Velodyne Mic-5 Add-on Supplementary Review

Product Name: Mic-5
Manufacturer: Velodyne
Review Date: April 6, 2007
MSRP: $799

Pros

• No harder to use than the standard SMS system
• Allows EQing across multiple seats

Cons

• Expensive
• Short mic stands can make placing mics difficult

The proprietary Velodyne subwoofer correction system is included in all the higher end Velodyne subs as well as a standalone unit called the SMS-1. Anyone that has done much research about subwoofers has undoubtedly run across the SMS-1. A 1/3 octave smoothed, on-screen graph in real time makes adjusting and parametric eq’ing a subwoofer an exercise even the most technologically challenged can excel at. While some argue that the smoothing of the graph can hide some real problem areas, the fact remains that the SMS-1 is one of the only products available at ANY price point that is this user friendly. Just about all other solutions require multiple measurements by hand or a college degree of some sort. Most cost significantly more than the SMS-1. But the SMS-1 has one major drawback – no way of taking multiple measurements in order to get a more representative response across a large area. No longer. The Mic-5 add-on allows the user to take into account multiple simultaneous measurement positions (up to five, obviously) and adjust their SMS-1 to get the smoothest bass response over a greater number of seating positions by averaging the measured response envelop.

 

Setup

The Mic-5 really doesn’t require all that much setup except where and how to insert the battery (oddly enough, this step is not included in the user manual). For some reason, Velodyne decided that it would be neat to have the user have to disassemble the Mic-5 hub in order to insert the battery rather than providing a little door like every other product on the market. After you’ve done that, it is simply a matter of plugging the 20 foot XLR cable from the SMS-1 (or the back of your Velodyne sub) to the Mic-5 hub, and the 6 foot XLR cables to all the different microphones you plan on using. There is a power button on the top and a second “selector” button that cycles through 1 to 5 mics.

There are small stands provided for each of the mics as well as a separate threaded holder that can be attached to a telescoping mic stand (if you have a few of those lying around – I don’t). The small stands are perfect for setting on top of the back of your chair if your ears typically settle in that area. Otherwise, you’re going to need to try to get the tip of the mics near ear level.

Use

I seriously suggest you read Gene and Clint’s review of the SMS-1 as it makes sense of an indecipherable user manual. As it is so well done, I won’t rehash it here. If you are anything like me, you’ll be very careful about where you set up the mics and their positioning, but you’ll just plug them into the Mic-5 hub at random. Fight this urge. If you take a little time to think about it, you can basically set up multiple zones. Since the Mic-5 adds mics numerically (1, 1+2, 1+2+3, 1+2+3+4, 1+2+3+4+5), you should probably set mic 1 as the Primary Listening Position (PLP). Mics 2 and 3 should probably flank the PLP creating an “expanded” sweet spot (or enough room for you and the missus or you can place them in the main listening area to apply heavier weighting to the sweet spot). The last two mics can extend out from there to include other seats in the room (the Tertiary Listening Positions – TLP). Now, this works best if you have a single couch. If you have two rows then mic 1 should be the PLP, mic 2 and 3 at the ends of the row, and 4 and 5 in the second row. That way you can calibrate for multiple seating arrangements without having to unplug or move mics. You just have to press the button on the hub.

One issue that I had was that the onscreen graph didn’t adjust for increased volume. Because my room is small and my sub is so big, too much volume on the sub would push the graph past its upper limits. Too little volume and the sub wouldn’t engage. I ended up having to adjust the volume on my Denon AVR-3805 until it was high enough for the sub to engage on all frequencies but not so loud that it overshot the top of the graph. I’d like to see an auto scaling feature which would automatically adjust the graph for higher SPLs.

Results

In my fairly small listening room, I first set up a mic at the PLP, two on either side creating the “expanded” sweet spot, and the final two in the outside seats (which would be considered my TLPs). With my room size, that many mics basically made it impossible to do much with the EQ as room effects were canceling most everything out. I ended up going with a mic at the PLP (center of the couch) and one on each of the TLPs (the outside seats). This gave me enough separation to actually make some changes. With a larger listening room I could have utilized all the mics.

As I’ve recently started using floorstanding speakers rather than bookshelves, I want to see how things would work with the sub engaged and the speakers set to Small vs Large:

Single mic at the PLP

Speakers set to Small                      Speakers set to Large

Three mics

Speakers set to Small                Speakers set to Large

As you can clearly see, there's not really much difference in my room. The Axiom m60 v2’s aren’t truly full range so this isn’t exactly surprising. With speaker set to Large, the problems are a little bit improved as the low end extension helps to smooth out the crossover frequency. The gains, however, may not be enough for me to risk bottoming out the speakers on reference level playback of the Lord of the Rings movies. With this in mind, and for purposes of this review, I went ahead and set the speakers to Small and started my adjustments. Since my crossover is set at 80 Hz, we are really only looking at the flatness of the line below that point. Recalibrating the speaker levels after this process will bring the two halves of the graph more in line. With a few minutes of tweaks, this is what I ended up with:

Single mic                               Three mics

Much, much improved on all counts. I set both up on different presets so that I can easily switch between the two if I decide to change on the fly. The process was relatively simple and painless. With a couple of button presses I was able to switch between a single mic and tri-mic configuration. It didn’t take long to dial the system in to what you see above. See our SMS-1 review for specifics on use.

Listening Tests

Listening tests… well with these graphs do you think we really need them? It is such an obvious difference. Any movie, any music with a descending/ascending low bass line will immediately demonstrate the differences. There are lots of ways to do a test like this, but I find that the easiest is to find something with a bass run. Now, I could stick in a test CD or DVD and just select “20 Hz to 200 Hz sweep” or something but what fun is that? No, I’d much rather listen to something more interesting not only because it is more fun, but so that you can replicate it at home. For music I use Yello: the eye, "Junior B". It has a number of descending bass sweeps in the track that are just perfect for this type of thing. But you probably don’t have that album. But I bet you DO have Star Wars Episode II: Attack of the Clones. If you don’t, you can rent it. At the beginning of this movie (chapter 3) there is a ship that flies by three times (and lands once but the landing isn’t quite as “sweepy” as it is “rumbly”). Each of these flybys constitutes a low frequency sweep. Play these at a fairly high volume and listen for any real big changes in volume. Now, these aren’t perfect sweeps so don’t expect a perfectly uniform sound but it should sound pretty consistent. If it doesn’t, you’ve got problems.

More than anything with these listening tests I was curious about how the multiple mic calibration would compare to the single mic. I expected that with the single mic, the PLP would be best at the expense of the two TLPs. What I found was that the tri-mic setup worked best at ALL positions. As I look back at the graphs, I can see that the tri-mic graph is flatter but I attributed some of that to the averaging across the three mics. I’m guessing that with a little more tweaking of the single mic setup, I’d get the results I expected. When I compared the two to preset 6 (which bypasses all EQ settings on the SMS-1) both are huge improvements at the expense of a bit of extension. Now those of you who place primary importance on every last frequency may be appalled by this but I’m happy to lose a little of the bottom end as a trade off for a flatter bass response. Every time.

Conclusion

What I found was that the three mic calibrated setup worked best at ALL positions!

It is so easy to get used to bad bass. You start to think that your 40 Hz bump or 70 Hz suckout is “normal”. So much so that when you start to hear corrected bass, you feel like something is missing. But after a few hours you’ll start to think, “Hey, I never noticed how low this passage goes” or “This sounds so much cleaner than before.” The fact of the matter is that 'boom' might impress your friends but good clean bass will impress everyone. You’ll be able to turn your system up louder because your 10 dB bump will be tamed. You’ll hear more articulate bass at lower levels because you’ll have a more even response across all frequencies.

There are very few additions to a full surround system that have the impact of a room correction system. You’ll wonder how you ever got along without it. And with the addition of the Mic-5, you now have the ability to correct for multiple seating positions creating a better experience for everyone. While the Mic-5 add-on may be a bit pricy for the average consumer, I can see it as a very good investment for an installer or perhaps a group of friends that can split the cost. It is nice to be able to correct for a sweet spot, but multiple seats takes it to a whole other level.