Parts Express Midwest Audiofest DIY Speaker Show Report

Parts Express recently held their annual audio festival that they call the “Midwest Audiofest” which is a gathering of audio aficionados and related groups for a day of trade, competition, and socializing. The festival features three events: a DIY speaker competition, a tent sale, and a swap meet. The tent sale is where Parts Express and other manufacturers put their products out on display and also sell other products at hefty discounts. The swap meet is where enthusiasts can buy or trade different audio components from each other, so it is almost like a garage sale of audio gear. The speaker design competition is where DIY speaker makers bring their creations to be evaluated by a panel of judges who assigns winners and awarded prizes. Parts Express invited Audioholics to attend this year's Audiofest to see what all the buzz was about. We decided to have a look, not being one to miss out on a spirited audio event whenever possible.

The big draw for us was the speaker design competition. One of the cool things about loudspeakers is the many different ways there are to achieve the same end result of a great sound. This is what sustains our interest in speaker design. A DIY speaker design competition is a great place to see how different approaches can all add up to great sound, so this is where we spent most of our time. Midwest Audiofest holds four competitions in different categories of speaker design:

• Under $200 (where the total parts cost of the speaker must not exceed $200).
• Over $200 (where the total parts cost of the speaker is over $200).
• Dayton Audio (where only Dayton Audio drivers are used in the design).
• and Open Unlimited (speaker designs that don’t quite fit into the other categories).

Parts Express assembled a very distinguished panel of judges for the design competition: Jerry McNutt, who is the product design manager at Eminence Speakers LLC, which is a major driver manufacturer. Peter Noerbaek, founder of the highly-regarded high-end audio company PBN Audio was also a judge. The last judge, Vance Dickason, is well-known to speaker designers, both amatuer and professional, as the author of the speaker building bible, the “Loudspeaker Design Cookbook,” which is just one of the many contributions he is known for within the audio world. These are a trio of guys who know what a speaker should sound like! The DIY entrants were going to be facing some finely tuned ears.

There were a lot of great designs at the show, but we only had time and space enough to cover a handful. Sadly, we had to omit some really cool speakers. We will share with you at least some of the interesting creations made by the DIY community that we saw there. One such speaker was the “Reference Mini” by Brian Zheng.

With the Reference Mini, Brian set out to make the best possible full-range speaker in as small enclosure as possible. Since Brian relocates frequently he wanted something high-quality that could be transported easily. The Reference Mini is an active, three-way design that uses some of the best components that can be had for the money. It is an all-out effort that took many months of design, construction and tweaks, not to mention thousands of dollars. Much about the Reference Mini can be read in this epic forum thread which follows the design and construction stages of the Reference Mini. On display is the sheer perfectionism that Brian wanted for his speakers. Such attention to detail surpasses even most commercial loudspeaker designs. As one would expect, the resultant sound that we were lucky enough to hear was outstanding, a loudspeaker of extraordinary high-fidelity.

A not-so-compact speaker that impressed us was the “EPQ-3W” by Javad Shadzi. These floor-standing beauties wowed us not only with their elegant looks but also their terrific sound. The EPQ-3W is a three-way design using Dayton Audio’s top-of-the-line drivers, including a high-output 8”x4” midrange AMT driver (the AMTPRO-4), a higher-end AMT tweeter (the AMT2-4), and Dayton Audio’s new high-end Epique woofer in an 8” diameter (the Epique E220CF-8). This may will be one of the highest-end loudspeakers built using Dayton Audio drivers. A commercial equivalent would run from five to ten thousand dollars. The cabinet is constructed of Russian Birch with a gorgeous Chechen wood baffle and a carbon fiber veneer on the side panels. The frequency band that midrange AMT driver takes is quite surprising, crossing over from 1.15kHz to 9kHz. That isn’t the kind of range that can normally be used very well with conventional cone drivers (with a few exceptions), and it makes that midrange driver the heart of that particular speaker. It sounded outstanding, and the design suggests an enormous dynamic range potential relative to most home audio loudspeakers.

Loudspeakers are more than just stationary objects that sit on your living room, and a great reminder of this is the “DeadWagon3.Glow” by Tim Miller. The DeadWagon3.Glow is a battery-powered audio system on wheels. It is essentially a high-quality car audio system mounted on yard cart. It uses four coaxial speakers (the NVX VSP65) mounted on both sides of an angled, sealed cabinet and powered by a 400-watt amplifier (the NVX MVPA4). The amplifier is fed by a 12v battery (XS Power A3400) and uses a Pioneer car audio head unit (DEH-S4000BT) mounted at the front. Sadly, this particular system was not entered in the competition itself, as it was not registered in time, but its appearance was a delight to everyone who came across its path. I'm sure Tim could hardly get anywhere at Midwest Audiofest at more than a snail's pace since fellows like me kept stopping to ask about his unusual creation. It sounded great and looked sensational, especially with the undercarriage lighting. The ‘3’ in the name DeadWagon3.Glow signifies that this is the third iteration of this project by Tim. The previous two versions of this project were experiments that didn’t quite turn out as well as he had hoped, but this was the one that clicked. When I think about the usefulness of such a device, a high-powered, high-quality, mobile audio system for events such as music for outdoor parties, camping trips, barbecues, or pretty much any outdoor activity, it’s hard to believe that this is the first time I have seen anything like it. It’s a testament to the ingenuity of the DIY community, and I would honestly not be surprised to see this in some sort of commercially manufactured form in the future. Very nice work, Tim!

One very nice design that caught my eye was the “JaWZ Pause” speaker system by Steve Vinson. Steve’s objective in creating this system was something that had high-fidelity sound without sacrificing a wide dynamic range. While the central idea for the JaWZ Pause were Steve’s, he did have a lot of help in putting together the overall design, and this is the reason for the odd name where letters stand for the names of individuals who assisted (J is for Javad Shadzi, W is for Ben “Wolf” Shaffer, Z is for Jeff “Godzilla” Feith, and Pause is in recognition of Rick Craig of Selah Audio). The JaWS Pause uses some pretty heavy-duty drivers, hence its extremely wide dynamic range: two FaitalPro 8” Professional mid-bass drivers (the 8FE200) in an MTM configuration with a B&C DE250-8 compression driver which is set in a SEOS 10” horn. The crossover is a 12-element, 4rth order (acoustic) slope that occurs at 3kHz. The front baffle uses a gorgeous ‘Poplar Heartwood’ finish.

While the speakers were very powerful, they are intended to be used with a subwoofer and so do not dig very deep, which is why two 12” ported subwoofers were made to compliment the main speakers. The subs share the same finish and use SB Acoustics 12” drivers. As a entire speaker system, the JaWS Pause rocked! It is a case study in how to get good looks and great sound from Pro-audio components.

A cool and unusual design that caught my attention is the “Rhynos” by Taylor and Adrienne Hansen. Taylor and Adrienne decided to use a cinder block for the enclosure! This is not an intuitive idea at first but actually holds some real advantages when it is considered. Clearly, an enclosure made from a cinder block will have much less problems with cabinet resonance than ordinary MDF, so long as the front and back panels are properly secured and braced. What’s more, it saves a lot of time in the cabinet construction phase when half the cabinet is already assembled. I also thought it was a cool way to reuse something common and very inexpensive in another unintended application where it has an interesting new use and potential. The challenge for Taylor and Adrienne was getting as much bass extension as possible out of the predetermined volume of space of the interior of the cinder block. They decided to use an actual small-cone subwoofer driver to take care of bass and a very wide band tweeter to meet its upper end response. The bass driver is the Tang Band W5-1138SMF and the tweeter is the now discontinued Tang Band 28-847SD. The tweeter has a remarkably low resonant frequency of 850 Hz which make it a great pairing for a two-way speaker that uses a subwoofer driver for low frequencies. The Rhynos speakers sounded terrific from the demo that we were given, and they measure very nicely from the responses that I was shown. Personally, I would love to see them inspire more DIY speaker builders to look at cinder blocks or other construction material as an easy and inexpensive way to make an extremely strong cabinet.

For something really unique, Meredith Cargill built a massive horn-loaded subwoofer tuned to 20 Hz using the corners of the main competition room itself as the mouth of the horn. He has dubbed it the “Pontecorvo Leviathan” (Pontecorvo is the name of the studio room that the competition was being held in). This is, by far, the largest subwoofer I have ever seen. To be sure, it wasn’t a serious attempt to build a truly high-fidelity device, and it was more like a fun experiment made for a one time use only. It is essentially a series of cardboard tubes and paths that were duct taped together across the length of the room. A true horn of such a deep frequency is a rarity since the horn length has to be a quarter of the lowest frequency wavelength that it intends to produce, and a quarter of a wavelength of 20 Hz is 14 feet. The path length of the main horn of the Leviathan is 32 feet which is the quarter wavelength of 8.7 Hz. Furthermore, the ‘main horn’ of the Leviathan is abetted by a shorter pipe that functions as a quarter-wavelength resonator tuned to 19 Hz; the quarter-wavelength resonator is 19 feet long. The main horn and the quarter-wavelength resonator are driven by a pair of 15” infinite baffle subwoofer drivers mounted in an isobaric configuration. For a brief time, the Pontecorvo Leviathan roared with life and managed to pressurize the very large room that it was installed in, much to the delight of everyone who was fortunate enough to witness it. To be sure, much of the sound was the cardboard buzzing with resonance rather than clean bass, but it was a blast to hear and see anyway. The mighty Pontecorvo Leviathan was then unceremoniously destroyed only a day after it was installed. One is reminded of the famous quote from the Tao Te Ching: “The flame that burns twice as bright burns half as long”.

Conclusion

While there was plenty of things to see and do at the Midwest Audiofest, at the tent sale, swap meet, or competition, it seemed to me that the overall point of the festival wasn’t any specific activity so much as it was about Parts Express fostering a sense of community. This is a smart move on behalf of Parts Express, since most of their business is done through the anonymity of the internet. There is a passion for audio systems that brings people from all over the country to events such as this. Setting the stage for face-to-face contact from fellow hobbyists is smart from a business perspective because cultivating those kinds of relationships helps to create brand loyalty more than merely gazing at some webpages which would be the extent of their business otherwise. However, there is more to Midwest Audiofest than just a business decision for Parts Express. It has to be gratifying for Parts Express’ employees to see the components that they manufacture and sell being used in such superb creations. Also, helping to create a community and establishing friendships has to be a rewarding feeling as well. I enjoyed my time at Midwest Audiofest and hope to attend it again. For those especially passionate audio enthusiasts out there, I would highly recommend they attend as well, because I am sure they would enjoy their time there.