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Audio Circle Forum > Visaton b200 Phase Plugs from Planet10 Hifi

(FE207e) I finished installing them. It has helped the upper end distortion quite a bit. I'm enjoying these speakers all over again.

(FE103A) I did get over to ChrisB's to listen to his BHorns with the phasePlugged FE103As... they are good. Last Sunday we were complaining about a bit of chestiness in some male vocals -- today it was completely gone. Before there would be a wish sometimes for a bit more sheen in the top-end (and we'd hook up the super-tweeters), now i see no need. And i continue to be quite impressed with the quantity & quality of bottem end these little 4" drivers can generate in this horn.

Two major differences we got with the phase plugs were the virtual elimination of the last of the chestiness in male vocals (ductseal around the magnet/basket join cleans up most of it), and an extension of the HF range of the driver.

Chris Bobiak

(RS40-1354) Copied froma post by Jeremy Epstein in this thread on the Full Range Forum (with Jeremy's encouragement)

Well, I did install a pair this morning and David asked me to jot down a few comments. I hadn't realized I was the "first adopter" but I guess I'm used to that by now, let Mikey try it, he'll eat ANYTHING . . . .

1) I was unable to use the "loosen the glue with heat" method due to a lack of patience so I took an Exacto knife and cut out the dustcaps instead.

2) That's OK, I don't think I'd want to go backwards. There is a clear change for the better in terms of clarity/speed/smoothness, which initially I worried I had perhaps paid for with a loss of low end. However, after listening a bit more all day today, I don't think that was the case. I think it's a win all around. And this is not one of those "sit in the sweet spot and squint till you think you hear something" improvements - it just immediately sounds like a driver that you paid five times as much for. (Or more, I guess, these 40-1354's were so damn cheap!) The rattles on tambourines sound more clearly, percussion transients seem to have less grunge to them, vocal timbres seem clearer. It all just sounds more coherent and less congested.

Installation (including the two minutes lost trying to use the hot air to heat the glue) took less than 10 minutes, more like 5 really. The magnetic fixing mathod is a snap - literally - the only part the least bit tricky was first sucking any stray bits of paper out of the cavity which I did via the Lewinsky maneuver.

I'll report in after a few weeks of listening but I doubt very much I'll be having any second thoughts, there is a clear improvement with the phase plugs.

3) They look snazzy too.

4) Full disclosure: I paid full price cash for two pairs of the plugs and I have no affiliation with David except that I like him and he explains Mac computer stuff to me VERY SLOWLY so I understand it, for which I am eternally grateful.


(RS40-1197) I had thought about replacing my blue box 1197's, as I wasn't totally satisfied with the midrange, until I tried Dave's "Planet 10" phase plugs and puzzlecoat application (2 coats). For several months now I have been perfectly content with the sound I'm getting. It wasn't bad before, Dan Wiggins of Adire Audio has measured them and they spec'd out at plus/minus 2.5dB from 65 Hz to 15 kHz. I will say that to my ears they have been transformed from a great bargin speaker to a great speaker, period.

So to get to the point, if you must have Fostex drivers to replace your 1197's, please send your discards to me, I'll try to find a use for them.

Best Regards,

(FE207e) Wow Dave!
These phase plugs are a significant improvement over the Steve Deckert socket wrench mod. Much more even tempered from top to bottom. Whatever seemed 'wrong' with the original 207 driver has been eliminated, and are more involving even when you aren't sitting in the sweet spot. Maybe the mids are more detailed, who knows, but they are certainly worth the purchase price even if it seems like a lot of $$ when you first look at them.

Thanks again,
Bob Eckert

(FE206e) I received the phase plugs Monday evening and got them in after some very nervous cutting of the dust cap! I had hoped that I might hear some difference but was quite surprized to hear a much smoother sound through the high's and mid's! The harshness in the human voice range has smoothed out too. I cant believe fostex doesnt build the 206 with the phase plug already in it!


(FE166e) I didn't want to cut up the 166's as I thought fostex would have it right, and I'm a big advocate of the 'if it ain't broke, don't fix it' approach so it's taken me 'till tonight to pop the plugs in, following glowing reports.

Well I must say I can't believe the improvement. An aquaintance told me of his positive experience, so I thought it was about time I 'butchered' mine.

The treble is so much smoother for the mod, and the touch of sibilance the standard drivers exibit is gone. Considering fostex' published frequency response curve looks pretty good on paper, the difference on the ear with the plugs is remarkable. Makes me think the standard driver sounded a little mechanical in comparison.

Thanks Dave.
Bob Hayes
(Designer of the

(FE167e) Just wanted to add my tuppence worth on the subject. I installed a pair of Dave's phase plugs into my FE167Es at the beginning of last week, and I've been listening whenever I've had chance. I'll quickly stress that Dave had no idea that I was going to write this; honest opinion only guys, and I'm impressed with what I'm hearing.

First up, I'll say that installing the things was as easy as anything I've ever done in the practical side of DIY speakers. Took 30 minutes at the outside, and I was taking it carefully. Fruits of a youth misspent making model kits perhaps, but it has its benefits. Their build, fit and finish is lovely, and they do add a certain something to the appearence of the drivers when installed.

As for their subjective effect on sound; they've brought quite a few benefits to my ears. The 167 is inherently smooth as FR drivers go, but installing these things has brought some real gains to the upper and midranges. Things sound somewhat more precise, and smoother / cleaner too in the HF. A slight ring in the upper midrange has gone completely. If there's a downside, I haven't found it. And that's with the FE167E. I have more than a suspicion that they'll do all this and more for the 166, which is a much less forgiving unit with that rising response. Either way, if you've got these drivers, then you want to seriously consider getting a set of phase plugs for them. They work. Extremely well. Anone else out there running a set of drivers with them in? I'd be interested to see if our experiences match.

Scott Lindgren

(extracted from this diyAudio thread)

(FE108eSigma) Received the phase plugs yesterday. It took about 15 minutes to fit them after I'd steadied my nerves.

It is a nice little upgrade and well worth the initial terror at the thought of taking a scalpel to my cherished FE108E Sigmas.

The little bit of shout the drivers had has now gone The treble has smoothed out and there seems to be much more detail in the upper midband,

An already good driver has been turned into an outstanding transducer. Why Fostex don't fit these as standard is a mystery.

Steve Cresswell

(originator of the Metronome)

Bob Brines was sent a pair of FE167 Phase Plugs to try in his FT1600 -- his report

(FE167) Adam Walker on HiFi Wigwam