Benefit of suwoovers

Bass in Yo’ Face!: The Benefits of Stereo Subwoofers

On a whim I purchased a couple of DIY passive subwoofers in order to experiment with stereo bass on my 2-channel system. The drivers are 10″ Ascendant Audio Arsenal subwoofers. I’ve owned two different Ascendant Audio drivers before, so I know they are top notch performers. At first, I was skeptical about getting small drivers, but I didn’t have the space near my front speakers for larger ones, so I figured I’d take a chance and try these out. The seller made the cabinets from 3/4″ plywood and they are heavily damped. The subs are 17″ tall, 23″ deep, and 12″ wide with a textured finish. They definitely have that DIY look to them, but who cares?

Anyway, I’m temporarily powering them with the 6th & 7th channels of my multichannel amp (Emotiva LPA-1). It’s only 95 wpc into 4 ohms, but enough power for these particular drivers. I’m using a Reckhorn B-1 bass management controller. It’s a great little device, and perhaps the subject of a subsequent review. The subs are hooked up to the line outs on my Emotiva LMC-1 pre/pro.

I have a pair of “full range” front speakers (VMPS Tower II SE’s); each speaker has dual 12″ woofers and a 12″ passive radiator. These speakers create tremendously tight bass, but in spite of their size and power, they still don’t pump out the lowest levels of bass. I always knew it, but was afraid to admit it to myself for fear of spending too much money on upgrading. The speakers, as impressive as they are with bass, still left me wanting more.

The DIY subs make a HUGE difference! Upon introducing the stereo subwoofers, everything changed. In fact, the subs catapulted my system to another level and the sound far exceeded my expectations, not only in bass, but in soundstage, detail and clarity, as well.

With music, the bass is very tight and tuneful. It sounds like an entire wall of sound. Some of my bass heavy music sounds entirely different with the subs. Even a few of my jazz cuts have surprisingly deep bass.

The subs offer not only bass, but a whole new dimension to the music. The sound is fuller, deeper, and simply more realistic. For some reason, I can play it louder without fatigue, and the bass is often gut wrenching, even on music I hadn’t heretofore considered bass-heavy. Because I can play music louder, I hear more subtleties, and the ones I faintly heard before are magnified. I am hearing musical passages that I didn’t know were there before, and this has fueled new excitement and improved listening enjoyment.

To show off my subs, I purchased a couple of bass-heavy CDs – Heartbeat Kodo 25th Anniversary (Japanese drummers) and the old school “Planet Rock” by Afrika Bambataa and the Subsonic Force Remix EP. The Kodo CD has the lowest bass I’ve ever encountered on a music CD, so when friends visit, they’ll get to hear what serious bass ought to sound like in a stereo system.

In the past I have used single subs for bass reproduction and it has sounded very good, especially when the sub blends well with the mains. However, stereo subs are a much better choice because, ugh, music is in stereo. Some people will argue that most CDs aren’t mixed to produce stereo bass. I won’t argue with such logic. All I can do is report what I hear, and I hear more bass separation from stereo subs than I do with a single sub. Nevertheless, in my opinion, one can never have enough bass.

To gain a greater appreciation of subwoofers in a 2-channel system, let’s use the analogy of a home theater system. Imagine watching a movie with a high end HT system with floorstanding speakers, but no subwoofer. You know there’s something missing, don’t you? Now imagine the same system with a nice subwoofer. The movie experience has increased dramatically. We’re not done yet. Now imagine adding another well calibrated subwoofer, and the experience improves even more. So if bass makes such a huge impact on sound quality for home theater, shouldn’t bass have a similar impact in a 2-channel environment?

Even large floorstanders benefit from a sub, no matter how well the manufacturer claims that their speaker can reproduce the lowest bass frequencies. Moreover, separating the bass is important for other reasons. Typically, optimum room placement for bass is in the corners. By using stereo subs, there’s more placement flexibility for optimum bass.

OK, so how do the DIY subs sound with movies? Well, think about adding two more killer subs to your HT system and you’ll get an idea of what I’m hearing and feeling. I already had a huge VMPS sub with a 15″ driver and 15″ passive radiator. Now I have three subs and the bass is ridiculous. My room size is 13′ x 20′ x 8′. And no, I haven’t reached overkill yet.

I played scenes 5 & 6 of War of the Worlds. It was insane! A couple pieces of insulation blew out of the port on one of the subs. The vibration it caused I actually thought the whole house was shaking, and maybe it was I dunno. It was an obscene amount of bass. In addition, there was more clarity, too. I heard stuff in those scenes I hadn’t heard before. There is more weight, substance, and overall feeling of realism that was simply remarkable.

And with bass, bigger is better.

In my opinion, subwoofer drivers belong in big boxes, and another reason for separating the bass from the main speakers. For instance, a small drum gives off a small sound no matter how hard you whack it; the bigger the drum, the bigger the bass. Small subs are fine for small rooms and certain kinds of music, but if you get a sub for a nice 2-channel system in a moderate or large room, it ought to be capable of playing loud and digging deep with minimal cone movement and little stress on the amp to keep distortion low.

Integrating a subwoofer with the main speakers requires patience with placement and a bit of crossover tweaking. The main speakers and the subwoofer should overlap each other for at least one full octave. Additionally, the main speakers should have a fairly decent bass so the subs can be crossed over fairly low.

By the way, don’t listen to those who tell you that your main speakers are OK if they are flat to about 30 Hz because the vast majority musical instruments don’t go any lower than that. You’d be surprised at what you’re not hearing on your CDs (if that makes sense). Likewise, never take advice from someone who says, “Subwoofer X is equally good for music and movies.” Most subwoofers are made for home theater. If you are looking for subwoofers for music, your choices are limited. Check out those manufacturers who design subs primarily for music.

If you decide to take the stereo sub route, watch your spending because stereo subs can quickly become pricey once you take into consideration the associated components – external crossover, speaker cables, interconnects, power cords, and amplifier. Don’t even think about using a standard plate amp for music. (The exception is the 1,000 watt plate amp offered by Parts Express.)

Final Thoughts

No matter how much money you spend on a 2-channel system, it will sound anemic if it does not convey the full spectrum of musical frequencies. Omitting the lowest frequencies doesn’t represent an accurate reproduction of music. Unless you have speakers that can easily dig down to about 20 Hz, you need a properly integrated subwoofer or two to complete the sound.

Most audiophiles constantly swap out gear looking for the elusive holy grail of music (whatever that is). But what we often forget to realize is that no matter what gear we own, the sound emanates from speakers. And those speakers should be able to deliver all of the music on the CD and not truncate the lower octaves. It’s kinda like eating dinner and leaving before dessert is served. So unless you’re on a music diet, treat yourself some bass in yo’ face!

from affordableaudio, By Brad Mitchell