I posted this over the lengthy Gravity Well thread also, but since some folks will come here for most of their OB information, I figured it worth including in this circle.

I have made the leap, and cut the dust caps off my b200's. 

Took me about 30 minutes total, once I gathered the courage to take a sharp blade to my drivers.

I have no measuring gear, and have no stock drivers to compare them to.  I have what must be at least 1000 hours on these drivers (been using them in OB for 2 years), and am unsure how many hours Dave put on them when he initially had them.

First and foremost, I would to thank Planet10 (Dave) for his excellent service.  Simple transation, easy to work with, and great packaging.  The instructions on his website are also quite useful, for those seeking to undertake their own surgery.

http://www.planet10-hifi.com/ - and the b200 specifically here - http://homepage.mac.com/tlinespeakers/FAL/B200-surgery/B200-surgery.html

It was not hard work, just hard to bring myself to start slicing.  Once I did, it went along OK.  It was challenging to remove enough of the glue ring to get the phase plug in place, and the cone moving freely around it, but some patience, and one sharp Xacto did the trick.

For me, I have really enjoyed these drivers, especially with either my JVC EX-A1, or my Magnavox EL84 amp – great synergy, and a strange ability to throw a centered image from way outside the sweet spot.  BUT, the treble absolutely beams, for me, in my room, with the stock driver.  When I stand up, the treble fades immediately, until I am double my usual listening distance, then it seems to gel again.

Truthfully, I have many times knelt down in the listening spot, in order to get my ears directly in line with the drivers, and found that the most entrancing, if not comfortable!, way to get the best out of the b200.  My best friend heard these with stock drivers, and immediately said – no treble.  He is 6’8, I am 5’8.  When he took the time to sit on the floor, and get his head closer to where mine normally is, it locked in much better for him.

The addition of the phase plugs does a couple of things.  First and foremost, the dispersion of the highs is significantly improved – less urges to kneel in front of my speakers now!  The air and dimensionality also seems to be improved.  The treble still falls off if I stand at the listening distance (7 feet), but the “sweet” spot is at least 3x the size – ie the shift in FR does not change 1 foot above my listening chair, it is when standing fully, that it is less coherent.

No regrets, this seems well worth the $65 or so, and if careful, you are unlikely to damage anything.

Recommended, IF you personally find that the treble beams for you.

Not sure if that really communciates what I am hearing, but I am happy to try and field questions, as we play along together.

Mark,

I would be interested in if you use the LR-correction circuit also with the Phase-plugged B200.
I understand you tested it favourably as posted in the MOX-thread.

/Erling

What Dave from Planet10 Hifi said is true about the phase plug. Once installed, the Visaton B200 doesn’t need a tweeter.

I have compared the  the stock B200 (with a 0,68 Alphacore inductor and a 6,8 Ohm resistor) with the B200 with the phase plug.  It’s a simple comparison: both driver played at the time. I just need to place my ear near each B200. It only took a minute, because the result is so obvious.

Without the phase plug, the B200 has a nasal sound and it ‘s beaming. With the phase plug, no beaming and with the improvement of the treble, I got a much much better clarity. It’s not a small improvement, but a really good one.

When both phase plug are in place, the sound is more lively and more enjoyable. The imaging and  sweespot are improve, more detail, air.  My Visaton sounds better than ever.

The phase plug cost me 66 cad, shipped from west cost Canada to the east cost. At first, the phase plug look expensive for 2 small pieces of wood, but with the improvement for the B200, the phase plug is worth more than the asking price. I’m very happy the result and I highly recommend it.

You don’t what you’re missing without a phase plug. Same thing can be said about adding a tweeter, but a adding a tweeter may not be easy as it seems because of crossover, cancellation, phase problem.

It’s hard to imagine how can 2 small pieces of wood can improve the treble, but it definely does and does it very well.

Two thumbs up for Dave.

Shogun;
Are you still using the bsc circuit with the phase plugs?

That makes me smile, 'cause I'm the one who came up with those values, (as far as I know).
Initial recommendations were 1 mH and 8-10 ohm. A little run through spice software showed that the .68 + 6.8 hang on to the low end of the b200 a little better.

I'll another conformation.  I'm had my phase plugs for a while, and I love them.  I was using a 1.5mh with a 5ohm notch filter.  I didn't like too much.  I finally bought the parts for the .68mh and I'm using 7 ohm.  I'm very pleased, but I have to increase baffle height now because mids too muddy.  Baffle 22" x 24" driver at 16" from floor tilted 8 deg.

Marc, could please you say a bit more about what you mean by

".68 + 6.8 hang on to the low end of the b200 a little better."?

I'm using 1mH/10 ohm. Though I might go DEQ and take out the bsc. I'll keep it to use on some rear B200's when I get the funds.

I'm also interested in trying a 2k crossover eventually. Got some Neo3 ribbons on their way(in addition to phase plugs) and will give them a good try at the back of the baffles before I try a crossover. I'll have to get someone to make it for me as I think it may be beyond my present skills, but if you discover anything relevant that may be of help please post here for those of us that follow bravely in your footsteps.

Today I pulled down thick wall hangings that I've had behind my speakers since before I even got them. Me like:) More life to low volume listening. And I dont notice focus and imaging to suffer. But its interesting that with complete toe in and inside wings swept back at 60 degrees that there is no point of first reflection on the reflective wall behind the speaker i.e the inside wings block any rear firing energy to everything but the left and right edges of the front wall. This might be significant in terms of 'sidedness' (a very interesting and new idea to me - see here for those unfamiliar: http://homepage.mac.com/tzagar/goodSound.html)

Other than those developments, I'm considering scaling down my 51x35" baffles. As is my B200 are flat to about 50hz(good by most accounts) but have a room induced peak of 7db at about 56hz. I want to try lower that peak. I'm running dual dipole subs so can compensate for any loss with the subs (the sub has its own equalizer)

Had 30 people over yesterday for the Queensland Audio Club meeting and I think Visaton is about to sell another few pairs.

cheers for now

Bevan

cool, thanks. i'll sleep better tonight

b.

The addition of the plugs makes me happy, no question there.

I owe MarkC at LEAST 2 visits, after standing him up!  Now that I have a minivan (please, I have 2 kids, I NEEDED one...) I might even be able to just bring my baffles with me, and we can play around with that too!

Will have to sort it out with the family etc, maybe a Friday evening later in May?

I will have to get some quality components, and install that filter, I did it briefly with the starter kit that MarkC lent me, but the mess of alligator clips, and dangling parts is TOO attractive to my kids, so I cannot leave it in there long term.  I am still in the process of redesigning my baffles, and will include a spot for that filter, for permanent install.  My 3-5wpc Maggie EL84 amp has plenty of power for me, even with the loss of efficiency with those filters.  I have been using 10db of preamp attenuation with the SB3 anyway, so when I put the filters in, I can change that to 0, and be right around where I am anyway.

The hard part for me remains getting my subs and mains integrated.  The b200 and Maggie amp LOVE being relieved of 80Hz and down, but I don't want to use the Xover in my sub amp - it does not sound too bad, but there must be better solutions out there...

I'm thinking of baby proof baffles

Small diameter BBQ grates attatched in front of the driver??
Isolated of course so they don't ring like a bell??
Whatcha think?

bob