Search found 12 matches

by Helen Bach
Thu Nov 09, 2017 12:43 am
Forum: General Audio
Topic: JPW Sonatas
Replies: 45
Views: 14031

Re: JPW Sonatas

You came here on a lie and to spam the forum, that is enough of an insult and rudeness. The good thing about forums is the train of posts creating a history, so what I say is as plain as the nose on your face. You will get no respect from people you lie to and troll, it is that simple. The other cl...
by Helen Bach
Thu Nov 09, 2017 12:36 am
Forum: General Audio
Topic: JPW Sonatas
Replies: 45
Views: 14031

Re: JPW Sonatas

The paper referenced by Hell And Back is not hugely helpful in this context. Post 17 from Bob Brines in this thread http://www.diyaudio.com/forums/full-range/197129-metal-speaker-enclosures-bad-idea.html is, I suspect a little more relevant. well, not so. He talks of 'bell modes' which I don't thin...
by Helen Bach
Wed Nov 08, 2017 11:41 pm
Forum: General Audio
Topic: JPW Sonatas
Replies: 45
Views: 14031

Re: JPW Sonatas

I'm not the rude one here. I came here looking for some info on JPW Sonatas, as vectored by Google. No-one sent me. I don't work for any company, but a few have used my help. I see now that this is not the forum I should be on, where there are no discussions making any sense, and where one is insult...
by Helen Bach
Wed Nov 08, 2017 11:27 pm
Forum: General Audio
Topic: JPW Sonatas
Replies: 45
Views: 14031

Re: JPW Sonatas

These little chaps http://www.hifiandmusicsource.com/2017/10/jern-14-es-speaker-review/ are interesting. The statement in the review that "The cast iron material is apparently over 50 times better at reducing cabinet vibration than conventional wood" is useful. So I would expect a steel l...
by Helen Bach
Wed Nov 08, 2017 5:39 pm
Forum: General Audio
Topic: JPW Sonatas
Replies: 45
Views: 14031

Re: JPW Sonatas

the damping factor of steel is just less than the square root of sod all. If you stick it on to 'speaker walls, all you do is increase mass and bending stiffness. There will be some damping (as you have made a new material, eg mdf/steel), so sound inside the cabinet will increase until some kind of ...
by Helen Bach
Wed Nov 08, 2017 5:09 pm
Forum: General Audio
Topic: JPW Sonatas
Replies: 45
Views: 14031

Re: JPW Sonatas

no-one sent me here, I came to it by Googling 'Sonata'. I do believe that science/technology will help in suggesting a way forward. It has always served me well. Science would suggest that taking wadding out of a box would make it sound more lively, more muddled and need a little less power. That it...
by Helen Bach
Wed Nov 08, 2017 4:39 pm
Forum: General Audio
Topic: JPW Sonatas
Replies: 45
Views: 14031

Re: JPW Sonatas

ah, that old 'mass damping' thing! Well, science will tell you that mass doesn't damp, it just attenuates amplitude, thus not dissipating energy. The big problem, or one of them, is getting rid of the unwanted energy, quickly, which is where damping comes in, not mass! So called 'mass dampers' are u...
by Helen Bach
Wed Nov 08, 2017 4:11 pm
Forum: General Audio
Topic: JPW Sonatas
Replies: 45
Views: 14031

Re: JPW Sonatas

thanks for the offer, Paul, but I like the Sonatas, but I think I need to do some remedial damping on those boxes. Acrylic seems to work very well. Shame you are running away, Richard, I thought you might be able to throw some light on the reasons why you have chosen to incorporate certain aspects i...
by Helen Bach
Wed Nov 08, 2017 3:52 pm
Forum: General Audio
Topic: JPW Sonatas
Replies: 45
Views: 14031

Re: JPW Sonatas

yes it is! Bending stiffness is proportional to Young's Modulus and the second moment of inertia, resonance frequencies are related to bending stiffness and (surface) mass. So when you add steel (of considerable mass compared to the box wood) then the resonance frequencies will go up. Basic physics,...
by Helen Bach
Wed Nov 08, 2017 3:40 pm
Forum: General Audio
Topic: JPW Sonatas
Replies: 45
Views: 14031

Re: JPW Sonatas

not making presumptions, it's basic physics, Doc.