OK soo its time for a little review on THE Hammer since I believe I am the first one with a finished build and setup.
So I've been contemplating for a long time whether to purchase a second Martin Logan Balanced Force sub as the one 210 just wasn't enough no matter how clean and tight it was.
I've been looking for advice on this forum and received some really good ones but generally advising to go large and multiple subs, which is fair enough as we all want the best bass however I felt I don't really need a commercial cinema at this point, I just wanted to start safe and relatively easy. I am a busy professional and don't have much spare time at the moment so I was looking for a relatively easy path with a ready made cut sheet and parts readily available and easy to order to Europe where I currently reside.
I started to watch
's channel on youtube and found that his design and explanations were the most straight forward and easiest to understand. Naturally I wanted to learn WinISD to design my own sub but the lack of time just wouldn't allow so I got excited when Steve got to design The Hammer. This was pretty much what I needed to quickly get into building my first DIY sub. He just made it very simple by providing a cut sheet and even detailed video build instructions.
So I got to it ordered the parts from Soundimports in the EU.
This is what I ordered:
MiniDSP 2x4 HD
Dayton Audio UM12-22 12" Ultimax subwoofer
Cables and bits
The build process of the enclosure took me about a week to complete, I used clamps and extra strong glue to ensure rigidity and always allowed enough time for the glue to set (about a day after each step) as I didn't want anything to get lose causing vibrations or leaks.
One thing I need to mention is DO not cut the baffle holes until you receive your driver as the manufacturers baffle cutout numbers are incorrect on the website (at least they were on Soundimports) but luckily they were smaller so I could just enlarge the cutout when the woofer arrived.
For the paint job I decided to use a spray gun for the Duratex but it's very thick so I added approx 5% of water and it worked really well. Sprayed on 3 or 4 coats and that was it. It looked great. Next time I will sand more of the MDF surfaces along the joints and seal them more evenly as some joints are visible if you look hard but there are no leaks and can't be seen in the cinema whatsoever.
So all was ready to install the woofer and line the inside of the box with some insulation ( I do not use fiberglass as it is a breathing ported sub so I don't want nasty particles floating around in the room).
I wasn't expecting much from a 12" DIY sub so I went in with low expectations.
Plugged it all in and it worked perfectly for the first time. Note I used a cable tester as well to ensure all connections were done well.
The first thing I noticed was that the Behringer needed to be cranked up to near max to allow for 75 db levels and I also had to boost about 5 db in the miniDSP. Later I settled on about 75% and + 5db in the miniDSP and sub level 0 in the AVR.
Raw response was pretty good but it all felt lose. I placed a filter at 17hz to protect the driver, used REW and the miniDSP to dial it all in and integrate with the mains then ran Anthem's ARC Genesis and also created a house curve to allow for a slight rise in response from about 70hz down to 20hz. I was able to EQ it in very nicely using the miniDSP.
I was hugely surprised by what I experienced once it was all set up, the response is tight and powerful, I don't listen at reference levels much but even at my normal listening levels at -15-20 db it sounds excellent. I was worried that it might not sound as tight and composed as the Martin Logan sub did but it not only does sounds as good but exceeds it in almost every way. The ML had to be crancked up high to get acceptable bass but The Hammer just provides that efficient effortless ULF response that I've been missing for a long time, and the great thing about it is that I don't need to crank up the volume sky high to experince it. Of coourse if I crank it gets even better. Mid bass is excellent as well the shutgun shots in John Wick 3 never sounded this good and the chest kick is there and nicely pronounced.
After watching Blade Runner 2049 I checked the walls for cracks as I heard a window next door complaining which I never heard before with the previous sub. It handled all I threw at it very well.
I was worried about music that it may not be as tight as the ML was and I am relieved to hear that it is not the case, while it is not quite as composed as the ML sub it's perfectly acceptable.
...and all of this at a fraction of the price of the ML is quite a bargain. Adding a second Hammer would be much less $$ as the electronics are already there. I could easily build three or four hammers on the price of one ML I had, its an absolute no brainer.
Also checked for power usage and I was rather surprised to find how efficient it is. The max it drew during my tests was 305watts and 4.5 amps.
Overall I am very satisfied with this sub and can only recommend to anyone looking to get into the DIY space with a first easy build. I need to stress though, thorough build and setup is crucial for it to work well, do your homework in that regard otherwise you may get disappointed.
Excellent job Steve well done! You may use my photos as reference if you like.