I'll be honest, I'm struggling to see the differences in these designs! It's it just a box with a hole in it?
Pensil 10.3 = 1092x241x356 = 93.69 Litres
Mark Audio Alpair 10.3 = 1054x190x228 = 45.66 Litres
TABAC Large for 10.3 = 1381x188x226 = 58.68 Litres
So it seems that the Pensil is almost twice the size as the other 2. Why is that?
TylerDurden,
When calculating cabinet volume, you should take the internal dimensions. If you choose thicker material (say 25mm instead of 19mm) then if you keep external dimensions the same, you'll end up with a smaller cab.
Why these cabinets have difference in volume, dimensions, and port size? Without getting too technical (and lot of the stuff is still beyond my understanding) let me try and answer... though all are MLTL variants, the designers have chosen slightly different alignments and tuning goals based on their preferences.
When calculating cabinet volume, you should take the internal dimensions. If you choose thicker material (say 25mm instead of 19mm) then if you keep external dimensions the same, you'll end up with a smaller cab.
Why these cabinets have difference in volume, dimensions, and port size? Without getting too technical (and lot of the stuff is still beyond my understanding) let me try and answer... though all are MLTL variants, the designers have chosen slightly different alignments and tuning goals based on their preferences.
Ok. Do you know which design will give me the best bass extension? Is it the biggest?
Ahhh... now you really put me on the spot... But hey, I didn't build any of those 4 listed...
"Best" will depend on many things and very importantly, on your own preferences regarding "good bass". Also for bass, the room tends to dominate - some rooms add extra gain, where even a "thin" speaker will sound balanced, but a neutral speaker might sound bass heavy... the opposite can also happen!
Am I confusing you yet?
And fear not, this is DIY and many a time time you can tweak things to your liking.
Well, from eyeballing the modeled frequency response graphs and reading some of the commentary, the Jim Griffin design has the lowest F3 point, while all have a very similar F10 (low 30s). So I am expecting in room bass extension to be quite similar, but only guessing. I do not have the modeled frequency response for the Pensil 10.3, but IIRC Scott Lindgren designed the Pensils for stronger mid-bass performance and not the lowest F3 point. Again Dr. Lindgren will be the right person to confirm this, as it is his design. Apologies in advance to the designers if I have misquoted anything above.
If you want to know more about the actual experiences of folks who have built these designs, do a forum search or Google search. In conclusion, the designs being discussed are all from respected designers, and there are satisfied builders within the diyA community.
Best of luck!
Are his
The external or internal measurements?
Jim Griffin said:overall box size (with 0.75" thick material) is 41.5"H x 7.5"W x 9.0"D.
The external or internal measurements?
Are his
The external or internal measurements?
Those are external measurements assuming 3/4" material.
Also please go through the follow up posts on that thread where there's a suggestion on building the cabinet 7.5" wide and 6" deep.
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Think I've found my port material - FloPlast Downpipe 68mm x 2.5m Black | Half Round Guttering | Screwfix.com
I'll be honest, I'm struggling to see the differences in these designs! It's it just a box with a hole in it?
Even for sealed enclosures it's not quite that simple - and definitely not the case for vented alignments. At the very least, I'd suggest you read and attempt to fully digest the content at Martin King's site to understand that the shape of a box and location of drivers and vents / ports can be significant.
Quarter Wavelength Loudspeaker Design
Several of the enclosures on the list used the methodology if not the actual MathCad worksheets during the development. As to why the differences, the performance goals & compromises targeted by the designer are a big part of that calculus.
edit: as for "best" - please define that term
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Thanks for the link. I'll give it some attention when I can.
"Best bass" for would be a good clean fast response down as low as possible. This is the reason my sub is a sealed unit, I consider this key in the speed of response.
I'm realistic enough to realise I'm not going to achieve bery low bass with a 6" driver.
"Best bass" for would be a good clean fast response down as low as possible. This is the reason my sub is a sealed unit, I consider this key in the speed of response.
I'm realistic enough to realise I'm not going to achieve bery low bass with a 6" driver.
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