From the designer: Info coming soon.
The Helix Dome MT makes for a great full range monitor style speaker using one of Jeffs favorite dome tweeters. It uses a custom high end woofer with a 3 layer cone. The middle layer is a hexagon matrix similar to a honeycomb that gets 'sandwiched' between the two other layers to make for a strong light weight cone. I'll upload some more photos soon. I was able to get a smaller batch of these made at first to see how people liked them, but the price shown on woofers might have to go up a bit when they're made again. The list price is supposed to be much higher. That may or may not change the price of the kit later.
- Uses a hidden gem of a tweeter: The SB Acoustics SB29SDAC.
- High end woofer with 3 layer sandwiched hexagon matrix.
- Smooth and detailed sound.
- Timbre matched to the dual woofer version.
Minimum order is 2 speakers: If you ordered one in the past and need one for a center, please contact me. Kits are sold as full kits, sorry no substitutions or subtractions. Don't forget binding posts, terminal cups, or speaker spikes if you need them because they can be shipped for free with any kit or flat pack purchase.
Shipping Note: Most speaker kits currently ship for free, but flat packs normally do not. We try to get your order packaged and shipped in 5-8 days depending on how many orders have come in. Please read the 'Frequently Asked Questions' section for more information.
Price Break Down:
1 - 7" Denovo Hexcore woofers: $82.55
1 - SB Acoustics SB29SDAC-C000-4 tweeter: $46.201 - Set of crossover parts: $28.771 - 2" adjustable port: $3.18
1 - 3/4" thick CNC cut front baffle: $101 - Set of screws and gaskets: $1.50
Packaging Material: $2.50
Paypal Fee: $5.10
Retail Cost: $179.80
Discount Cost: $171 and shipped for free.
Please read the 'About Us' section for more information on pricing structure and quality parts used.
Specific Helix Dome MT Assembly Notes:
Your enclosure should be built with 3/4" thick material with two horizontal "window pane" style braces to the dimensions listed. It is recommended that you lightly stuff your enclosure with polyfill withough blocking the ports.
Recommended Tools and Supplies:
- Quality wood glue like TiteBond.
- At least 2 clamps 16" wide or bigger.
- Soldering Iron and solder unless there is an optional assembled crossover for your kit.
- Wire cutters
- Drill to predrill all screw holes.
- Sanding block or power sander.
- About 8' of speaker wire to connect your woofers and tweeter to the crossover board.
- VERY IMPORTANT - Inductors are the parts that look like small rolls of copper wire. Notice that the two ends of wire are silver and have been 'tinned' with solder. Those are the parts of the inductor that you should be soldering to, so don't cut it off to get to the copper colored portion. Inductors should not be installed directly next to each other on your board.
- None of the crossover parts have a positive or negative side so it doesn't matter which way they are facing when you assemble your crossover. 16-18 gauge wire is thick enough to use for your crossover or to go from your crossover board to the woofer or tweeter.
- Your crossover can be assembled on a thin piece of MDF or pegboard if the kit doesn't come with a circuit board.
- It doesn't matter where you put the crossover inside your speaker. You could mount it on the outside if you wanted to.
- Normally you wire red wires to positive and black wires to negative. If (and only if) your crossover schemtaic has a note saying 'Inverted Polarity', that means you need to connect the negative from the crossover to the positive on the tweeter and positive from the crossover to the negative on the tweeter. This is only done on some tweeters, not woofers.
- Click Here for a good assembly video by Matt Grant.
Screws and Gaskets:
- Predrill all screw holes with a bit that's slightly smaller than your screws to prevent the wood from splitting. Most screws are #8 panhead and you can use a 7/64" or 1/8" drill bit. Overnight Sensations use a #6 panhead so you can use a 3/32" bit.
- VERY IMPORTANT: Protect your woofer or tweeter when installing screws because you don't want the screwdriver to slip and puncture one of your components....that will ruin your day! Consider putting your free hand next to the screw to cover up the edge of the woofer or tweeter.
- If your kit comes with gasket tape, it should be applied to the back of the waveguide. Peel the paper off the back to expose the sticky side and slowly work it around the perimeter on the back side of the part. Some woofers will need gasket tape as well.
Stuffing or Lining the Speaker Cabinet:
- If your speaker or subwoofer is a sealed cabinet, most designers recommend that you lightly fill the inside with polyfill (pillow stuffing). If you don't have polyfill, then you can line the walls with 1" - 1.5" thick light weight open cell foam (like acoustic foam) or fiberglass insulation. You can also use 2-3" recyled denim insulation that can be bought at Home Depot.
- It's okay to cover up your crossover with the polyfill, insulation, or foam.
- If you're using a ported enclosure you should lightly fill the cabinet with polyfill and be sure not to block the ports. If you do not have polyfill then line the walls with 1" - 1.5" thick open cell foam (like acoustic foam), 2" - 3" of denim insulation, or 2" - 3" thick poly batting.
- Some of the speaker designers like to lines the walls of their ported enclosures with a 1" - 1.5" acoustic foam, and then lightly fill the remainder of the cabinet with polyfill. If this is a required method, it will be listed at the top of the page under 'Assembly Notes'.
Links to Build Threads for this Speaker:
Frequently Asked Questions:
* Does the baffle come with roundovers? Answer: No. If you really need roundovers, please send me an email and I can try to put them on the edges for you.