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haystacK
Registered User Joined: 12 March 2010 Location: California Status: Offline Points: 35 |
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Posted: 25 April 2019 at 5:58pm |
Greetings gents, this likely has been discussed but I don't remember a specific thread so apologies for redundancy. Would curved deflectors and throat have a noticeable/measurable difference and worth doing if cnc'd? This is from the Eminence wardrobe so the throat is 97mm I believe. A friend asked if it would be beneficial so I though I would make a post. Thanks for any inputs!
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odc04r
Old Croc Joined: 12 July 2006 Location: Sarfampton Status: Offline Points: 5482 |
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People have different opinions on the subject, it is very much a question of wavelengths involved and geometry of the folded horn part in question.
Given you are talking very large wavelengths relative to bend radius and length I would be inclined to say the extra pain of constructing smooth deflectors that do not resonate under the high internal pressures of a scoop design at high volume is not worth the trouble. I would personally go no farther than straight pieces of wood as corner deflectors at the top horn 180 degree bend because if nothing else they will add some bracing to the design. The re-design at the throat is almost certainly not worth the bother (in my opinion and based on nothing but my thinking!) |
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snowflake
Old Croc Joined: 29 December 2004 Location: Bristol Status: Offline Points: 3121 |
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two other advantages of curves are that they are very stiff compared to flat panels, and that they help avoid parallel surfaces that can cause standing waves. if you can work them into your desing then they help a bit. wasting internal volume is always bad for bass cabs though. If you are going to cut off corners to mount wheels or handles maybe, but otherwise use all the internal volume.
that desing is a bit of a 'classic' but nothing special. BTW your drawing seemst to have a negative expansion around the top right bend! |
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haystacK
Registered User Joined: 12 March 2010 Location: California Status: Offline Points: 35 |
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Ok, thank you for the replies. Layering a few small curved sheets under the throat could be a chore for sure. From reading older posts I understand the negative expansion in this particular cabinet works and I see that the actual distance between the back panel and the last expanding piece may be at maximum distance otherwise choking would be the result. I could make the back deflector smaller or course but yes it will still have negative expansion. Are there any other free plans out there other than Hogs and Supers that would give Wardrobes a run for their money with PD's? Now i'm really stirring up the pot here because i'm not caught up on recent posts on modded or free plans...
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studio45
Old Croc Joined: 16 October 2007 Location: United Kingdom Status: Offline Points: 3864 |
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My colleague and I built a triple folded, 10" driver tapped horn for his car in 2017 - he wanted to use curved reflectors on every bend, so we went ahead. It was a HUGE pain in the arse to make all the curved bits, however, on completion, the bin did sound *very* good indeed.
The distortion was very very low, much less than a ported sub. Also much less than my MTH30 bins with conventional square corners. Just a super smooth sound, one of those bins where you don't realise how loud it is until you see the windows flexing and set off the alarm of the car parked behind you....
Conceptually, the extra space in a corner constitutes a bulge in the horn path. So it is a bit like adding resonant chambers along the horn, between segments. This could probably be simulated accurately in AKABAK, but Hornresp doesn't really have a way of accounting for it. From my experience, there would be only a small difference in actual output, but the distortion graph would look quite different. |
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Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA
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