Once in a lifetime IB Subwoofer Blowout

jermmd · « **Reply #40 on:** 20 Jul 2007, 12:13 am »

Can you link me to a site that explains how to build an IB subwoofer using the 15" drivers? I may have a perfect space for one in my home theater and wouldn't mind doing a little project at home.

zybar · « **Reply #41 on:** 20 Jul 2007, 12:18 am »

Quote from: jermmd on 20 Jul 2007, 12:13 am

Can you link me to a site that explains how to build an IB subwoofer using the 15" drivers? I may have a perfect space for one in my home theater and wouldn't mind doing a little project at home.

Joe,

Here are a few sites:

https://home.comcast.net/~infinitelybaffled/

http://ibsubwoofers.proboards51.com/

Doesn't look too hard (I know, famous last words).

George

JoshK · « **Reply #42 on:** 20 Jul 2007, 12:22 am »

or you can pay me gobs of money to set it up for you.

wildfire99 · « **Reply #43 on:** 20 Jul 2007, 02:55 am »

Quote from: Kevin Haskins on 19 Jul 2007, 08:53 pm

What I recommend to people is rather than build one large enclosure with multiple drivers, but two completely different subs. As boxes get larger their panel sizes become problematic to damp. You start to need LOTS of bracing.

I was looking at the 12... modeling it shows it wants a fairly huge box... double the quoted 3.7 cubic feet, to get a good response ported to 20hz. What's with that, or was the box size taking into account a massive amount of room gain?

Kevin Haskins · « **Reply #44 on:** 20 Jul 2007, 05:45 am »

Look a page 2. I simultated it with & without room gain in the 3.5 ft^3 box. This is a high Qts woofer.... its going to take large boxes if you want flat to 20Hz anechoic. Its the nature of the beast.

HT cOz · « **Reply #45 on:** 20 Jul 2007, 01:10 pm »

Hey Kevin,

In a OB dipole, how high could you cross over the 12 and 15?

Thanks,
Robert

zapper7 · « **Reply #46 on:** 20 Jul 2007, 03:25 pm »

jermmd,

It is really not that hard. You will need the eq, amp(s), and in an average 2400ft3 (?) theater, I would suggest (4) 15" drivers. I have several pictures here of how I did mine in a crawl space, so the floor shakes when playing movies, which is of course very cool. I have never done anything that has made this kind of difference for subs around $1000 total. I did build them and install myself. Follow the advice in the infinitely baffled site, it all is really good stuff. The difference in music is also very impressive. I never had the box-type subs on for music before, but almost can't live without these subs with music now. They are effortless when it comes to music. These drivers here seem to be better than my TC2000, but also cost more. 4 will be unbelievable.

Enjoy

Voodoo Rufus · « **Reply #47 on:** 20 Jul 2007, 03:48 pm »

I need one more tidbit of info, Kevin. What is the motor/magnet diameter?

Kevin Haskins · « **Reply #48 on:** 20 Jul 2007, 05:30 pm »

Quote from: Voodoo Rufus on 20 Jul 2007, 03:48 pm

I need one more tidbit of info, Kevin. What is the motor/magnet diameter?

About 7" .... I'd go a little over, lets say 8" to clear the ferrite magnets.

Kevin Haskins · « **Reply #49 on:** 20 Jul 2007, 05:41 pm »

Quote from: HT cOz on 20 Jul 2007, 01:10 pm

Hey Kevin,

In a OB dipole, how high could you cross over the 12 and 15?

Thanks,
Robert

Don't know until I take a FR. XBL^2 motors tend to have a lot more FR upward because of their low inductance. That is good... low inductance means lower distortion as its one of the fundamental non-linearities in transducer design but it also might mean that the typical 400-500Hz break-up of the woofer is at a higher level. With an underhung VC you have a built-in LP filter due to the large inductance.

Give me a week and I'll take some FR measurements as well as having more published dipole designs and a design guide for their use in IB.

Eric Jones · « **Reply #50 on:** 20 Jul 2007, 10:01 pm »

Just took delivery of two of theses baby's... Or should I say Monsters! aa

Kevin sure is quick to ship!!

-EJ

Kevin Haskins · « **Reply #51 on:** 20 Jul 2007, 10:53 pm »

Your a quick trip for the UPS man.

jonwb · « **Reply #52 on:** 20 Jul 2007, 11:48 pm »

Eric, that might be the most boring speaker you've ever made!

Voodoo Rufus · « **Reply #53 on:** 21 Jul 2007, 12:44 am »

Well, just bit it and bought 2 12". Might put one in the car and one in the living room. Or if I don't want to put one in the car (weight is The Enemy), I might put one under each of my FR125s to fill out the bass section of my stereo setup.

poseidonsvoice · « **Reply #54 on:** 21 Jul 2007, 03:54 am »

Eric,

If you do use it with your FR125's let us know what crossover point you chose, slope, and what you think of the sound.

Best,
Anand.

TerryO · « **Reply #55 on:** 21 Jul 2007, 04:26 am »

Quote from: Eric Jones on 20 Jul 2007, 10:01 pm

Just took delivery of two of theses baby's... Or should I say Monsters! aa

Kevin sure is quick to ship!!

-EJ

Eric,
Nice set of Texas Tweeters aa

That's an inside joke, son!
Seriously, that's quite the setup, let us know how it sounds.
Best Regards,
TerryO

poseidonsvoice · « **Reply #56 on:** 21 Jul 2007, 04:58 pm »

This post has been cleared by Kevin Haskins of DIYcable and John Kreskovsky of Music and Design.

As some of you already know, John K designs dipole based loudspeakers, including his infamous NaO II loudspeaker system. I approached John with the XJ12 driver that Kevin is selling and asked him to design an active crossover for a U-frame system. I knew he could design a bass active crossover which is an active woofer alignment circuit with equalization (http://musicanddesign.com/PCB.html). High pass is set at 100 Hz via resistors but is completely configurable for other crossover points. It will be a high pass/low pass 4th order Linkwitz-Riley. John will sell the PCB boards with a list of parts, enclosure design all for ~ $100. If you want the active crossover completely built including its own enclosure, the unofficial price is about ~ $300, which will include all knobs, I/O jacks, AC input, etc...fully built. The enclosure for the XJ12 is simply going to be a box, with rear fully open, like a U-frame, cardiod based system. For more details on the differences between cardiod subs (U-frame) and dipole based subs (H-frame), please see John's website http://musicanddesign.com/NaO-II-U-frame.html. I have heard John's NaO II loudspeaker and what I was most impressed with was the cardiod bass. For the plans/PCB or fully built active crossover, please contact John directly, his e-mail is: info@musicanddesign.com. Don't bother Kevin with this! He has been kind enough to let me post it on his forum.

I have a pair of XJ12's coming to me. One of them is on its way to John K so he can measure, test, etc...Pretty excited about this project.

Hope this helps some of you. These XJ12 drivers look truly awesome. Using them in a system other than a dipole or cardiod based system is a waste imho opinion. The higher Qts practically begs for an infinite baffle/dipole/cardiod subwoofer system. The Xmax is truly enormous. The XBL technology cuts distortion significantly. And $125 is biggest steal I've heard.

If some of you want to use the XJ15 subwoofer, contact John K directly, I'm sure he can help you.

Best regards and rumblings

,

Anand.

Kevin Haskins · « **Reply #57 on:** 21 Jul 2007, 07:01 pm »

I don't want to sound like a used car salesman but if you are interested in these you better move quick. I have someone who is a wholesaler that is eyeballing my entire inventory. They could be gone next week.

johnk... · « **Reply #58 on:** 21 Jul 2007, 10:59 pm »

I apologize for jumping in here but Anand emailed me that he posted about my crossover design. I just wanted to add a couple of comments. Anand requested a U-frame format but the crossover can be easily tuned for a dipole format in H-frame or flat baffle. I'd be happy to discuss details with anyone interested. You can email me directly at the email address in Anand's post or post here and I will response, assuming Kevin doesn't mind. I think Kevin is offering a very good value here. FYI, the 12" woofer in an 18" u-frame should be capable of about 104dB/M @ 30 Hz. In an 18" H frame about 98dB/M @ 30 Hz.

Kevin Haskins · « **Reply #59 on:** 21 Jul 2007, 11:48 pm »

John & Anand: No problem at all posting. I'd obviously like to see people using them.

There has been a lot of demand. I think the price has a lot to do with that but I think if these where $155 & $175 we would still have a market. That is realistically about the lowest sustainable price we could sell them at.

I'm considering making them a permanent product, along with the original specs we had planned for a high excursion XBL^2 Shiva & XBL^2 Tempest.

On another note, I have a dipole based 10" driver that will be out soon along with the Tempest & Shiva replacements. Its an actual dipole by design rather than mistake.

It would allow a smaller footprint and the models show a pair of them having good output down under 30Hz.