Search found 5519 matches

by karatestu
Fri Jun 25, 2021 7:11 pm
Forum: DIY
Topic: Doc modding Marantz imperial 7
Replies: 1932
Views: 405341
Great Britain

Re: Doc modding Marantz imperial 7

Some quote I found about diffraction, imaging blah blah "Imo the Precedence Effect explains many observations made about correlations between imaging precision and baffle width, in particular those posted by @shadorne on the previous page. The Precedence Effect kicks in at about .68 millisecond...
by karatestu
Fri Jun 25, 2021 7:03 pm
Forum: DIY
Topic: Doc modding Marantz imperial 7
Replies: 1932
Views: 405341
Great Britain

Re: Doc modding Marantz imperial 7

I'm not sure the internal profile would be all that important: it's the reflections on the outside you're worried about right? Just think how gnarly the insides of a Doc-Modded speaker are after random plates of steel have been slapped all over the place! The inside isn't as important as the outsid...
by karatestu
Fri Jun 25, 2021 11:24 am
Forum: DIY
Topic: Doc modding Marantz imperial 7
Replies: 1932
Views: 405341
Great Britain

Re: Doc modding Marantz imperial 7

Firebug1 wrote: Fri Jun 25, 2021 11:20 am Stu, you could use chain saw to hollow out the centre😄
Ha Ha. :lol: Not sure about the precision :grin:
by karatestu
Fri Jun 25, 2021 11:09 am
Forum: DIY
Topic: Doc modding Marantz imperial 7
Replies: 1932
Views: 405341
Great Britain

Re: Doc modding Marantz imperial 7

How to make an accurate wooden sphere with a router. No need to buy a wood lathe. https://i.imgur.com/ix1bhuX.jpg Yes, but, the inside won't be spherical and you thus retain some of the apparent complexities of flat internal surfaces. You found the flaw in this Geoff but being an engineer you were ...
by karatestu
Fri Jun 25, 2021 9:09 am
Forum: DIY
Topic: Doc modding Marantz imperial 7
Replies: 1932
Views: 405341
Great Britain

Re: Doc modding Marantz imperial 7

How to make an accurate wooden sphere with a router. No need to buy a wood lathe.

Image
by karatestu
Thu Jun 24, 2021 6:46 pm
Forum: Admin-Intro-Chitchat
Topic: The joy of surveys
Replies: 9
Views: 1319
Great Britain

Re: The joy of surveys

I could maybe stretch to a Technics SL-1000R
by karatestu
Thu Jun 24, 2021 5:10 pm
Forum: DIY
Topic: Doc modding Marantz imperial 7
Replies: 1932
Views: 405341
Great Britain

Re: Doc modding Marantz imperial 7

I am now reconsidering the hemispheres as they can be done in black and two joined together. Cost is the same. It is just the join that bothers me but these acrylic weld "glues" melt the two surfaces together which is a different prospect altogether to using glue. The websites states they ...
by karatestu
Thu Jun 24, 2021 4:56 pm
Forum: DIY
Topic: Doc modding Marantz imperial 7
Replies: 1932
Views: 405341
Great Britain

Re: Doc modding Marantz imperial 7

Well, partly to get you to ask but mainly because, if you paint the spheres you won't know what they sound like unpainted. If you build them unpainted and then use them you can decide later whether painting them is/might be a good idea. Painting will make a difference but why not find out what the ...
by karatestu
Thu Jun 24, 2021 4:54 pm
Forum: DIY
Topic: Doc modding Marantz imperial 7
Replies: 1932
Views: 405341
Great Britain

Re: Doc modding Marantz imperial 7

Been thinking about the mechanical coupling of the two opposing mid bass to get the most effective force cancellation. What ever links them needs to be as rigid as possible so I might use some of the extensive stock of round brass bar. There needs to be no dampening between each driver magnet and th...
by karatestu
Thu Jun 24, 2021 4:29 pm
Forum: DIY
Topic: Doc modding Marantz imperial 7
Replies: 1932
Views: 405341
Great Britain

Re: Doc modding Marantz imperial 7

At this rate I will be spraying both mid bass and tweeter spheres in plastidip primer and then a colour topcoat. It doesn't have to be black :naughty: I fancy Black Cherry colour https://www.plastidip.co.uk/colour-swatches/ There are some special top coats as well that can make it glossy, satin, met...