In-Car Frequency Response
Test of Four Loaded Subwoofers
Purpose
The purpose of this test is to accurately compare the differences in
frequency response of four different automotive subwoofers in their
proper enclosures:
- Advanced Composite Audio ACAW160 - dual voice coil, 6.5" driver in a fourth order, bandpass enclosure. Gross Volume 0.88 cu. ft.
- SAS Bazooka T80 - single voice coil 8" driver in an 8" tube, Gross Volume 0.83 cu. ft.
- JBL GTM80 - single voice coil 8" driver in a 10" tube, Gross Volume 1.3 cu. ft.
- Acoustic Solutions TSSS - single voice coil 6.5" driver in an IntraPortedTM bandpass enclosure, Gross Volume 0.68 cu. ft.
Conditions
- Test Environment: compact car, hatchback style
- Amplifier Zapco Z150 used in mono mode
- Analyzer/source: Ono Sokki CF360Z
- Microphone: Lectret L120
- All equipment levels and gains were constant throughout the test.
- The microphone was placed over the center of the drivers seat at ear level.
- The analyzer was set up in a fast sine sweep mode with 16 averages.
- All but the ACA W160 present a 4 ohm load. The W160 was wired in series, presenting an 8 ohm load and so the graph was shifted up 3db to make up for the impedance difference.
The Results
The graph accurately shows the frequency response of each speaker system
in the same acoustic environment. The ACA W160 is a fourth order
bandpass enclosure with a high "s" Ratio and high gain which provides
more SPL, but results in a extremely narrow bandwidth. The SAS T80 is a
bass reflex design with its acoustic power centered at 60 hz. and
typical sharp roll-off. The JBL GTM80 is also a bass reflex enclosure
with a 60 hz. center frequency. However, the vent on the JBL is located
on the opposite end of the enclosure from the driver, whereas the driver
and vent on the SAS unit are on the same plane. This explains the
difference in the response curves in the 20 to 40 hz range. The Acoustic
Solutions TSSS enclosure design is called an IntraportedTM Bandpass.
Similar to a 4th order bandpass design but with an additional vent
between the front and rear volumes. The acoustic center of the TSSS is
50hz and it exhibits an unusually broad bandwidth. Achieving this wide
of a bandwidth with a 4th order design would use a "s" of .4 and would
suffer the subsequent 2.7db dip in middle of the passband. As the graph
shows, however, the TSSS not only avoids the center frequency dip, it
actually goes up about 1.5db! The response curve of the Acoustic
Solutions TSSS looks like the smooth, "s" ratio of .7 or higher, but
without the narrow bandwidth limitations.
Dave’s Top Ten reasons NOT to get a SubSolutions subwoofer:
10. Having a sub box that takes up all of my cargo room means that my
wife can’t ask me to run errands.
9. I don’t need to hear full, deep, linear bass. Just “one-note” bass is
fine for me.
8. My gas mileage is too good, so, having an extremely heavy sub box
helps me waste gas.
7. Having subs that show, gives my young kids something to poke holes in
while I drive.
6. Even though I have a beautiful new vehicle, I want to clutter it up
with a big ugly sub box.
5. I like the idea of an in-efficient sub, so that I can buy a huge,
gigantic amp to run it.
4. I enjoy hearing the slop and delay of large drivers. It makes the
notes blur together nicely.
3. If I’m in an accident, my huge box can kill me, so I won’t have to
pay the deductible.
2. I like having a standard, ordinary, big box, like everyone else. I’m
unique like everyone else.
AND, …the number one reason not to get a SubSolutions subwoofer…..
1. If my subs show, it’ll attract thieves, and get my system and CD’s
stolen, so I can get new ones!
Download SubSolutions Owner's Manual
Typical 5th Order enclosure vs. The Small Sub Solution™
Recently, some audio engineers working on noise cancellation
technology, made a major breakthrough in small enclosure/speaker
designs. This technology represents the most dramatic development in
small-sized subwoofer engineering since the emergence of band pass
enclosures in the 1980s and is fully implemented for the first time in
the form of SubSolutions™.
Utilizing a specially constructed driver in a unique, multi-ported
enclosure, this new subwoofer system produces extremely high Sound
Pressure Levels at low frequencies. So far, this has only been possible
from drivers and enclosures three times the size!Although everyone
agrees that smaller drivers sound better because they react to the music
faster (transient response), smaller cones have also meant lower
efficiency - until now!
The SubSolution™ design utilizes an extremely long excursion driver,
controlled by the IntraPortTM enclosure technology, which produces tile
accurate sound of a small woofer and the high output of a large one!The
result of this new design is clearly audible upon first audition.
Critics are saying the sound is "tight" and much more musical than that
of a 5th order band-pass. Sam Zamora of Xtant called it "excellent sound
quality" and said it sounds "amazingly bigger than it is."
The SubSolution™ is not only the smallest and loudest subwoofer
available, it is just possibly the best sounding subwoofer of any size
-- anywhere!
