I really am enjoying our forum over at HomeTheaterEquipment.com because so many new, unique and exciting products are being brought to my attention en masse that would've otherwise gone unnoticed for one reason or another. Among them is a small black box from a company called miniDSP. The miniDSP 2x4 reviewed here is a unassuming piece of kit at $125 retail and yet, as I found out during my time spent with it, is among the more versatile home theater products I've encountered. You see, the miniDSP isn't a standalone product, but is instead a small device that you can use to load home theater programs that carry out a variety of chores. For me, and for the purposes of this review, this meant subwoofer parametric equalization.
The miniDSP itself is roughly three inches square and maybe an inch tall. Its all-black housing plays host to two RCA-style analog inputs on one end and four analog audio outputs on the other. A USB input is also present and serves as the unit's power supply, though the required USB to power adaptor is not provided. This leads me to believe that it is the intent of the miniDSP's creators that it remain plugged into a PC or Mac 24/7, though I did not use it in that capacity.
Inside the small aluminum housing is a small circuit or motherboard that houses the unit's 28/56-bit Digital Signal Processing Engine and its 48MHz microcontroller. The miniDSP uses Nichicon Audiophile capacitors, but otherwise, not much else is specified about what is happening under the hood. Truthfully, what makes the miniDSP tick are its proprietary plug-ins (think apps) that make it "dance." Each plug-in costs an additional $10 and can be downloaded via miniDSP's website, uploaded and used as needed by the end user. If you want to use the miniDSP to control and provide parametric EQ to multiple subwoofers, as I did, you'd simply download the appropriate plug-in, which for me was the two-way PEQ 21 plug-in.
Buying the required plug-ins are easy and straightforward, provided you don't rely on satellite Internet as I have to do. I'm confident this is not the case for many other people, so getting your miniDSP up and running should be rather painless. For me, it meant having to rely on a friend to download the software, then email me the file (it's small) so that I could install it on my laptop. Thankfully, miniDSP's plug-ins are both PC- and Mac-compatible, so those loyal to one or the other won't be forced to run emulation software. The plug-in itself resides on your computer's hard drive and merely serves as an interface to the miniDSP itself. The two-way PEQ 21 plug-in is a self-contained program that was initially designed to be used in an active stereo-plus-subwoofer application but, due to its somewhat step-by-step nature, you can pick and choose which of its feature sets you wish to utilize once you're inside the program. Like I said, I was only interested in the PEQ 21's subwoofer capabilities which makes for a powerful combination when in conjunction with Room EQ Wizard (REW).
If you know anything about EQ and have the requisite tools and knowledge to go it alone, then the PEQ 21 plug-in is all that you require. However, if you're like me and appreciate it when technology helps streamline the process, then I urge you to download REW and use it in conjunction with the miniDSP device. With REW, I was able to generate a six-band filter pack very easily, using an outboard Behringer USB interface, a Radio Shack SPL meter and some inexpensive RCA cables running to my two JL Audio Fathom f110 subwoofers. With the filter pack data in tow, I was then able to manually enter it into the PEQ 21 plug-in and then upload it to the miniDSP itself. I have only three caveats about this process. First, the PEQ 21 plug-in rounds up to the nearest whole or half integer when entering in your frequency, gain and Q settings, making absolute equalization somewhat of a compromise. Second, there is no indicator light letting you know that your settings have taken hold inside the miniDSP's processor. Third, I didn't like having to toggle between two different programs, even when miniDSP claims to have direct support from REW. Either they do or they are working on it, but using the version that was available to me, I had to toggle between REW and PEQ 21, which simply isn't as smooth, or as easy, as what I do with my reference Behringer Feedback Destroyer Pro that I normally use for my subwoofer equalization. Once the filter pack was uploaded to the miniDSP and I connected its included USB cable to a USB power adaptor, it performed as advertised and provided me with smoother, more accurate bass response from my two JL Audio subwoofers.
Read about the high points and low points of the miniDSP processor on Page 2.High Points
• For an equalization solution, the miniDSP is
about as compact and easy to use as they come, provided you're willing
to do a bit of program installation and know how to use software such as
Room EQ Wizard.
• Because of its two-input and four-output
configuration (other configurations are also available), the miniDSP 2x4
will allow you to run and EQ up to four subwoofers in your system, even
if your AV preamp or receiver only has one or two subwoofer outs.
The miniDSP's plug-in or app-based interface is rather ingenious and
allows it to change easily to your needs, as well as making it virtually
• The various apps or plug-in GUIs are very clearly
and intelligently laid out, making the need for in-depth instruction
somewhat null and void. However, miniDSP and its designers have clearly
aimed the product at the enthusiast with a DIY spirit and a fairly
robust working knowledge of topics such as EQ, crossovers, etc.
I didn't like that there was no onboard way of indicating whether or
not the upload had taken affect. Something as simple as a red/green LED
would've been appreciated.
• I didn't like that the plug-in I used
for subwoofer equalization rounded up to the nearest whole frequency
value and, as was the case with Q and Gain, the nearest half value.
There are options available out there that cost about the same as the
miniDSP and that interface with REW, and yet don't do this. Is the PEQ
21 plug-in better than nothing or even better than some onboard EQs that
are all the rage among subwoofers these days? Yes, absolutely. It just
isn't as good as my reference.
• While miniDSP claims their products
interface seamlessly with REW, I didn't find this to be the case, as I
continually had to manually enter my REW figures into the PEQ 21
plug-in, instead of simply importing an already saved file. Hopefully
this is just a temporary bug that has an easy solution. Regardless, I
was always able to manually enter in my filters and achieve suitable
results and performance that way, so it's not like you're going to be
left out in the cold.
Competition and Comparison
starting to dive into the concept of outboard and/or specialty subwoofer
equalization, so my experience with comparable products is somewhat
limited. This said, I have no qualms about suggesting that the miniDSP
and its PEQ 21 plug-in are every bit as good as, if not better and more
flexible than, the low-end EQ you'll achieve through Audyssey. Now, is it
as automatic as Audyssey? No, but if you're one to get your hands
dirty, as they say, then the miniDSP may be worthwhile. For me, it still
falls a bit short of the performance of my Behringer Feedback Destroyer
Pro, which for roughly the same money is a bit more robust and easier to
use as a subwoofer EQ. Then again, you can't upload other plug-ins to
the Behringer, making the miniDSP far more flexible, not to mention
compact. Since I was only evaluating the miniDSP as a subwoofer
equalization device, I feel it comes in second place to my Behringer.
However, as a broader equalization/tuning tool, it takes the cake, for I
feel as if I've only barely scratched the surface of what it can do.
more on these topics, as well as subwoofers in general, please check
out Home Theater Review's Subwoofer Review page.
miniDSP is one of those rare finds that I'm coming across more and more
these days since the advent of our forum, in that it's a product that
does more than one would expect, given its modest asking price of just
over $100. Granted, I demoed it to only a small fraction of its true
potential. The miniDSP is a more or less like a Swiss Army knife for
home theater and two-channel enthusiasts. As a subwoofer EQ, it's quite
good, though I have encountered better; as a somewhat future-proof
speaker system "tuning fork," it may have no equal. If you fancy
yourself a DIY'er with an adventurous spirit, the miniDSP and its host
of download-friendly plug-ins are ready and waiting.