of line-level crossovers and bi/tri-amping can
also improve performance both measureably and audibly, as can
tweaking some of the crossover component values, to flatten the
response. But as I've noted above, there are some areas which don't
seem to be worth the time. Why not concentrate on the obvious areas
with known improvements, rather than dubitable and blind changes?
Carmen Margiatto
You seem to be somewhat overwhelmed (as was I, after reading all the
work done) from Phil on B&W modifications. I have a pair of Series II
Matrix 801's that I recently improved by doing the following, (and it cost
$0.00) . . .
1) I removed all the protective circuitry components from the
crossovers. This involved first obtaining a schematic of the components,
and then carefully choosing and removing all the diodes and solid state
current switching relays that are in the signal paths. Not a very hard
task, just somewhat time consuming. You can check the B&W website for
support phone numbers and see if they will send you a copy of the schematic
of your speaker; including a detail of the crossover.
2) In the case of the 801 Series II, I reoriented a midrange inductor
which was being magnetically coupled to a bass coil due to poor placement
geometry.
Well, that's it. The sound improved quite nicely, with more detail,
openness and immediacy. Total time involved . . . approx. 3 - 4 hours.
This appealed to me for two reasons; B&W knew of the sound degrading as a
result of circuit protection devices in the signal path (removed for the
Series III) as well as the bad coil placement, and I couldn't beat the price
of the upgrade . . . $0.00.
I hope this helps
Carmen Margiatto cmarg...@myhost.com
mdem...@my-dejanews.com
"John Busenitz" <buse...@earthlink.net> wrote:
> philip ganderton wrote in message <74arhl$2u7$1...@agate.berkeley.edu>...
>
> > large awg aircore inductors,
>
> While air-core inductors have the advantage of not saturating, they
> do have a different series resistance than ferrite-core inductors.
> So you've just changed the transfer function of the crossover. This
> isn't a good thing to do, IMHO, unless you track the changes and
> compensate for them. Why do you think that automatically using air-
> core inductors is inherently better, anyway? Were the original inductors
> saturating?
>
> John
> buse...@earthlink.net
>
(quoted in brief... no comment on the rest)
John's point on the series resistance is critical. When I built my externals
for the 801s I sized the wire in the air-core inductors to match that of the
original iron core units. This requires SIGNIFICANTLY larger wire. Also the
reason to go to Litz wire on the high end.
And yes, John, at least one of the iron core units was saturating at
reasonably high levels, resulting in measurable distortion in the LF section.
And the changes B&W made in the Series III were mostly aimed at correcting
these weaknesses in the Series II. The protection circuits were removed in
conjunction with the introduction of a more efficient tweeter (sounds same,
but is a couple db more efficient), allowing it to be padded down more
compared to the mid and reducing the risk of overload.
Happy music, and keep those soldering irons fired up!
Michael Demeyer
Ann Arbor, MI
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Change Later
If so, would you please list your findings and possible upgrade
reccomendations.
The power handling capabilities of the 801 and 802 Nautilus are substantial.
According to B&W the 801 Nautilus can handle more power than the
huge Matrix 800, which I previously owned. The 'old' 6'4" matrix 800
behemoths easily took the full output of the Bryston 7BST in series
mode (approximately 800 watts) without any audible distortion-- so it is
amazing that the new 801 nautilus is rated at 1000 watts, assuming B&W
has kept the same rating scale.
The 802 Nautilus is rated at 500 watts, even though they have the identical
mid-range and tweeter of the 1000 watt 801 Nautilus. So If I understand
correctly, the midrange and tweeter of the Natilus 802 are actually capable
of handling 1000 watts (relative to Matrix 800 rating at 800 watts).
However, the smaller 8 inch bass drivers are the limiting factor of the
power handling in the Nautilus 802. This is a concern for me because
I occasionally like to test the SPL limits of a system. I have fun shaking
the room once in a while.
1) If I cut the bass off at 65 Hz using the EAD Signature digital
crossover (fourth order high and low), I should get similar power
handling
to the Nautilus 801?
2) Did B&W lower the power handling values on the crossover components
in the Nautilus 802 versus the Nautilus 801?
3) If anyone has seen the Nautilus crossover and could explain the
quality of the crossover and any possible improvements I would
appreciate it, especially if there are ferrite-core inductors, etc.
Any difference between the 801N and 802N would also be
appreciated...
Thank-you Sincerely!
> "John Busenitz" <buse...@earthlink.net> wrote:
>> philip ganderton wrote in message <74arhl$2u7$1...@agate.berkeley.edu>...
>>
>>
>> While air-core inductors have the advantage of not saturating, they
>> do have a different series resistance than ferrite-core inductors.
>> So you've just changed the transfer function of the crossover. This
>> isn't a good thing to do, IMHO, unless you track the changes and
>> compensate for them. Why do you think that automatically using air-
>> core inductors is inherently better, anyway? Were the original inductors
>> saturating?
>>
>> John
>> buse...@earthlink.net
>>
>John's point on the series resistance is critical. When I built my
externals
>for the 801s I sized the wire in the air-core inductors to match that of
the
>original iron core units. This requires SIGNIFICANTLY larger wire. Also
the
>reason to go to Litz wire on the high end.
>
>And yes, John, at least one of the iron core units was saturating at
>reasonably high levels, resulting in measurable distortion in the LF
section.
>
>
mdem...@my-dejanews.com
results. I used Solen air core inductors (Litz-wire for the tweets) and
Polypropolyne film Fastcaps bypassed with MIT caps. As I remember the parts
cost for the tweeter and midrange sections was about $350... I only replaced
one inductor in the woofer section (the first one, L6 I think, which has a
tendency to saturate its iron core in the stock unit).
Worth the time and effort, but care should be taken to make the changes in a
reversable way to protect resale value. (I never did the internal wire
upgrade, although I seriously considered eliminating the shared gound wire
running to the mid and tweet in the 801M. I suspect that would make an
incremental improvement.
Michael Demeyer
In article <74arhl$2u7$1...@agate.berkeley.edu>,
philip ganderton <gan...@unm.edu> wrote:
[excessive quoting vigorously tamped -- djd ]
-
PSiu89449
>The 802 Nautilus is rated at 500 watts, even though they have the identical
>mid-range and tweeter of the 1000 watt 801 Nautilus. So If I understand
>correctly, the midrange and tweeter of the Natilus 802 are actually capable
>of handling 1000 watts (relative to Matrix 800 rating at 800 watts).
>However, the smaller 8 inch bass drivers are the limiting factor of the
>power handling in the Nautilus 802. This is a concern for me because
>I occasionally like to test the SPL limits of a system. I have fun shaking
>the room once in a while.
Why would anyone want to test the maximum SPL and power handling capability of
their speakers is beyond me. House damaging is for one but precious hearing and
sanity of fellow neighbor is another.
It is important to know the ratings of these drivers in terms of short term
burst headroom or long term power ratings. It is okay for many high quality to
absorb short time burst of 1000 watts or over in a matter of 10-20mS. But only
providing that these drivers are operating within their intended operating
range, properly crossovered that is. If one is to insert sustained 1000 watts
into most any drivers, internal melt down is certain. This is not the most
civilized way to exercise the power of any amp. Bryston 7B-ST inclusive.
Best Regards
Paul Siu
mdem...@my-dejanews.com
Stereophile in 1990 or so. They work as advertised and are easy to
do.
Michael
In article <74ccsf$s6e$1...@ccsi.com>,
"Carmen Margiatto" <cmarg...@myhost.com> wrote:
> Hi Mike,
> You seem to be somewhat overwhelmed (as was I, after reading all the
> work done) from Phil on B&W modifications. I have a pair of Series II
> Matrix 801's that I recently improved by doing the following, (and it cost
> $0.00) . . .
[quoted text deleted -- deb]
--
Michael Demeyer
Ann Arbor, MI
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