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Sealed, Ported, or Passive Radiators?

What do you use? And more importantly, why? Since my setup is made up of a Sh**load of left overs, I use all three. Do you think that would be better or worse? When I built them I tuned all of my sub boxes to cover specific frequency ranges.

For instance two 12" ported subs (in a very large box of about 18 cubes or so) handle 45Hz and below, four sealed 12" subs handle 35Hz to 80Hz, six ported 6" woofers (tuned at 50Hz) take care of the 50Hz to 120Hz range, and four ported 8" subs (tuned to 20hz) handle super low quick transitions, two 12" subs in a band pass box (tuned to about 38Hz) and a single 12" sub with a 15" passive radiator (tuned to 45Hz).

Yeah I know, overkill, but like I said I had a lot of left over equipment.... and I was bored.

I don't drive them with tons of power and only the subs in the same frequency ranges share amps. The super large two 12" ported box gets its own amp. I mean three amps just for the subs is already ridiculous.

Sure it is powerful but that wasn't my goal, I was simply doing what everybody else does with mid-bass drivers and super tweeters, just kinda in reverse.

So should we be splitting up subs like we do with the upper frequency ranges?

Shahinian's Diapason setup uses many drivers aimed at specific frequency ranges. And I have yet to hear anything as good as his design. So I tried the same with my sub woofer setup and at least in my opinion it worked. I can still refine it down to something less insane. But it is the idea that I can't help but think this would work well, even scaled way down.

I don't know maybe I'm just a little loose in the screws.

Please let me know what you think of the concept and if anyone's tried this already.
Thanks

Andrew
Synesthesia Studios
dynami28
dynami28 OP
55 posts
 
01-06-13: Rower30, I agree with your take on how passives sound and work, we just have a difference in opinion about how much bandwidth should be available from a system. To be taken to the literal edge would mean constructing an I.E.D. series of Loudspeakers. While that sounds tempting and profitable, from a military standpoint, I don't think that is what I'm after...... Well only if I get a controlling stake in the company.(LOL!!!)

I imagine we don't listen to the same music either, you see, I listen to some music that was designed to be turned up. I don't mean to judge or any thing, but, I don't know many people that enjoy 28Hz bass-lines playing away at 120db. I also believe that constantly (and by choice) listening to music from inferior setups can be an injustice to it's composer/creators.

One of my favorite little "prototypes" I built used Two massively overbuilt 5" drivers/woofers (I forget the actual size of the magnet, but it is the same diameter as the cut-out hole for the woofer!) mated to a 15" passive radiator in a 2 cubic foot enclosure. That became my "little" sub-woofer of choice for listening to Pink Floyd's album "Wish you Were Here".

Also - What do you think of the idea about using different woofers in the same system? Split up to cover specific frequencies. Just like mid-bass, mids, & mid-tweeters.

Andrew
Synesthesia Studios
rower30
211 posts
 
At 120dB you may not get to support your artist too long, or hear them anyway!

Multiple drivers are simply super hard to integrate as every driver is a slave to what it sounds like and is made from, and the overlap to the drivers above and below is critical to sonic integration. The electronics are probably the easier part.

Playing 120 dB, just about any driver will be seeing near maximum cone excursions, and lots of doppler or intermodulation distortion, too. That is a sound that gets hard to hide, so more driver that are driven less for 120dB, may actually be better, even if they aren't as "like" sounding as the mains on up.

So the answer isn't obvious to me at 120 dB!

audiokinesis
2,743 posts
 
I'd be more interested in using multiple distributed subs covering the whole bass spectrum than in using different subs for different portions of the spectrum. The reason is, if you spread multiple low frequency sources around the room, each one will interact with the room's modes differently, and the net result will be a significant smoothing of the bass response throughout the room (of course this is only true down to the lowest room mode, below which we are in the "pressure zone"). Smooth bass = fast bass, tight bass, good pitch definition bass.

As for what type of sub is best, imo the ideal would be a sub whose native response is roughly the inverse of room gain. This can be achieved with ported or passive radiators tuned properly, and approximated with a low-Q sealed box, or achieved with an equalized sealed box.

Duke
dealer/manufacturer
dynami28 OP
55 posts
 
01-10-13: Rower30, I agree that some of my sustained SPL levels are certainly high enough. I am quite aware that my tastes are off pace with the normal:-) And definitely agree that it is very difficult to get everybody to cooperate, all the different subs I mean. I've spent most of my time tuning and keeping the frequency spectrum from having any huge lumps in it. It has worked out a bit, although I've only had a few trusted heads listen to it. Keeping in mind the number of subs, on a single plane, and the timing issues, phasing, and so on. I'd say it's definitely not for the easily discouraged types. Although, since I have so many subs playing together I do benefit from a shared workload. It's probably just as well, my job doesn't go well for people that flinch at loud noises anyway.

01-12-13: Audiokinesis, I have to say if some one wanted to pay me to make this for them..... I wouldn't. I've built and seen sound rooms with multiple distributed subs, and the results are outstanding. Say using four 12" drivers one in each pocket but, not quite in the corners, right? And as far as the right sub/setup, I just don't know. Maybe I just feel like a single source can't operate efficiently at 30hz and 100hz simultaneously.... So perhaps I achieved one goal with my idea there.

Andrew
Synesthesia Studios
jafant's avatar
jafant
19,745 posts
 
I am thinking that the newest Thiel designs have dropped the passive radiator?
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