If you want the best advice, limit your own design ambitions to closed and "normal" vented cabinets. This will save you a lot of time on your way to a well working DIYS sub. Maybe later go for the more complicated stuff.
The complications of other constructions rise exponentially, just like the volume needed, costs and risk of a complete failure. Simulations have reduced the large number of failing test cabinets significantly, but no one can promise you to be spot on with such a build. Professional products are often protected with copy rights, because the way to, for example, a well functioning tapped horn can take month or even years of expensive development. Also, notice that successful speaker developers, making a living from this art, are a very rare breed.
So please do not take this whole theme too easy, as many do in the beginning. Almost any one can pass the exam to a drivers license, but hardly no one will ever be finished with learning speaker development.
The complications of other constructions rise exponentially, just like the volume needed, costs and risk of a complete failure. Simulations have reduced the large number of failing test cabinets significantly, but no one can promise you to be spot on with such a build. Professional products are often protected with copy rights, because the way to, for example, a well functioning tapped horn can take month or even years of expensive development. Also, notice that successful speaker developers, making a living from this art, are a very rare breed.
So please do not take this whole theme too easy, as many do in the beginning. Almost any one can pass the exam to a drivers license, but hardly no one will ever be finished with learning speaker development.
‘Normal’ vented subwoofer is just a plain qw pipe. horn response has been Far too successful and repeatedly so in these areas to bother with the bass reflex unless you just need a simple little design, maybe?
These things are very hard to argue unless you decide there is no argument and you just go for transmission line instead and of course, don’t try to sell it as somehow it’s more difficult(it’s actually easier)
The problem I’m having is try to argue with myself , not using a sealed box and a DSP at some point…. And most of this have to do with chasing infrasonic subs for fun . Before that it was all about the multiple ways to do a transmission line with an offset three to one ratio. (od qw pipe or parallel/series exit qw pipe, the 3:1 wave cannon folded together )
mass loaded solves the size issue often and still keeps us outta bass reflex port compression and turbulent (in an ideal version of this endless thing to ponder/ argue 😝😝👍🏼)
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the biggest problem Seems to be the car audio type drivers (or anything that’s made to fit in a small box and conveniently so ) with the incredibly tight suspensions( and small VAS) calling for an incredibly small port as a result, if using a transmission line, it also poops the bed as turbulent /etc just like reflex ports
where’s ‘camplo’? This is what he likes to debate 😝
where’s ‘camplo’? This is what he likes to debate 😝
sound and light are the exact same thing. if you use these concepts in ‘qw resonators’ or foldedup transmission lines…. You get to experience this uniqueness as well.
https://www.facebook.com/reel/697657621727135?mibextid=0NULKw&fs=e&s=TIeQ9V
https://www.facebook.com/reel/697657621727135?mibextid=0NULKw&fs=e&s=TIeQ9V
Uh, Tom Danley did that decades ago on the late, lamented, Basslist, where ya'll missed a fairly polite 'battle of horn theories' when the late JMMLC and some of his French? Belgian? horn cognoscenti took extreme exception to my saying among other things that we want more mass as we go lower and they being classically trained like me the historic goal was as light and powerful as it can be as proven by the pioneers with such drivers as my legendary Altec 515B bass horn driver, but lacked the necessary technical argument knowledge to back up my absurd/heretical ideas, so Tom stepped in and laid it all out complete with an actual example IIRC and they still didn't agree, though JMMLC finally did, not sure about the others at this late date.
Also, when the 'dust had settled', Dan Wiggins (Avatar/Adire Audio) summed it up as a 'woofer speed' doc or at least I think this was the core issue of contention IIRC that TTBOMK there's still? quite a few folks across the WWW that believe it's a bunch of BS.
Also, when the 'dust had settled', Dan Wiggins (Avatar/Adire Audio) summed it up as a 'woofer speed' doc or at least I think this was the core issue of contention IIRC that TTBOMK there's still? quite a few folks across the WWW that believe it's a bunch of BS.
I’m sorry…..given the volume of the enclosure, the volume of your space and the power you’ll be applying to the system, I see NO reason for a dual opposed system….you’ll wind up with FAR GREATER nulls and peaks with 2 subs over one. A single UM18 sealed in that volume will give you an F3 of 28hz…….factor in room gain and boundary gain from the floor and it’s closer to 25hz.…..there’s no reason to overthink this. Make sure the box is sealed and low/no resonant. One and done…enjoy.
Thanks for chiming in!
That’s what I’ll do! That’s what’s everyone seems to go for, they must have a reason.
But will dual opposed give me a better f3?
I’ll go crazy with the second living room setup when I get there. 🤪
But the F3 isn't all that important in knowing how the total system will sound, it's the F10 I look at
I think he talks about the size I mentionned ealier, which is 5ft3
Sorry thats not at all what I understood this morning when I read your answer. I thought having 2 sub was always better to counter the peaks and nulls and have smoother bass response
Well, yes and no in that as I noted early on, his performance goals dictates an adjustable non flat response plus 'forced' to use the THX's lower 80 Hz LFE XO point, so with the dictum that there's 'no replacement for displacement', the dual opposed setup is the best overall compromise IME.
Design for an F3 perhaps but what do the simulations say about the F10?
One of the boxes I am simulating has an F3 of 19.4Hz but the F10 is only a few dB lower at 15.6Hz and I'm not able to simulate in-room response.
But I can only get 116dB at 25hz with 500 watts, I'd need to use DSP and a kilowatt to get much more and drive the woofer to X-Max and I'd need a crowbar filter at 15Hz to do that or lose the driver to over excursion [ It only has 20mm of travel and only a 15"] so for me F10 is important and shouldn't be ignored
Don’t think it was the most optimal boxes,
But the f10 seems to be at 20hz @ 104db. Not factoring in room gain.
If I understand the graph well.
https://www.diyaudio.com/community/...-a-home-theater-subwoofer.393057/post-7196793