PatrickS

Sealed or custom Mini-Thunder to be used 50/50 for music and HT?

I currently have the 2 cu. ft. Custom Mini-Thunder with external measurements of 17" x 17" x 20" and is down-firing (the standard Mini-Thunder is 16" squared) which I've used with the original AV12 (sold with another cabinet), and the Rythnik Servo Amp/Driver (not enough punch for HT, and kept bottoming out). the Mini-Thunder really puts out with the AV12, but I decided to go with the better warranty of the Titanic.

NOW, after doing some more research, I've read that many people recommend the 12" MKIII with a "sealed" 2 cu. ft. enclosure. Which of course would be much better for music, I just don't know if it will be enough for movies. The Mini-Thunder actually does fairly well with music in my room, and I really don't want to deal with the hastle of selling it, unless it will be a marked improvement.

To give a little background:
The Mini-Thunder has dual 12" 970 gram PR's from Stryke audio and the cabinet is tuned to 20 Hz. Besides a substatial dip (11 dB) at 28 Hz, freq. is very flat between 17.5 Hz and 80 Hz within 4-6 dB. I had Parts Express run bassbox with the 12" MKII in the Min-Thunder, and they said it was pretty flat from 100Hz down to 18Hz (within 8 dB).

Because of room limitations the sub sits right behind the center of my couch (listening position)against the wall. The couch is out 2 ft. from the back wall in a room that has 3 walls (15 ft. x 12" by vaulted ceiling), with the fourth wall not being there and opening into family/kitchen/dining room. The total floor space of the combined rooms is about 25 ft. x 20 ft. with the vaulted ceiling going from 10 ft. to 13 ft. in the center. A VERY bad room, but with acoustical treatment, having the sub right behind the listening position, and mains that go down to 30 Hz, I have it sounding pretty good.

But as usual I want better if I can, with what I have. That being the Titanic 12" MKIII and the rythmik amp. I already have the Mini-Thunder as I've explained, but given my situation (room constraints and 50/50 listening preferences)would anyone recommend going to a downfiring 2 cu. ft. SEALED enclosure? I definately have to stay with the 2 cu. ft. size regardless, and I really prefer the downfiring cofiguration.

Any input would be greatly appreciated!

Thanks and Best Regards,
Patrick

ThomasW

Nope that's a room placement issue, it's not a problem with the sub itself. You'll have the same problem with any sub if you put it in the same spot.

That's meaningless since it doesn't take your room placement problem into account.

If you were bottoming the AV-12 you'll certainly have problems with the 12"MKIII in a sealed box. To start off you'll loose 3dB of output changing over to a sealed box from the PR based design.

Since you have a BIG room (note that most people would use a pair of 15"s in that size room), it really sounds like you need something like a Adire Brahma with PR's and a bigger amp IF you must stay with that small a box and 12" driver

theAudioWorx Klone-Audio
Cult of the Infinitely Baffled (Resource for IB sub builders)

PatrickS

Sorry, but I thought that was implied, I know it's a room issue. But, it IS the best spot for a sub in my small 12' x 15' room. I've done freq. sweeps in every possible location. Upfront by the mains is not an option as that wall is only 9' long, opening into the larger room and the wall does not even go to the ceiling (it's 8' high). So there is only the one corner up front where I have the space to put it, and I get HUGE dips and peaks there (15db in some cases). The opening obviously is not an option with no wall to reinforce it for "room gain" (not to mention the wife will not allow it as there is no space with the other furniture). The other side wall is much worse than behind the couch.

And no, moving is not an option I can't really change anything either, as it's a rent trade for being a caretaker.


Again, I know the different driver is not going to effect the null at 28Hz.

I was NOT bottoming out the AV12. I was bottoming out the Rythmic Servo Amp/12" Driver combo (please see my first post). I said that with the AV12: "the Mini-Thunder really puts out with the AV12, but I decided to go with the better warranty of the Titanic". By that I mean it shakes my room violently (and I have a carpeted concrete floor), and is pretty tight as well!

So my guess is the 12" MKIII would NOT bottom out either! Sounds like I just need to figure if I'm willing to lose 3dB with the sealed config in exchange for tighter, more accurate bass.

With the sub being 1' away from my listening position and the fact has the ability to shake everything in the room on a concrete floor (that is with the AV12 in the Mini-Thunder box) , there is no way (I personally) think I need a pair of 15". Yes, I must stay with a 12" driver in a box that small. I just don't have the space in my room for anything bigger, it's that simple. Based on my experience with the AV12, I don't think I need the Brahma either. I just wanted some advice if going to a sealed 2 cu. ft. enclosure would potentially sound better given my listening preferences.

Hope this clears things up, sorry if was not clear in the first post (it was late, and I was tired).

Thanks,
Patrick

Rob Formica

In other words, the proposed Titanic MKIII will not provide you with a large improvement/difference over the original AV12.

The PR version will dig deeper and play louder than a sealed version, and PR's are a great way of venting an enclosure esp for music. Many people feel eliminating the lowest frequency makes a sub more musical... but we are basically removing or "correcting" the sound engineers mix.

Rob

*Shedding light by means of the combustion of snake oil* PC-ABX

PatrickS

Rob,

Thanks, I pretty much know the MKIII will not be much of a difference from the AV12 (again, I just like the better warranty).

Do you think a sealed version would sound that much better for music, but still give a good punch for movies?

P.S. I just read your EDIT, sounds like it might be best just to stay with the Mini-Thunder!

Thanks,
Patrick

Rob Formica

:b ... sorry about the edit... but yes, I do think it would be best to stick with the PR version versus sealed.

*Shedding light by means of the combustion of snake oil* PC-ABX

PatrickS

That's cool, I do it ALL the time...

Thanks again!