Sound System of the Week: DIY Inspiration

For this Sound System of the Week, I have chosen another home theater-centric DIY home theater system that focuses on a pragmatic approach to achieving top-tier performance. Jared Kappeli, aka @jk7.2 on online-shashki Forum, got his inspiration in the DIY Speakers and Subs section of this site. And with the help of the community, he quickly found himself more involved in audio (as a hobby) than he ever expected to be.

Jared has come a long way from the Klipsch 5.2 bookshelf system that got him started. Because Jared’s system is in a home theater, he uses it mostly for movies. He estimates that his investment in the current system is near $20,000, and he considers it to be worth every penny because his friends and family love to hang out in the theater. Plus, Jared has graciously hosted several online-shashki Forum get-togethers that included system demos.

While 20 grand may seem like a high price, in the context of a powerful, dedicated home theater it’s actually quite low. Even if you look at pre-packaged “custom” home theaters at triple the price, what you get in terms of capability is truly “weak sauce” when compared to a system such as this. Once you go for large, pro-style, high-sensitivity speakers like the ones in Jared’s system, it’s hard to get the of bang-for-the-buck that DIY delivers any other way.

Looking at Jared’s system, it’s clear he has allocated his power amplification wisely, which is to say the vast majority of it is dedicated to reproducing high impact, and when the situation calls for it, extremely deep bass.

Indeed, as you can see in this chart, Jared takes the strategy of boosting infrasonic frequencies by 15 decibels or so. Since these frequencies are felt more than they are heard, this kind of boost adds a physicality to movies (and yes, also music) that possess mixes which dip into this difficult to reproduce realm.


Jared boosts the bass in the infrasonic realm because at those frequencies you feel it more than you hear it

So, how do you handle the need for this sort of output at these extremely low frequencies? You supply lots of power and provide lots of displacement. Specifically, this system relies on 6 stereo Integrity DS4 18” subwoofer drivers—four in “mini Marty” boxes and two in “Cyclops 18” boxes. These passive subs in turn get their juice from a bank of Behringer iNuke 3000DSP amps (one bridged amp per sub).

This system also employs twin dedicate MBMs (mid-bass modules) which get an iNuke 30000DSP to power ’em. Plus, for some extra rumble, there are two Buttkicker LFE units installed in the seating area, which also get an iNuke.


A rack of Behringer iNuke 3000DSP amps perform the heavy lifting in this system

Processing comes courtesy of a Denon X-6300h AV receiver, which is relieved of speaker amplification duties by a pair of Emotiva multi-channel amps: An XPA-7 takes care of the base channels while an A-700 handles the four Atmos channels. A pair of the spare channels are used to power a separate two-channel zone 2 system.

As for the speakers, what we’ve got is a system that takes full advantage of the designs available on diysoundgroup.com. There are three Titan 615LX speakers up front, four Volt 10s serving as surrounds, and four Volt 6s handling Atmos/DTS:X elevation channel duties. There are all proven, maximum bang-for-the-buck DIY designs.


Here’s the seating area for Jared’s system with the rack, surrounds, and a pair of elevation speakers for Atmos & DTS:X visible

Taken together, these ingredients deliver impressive power. Check out these clips Jared sent me as he measured dB levels during scenes from Jurassic Park and Flight of the Phoenix:



Jared’s Words

I use my theater mostly for movies. Some of my favorite scenes are the Flight of the Phoenix crash scene, War of the Worlds pod emergence scene, and the Jurassic Park T-Rex vs Ford Explorer scene. And when watching San Andreas, I had to pause the movie several times because I thought there were people in my house, or knocking loudly on my door.

I have build threads for my Titan 615’s, my Cyclops 18’s and a pair of the diysoundgroup.com Elusive 1099’s I just built and sold. My inspiration to do all this was the DIY section of online-shashki Forum. I started reading about everyone’s builds and got onto DIYSG site. My first DIY build was an IB (infinite baffle) manifold system with 6 Dayton Audio IB385 drivers. That subwoofer system was nearfield, located directly behind my seats which were up against the back wall. After that, I built the Cinema 10 Max speakers from diysoundgroup.com and the first time I hooked those up for a comparison to my Klipsch RF-62 II speakers, it was all over for me—DIY won.”

“As far as upgrades go, in the future I’d like to improve my acoustic treatments.  While I have one dedicated 20A circuit for the inukes and one more at the equipment rack, I hope to add another circuit for the eight iNukes. And, maybe one day I’ll add a baffle wall. In this hobby, it’s impossible to ever be fully done; tweaking the system will always be part of it.”

“I am a product of online-shashki Forum. Without it, I wouldn’t know anything about DIY speakers and subs. I am so glad I do know what I know now!”


That’s a wrap for this week. Thank you Jared Kappeli for sharing your system, it is an impressive demonstration of what a frugal DIY approach can get you performance-wise. I’m sure that the final effect is very impactful and it’s great that you’ve shared your experiences with the community in build threads.

Want to discuss this system? Leave a comment in the forum.


online-shashki Forum members, are you proud of your stereo or surround-sound system? Here’s your chance to show it off at its best. Whether you are into two-channel systems, multi-channel surround-sound, or 3D immersive audio, you are invited to submit your system for consideration. Please click here to find out more.