Yes, the vibrations (and therefore opposing drivers) aren't really a big issue, and can be addressed in other ways if needed. Opposing drivers are just quite a neat way, which appealed to me where small and reasonably light are desirable characteristics. But given the down-sides of slots and/or bandpass ports (some of which I hadn't considered before these threads), there would be a fair argument to simply go with individual forward-facing drivers.
No cabinet is going to be perfect or without compromise of course, but simple sealed subs must be amongst the more blameless options, for small rooms. Rather boring perhaps, but in current circumstances things that need less testing/tinkering/iterations would be much easier to get around to actually finishing. At least things like air-spring compression and acceptable levels of distortion have been raised, which will mean better results; reducing my temptation to (e.g.) get carried away with ever smaller boxes.
No cabinet is going to be perfect or without compromise of course, but simple sealed subs must be amongst the more blameless options, for small rooms. Rather boring perhaps, but in current circumstances things that need less testing/tinkering/iterations would be much easier to get around to actually finishing. At least things like air-spring compression and acceptable levels of distortion have been raised, which will mean better results; reducing my temptation to (e.g.) get carried away with ever smaller boxes.
For me, using opposed drivers is primarily about keeping my sub from trying to walk when cranked.
If I make a single pro 18" reflex lite enough to be able to move around... it will try to walk. Regular forward facing doubles will too.
Walking sucks,.... and ratchet straps, weights, gripping rubber feet, etc to combat walking ..... are all a pain and just a crutch imo..
And opposed is secondarily about not vibrating a main speaker stacked on top of the sub(s). Seems it almost has to help SQ to squelch that vibration.
I know air born vibration will hit mains no matter...heck, my 9ft heavy slate pool table vibrates from air born....but cabinet vibrating-against-cabinet, even with neoprene or something similar between them seems like something to avoid.
I'd do opposed on sides facing outward, but like everyone else, don't like the placement implications.
So a slot, as big a pain as one is to build, and with no real sonic benefit (my meas don't show reduced distortion)....becomes my preferred opposed driver, sub technique.
If I make a single pro 18" reflex lite enough to be able to move around... it will try to walk. Regular forward facing doubles will too.
Walking sucks,.... and ratchet straps, weights, gripping rubber feet, etc to combat walking ..... are all a pain and just a crutch imo..
And opposed is secondarily about not vibrating a main speaker stacked on top of the sub(s). Seems it almost has to help SQ to squelch that vibration.
I know air born vibration will hit mains no matter...heck, my 9ft heavy slate pool table vibrates from air born....but cabinet vibrating-against-cabinet, even with neoprene or something similar between them seems like something to avoid.
I'd do opposed on sides facing outward, but like everyone else, don't like the placement implications.
So a slot, as big a pain as one is to build, and with no real sonic benefit (my meas don't show reduced distortion)....becomes my preferred opposed driver, sub technique.
Thank you, Mark. Quite a lot in common with what I too want/hope to achive, there. I must admit that I'm in two minds about this, and go back and forth between plain sealed vs opposed+slot. But you remind me of all the good (mostly practical) reasons that I looked so seriously at this option, and I shouldn't give up on that so easily.
The answer, by this point, simply lies in building something to see how much I can negate the ill effects of a slot. I think the answer 'could' be quite a lot, which would make it my preferred choice.
I just need to time off work to coincide with warmer days, then I can go outside and spend pleasant hours making things! 🙂
The answer, by this point, simply lies in building something to see how much I can negate the ill effects of a slot. I think the answer 'could' be quite a lot, which would make it my preferred choice.
I just need to time off work to coincide with warmer days, then I can go outside and spend pleasant hours making things! 🙂
Hi Kev,
I've been going back and forth too with regard to subs. Damn compromises one way or another, huh?
Good luck whichever way you go.
Don't laugh, but since I have so much excess indoor sub capacity with the three double 18" V-twins in LCR,
my next project is pull the drivers and make 6 single 18" sealed boxes.
I figure why not live with a good strong sealed setup for a few months and see what I think.
I've been going back and forth too with regard to subs. Damn compromises one way or another, huh?
Good luck whichever way you go.
Don't laugh, but since I have so much excess indoor sub capacity with the three double 18" V-twins in LCR,
my next project is pull the drivers and make 6 single 18" sealed boxes.
I figure why not live with a good strong sealed setup for a few months and see what I think.
If you open the slot on both sides (front and back) you could reduce the slot resonance effect and raise the resonance frequency. Just a quick thought.
That sounds like a worthwhile test, Mark. With three you can already do the distributed sub thing, of course. But more half-sized ones might still allow for more placement options.
In my case I could make bigger ones, and actually would like to. But then I'd be restricted to one or just possibly two, which could only be put in one or two places. Places which wouldn't necessarily be the best for room modes. So smaller ones are best for me, at least. Though I appreciate that a lot of people have less restrictively sized rooms.
Yes, that is true. I hadn't i nitially considered it because I'd need to be placing these close to walls, or in extreme cases even in cupboards. Which I think would likely still act as a rear to the slot. In that case it might be better to build in a back that is more under control, and as shallow as possible.
Though the damping idea could change that. In fact an open/through slot could possibly allow for deeper pieces of damping. Hmm, that would be worth adding to the 'to try' list.
Thanks,
Kev