Minimal displacement for the system is ”0.1 mil (2.5 µm) at 3.3 ft (1m) with 50mm lens at max brightness”
Error in measured Geometry for the Klippel “SCANNING VIBROMETER SYSTEM (SCN)” is 5 µm. Sure, klippel are not used for measuring cabinets. So it is comparing apples with oranges.
But the iris m system would be a great tool for the advertising department, film the cone moving 1mm and turn up the amplification x50
Error in measured Geometry for the Klippel “SCANNING VIBROMETER SYSTEM (SCN)” is 5 µm. Sure, klippel are not used for measuring cabinets. So it is comparing apples with oranges.
But the iris m system would be a great tool for the advertising department, film the cone moving 1mm and turn up the amplification x50
It would seem to mean that you need to do some homework if it was not to have been a waste of time.
That's up to you.
That would seem to be one for a marketing department selling to non-technical enthusiasts.
It depends on your goal. For those interested in a high technical sound quality then the objective is to reduce the sound radiation below the level it is audible because it distorts the sound radiated by the drivers. Others may be less interested in sound quality and more interested in distinguishing their designs from their competitors, cheaper cabinets, including audible cabinet resonances as sound effects, etc...
Well, since you took the time to slam me, ouch..
Let me just say there is no subjective or objective proof (that I know of) that positively relates cabinet resonances to the overall musicality or accuracy of loudspeakers. There are highly regarded loudspeakers made of esoteric and expensive materials and some made of MDF. That is not to say cabinet resonances are unimportant and if they are bad enough to show up on a impedance plot they should definitely be addressed. My point is, using generally accepted practices it is not difficult to make a really good if not excellent cabinet.
Figure 12 in this Classic BBC report show the audibility of cabinet resonance: http://downloads.bbc.co.uk/rd/pubs/reports/1977-03.pdf
So there is the goal, get below the thresholds and your done.. cabinet is not a part of the production of noticeable sound anymore.
If one is not trying to sell speakers to the masses then why not go overkill.
It more fun that way.
So there is the goal, get below the thresholds and your done.. cabinet is not a part of the production of noticeable sound anymore.
If one is not trying to sell speakers to the masses then why not go overkill.
It more fun that way.
What is generally accepted by many, possibly most, DIYers is incorrect. Thick walls, lots of bracing, etc... does not make an excellent cabinet. The physics of mechanical vibration and sound radiation is understood by engineers in the larger mainstream speaker companies and so for them it is a straightforward engineering task as you claim. However, they will still have to work with input from the sales and design side and this will shift things away from form follows function.
I've been knocking on cabs for 60 years. Love doing it. And clapping my hands sharply in concert halls. I think I've learned a lot more from the latter.
I built my 17-foot labyrinth from quarter-inch plywood and some design smarts. Yes, some walls are "dancing" along with the music but I don't think it is audible.
And I don't recall seeing evidence of box vibration detection from users in their chair. Anybody have data? Beyond acceptable practice, as Speaker Dude puts it, not sure box needs to be made of steel, not even sealed boxes which are the only ones where it would matter much anyway.
B.
I built my 17-foot labyrinth from quarter-inch plywood and some design smarts. Yes, some walls are "dancing" along with the music but I don't think it is audible.
And I don't recall seeing evidence of box vibration detection from users in their chair. Anybody have data? Beyond acceptable practice, as Speaker Dude puts it, not sure box needs to be made of steel, not even sealed boxes which are the only ones where it would matter much anyway.
B.
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The pics are gone...I know generally what you mean, but what part exactly did you buy?
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