Hello, Forum!
I'm building a sealed enclosure for two 12s, which will be directed toward the rear of a hatchback (about 24" from the back). That's really not relevant to the question, but in case it comes up. So, here's the question:
Any problems/considerations with facing the drivers toward each other in a 90-degree angle (as shown below)?
It's really just two sealed enclosures facing each other (even though it looks 'bandpassy'). I wanted to do something a little sexier than a 'standard' mounting on the baffle, but I've never done it before (although I've seen it done) and wanted to see if people smarter than I saw something I didn't (that's you all!). lol
Thanks for the help!
I'm building a sealed enclosure for two 12s, which will be directed toward the rear of a hatchback (about 24" from the back). That's really not relevant to the question, but in case it comes up. So, here's the question:
Any problems/considerations with facing the drivers toward each other in a 90-degree angle (as shown below)?
It's really just two sealed enclosures facing each other (even though it looks 'bandpassy'). I wanted to do something a little sexier than a 'standard' mounting on the baffle, but I've never done it before (although I've seen it done) and wanted to see if people smarter than I saw something I didn't (that's you all!). lol
Thanks for the help!
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If you instead placed the two woofers in an isobaric cabinet, it would be 1/4 the volume of your two boxes, and that would be pretty sexy in a small hatch.
Is it cool that we're talking "sexy" subwoofer enclosures? Should we be concerned? lol
I've always been fascinated by isobaric loading, and I still might do that someday, but I tore everything out of my hatchback and "floored it out," so I have PLENTY of space.
Plus, I've always loved the look of plexiglass windows, and I figure this will give me a 'faux window' of sorts.
Thanks for weighing in, Anderson!
It's an extremely short horn. In free space, almost no gain more than just setting two drivers adjacent. In the odd acoustics of a gutted hatchback, this detail is probably insignificant.
Interesting idea with the 90 deg panel. Certainly looks good. I don't think it will make much acoustic difference, one way or the other, compared to a flat panel, especially in the small environment of a car.
I've had DIY dual sealed subs in all my cars for decades. Just love every note of the detailed bass. Much success with your project.
I've had DIY dual sealed subs in all my cars for decades. Just love every note of the detailed bass. Much success with your project.
Yeah, this is actually my first sealed enclosure for these 12s. I had four of them in a 4th-order bandpass back in the day (20 years ago!), and it seemed to be the perfect SQL enclosure--super loud and super detailed. But I'm starting to think it may have been my young, inexperienced ears telling me that (plus, two of the drivers seized up, so there's that!). I recently installed two sealed 8s in my car (I had to have something to hold me over!), and that snappy punch of the good transient response is just what I need now that I'm in my mid-40s. haha As you said, you gotta' love every note!
I'm looking forward to installing these 12s, and I think I'm excited about the sealed enclosure. Thanks for the compliment on the design and the well wishes!
Angling the baffle gives it more stiffness, relatively. And also might give you more placement options, like upward or sideways. But I think you should make two separate boxes, for max flexibility in the placement (and save your old back). One might even be tempted to place them back to back and try force-cancelling?
Given the frequencies being reproduced are so long, the driver cares little about the shape of the box.
But every time i so 2 woofers in one cabinet, i have to ask, why aren’t you taking advantage of push-push loading to gain the active reaction force cancelation.
Even Apple has glommed onto the technique, they have specially developed reaction cncelling woofers in the ltest iMac and the new display.
dave
But every time i so 2 woofers in one cabinet, i have to ask, why aren’t you taking advantage of push-push loading to gain the active reaction force cancelation.
Even Apple has glommed onto the technique, they have specially developed reaction cncelling woofers in the ltest iMac and the new display.
dave
Yeah, Dave, I went down a rabbit hole reading about push-push (even saw that about Apple). It's intriguing, but I'm not smart/experienced enough to know how to do it. I see pictures, but I don't know how to apply them. Do you use the same airspace? Do the drivers just fire into the space on opposite sides?
I don't want to pull you into the weeds of my ignorance... just trying to explain why I didn't go there!
I don't want to pull you into the weeds of my ignorance... just trying to explain why I didn't go there!
Take a rectangular box. Mount a driver on each of 2 opposite faces. Tightely couple the drivers (you see the brace in the picture which i find sufficient but you can take it further. Drivers are wired in phase. Drivers can be in same or separate boxes, down that low it makes little difference and no difference in a car.
dave
dave
Hey, Dave. Thanks for this summary. I've followed some of your other threads on the matter, so the picture is starting to get clearer in my mind.
I think I understand the configuration and rationale. Where I'm struggling is how to design it while respecting the required air space. For subs that require little airspace, I can see how you would basically have a cube. But the subs I'm using require 2.0 ft^3 of airspace EACH!
So, how would you design a push-push box (I love the idea, of course) with this much air space? Wouldn't it have to look something like this (you could be more creative, I'm sure, but this gets the point across, I think):
Or does the push-push configuration alter the amount of air space you need?
I've tried to figure this out by looking at other threads, the web, and pictures... just can't! Thanks for indulging me!
Hey, Anderson... just realized I didn't respond to this. I think I was side-tracked because when I read your post, I relayed your comment about 'my old back' to my girlfriend (and we had a good laugh). lol
Funny... I don't know why, but I didn't even consider other placement options. I just assumed it made more sense to fire them backwards, but you might be right... sideways or upwards certainly could sound good.
I'm in discussions with another member right now (on this thread) about how to do a push-push design ('force-cancelling'), so we'll see how that goes.
Thanks for ringing in!
It is just 2 enclosures glued together. So the only compliction is orienting the 2 boxes so that you satisfy the basik premise of the drawing you did (correct, but i do usually like having something between the 2 magnets, and with woofers with polepiece vents you do not want to cover them up.
So if you have a 2ft3 for one driver then you need 4ft3 for the pair.
What woofer?
dave
For the frequencies involved it makes little difference how they are oriented.
dave
You could make two cabinets and lock them together using hardware (like peg and hook) to achieve the force cancelling. And if the cabinets had the right proportions, the cabinets could lock together in other pleasing arrangements.
Isn't the only downside to back-to-back woofers a suck-out at a frequency having the wavelength of the distance between them (or something)?
Isn't the only downside to back-to-back woofers a suck-out at a frequency having the wavelength of the distance between them (or something)?
I did a basic design for a fellow and he did something like you described to connectthe 2 drivers together. A quite elegant solution.
dave
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OH! So... let's say for simplicity and sake of discussion that you took two cubical boxes and attached their backs with the subs firing in opposite directions... that would give you the 'cancellation effect'??
If it is, then it's all making sense to me now!
As for the 'suck-out' at a frequency'... sorry, brother, but that's way above my head!
Thanks, Anderson!