Stereo tips… Subwoofers

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There is an excellent thread about everything you could ever want to know about stereo equipment for your S2000 in the Electronics forum. S2ki veteran (and mechanical engineer) PJK3 (Phillip) really did the homework on this and we strongly recommend the full thread as must reading. It’s so good, in fact, that we will be excerpting it here on the front page over the next few weeks. There’s a link to the original thread at the end of this article. Today: Subwoofers!

Do I need a subwoofer?

In the first order of needs, no. You will be able to make out words and music fine with just a component set. The ear is most sensitive to music within the 500 Hz to 2000 Hz frequency range. But if your only goal is to be able to hear the music, you could just run a pair of pro audio 5 1/4″ speakers in mono and full range and be done with it. However, your music will sound fuller and thus more realistic with subwoofers.

But I don’t listen to rap, do I still want or need a subwoofer?

Yes. In fact, I’d argue that big subwoofers are actually less important in rap music when compared to other music. One reason is that the bass hits in rap are usually in the 60 -100 Hz range, a place where many 6.5″ midbass woofers aren’t afraid to visit. The bass is used more to keep time rather than add to the harmony of the music. Also, as you’re far more likely to hear a synthesized bass tone in rap rather than a bass guitar or tuba, your brain has no reference upon which to judge whether the bass is coming from a live source or not. By adding a subwoofer, your music is much more likely to come alive and provide you with a realistic sound.

How big a sealed enclosure should I use for my subs?

For the purposes of the S2000, the answer will almost always be, “As big as can fit.” For generic subs, expect about 1/3 to 1/2 cu ft for an 8″ sub, 2/3 cu ft for a 10″ sub, and 1 cu ft for a 12″ sub. Want an even more specific answer? Look up the Vas, Fs, and Qts in your sub’s manual or online. Plug everything into this equation:

Min Volume = vas / (2 x QTC²) – 1

A little less than this amount and you should be fine because of cabin gain but don’t get too small or else your sub will sound boomy. Bigger is also okay within the limits of the S2000’s trunk. You can also refer to the manufacturer’s specification sheet. They will generally list either or both a sealed and ported enclosure size.

What’s the minimum amount of power I should give my subwoofer?

The minimum is dependent upon the sub’s sensitivity, the size of your enclosure, the sub’s T-S parameters, and your listening style. That said, 250 watts should be more than enough for most sub/listener combinations. Do note that one thing the minimum power is not dependent upon is the power handling of your sub (listed as either nominal power handling or RMS power handling on your sub box). This number has a lot to do with the maximum amount of power you should give but absolutely nothing to do with the minimum amount.

At your local car audio shop where they work on commission and would like you to spend as much as possible, they may ask you, “Why would you only want to give a 600 rms sub 250 watts? You should at least give it 500 watts or else you’ll be starving it.”

You tell him, “Because that’s all me and the sub need. It would be like me saying ‘My S2000 is capable of going 120 miles per hour so I never drive it slower than 75–even in my driveway.'”

Do I want a ported or sealed enclosure?

Sealed enclosures are more likely to sound tight with a smooth response. There may be some rolloff in output for very deep bass. Sealed enclosures can also be made quite small and are space friendly. Sealed enclosures will generally require more power, as the sub has to counter back pressure in the enclosure and will loose some efficiency.
Ported enclosures will generally be a bit more boomy, with a peak centered around the port frequency. They are generally more efficient and require less amplifier power to obtain the same output levels as a sealed box. A ported enclosure can also represent a potential for damage to the sub if music is fed to the sub that is below the tuning frequency of the port. A ported enclosure also requires more volume, both for the sub and for the additional port volume.


Here’s a link to the full original thread:


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