Well, bad news, Parts Express use UPS and in HK, UPS have decided to dump the package with a third/fourth party company called COE who never answer the phone and never update their tracking... and don't deliver! I've had this problem with COE before. I got one package after a multi-week delay, and one package never arrived. What a disappointment. :-( Someone else will have to test the Tang Band RBM THD claim. Crap. Very disappointed.
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Well,
I see you are located "Beyond Infinity" so don`t blame the parcel service.
Yes, but my neighbour Emporer Zurg gets his deliveries no problem at all. I really should switch to Buzz Lightyear shipping...
My package is now showing as "shipment damaged" so I guess I have to return it even if it arrives.
Been pondering the design - both cones are fitted to the same centre former, so the cone surfaces near that centre former will have a constant distance between them, which can only change as much the strength of the joints to the centre former allow, and that has to be minimised to avoid distortion. Thus the air nearest the centre former between the two cones has the potential to be isobaric. However, at the rubber surround, both cones are free to flex as much as the cone material allows, so the distance between the outer edges of the two cones will not have such a constant relationship and thus may experience (significant?) changes in pressure, which, I assume, is the need for the venting, and why the air nearest the centre former can't maintain constant pressure for the full isobaric benefits. So, my back of a beer mat hypothesis is that the quasi isobaric benefit of the double cone is inversely related to cone stiffness. I still think that the front cone will experience less stress because of the rear, and this is why distortion might be lower for this design.
And following from that, I'm really very curious about the venting of the air between the cones - the size and placement and shape of the holes might suggest the application of fluid dynamics to use the air pressure changes/flow through the holes as a form of damping to arrest cone flex, not dissimilar to oil being forced through an aperture to provide a vehicle with spring damping in its suspension struts. I think this is somewhat unlikely though, since this kind of flow is turbulent and turbulence could, if significant, generate noise.
I am struggling to accept that this driver is isobaric.
I thought isobaric was the addition of another driver in order to, effectively, double the motor force and reduce/halve the size of the box needed for a given application.
Here, it's still one driver with 1x the motor force - all they've really done is double the thickness of the cone and then add a surround (in reverse) to the rear cone, to cancel out any irregularities in the linearity of the surround (which is, I guess, similar to how a PPSL arrangement cancels out irregularities by using 1x 'normal' driver and 1x 'reversed' driver, except in this case there is only one driver).
I thought isobaric was the addition of another driver in order to, effectively, double the motor force and reduce/halve the size of the box needed for a given application.
Here, it's still one driver with 1x the motor force - all they've really done is double the thickness of the cone and then add a surround (in reverse) to the rear cone, to cancel out any irregularities in the linearity of the surround (which is, I guess, similar to how a PPSL arrangement cancels out irregularities by using 1x 'normal' driver and 1x 'reversed' driver, except in this case there is only one driver).
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What TB has done here is use a mirrored suspension system. Typically a suspension component will exhibit non uniformity in performance in opposing directions. This causes distortion. When the a pair are mirrored they should even each other out to some extent so that the nonlinearity is more identical in both directions. This is a trick that can be used with spiders as well with a mirrored pair. Typically you have a surround and a spider and these both may behave a bit differently. By ditching the spider and using a 2nd mirrored surround this removes that difference and makes the surround behavior more symmetric in both directions.
The other measures taken are a pair of shorting rings in the motor to linearize inductance variation.
The other measures taken are a pair of shorting rings in the motor to linearize inductance variation.
Quite an honour to see Josh Ricci validate my post #5. But Josh, what about my earlier comments on "isobaric"? I've been thinking about "isobaric" which goes way back to Olson, of sainted memory and has a few separate bits of theory that have to be kept apart conceptually.
IF T-B (or any future manufacturer) has a sealed space between the two "cones" with mirrored suspensions, then the lower VC cone is driving the other cone. The air force driving the upper cone is uniformly spread across the upper cone, even if it is not uniform on the lower VC cone*. That greatly reduces all kinds of cone flexing distortion that are impossible to eliminate in ordinary cones (except for the KEF B139, of course... which this new driver also resembles).
B.
*yup, my 1960 15-inch Stephens TruSonic had a 4-inch VC... a large VC is always a mark of quality
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Indeed - replace the spider with a second inverse cone and thus reduce distortion - in theory it should sound superior - it's most obvious drawback is lower efficiency but at least being one driver, it is less expense than a sealed inverse pair of drivers. But it seems no-one has actually run any tests so ... anyway, Happy Chinese Year of the Dog y'all ! It is the year of woofers here ;-)
They're virtually identical except for the mounting - the W4 is square and very deep, the W5 is somewhat octagonal and quite deep. The tech specs are identical except for BL, Le, QMS, and moving mass, but even these are very similar. Even though one is 4.5 and the other 5, they both have the same effective piston area. WinISD gives virtually identical results for them. Biggest difference seems to be price?
My mini delivery saga rolls on - I got an anonymous whatsapp with a picture of my package, like someone had kidnapped it. Didn't manage to find out who and didn't manage to arrange delivery, then no replies at all. A few hours later I get a call from "Jiaxong Express" confirming my name and asking me if I had an order from Amazon. The UPS delivery from Parts Express is the only outstanding one. The lady with a mainland China accent said she'd call back but hasn't. UPS can't get a reply from COE either.
And so Parts Express have kindly refunded me in full. All's well that ends well refunded?
A common topic of conversation here is how everything seems to be in decline as the city is becoming more integrated with China. Many people look at Taiwan's democracy and think, if only. I look at Taiwan and think, Tang Band W8 2022 on my next visit ;-)
My mini delivery saga rolls on - I got an anonymous whatsapp with a picture of my package, like someone had kidnapped it. Didn't manage to find out who and didn't manage to arrange delivery, then no replies at all. A few hours later I get a call from "Jiaxong Express" confirming my name and asking me if I had an order from Amazon. The UPS delivery from Parts Express is the only outstanding one. The lady with a mainland China accent said she'd call back but hasn't. UPS can't get a reply from COE either.
And so Parts Express have kindly refunded me in full. All's well that ends well refunded?
A common topic of conversation here is how everything seems to be in decline as the city is becoming more integrated with China. Many people look at Taiwan's democracy and think, if only. I look at Taiwan and think, Tang Band W8 2022 on my next visit ;-)
Glad that you got the refund at least. It always sucks yo lose a package in transit and feel like your money is up in the air somewhere. I live in the USA and shipped something to Australia that got lost... I finally got it back 6 months later! Definitely wasn't fun trying to track it down.
Sidenote: I'm building the W5 into a 2.08 Liter enclosure with 3x 3.5" passive radiators. Really surprising how small of a volume this sub needs to hit 40dB at the 3dB point. Looking forward to building with it. I hope Parts Express stocks up soon... Seems they only have 1 available right now.
Sidenote: I'm building the W5 into a 2.08 Liter enclosure with 3x 3.5" passive radiators. Really surprising how small of a volume this sub needs to hit 40dB at the 3dB point. Looking forward to building with it. I hope Parts Express stocks up soon... Seems they only have 1 available right now.
Thanks, but yeah, it is a bummer - I had it planned for 3.5 litres with a 5" PR - an 18cm cube with 18mm mdf. I even had the adjustable PR ready to go. I had made two PRs - one for this and the other for a sub using the W5 1038SMF ... thankfully I can simply go to Taiwan for a holiday and buy a driver there. Here's pics of the PR. Bought two cheap Sansui drivers and cut the magnets off. Then painted the cones and used epoxy putty to add a bolt so I can tune the PR by adding washers. Please post pics of the driver when you get it... and your build if you don't mind
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
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the video is in Spanish and the driver us not Tang Band. Is this relevant at all?
So I'm actually building a 360 degree speaker with the Tang Band W5-2053. The Tang Band is downfiring into a cone and then I'm going to have 3x PS95 Full Range drivers pointed in different directions.
I've modeled the crossover in Jeff Bagby's software for a 2 way speaker design and based it off of the Microfarad v2 build on Parts express. Thr speaker will be mono not stereo. My biggest issue is how to model 3 full range drivers in parallel with the woofer.
Should I duplicate the full range driver crossover two more times? Or try to chain these full range drivers together and modify the impedance of the parallel circuit to avoid increasing the number of components. That way it would be the woofer low pass and then a single high pass for 3 drivers rather than 3 separate but identical high pass circuits.
I don't know how to model this and ordered some crossover textbooks and a MiniDsp microphone. I realize adding full range drivers is considered a novice move due to phase shifts and suckouts.... these will be mounted ever 120 degrees (Hexagon arrangement, every other side). So suckouts and constructive interfetence shouldn't be an issue unless listening within less than two feet.
I've modeled the crossover in Jeff Bagby's software for a 2 way speaker design and based it off of the Microfarad v2 build on Parts express. Thr speaker will be mono not stereo. My biggest issue is how to model 3 full range drivers in parallel with the woofer.
Should I duplicate the full range driver crossover two more times? Or try to chain these full range drivers together and modify the impedance of the parallel circuit to avoid increasing the number of components. That way it would be the woofer low pass and then a single high pass for 3 drivers rather than 3 separate but identical high pass circuits.
I don't know how to model this and ordered some crossover textbooks and a MiniDsp microphone. I realize adding full range drivers is considered a novice move due to phase shifts and suckouts.... these will be mounted ever 120 degrees (Hexagon arrangement, every other side). So suckouts and constructive interfetence shouldn't be an issue unless listening within less than two feet.
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