Are you using the aluminum phase plug?

[RebelMan]

I was curious how many people are using the optional aluminum phase plug (in lieu of the plastic one) that is included with their 802 speakers and up and why, i.e, for sound or vision or both? Thanks!

[tboooe]

I use them for no other reason than the fact that they were included with the speakers and they look better than the plastic ones with the hole in them (I do not use the midrange speaker grill). I have no idea if they sound better. Sorry for the lack of any useful information...

[Indytown]

I use them for no other reason than the fact that they were included with the speakers and they look better than the plastic ones with the hole in them (I do not use the midrange speaker grill). I have no idea if they sound better. Sorry for the lack of any useful information...

tboooe,

Go to the Monitor Audio site, go to the Gold Line GR60 floorstanders. They use solid billit phase plugs. Read their thoughts on the use of the solid plugs in some of GR60 reviews, I think it makes audible sense. Some thoughts.

Indy

[miner]

Those who don't use the alum phase plug - please sell me yours. I need them for my N804. I ordered a pair from a member who was manufacturing them but never rcvd them.

[chinets]

yup,ordered a a pair from a member, like MINER did, who was manufacturing them, and I never ever received them.
Like MINER..If anyone wants to sell there Aluminum plugs..I need two pairs. Thanks.
Cheers

[Jesse111]

I don't use mine because I prefer less attention to the speakers. By using the covers everything is black and neutral looking with my decor. This allusion increasing the soundstage performance in my mind by helping the speakers disappear. Besides, my wife calls my beautiful 800D's "the march of the penguins" when I take off the covers.

But I might use them if I could find more info on their acoustic qualities, if any.

[RebelMan]

I don't use mine because I prefer less attention to the speakers.

I am still debating this myself. One the one hand, I prefer the grill covers removed when listening to music. On the other hand, I prefer the stealthy appearance with the grill covers on when watching movies. While I prefer the high-end quality look and feel of the aluminum phase plug, over the plastic one, I am not willing to entertain the idea of swaping them every time I want to remount the grill cover. This is one of those situations where I have mixed feelings on which to choose, with or without plastic? However, if there was compeling reason one way or the other ( maybe like majority rule ) that may help me to decide. Come to think of it, this might be enough justification for a dedicate two-channel room.

"Honey, I think it is time to move!" :rofl:

[tboooe]

The only reason that matters is that the speakers look awesome without the grills! its all about looks right?????

[Eliav]

I don't use mine because I prefer less attention to the speakers. By using the covers everything is black and neutral looking with my decor. This allusion increasing the soundstage performance in my mind by helping the speakers disappear. Besides, my wife calls my beautiful 800D's "the march of the penguins" when I take off the covers.

But I might use them if I could find more info on their acoustic qualities, if any.

Likewise. I have heard it should sound better with the metal ones ( " 10% more transparent" per my dealer, supposedly allowing better midrange driver's motion/vibration), i personally prefer the more "humble"- dressed-up ( ops: )look of the speakers..... :W .
Eliav

[Jesse111]

The only reason that matters is that the speakers look awesome without the grills! its all about looks right?????

I have searched and searched but I can not find any information supporting the metal phase plugs. I've seen some opinions and speculation but nothing more. I would readily admit a blind test would only prove to me that I couldn't tell the difference. Perhaps others could. I would agree with tboooe on this one. If you like the looks of grills, then we use the plastic ones with a whole in it to hold the grill on. If you don't like grills, then you get to use those cool heavy metal ones that look great.

But here's a related question. Is there an audible diifference with or without the midrange grill? I personally can not tell a difference.

[Eliav]

I have searched and searched but I can not find any information supporting the metal phase plugs. I've seen some opinions and speculation but nothing more. I would readily admit a blind test would only prove to me that I couldn't tell the difference. Perhaps others could. I would agree with tboooe on this one. If you like the looks of grills, then we use the plastic ones with a whole in it to hold the grill on. If you don't like grills, then you get to use those cool heavy metal ones that look great.

But here's a related question. Is there an audible diifference with or without the midrange grill? I personally can not tell a difference.

Jesse
I could definitely tell a difference between grills -off and grills -on with my previous 803s, that was, I guess, attributed to the fact that removing the grill exposed the entire cabinet, it was also very easy to do, in and out in seconds. Now, in order to compare these two you have to unscrew, screw, put the grill on and go back to listening position, pain in the neck, I may try this some day.....
Eliav

[Angioguy]

Still can't figure out what the benefits of aluminum phase plugs are and if they are measurable, but if B&W includes them with the 802D/801D/800D, then shouldn't there be an explanation?

The only thing I see in the owner's manual is the following: "If you use these systems without the midrange grille, replace the plastic centre plug of the midrange drive unit with the solid aluminum plug in the accessory pack." That's it??? It can't be for aesthetic reasons, can it?

How is sound affected by an aluminum plug without the grill versus a plastic plug with the grill? Is the answer related to the physics of sound waves and their interaction with materials-- moreover, how does that translate to more musical enjoyment?

[watchthewaves]

I know this is a rather old thread. Stumbled upon it in a search, but just in case any one is still interested in a reply/more info.

From this thread, http://www.htguide.com/forum/showthr...ght=phase+plug

I also took a look at the Signature 800 manual and this is what it says:

"Fitting the midrange grille:
A grille is supplied in the accessory pack to
cover the midrange drive unit if desired.
Fitting the grille also requires the centre
bullet of the drive unit to be replaced by the
alternative version with a hole in the tip
from the accessory pack.To fit the
alternative centre bullet, simply unscrew the
fitted part and screw in the replacement,
taking care not to damage the voice coil
former. Hand tighten only."

And the Signature 800 white paper says:

"In addition to the reducing source effect described in
Appendix I, the dispersion of the drive unit is improved
by the use of a bullet-shaped plug protruding from
the centre pole of the magnet. To complement the
aesthetics of the system, an aluminium plug is fitted
on delivery, but the original plastic version of the
Nautilus™801 is supplied should it be required to
secure the optional midrange grille."

And the 700 series white paper says:

"Because of the lower excursion in a midrange
driver, distortion created in the motor system is
inherently lower than in bass or bass/midrange
drivers. Nevertheless, the centre pole has a layer
of copper and the aluminium centre bullet also
helps control variations in voice coil inductance.
The result is a driver with unparalleled levels of
detail retrieval."

and,

"The second stage came out of work to
investigate how and why the sound of drivers
was affected by the material used for fixed centre
phase plugs. It consists of adding a disc of
aluminium to the pole tip and the induced eddy
currents further affect changes in coil inductance.
The graph (figure 10) shows the line gradient
reduced virtually to flat and it is one of the rare
cases that one can actually claim that a type
of distortion has been truly eliminated, rather
than simply reduced.
It is the combination of copper cap and
aluminium disc that constitutes Balanced Drive
and it is new to the 700 Series. The reduction
in intermodulation distortion is a major factor
in the improvement in detail retrieval and realism
shown by the drive units compared to equivalent
older designs."

What does this all mean? That B&W initially thot that using aluminium for the phase plug was just aesthetic, but by the time they did R&D for the 700 series, they found that the material does matter? For those more technologically knowledgeable, could you comment on the last excerpt above from the 700 series paper?

AND

Case in point, not to pick on anyone - I am not going to argue that these phase plugs do or do not make a difference, but I can accept the fact that they may based upon what engineering tells us.

and I quote:

"The type of material the wire is coiled around greatly impacts the strength of the magnetic field flux (and therefore how much stored energy) generated for any given amount of current through the coil. Coil cores made of ferromagnetic materials (such as soft iron) will encourage stronger field fluxes to develop with a given field force than nonmagnetic substances such as aluminum or air.

The measure of an inductor's ability to store energy for a given amount of current flow is called inductance. Not surprisingly, inductance is also a measure of the intensity of opposition to changes in current (exactly how much self-induced voltage will be produced for a given rate of change of current). Inductance is symbolically denoted with a capital "L," and is measured in the unit of the Henry, abbreviated as "H." "

My point is simply this: a material does not need to be ferrous or magnetic to affect inductance. As an example, many aluminum rolling mill use eddy current flaw detectors to scan for surface defects.

One can imagine how a phase plug change to Al or Cu could alter the way the mid range driver reacts to the current pumped through the coil. Do I know that it does, absolutely not, I've done no testing - but it might. Since none of us here have the equipment to test these things, IMHO, letting our ears determine wether or not it does is far better than stating things as "fact" that we really don't know or understand -

KEF

And from here http://www.htguide.com/forum/showthr...t=10031&page=9

This might be of interest for owners of the current Nautilus range:
I send an e-mail to B&W speakers, England, and got the following answer:

Dear Sir,
I replaced the original plastic phaseplugs by the aluminium Signature 800
phaseplugs and noticed an improvement in the midrangeclarity of my Nautilus
802's. Recently I removed the ( grey )paint on the bottom of the phaseplug
with a piece of sandpaper, so that the alumunium material is in DIRECT
contact with the copper on the midrange magnetpole. The improvement is
immediately audible, even by a bigger margin than just by changing the
original phaseplug by the "untreated"aluminium one. I think, removing the
paint on the bottom makes a dramatic difference for the better: i.e. less
grain, less distortion. Now I am able to play even louder withoud any
strain. I am curious, what your findings are on this matter.
Kind regards,
Bram Hillen. ( Holland )


Dear Bram
Thank you for your comments.
Yes, we have also found that the aluminium plug sounds better and smoother
in the mid range, than the plastic one. The aluminium one also sounds better
than the brass and copper versions, that we have made ourselves, and also
some very expensive after sales items, marketted by other people. Why? well
that's another question altogether.... We have used some pretty
sophisticated measuring apparatus, including the "Klippel" distortion
analyser, but we have yet to show any measurable difference, between them.
Ask me in a few years time - we may have figured it out by then. For now
just trust your ears.

Best regards
Stephan Baker, B&W UK

[caleb]

Aluminium phase plug

Hi Simon,

You certainly have done your research on this one.

Early last year, I experimented with some aluminium phase plugs that my engineer made up for me exactly to the same shape as the plastic ones in my 802s.

The reason for this was that at the time B&W were not in the frame of mind to supply these as an aftermrket spare, and they were only fitted to the Signature range at this time.

I noticed a difference in the sound from the mid range driver - you will note that I DID NOT say better, smoother or any other description -just different.

However to my ears it made a worthwhile difference to the sound.

I therefore had some made for my other speakers - 805s and HTM1 and HTM2.

When I posted this on the forum, there were several members who asked me to make for them which I did and sold them at cost to me.

Everyone who took them posted a favourable reply as to the difference in sound that they made.

Now with the 800D series, thes espeakers come with the plastic plug for use with the mid range grille, and also with a metal phase plug for use without the grilles.

You can find on various web sites these phase plugs made from copper (from Japan and VERY expensive) and also aluminium - apparently they MUST NOT be made from ferrous metals.

So - do they work? ? ?

Do they "improve" the sound? ? ?

It is all down to your personal preference - what I can say is that the do make a difference to the sound in my experience

[RebelMan]

Since posting this thread I made up my mind (about two months ago) to run with the optional aluminum phase plug. I found that it does make a difference because I have no choice but to keep the accompaning grill cover removed and this is an audible improvement.