Boominator MINI (development thread)

You can spray the cone very lightly with impregnating silicone for added resistance to the elements. However, it is far better just to avoid water/sand coming into contact with the driver in the first place. You can do that by using a grill, either a fine mesh grill which can be difficult to find in the right size, but I also very much favour using a standard punched grill where you first take the rubber ring off, spray the top side with contact glue, glue on a speaker cloth of your liking, cut away excess, and lastly put the rubber ring back on. Remember, the grill goes on the inside, between the woofer and the baffle.

While we're on the subject of the baffle. If you have the wood lying around, you can make the baffles of 12mm instead of 9mm without changing the outside dimensions. The result is a slightly improved stiffness, slightly higher weight, but most importantly it will make the drivers fit without any gaps between the magnet and the center brace. The grill with rubber ring will probably be slightly more than 1mm, usually about 1.2mm, but it easily compresses. It will not have any significant effect on tuning due to smaller cabinet volume (it's less than 1/3 of a liter smaller).

Baffles = 2x 12mm, brace = 9mm, grills with rubber ring = 2x 1mm, woofers 2x 82.5mm. Total = 200mm.

Please note. I think I forgot to mention this before but I advise the cabinet to stuffed medium hard with acoustic wool.

I didn't use the amp6 because the original idea called for an fully closed enclosure where all drivers shared the same volume. With the change to a design with a central electronic enclosure that is no longer applicable. Adjust the size of the electronic compartment as you see fit to suit whatever battery and amplifier you choose. Remember to keep the speaker cabinet volume roughly the same size so adjust overall length accordingly.

The 9800mah li-ion is one similar to this http://www.aliexpress.com/store/product/New-DC-12V-Portable-9800mAh-Li-ion-Super-Rechargeable-li-on-Battery-Pack-for-wireless-transmitter/803611_564472693.html. It's 3 cell, so nominal voltage is between 10.8V and 11.4V. That works fine with any TA2020, TA2021, and (to some degree) TA2024 amp. The lower voltage of a 3-cell battery pack is actually a blessing in disguise as it makes a TA2024 amp capable of running a 4 ohms load which it would not do optimally on 12V or higher voltage. But you can use whatever battery you like. The electronic compartment is now sized so that it can host a standard 12V 7Ah SLA.

The amp I currently favour using for my own build is this http://www.ebay.com/itm/TA2024-MKV-Bluetooth-Tripath-amplifier-2X-15-Watts-12V-fully-finished-/251221801085?pt=UK_AudioTVElectronics_HomeAudioHiFi_Amplifiers&hash=item3a7dfc787d. Combined with the battery above and laid on it's side I can cut 34mm of the width of the electronics compartment making the overall length 666mm. Please note that for that to fit, you need to replace the large input caps on that amp to something more suited for a class D amplifiers, like standard small WIMA or EPCOS MKP types (the large caps are passive loudspeaker filter caps, they're not suited for places where they can and will receive large amount of RF noise). I favour this amp primarily because of the built-in bluetooth audio module which naturally isn't terribly good for critical listening like all bluetooth audio recievers but for use as a portable audio player, it's an absolute gem as you can just stream the music directly from you phone instead of having to worry about cables.