[WannaKatana]

Thank you for your great reply.

From that article these are the qualities that caused me to choose
sealed box:
1. sub to mid-bass blending as you mentioned
2. Good transient response (I'm not an engineer but I am a programmer
:-))
3. I mentioned more drivers to ensure good volume at very low
frequencies and based on the article, to overcome the increase in
distortion encountered when using high power (more drivers at moderate
power rather than less at high power). I'd rather "over engineer" it.
On the other hand, if I get a very good quality driver, I may not even
need more. I'm not looking to blow the neighbors out of their chairs.

Even though there are few opportunities in music to do it, it would be
cool to be able to reproduce very low tones (sub-30hz) with a decent
volume, just for a once-in-awhile wow factor.

In general I want accurate and smooth frequency response. No boom but
maybe a bit extra on the high side since years of loud music and drum
playing has left me a little deaf :-)

I appreciate your comments and suggestions. I really love car audio
appreciate learning from those more knowledgeable.

Anyone have a guess at the frequency of those bass synthesizer tones?

Thanks!

Joel

D.Kreft wrote:
On Dec 24, 10:50 pm, "WannaKatana" wrote:

I've always wanted a
sealed system for the accuracy and tight bass. I'm hoping sealed will
be good for this purpose as well.

If you're like 99.9% of all car audio enthusiasts, "tight bass" means
nothing more than having midbass drivers that blend nicely with your
subwoofer system. If you speak in quantitative terms (which nobody but
engineers do), "tight" speaks to the group delay characteristics (how
fast the driver responds to incoming signals) of the subwoofer
system--which is where sealed enclosures really excel--but I seriously
doubt that this is what you're looking for.

I may have to double the number of
subs since sealed enclosure rolls off so quickly so they are
sufficiently loud enough (no boom though!).

I'm not sure where you're getting your information here. A sealed
enclosure is a "1st-order" system, meaning its characteristic low
frequency roll-off occurs at a rate of 6dB/octave below the f3 (-3dB
point). Ported enclosures will roll off at no less than 12dB/octave (or
more, depending upon the alignment used). In short, a sealed system
will roll-off at least half as fast as a ported enclosure. Where you
may be getting confused, however, is where the -3dB point occurs. As a
general rule of thumb (and there is great room for variation here), the
f3 on a sealed enclosure will typically be a bit higher than that of a
comparable ported enclosure...so it is quite possible to have a ported
enclosure that plays much, much louder at 30 Hz than the same driver in
a sealed enclosure. If I had speaker modeling software on hand, I'd
plot some examples, but I don't so I can't. :-)

-dan