Axiom Home Page Forums General Discussion Technical Questions How do some subs go below 20Hz?

Send me a 600 and Mark and I will compare notes.

See? I showed restraint.

Alan and Johnk: Thank you very much for your replys. I love the science behind most everything—and I’m discovering more and more of it each day in the world of audio. It’s like being in High school AP Chemistry all over again. Loving it!!

Now I want to take this discussion to a more personal application level. As has been seen on my other posts lately, I have a family room that is open to a kitchen. They are roughly 16X24X9 (kitchen adding another 16X20X9).

I’m seriously looking at the following three subs:
Axiom EP350 12 inch driver, 200 Watts, Freq Resp +/- 3db (Hz) 25 ($650)
HSU STF-3, 12 inch driver, 300 Watts, Bass extension +/- 2 dB: 25Hz ($600)
SVS PB12-ISD 12 inch driver, 320 Watts, 22 Hz ($599)

Price is all comparable; frequency is all comparable, unless 3 Hz is a big difference in the low end. I honestly wouldn’t know.

Since sitting in a room and listening to each one individually is not really an option, how can the numbers game be worked to make a logical comparison? Now some would say that asking Alan that would only give me a biased opinion, since his check comes from Axiom; however, I somewhat disagree. I’ve seen your posts, Alan, over the past month or so and haven’t felt that you directly push people toward Axiom. You state the facts of science and encourage personal preference take presidence in listening—whenever possible. So, Alan, any assistance with how a person should look at subs to make a decision would be well received.

Thanks.

I think you are putting him in quite the position. Don't be surprised if he doesn't respond.

I don't agree. I'm not asking which one to choose, rather what should someone should look for when selecting a sub.

Look at it like a new car...the more you spend the more extras/options come with it, like adjustments on the back...hook-ups/gain/phase/crossover etc.etc.

Mark, I know that you were looking for a specific answer to the question of how low that we can actually hear, but as Alan implied, unfortunately you ain't gonna get it. You should look at these equal loudness graphs which don't appear to be Fletcher-Munson(the term is often applied to them generically)but rather from the work that Robinson and Dadson did in the 1950s. Note for example that to get the same subjective loudness as say 80 phons(80dB at 1,000Hz, a comfortably loud level)would require about 112dB at 20Hz. Even more recent investigations indicate that the previous results at very low frequencies may be optimistic. For example, the paper by Suzuki and Takashima summarizes much of this. Note in fig.1 on p. 919 that the latest results indicate even higher levels are needed at very low frequencies for audibility. I suppose that the bottom line may be that your walls will collapse before you'd actually hear below 20Hz.