I think you can use the effective Radius to calculate sd (pi*R^2).
The effective radius is reported in the datasheet to be 42mm.
Hope I'm right, never modelled a speaker!!
Ciao
Pi (4.2^2) = 55.417cm^2
That TL calculator is rubbish by the way. Avoid. Sd has no direct correlation to the optimal cross sectional area of a TL, nor have they accounted for the effects of the taper on the resonant frequency of the pipe. The claim that there is no T/S based design methodology for transmission lines is not true. George Augspurger and Martin King have both done just that, and many variations by others also exist.
That TL calculator is rubbish by the way. Avoid. Sd has no direct correlation to the optimal cross sectional area of a TL, nor have they accounted for the effects of the taper on the resonant frequency of the pipe. The claim that there is no T/S based design methodology for transmission lines is not true. George Augspurger and Martin King have both done just that, and many variations by others also exist.
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No. That is the resonant frequency of an untapered pipe of x length. It does not work for a tapered pipe, which is one of the many reasons why most of these on-line calculators are complete rubbish and should be ignored. The resonant frequency of a quarter-wave pipe is a function of both axial length & its taper, plus the relevant end correction (which the above hasn't accounted for either).
The necessary line cross section is derived from the volume the pipe requires for the desired alignment. I suggest you have a look here:
http://www.quarter-wave.com/TLs/Alignment_Tables.pdf
This is a spreadsheet derived from the alignment tables:http://www.quarter-wave.com/TLs/Alignment_Tables_Calculator_3_3_09.xls
Note that they assume you are tuning to Fs however, which is not necessarily going to give the results you want -basically, it depends what you're trying to do.
The necessary line cross section is derived from the volume the pipe requires for the desired alignment. I suggest you have a look here:
http://www.quarter-wave.com/TLs/Alignment_Tables.pdf
This is a spreadsheet derived from the alignment tables:http://www.quarter-wave.com/TLs/Alignment_Tables_Calculator_3_3_09.xls
Note that they assume you are tuning to Fs however, which is not necessarily going to give the results you want -basically, it depends what you're trying to do.
Is there a problem with doing these with a straight sided non folded transmission line?
Does one like that pile up the cabinets resonant frequency into the one note thump scenario?
There isnothing inherently wrong with an unteapered line. The classic TL design method, as used at the afore mentioned site, itnext to useless for designing a TL.
For reference only, here is a good treatise on Classic TL Design: Classic TL Design -- Jon Risch
dave
Thanks. Always looking for good links. Only luck my guesstimate for my first try turned out okay
just ran the cab to quarterwave length of f3 , internal volume 62% of vas. Now I can read up on some proper methods.
You're right Scott, the first one has neodimium magnet, the latter ferrite magnets, but they are almost the same driver.
As none answered you, I'll post my thoughts (even if I never design speakers!).
As stated in the white paper of Solo103, the box is "tuned by ear", so is highly customize for that Fostex driver (fe103).
I don't think you can use the same project for such different driver, I think it's better to design your own box from scratch.
Try some simulation tools on the net, and then tune it by your ear.
I think it's the only way to go.
Ciao!
Ciao ttan98,
after all these years I'm about to try your filter, but it seems (from the online spreadsheet) that your filter is set to give a -18db attenuation @15000Hz, is it corect?
Don't you think 27ohm is abit high? Did you mean 2.7ohm?
Thank you for your help!
Neo magnet version seems better according to freq. response graph provided by the seller.
Ferrite magnet version, in fact, seems a bit weak in bass region.
But I never heard them side to side.
PS: I spotted also a new Alnico version with a really big magnet!
Hello, I have the neodymium one, instead a friend of mine has the ferrite one: it seems that the latter is more smoother on high freqs, with a better neutral balance... In both cases, i think that it has great value for the money! Especially in a little (6-9litres) reflex box they sound bigger for the size and better than expected from the price!
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