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#1 |
diyAudio Member
Join Date: Aug 2002
Location: Eire
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Hi all,
I have had my current speakers up and running for a few years now. They are Bigger is Better cabs with some 8"x10" Alnico Isophon drivers and Alnico Isophon helper tweeter. I love the sound of them and am generally very happy with how they perform. Early on I Mass loaded the ports to tighten and tidy up the choppy bass. The thing is I listen to quite a bit of electronic music which has tight deep bass, and quite frankly the BIB goes deep, but not tight. Other than that I just love the sound of the Isophons. I have a pair of 10" Isophon woofer, which I was contemplating trying to mate with a nice pair of Foster FHT-5 tweeters, but last time I tried that with some big Tannoy's I failed. I really don't want the misery and expense of tunning a crossover from scratch. So I thought - why bother when I have some really nice full range speakers which do almost everything perfectly. So my idea is take the tuned Isophon combo of Fullrangers and helper tweeter and mount them into a aperiodic box. This will probably lead to a smooth drop off of bass from about 500hz down, but should let the Isophons breath adequately. So I have been messing about with the idea of some TL's for the Isophon woofers. My idea is to build a set of TL's with the Woofer firing vertically into an Aperiodic box. the box is vented on all four faces ie back,front and sides. the aperiodic vents will take care of rolling of the 7K response to meet the top Aperiodic box, and should be easily tuned via the aperiodic vent stuffing. The back transmission line can be tuned to take up where the vents leaves off. I have included a sketch to help you visualise the concept. So what would be the advantages of this approach; -the top aperiodic box would be easily tuned and optimised independently. -the aperiodic TL can be tuned independently, and the TL response can also be tuned independantly. -because the aperiodic TL is firing from all four faces in phase it should take care of baffle step losses. - there are no inductors in the system so phase shift and inductive loading of the amp should be less of an issue. As usual this is purely a thought experiment at this stage and so I may have missed some essential reason why this whole idea just won't work, but i would appreciate any input on this idea. Shoog |
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#2 | |
diyAudio Member
Join Date: Aug 2004
Location: Finland
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I know this is an old and long thread (yawn) but I got this mental association. The loudspeaker Esa Meriläinen built to demonstrate current-drive resembles a transmission line, although it is closed, so it does not breathe out of the box.
I refer to this page: Clean-current speaker project | Current-Drive - The Natural Way of Loudspeaker Operation That is one way to save some space and achieve good damping without expensive stuffing (such as angel hair, steel wool, etc.) I also refer to another writer, and I add a quote here: Quote:
I quoted the most interesting paragraph. Mr. Meriläinen used a speaker driver Scanspeak 15W/8434G00 with Qts = 0.25. There are many real full range speaker drivers with sufficiently low Qts, such as: Dynavox LY401F Qts = 0.26 Markaudio Alpair 12P Qts = 0.29 Markaudio Alpair 10P g1 Qts = 0.33 Tang Band W5-2143 Qts = 0.38 These all look like fine candidates.
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High-order harmonics are more offensive than low. — D.E.L. Shorter: "The Influence of High-Order Products in Non-Linear Distortion". Electronic Engineering, April 1950. |
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#3 |
diyAudio Member
Join Date: Aug 2004
Location: Finland
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On the other hand: The aperiodic enclosure could be constructed traditional way, with a small enclosure and an aperiodic vent on the back. Besides being aperiodic speaker that could also save space, and produce a subcardioid sound radiation pattern, which may be better than a conventional omnidirectional.
I was thinking about something resembling Gradient 1.4 but such way that it would be a woofer assisted wideband, completely aperiodic design. Gradient 1.4 is a three way speaker with a coaxial tweeter + midrange in a resistance enclosure, and the woofer is in a bass reflex enclosure.
__________________
High-order harmonics are more offensive than low. — D.E.L. Shorter: "The Influence of High-Order Products in Non-Linear Distortion". Electronic Engineering, April 1950. |
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#4 |
diyAudio Member
Join Date: Aug 2002
Location: Eire
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This is the way I add woofers to my OB fullrange driver projects. Done it twice now, one with Isophon bass drivers with rear firing leaky vented small enclosure and another with a larger cab and again rear firing.
They integrate very well and extend well. Shoog Last edited by Shoog; 25th November 2020 at 02:31 PM. |
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#5 |
diyAudio Member
Join Date: Mar 2005
Location: UK
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It is a transmission line. Sealed 1/2 wave line. Most famously employed by B&W with their Nautillus, but there are many, many other examples.
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www.wodendesign.com (commercial site) www.frugal-horn.com www.frugal-phile.com (community sites) |
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#6 |
frugal-phile(tm)
diyAudio Moderator
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Stay safe. Stay home. Respect the 2m bubble. |
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#7 |
diyAudio Member
Join Date: Jun 2003
Location: Chamblee, Ga.
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Let's not forget arguably the most 'famous' of all, the plane wave tube [PWT] used to test various [multiple] devices
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Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents. |
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#8 |
diyAudio Member
Join Date: Mar 2005
Location: UK
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That too.
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www.wodendesign.com (commercial site) www.frugal-horn.com www.frugal-phile.com (community sites) |
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#9 |
diyAudio Member
Join Date: Jul 2007
Location: Frederiksberg
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#10 |
diyAudio Member
Join Date: Jun 2003
Location: Chamblee, Ga.
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It's the late great real Altec Lansing's multiple entry PWT for testing [16] horn drivers at once.
GM
__________________
Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents. |
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Thread | Thread Starter | Forum | Replies | Last Post |
Aperiodic enclosures | Geoff H | Multi-Way | 142 | 6th January 2021 06:36 PM |
How should we model aperiodic boxes | otto88 | Multi-Way | 67 | 5th December 2020 12:02 AM |
BR/Aperiodic hybrid? can this be done? | Hezz | Multi-Way | 2 | 13th June 2007 04:57 AM |
Aperiodic boxes for Ciare CH250 | foniton | Full Range | 21 | 28th September 2006 08:17 PM |
Dual aperiodic box idea | Dave Jones | Multi-Way | 12 | 21st April 2005 04:48 PM |
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