From the designer: These speakers have very flat response and I think they will be very popular. You can make an entire home theater system with these speakers. They have an elegant crossover for textbook roll-offs and a nice summed response.
The 7" hexcore woofers are very easy to work with and had even less break up peak than the manufacturing sheet indicated. With only two parts I get baffle step compensation and a beautiful knee and roll-off. The crossover is LR4 at 2.2 kHz. Very nice. The motor, frame, and cone, are almost identical to the ***** brand. The fountek ribbon is exceptionally flat, shows no real diffraction at all due to the horn-loading, and can cross at around 2.5 kHz.
The Helix Ribbon MTM makes for a great full range monitor style speaker for those that love the sound of ribbon 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.
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.
As soon as Erich mentioned on the AVS forum that these were coming I knew they'd be my next speaker. I've built Jeff Bagby's Denham and Quark speakers along with about 6 other kits from other designers over the past 5 years. They've all been nice and I usually enjoy them for a while then gift them to my friends, family, or coworkers because I just like building and listening to different speakers. But these are going to stick around in my living room a bit longer than the others.
I've heard Fountek ribbons before, but not this particular model. It's at least as good as their other models, but something stands out to me that I can't put my finger on, maybe because it's horn loaded I don't know. The woofers are interesting looking and when tilted the right way you can make out the honeycomb outlines that are used in between the two layers of what I'm guessing are carbon fiber or kevlar. The crossover was straight forward and pretty easy to assemble. Eric said an assembled crossover option would be available, but I've done enough to know the ins and outs of soldering parts together correctly and didn't want to wait.
I did not order the flat pack because I enjoy woodworking. Parts fit the front baffle perfectly and the hardest part of the cabinet build was the port holes. I recommend precutting them on some thin wood as a trial before cutting them on your back panel. After assembling the cabinet I tried some fluffed up denim insulation glued to the rear wall along and a decent handful of polyfill behind each woofer. I fluffed it up and would consider it a light fill in the upper and lower section of the cabinet. I didn't add any polyfill behind the tweeter or around the ports and my braces keep the polyfill from moving into the middle of the cabinet.
Sound quality is quite high on these. To my ears these are the nicest sounding DIY speakers I've built yet. Smooth midrange, good bass response, and something special about the ribbon tweeter that just keeps me listening. Jeff and DIY Sound Group have a winner here. One recommendation if I can, please consider a rotated tweeter version for a dual woofer horizontal set up in case someone was interested in a center channel down the road.
|Speaker Kit Information|
|Model:|| The Helix MTM
|Designer:|| Jeff Bagby
|Frequency Response:||40hz - 20khz (+/-3db)|
|Power Range:||10 - 150 watts|
|Sensitivity:||91db - 2.83v/1m|
|Tweeter:|| Fountek NeoCD3.5H
|Woofer:|| Denovo 7" Hexcore woofers
|Dimensions:||9.5" W x 23.5" H x 13" D|
|Kit weight (no cabinet):||N/A|
Price Break Down:2 - 7" Denovo Hexcore woofers: $165.10
Packaging Material: $3.00
Paypal Fee: $8.49
Retail Cost: $291.60
Discount Cost: $280.00 and shipped for free.
Please read the 'About Us' section for more information on pricing structure and quality parts used.
Specific Helix MTM 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:
Screws and Gaskets:
Stuffing or Lining the Speaker Cabinet:
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.