Using WINisd and VituixCAD, I've come up with a reliable enclosure size for a woofer box I am building. This speaker project I have is fairly aesthetically driven, however, and I would like the enclosure to be a little bit larger than the results I am getting. Is it possible to suspend the enclosure in an outside enclosure (therefore having the appearance of it being bigger?), or can I dampen the box with a certain material to bring the inner volume back down to my tuned level? Thanks in advance for the help...
The easiest thing would be make the box the OD you want, and make the inner volume whatever you need with a false bottom or partition, etc… It’s been done many times.
A friend's speakers are in my room. He built them a box inside a box with sand between. Very heavy. Very clean sound. I don't know how they are joined together so vibration isn't transmitted from the inner to outer box but whatever he did is very effective. Maybe the sand is so effective the through connectors (and ports) don't matter? I can imagine gluing rubber blocks between to hold everything in place until the sand was put in. Corks on sides , back and bottom plug the holes used to fill. A lot of work for a first build though.
Good to know. If there was some sort of mechanical or glue means of joining them, that would certainly be best...but sand seems like a great option too. Not worried about it being a "first build", as I'm a cabinet maker who has made many many many boxes. Just none with sound emitting from them!
FYI/FWIW: A well received sand filled box design in French, but sufficient info to build one: https://onken.info/caisson-w-sable/
Thanks for the additional links. It seems as if the drivers I have aren't very well geared to do a true Onken...so I'm going back to my original idea of a bass reflex inside a larger enclosure. Beside filling these large cavities (5.25" x 14.75") with sand, is there another dampening material I could use that would limit the wall vibration?
Just curious, Does the enclosure need to be rectangular ? You could go trapezoidal for wide front narrow back. Or faceted like posted pic. If the facets are of different widths and thick enough it makes a nice stiff cabinet.
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I’ve built enclosures using two diameters of Sonotube concrete former tubes. One two inches larger in diameter than the other. One inside the other with sand between the two. It makes an incredibly inert cabinet. They make a bunch of different diameters so it’s easy to get what you need. I made the end caps out of mdf with routed grooves for the tubes. That holds them in the right place. Put the input wires in before you fill the gap with sand.
I’ve also done periscope shaped cabinets out of schedule 80 pvc pipe. It is as dead as it gets too.
I’ve also done periscope shaped cabinets out of schedule 80 pvc pipe. It is as dead as it gets too.
Getting back to 'square one'; Onkens are nothing special other than having lots of vents, cool look (for some), so what's the driver, specs? Desired outside dims (i.d.)? Curious what I can come up with in HR.
I suppose "need" would a strong term, but the way I've imagined it this whole time is as a rectangle. Though it makes sense that a different shape like that would result in more stiffness!
I already bought the drivers, so I'm a bit strapped. This is my first project, and it took me a long enough time to pull the trigger on a set of woofers, so I more or less have what I have. I know a lot better for next time! Though again, I'm still motivated by a certain look, so while I would love to make smaller or use different drivers (as I agree with you on material efficiency), I am where I am!
This is an any interesting suggestion! Thank you!
Oh wow, I didn't even think of hornresp being useful in this circumstance. granted, I have a lot of trouble understanding it to begin with. Anyways! I am using a 12PR310 woofer from FaitalPRO. I will have an HF10AK on top of the enclosure, mounted to a H808 horn I am in the process of manufacturing. I would be very interested to see what you come up with. I had to get that "n" number super high, which I kind of figured meant that it wouldn't sound very good? Again, wasn't quite sure of the consequences of altering certain parameters...For this project, I am trying to stay within the realm of known-ish outcomes to give myself the best chance of something usable and successful, though I know that also is an moving target in some ways, especially with a first project. But anyways, thanks for giving this a look!
You're welcome!
The Onken 'n' (Vb = (Vas*Qts'^2)) is from some folks in the early days of T/S apparently taking some of the pioneer's published, well proven DIY rules-of-thumb (ROT) cab design and 'constructing' a more complex (then new) T/S set of alignments to describe them as a way to ~ guarantee an excellent performing speaker based on the popular Jensen Ultraflex designs.
But these were based on using (relatively) low power, ~matching impedance (DF = 1) amps and/or higher ones, but still low DF with variable damping bass/treble tone controls whereas nowadays there's virtually no output impedance in comparison plus generally lower compliance (Vas) since modern speaker efficiency doesn't need to be as high due to (much) higher power handling capability.
In short, we're going to ignore 'n' and let it be whatever it turns out to be and for those folks that use it can always make their own 'n' chart collection based on theirs and others' proven alignments, though TTBOMK no one has ever posted one, so for now there's just the original two.
[Qts']: [Qts] + any added series resistance [Rs]: http://www.mh-audio.nl/Calculators/newqts.html
[Rs] = 0.5 ohm minimum for wiring, so may be higher if a super small gauge is used as a series resistor plus any added resistance from an XO/whatever.
More to come as time permits.
The Onken 'n' (Vb = (Vas*Qts'^2)) is from some folks in the early days of T/S apparently taking some of the pioneer's published, well proven DIY rules-of-thumb (ROT) cab design and 'constructing' a more complex (then new) T/S set of alignments to describe them as a way to ~ guarantee an excellent performing speaker based on the popular Jensen Ultraflex designs.
But these were based on using (relatively) low power, ~matching impedance (DF = 1) amps and/or higher ones, but still low DF with variable damping bass/treble tone controls whereas nowadays there's virtually no output impedance in comparison plus generally lower compliance (Vas) since modern speaker efficiency doesn't need to be as high due to (much) higher power handling capability.
In short, we're going to ignore 'n' and let it be whatever it turns out to be and for those folks that use it can always make their own 'n' chart collection based on theirs and others' proven alignments, though TTBOMK no one has ever posted one, so for now there's just the original two.
[Qts']: [Qts] + any added series resistance [Rs]: http://www.mh-audio.nl/Calculators/newqts.html
[Rs] = 0.5 ohm minimum for wiring, so may be higher if a super small gauge is used as a series resistor plus any added resistance from an XO/whatever.
More to come as time permits.