Re: Re: Re: the brick
The only thing off with the 3" Bamboo is the vas. It's .01 liters too much so I would imagine that the dimensions of the cabinet would have to be changed. I love that little cabinet. Is there anyone that would be kind enough to model one with the W3-1364SA as the driver?
planet10 said:
The only thing off with the 3" Bamboo is the vas. It's .01 liters too much so I would imagine that the dimensions of the cabinet would have to be changed. I love that little cabinet. Is there anyone that would be kind enough to model one with the W3-1364SA as the driver?
can you give a link to the FE103 datasheet (I'm lazy...), this link is to another design...raypalmer said:
I'd say fs, qt, vas, BL... but rather compex, best is to run it throug my excel sheet to see if it gives similar dimensionskristleifur said:
planet10 said:
Scottmoose said:
It was my understanding that a ML-TL (mass loaded transmission line) used a TL form but a much smaller "open area" or an actual port, which is not the case with the Pensil which is a line with an equal open end. Everything about the Pensil points to the QWTL. I'm obviously missing something. Perhaps you could provide a link that would identify the distinction differently so I could understand why the Pensil is not applicable to MJK's tables.
HareBrained said:
An ML-TL is a TL with a restricted terminus. The Pensil line is 90 x 130, the terminus is 78 x 130. That is a restriction. Not as dramatic as on some, but it still counts.
dave
loninappleton said:
Well, I've searched "LKO-120WFF" and "299-280" and "Peerless India" but it looks like I'm going to have to ask Lon (or anyone else) to point me in the direction of other discussions of these drivers.
😕 Looking forward to improved search after the forum upgrade...
AdamThorne said:
Well, I've searched "LKO-120WFF" and "299-280" and "Peerless India" but it looks like I'm going to have to ask Lon (or anyone else) to point me in the direction of other discussions of these drivers.
😕 Looking forward to improved search after the forum upgrade...
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=299-280
Parts Express is in Ohio... no need to go to India as far as I know.
PE also has a forum for their stuff. If a more detailed data sheet is needed than the specs in the description, some leads may be gotten there. In their a-b-c measurement system, B is usually the size of the cutout needed.
More than that I don't know myself.
If the link doesn't work right, go to www.partsexpress.com
and put the number 299-280 in their search box.
Report back with anything else you need.
🙂
planet10 said:
Barely smaller, and no length to it. I'll defer to your knowledge but I don't see how it can have a difference at 1W.
One assumes (I haven't looked at the plans) that it's the thickness of the build material.
Makes no odds to the principle of it. A restriction is a restriction. Period.
Makes no odds to the principle of it. A restriction is a restriction. Period.
OK, I've just taken a quick look for the sake of interest.
The Pensil is certainly a resonant QW line, & not an especially distinguished one at that; looks like only the most rudimentary QW math has gone into it, and it may be regarded in the same vein as the rather similar Zigmahornet. I have dark suspicions about harmonic nulls. F3 will probably be acceptably suppressed by the driver location, but higher modes will likely be more problematic.
FWIW, length / Fp has clearly been set to Fs; for the rest, it looks like raw guesswork, although, Vp appears is roughly in the region of a 4th order (reflex) vented alignment; whether that is accident or design, I wouldn't like to say.
Edit: I've just stuffed it through MathCAD for the sake of providing a few illustrative graphs.
Top plot: driver & vent output of the unstuffed pipe; you can clearly see the confirmation that the first mode is set to the 70Hz pipe tuning. Middle plot: FR of the cabinet when damped ~equivalent to plans. As suspected, note the harmonic null. Lower plot: FR of the cabinet with the same damping, but with the slight mass loading removed. It doesn't make a whole lot of difference, other than fractionally reducing the depth of the null at F5. Still, mass loading as suggested is purely a matter of degree. If there is a restriction, however slight, it's still technically mass loaded. Can't beat the laws of physics.
The Pensil is certainly a resonant QW line, & not an especially distinguished one at that; looks like only the most rudimentary QW math has gone into it, and it may be regarded in the same vein as the rather similar Zigmahornet. I have dark suspicions about harmonic nulls. F3 will probably be acceptably suppressed by the driver location, but higher modes will likely be more problematic.
FWIW, length / Fp has clearly been set to Fs; for the rest, it looks like raw guesswork, although, Vp appears is roughly in the region of a 4th order (reflex) vented alignment; whether that is accident or design, I wouldn't like to say.
Edit: I've just stuffed it through MathCAD for the sake of providing a few illustrative graphs.
Top plot: driver & vent output of the unstuffed pipe; you can clearly see the confirmation that the first mode is set to the 70Hz pipe tuning. Middle plot: FR of the cabinet when damped ~equivalent to plans. As suspected, note the harmonic null. Lower plot: FR of the cabinet with the same damping, but with the slight mass loading removed. It doesn't make a whole lot of difference, other than fractionally reducing the depth of the null at F5. Still, mass loading as suggested is purely a matter of degree. If there is a restriction, however slight, it's still technically mass loaded. Can't beat the laws of physics.
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Thanks muchly henkjan. Results look promising
FWIW I looked at the pensil before I built BJohannssen's TABAQ's, there was some conjecture about holes in the response and it being generally a little under-thought, leading me to settle on the TABAQ. Which has worked quite well for me!
FWIW I looked at the pensil before I built BJohannssen's TABAQ's, there was some conjecture about holes in the response and it being generally a little under-thought, leading me to settle on the TABAQ. Which has worked quite well for me!
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