VRK Midbass Modules Build
The VRK Midbass Modules are named after the initials of my 2nd Daughter. I bought the Magnum 12's on the evening she was born.
The box is 12.5" W x 18" H x 15.5" D with an ID cu ft of 1.47 cuft.
After bracing, port, and driver, I'm looking at 1.2 cuft.
It's tuned to 43Hz with an 11" x 1.5" x 7.5" slot port
HPF is a 2nd order butterworth at 35Hz
Powered by a Crown XLS 2002 at 375W RMS
The box is 3/4" MDF which will be veneered in walnut and stained to match my BDI media console and Paradigm LCR's. I will be experimenting with the impact on sound quality with a wooden grate that matches my media console to cover the driver (see attachment). If it impacts the sound I'll pivot on design and may even need to make a wider box
My Journey into DIY and mid-bass:
I have been annoying people on this DIY forum planning this build since the January of 2017. It's been over 18 months of discovering DIY and harassing people with questions like: "is there a difference in sound between a slot port", "will port placement impact tactile response at 8' away", "does the high excursion HST-11 sound boomy like the youtubes", "will a wood grate impact sound quality"...
You know, all the important things... I learned what I was missing, mid-bass, and heard of these Magnum-12 drivers. I did as much research as I could (primarily bothering folks with highly subjective questions)... Of course I learned about WinISD and T/S parameters (although I still don't know what the curve of transfer function magnitude is...)
On 8/11/2017 my second daughter was born and as my wife and her lay sleeping in the hospital bed, I was up salivating with DIY mania drawing pictures in Microsoft paint about various port placement options.... Out of complete DIY zietgiest, I pulled the trigger on these drivers. I contacted a friend that works at a instrument distributor and got a Crown XLS 2002, I contacted my local hacker space and was going to use their CNC machines because I can't cut a straight line to save my life...
I few months after my daughter was born the owner of the hackerspace got blown up in a propane accident (he's alive and well) but I was left to my own devices to cut straight lines. I got a router, cutting guide, and MDF for Xmas that year. I then waited for it to warm up and got busy, and then waited for it to cool down and had a day off.
Predictably, the cutting went terrible. I sold all of my battery operated tools on Craigslist and bought corded ones. Once again I wait for a cool day that I can take off which leads me to Monday July 2nd...
NAD 758 v3 with Dirac 7.4.4 + Rotel 976 + Panamax M5300-PM
Paradigm Prestige 75F's + 55C; 8x Paradigm CI Pro P65-R's
DIY MBMs: VRK Build thread
+ 2x Rotel 981 (bridged)
Sub: 2x Rythmik LVX12 + MiniDSP
DIY Room Treatments: Dutch Floral Prints