Doc Mods

Dedicated to those large boxes at one end of the room
B.B.C.
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#136 Re: Doc Mods

Post by B.B.C. »

I wondered about the tweeter. The metal domes don't appear to be highly regarded these days. Is the Linaeum tweeter for the Tandy sourced miniatures? Always been intrigued by those but new thougt of simply nicking the tweeters. Might be good for a super tweeter project?
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pre65
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#137 Re: Doc Mods

Post by pre65 »

Yes they were on a Tandy speaker of some sort.

Only hiccup is the low sensitivity, but there are ways round that.
The only thing necessary for the triumph of evil is for good men to do nothing.

Edmund Burke

G-Popz THE easy listening connoisseur. (Philip)
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Mudshark
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#138 Re: Doc Mods

Post by Mudshark »

pre65 wrote:
B.B.C. wrote:Out of interest, which MC2s are they? The earlier ones had a single port in the rear
Single rear port.

Main mod will be to replace the titanium dome tweeter with a Linaeum type mounted on top.
So yove hijacked Docs thread.
What is it Noddy Mods now, why not start yer own mod thread.
Smeege
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#139 Re: Doc Mods

Post by Smeege »

B.B.C. wrote:Whilst I accept and appreciate the value of the signal along with a bit of noise from Dr Bunsen, I can't say the same for Mudshark. There seems to be only noise. Have you anything to say about the Doc Mods Mudshark?
Don't worry about Mudshark Beeb because he really is a breath of fresh air and a top guy.

JR
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Mudshark
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#140 Re: Doc Mods

Post by Mudshark »

Aw gee Smeege........ :oops:

Shoosh, folk may talk. :lol:
Smeege
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#141 Re: Doc Mods

Post by Smeege »

Let em ! We've nuthin' to hide, well I haven't. Have you? Well other than that beautiful Italian pair you have hanging around.

God what I'd give to fondle that gorgeous profile of theirs :lol: :lol:

Go on post a piccie for us :D
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Dr Bunsen Honeydew
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#142 Re: Doc Mods

Post by Dr Bunsen Honeydew »

Mudshark wrote:
pre65 wrote:
B.B.C. wrote:Out of interest, which MC2s are they? The earlier ones had a single port in the rear
Single rear port.

Main mod will be to replace the titanium dome tweeter with a Linaeum type mounted on top.
So yove hijacked Docs thread.
What is it Noddy Mods now, why not start yer own mod thread.
Well i have asked him to fuck off four (or was it five) times, so apart from repeating it there is nothing more I can do, so I will let Mrs. Doyle do it for me

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DSJR
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#143 Re: Doc Mods

Post by DSJR »

pre65 wrote:
B.B.C. wrote:Out of interest, which MC2s are they? The earlier ones had a single port in the rear
Single rear port.

Main mod will be to replace the titanium dome tweeter with a Linaeum type mounted on top.
To hell with measurements just for a minute. The Visaton tweeter was new to me until a couple of years ago and I have to say it's a sweet toned thing once bedded in but never bland like other tweeters that found favour elsewhere and it does seem to do delicate brush strokes on cymbals as well as hard-rock crashes, with very little occurring as you move your head up and down, so in other words, there's little of a 'sweet spot' to worry about - I do appreciate that many tweeters wouldn't lend themselves to this method of drive, although many recent designs may be ok. I'd also suggest that any main driver with polypropylene cones may not be suitable for tautly sealed boxes as this material is so flexible* and may distort under sealed loading - possibly. The Kevlar cone donor drivers used in the Doc mods are tautly damped (by BBC standards) to start with, seem to be pretty well behaved in their natural state and easily cope with the extra doping added I think. The B&W 303 sized boxes I have here are incredibly well sealed, the cones needing a hefty push to move at all.

* Somewhere on the old Harbeth user group forum, the designer wanted to big-up his driver-cone material, especially compared to the polypropylene that was used before. He took an LS5/9 cone, which itself was carefully profiled and thicker at the neck for supposed added strength. This cone was so flexible in handling and easily crushed by a small brick placed on the neck (not quite the same as normal conditions for it as designed but the point was made). The new wonder-stuff they had researched and formulated for current use was perfectly strong, as I suspect a good paper formulation (or doped Kevlar) would be.
Daniel Quinn
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#144 Re: Doc Mods

Post by Daniel Quinn »

I have undertaken doc mods on 6 pairs of speakers since 2009, when I chanced upon Richard whilst surfing the net for information on how to build speakers as I had been trying to build a diy pair unsuccessfully for 6 months. I now use them in my hifi room , family room and kitchen .

An illustrative anecdote . In Dec 2012 , When I moved from a large flat to a house , the home made doc moddedd speakers I had were two large for my new listening room . I purchased a pair of wharfedale diamond 10's to get me over xmas from richer sounds . Now the owner of the other forum noddy frequents , had written how his wife had a pair of these peter j comeau designed speakers and how good they were .

o dear , when I plugged them in , they were whooly ,boomy , unmusical and the sound was shut in to the box , I watched tv that xmas .

These speakers were doc modded and I used them happily for 6 months .

the steel loading will give the sound more stability and solidity , it open up and delineate the sound and keep the bass as bass not boom. However for me the biggest revelation was the ditching of the crossover . I listen to exclusively 70's and 80's rock music [ that genre of music with no lyrics is for old people] and without the crossover , it sounds like music a band playing together , tight and rhythmic and the sound magically escapes the boxes and fills the room .

All my opinion of course Irene . :wink:
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Dr Bunsen Honeydew
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#145 Re: Doc Mods

Post by Dr Bunsen Honeydew »

I have yet to find a tweeter that doesn't musically benefit from a simple protection circuit, though some will need doping. I used and recommended the Visaton as it needed no work, but they are expensive. In the meantime I found a really cheap square wooden box that with steel lining made a workable Cube speaker, being small I called it the Cubette, but it was pretty daft to put two £50 tweeters in them. I had noticed a ridiculously cheap Chinese silk dome tweeter and found them pretty good, just not as good as I wanted. Now I had never tried doping tweeters as the concept didn't really make sense but following my usual mantra of "what if" I started work on them. I have them now to a stage I am happy to swop them with the Visaton. Tweeter doping is obviously a less gross and more delicate process, and I can now do it as I know what does what, so I am confident of listening to a tweeter and knowing what I have to do to it.

http://www.nva-hifi.co.uk/CUBETTE_HTML/
B.B.C.
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#146 Re: Doc Mods

Post by B.B.C. »

Daniel Quinn wrote:I have undertaken doc mods on 6 pairs of speakers since 2009, when I chanced upon Richard whilst surfing the net for information on how to build speakers as I had been trying to build a diy pair unsuccessfully for 6 months. I now use them in my hifi room , family room and kitchen .

An illustrative anecdote . In Dec 2012 , When I moved from a large flat to a house , the home made doc moddedd speakers I had were two large for my new listening room . I purchased a pair of wharfedale diamond 10's to get me over xmas from richer sounds . Now the owner of the other forum noddy frequents , had written how his wife had a pair of these peter j comeau designed speakers and how good they were .

o dear , when I plugged them in , they were whooly ,boomy , unmusical and the sound was shut in to the box , I watched tv that xmas .

These speakers were doc modded and I used them happily for 6 months .

the steel loading will give the sound more stability and solidity , it open up and delineate the sound and keep the bass as bass not boom. However for me the biggest revelation was the ditching of the crossover . I listen to exclusively 70's and 80's rock music [ that genre of music with no lyrics is for old people] and without the crossover , it sounds like music a band playing together , tight and rhythmic and the sound magically escapes the boxes and fills the room .

All my opinion of course Irene . :wink:
Good post (I think so anyway). Well expressed and an excellent signal to noise ratio :) I will dabble with some of the mods but the candidates are in storage until I get house renovation behind me. Hopefully some other members will have something to hand that they can attack more quickly.

My intended "nominees" are a pair of walnut Naim IBLs which it's a doddle to try the X/O mod with. Not so sure about doping given they have no dustcaps. I already took the foam out (but left a bit of long hair wool). Internals already have some steel plate.They are great with some music and just fail with other stuff, so not much to lose. They need to loosen up a bit, I feel. I keep them because I like the look of them and they take up little space.
Daniel Quinn
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#147 Re: Doc Mods

Post by Daniel Quinn »

Ta .

and
It is always a do and see situation as you do not known what the bass driver will do sans crossover , but I would hazard a guess the multi component pcb crossover is extracting the life from the music .
B.B.C.
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#148 Re: Doc Mods

Post by B.B.C. »

You're probably right, reading on PFM, the crossover isn't that great and even then it was simply lifted from the SBL and minimally tweaked. It's wired with NAC A5 which I don't like as a speaker cable so getting rid of this will be a bonus too. I've often thought (although I have no evidence to support me) that the big gains reported from going active might be partly down to getting shot of the crossover. The padding resistor and cap are easier and a lot cheaper than an active setup. Besides, Naim amps aren't really me.
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Dr Bunsen Honeydew
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#149 Re: Doc Mods

Post by Dr Bunsen Honeydew »

Active is a crossover, a series of filters built around unity gain op-amps working at line level. It has similar if not worse musical problems associated with it. It is a pro solution not a domestic solution.
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Paul Barker
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#150 Re: Doc Mods

Post by Paul Barker »

Dr Bunsen Honeydew wrote:Active is a crossover, a series of filters built around unity gain op-amps working at line level. It has similar if not worse musical problems associated with it. It is a pro solution not a domestic solution.
Absolutely, sold my Berrhinger active crossover premap long ago, no place in a subjective analogue home like mine.
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
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