Ever wonder why the bass at clubs sounds so awful- like just the huge booming thump of a bass drum no matter what music is being played?

The answer is simple, bass extension, or more clearly, a lack thereof.   Club sound system designers and club owners are faced with needing to provide maximum bass impact in a reasonably sized package.   The result is the popular Single and Dual, or maybe even quad 12", 15" and 18" horn loaded subs seen everywhere.  

These subs are characterized by responses which increase with increasing frequency up to 125Hz to 250Hz, depending on the box.   This increase in pressure is a result of the horns effectiveness at higher frequencies compared to lower ones, and also the fact that these huge horn mouths are becoming directional, even at these upper bass frequencies.   Unfortunately, this higher frequency output is useless, as crossing over the subs higher than 90 Hz or so is not practical due to interference (wavelength considerations).   The increased performance of the horn at higher frequencies also increases the distortion of the system by providing more gain for the harmonics.  

Back to the response of these horn loaded boxes.   As we go down in frequency, the output slowly drops as the horn is less and less effective.   Somewhere in the low end, there is a bump associated with the 1/4 wavelength resonance of the horn (the first pipe mode).   These boxes have a relative bump here in output with the corresponding horrific transient behavior associated with pipe resonances.   Below this resonance, the response drops like a rock, as the horn is useless.   This typically happens around 45-55Hz.   Sadly, these subs offer little to no bass extension over 2-Way and 3-Way 15" and 12" main systems.   Certainly, they offer more output, but not usually more extension.   This places any competent system engineer in a bit of a pickle.   Where do you cross the subs over? You can't cross them over much higher than 80Hz, or the system will suffer due to wavelength interference issues.   At the same time, if you don't cross them over higher than 70Hz, then what is the point? So these systems are usually crossed over at 70-90Hz in some desperate attempt to add some bass.   The output from the subs is then simply 50Hz to 80Hz or so.  The result is what we all in the audio industry refer to as the "One Note Bass Problem".   Many concert systems suffer from the same problem.

Acoupower has a solution to the one note bass problem.   Much more extension, less distortion, while providing still more output in the higher subwoofer region.   All of this, in the SAME size box.   The results are so midblowing, that people do not believe the A-B comparisons.   The resulting output is so massive, that our drivers have set a new standard for low frequency SPL for a given volume and -3dB points anywhere from 25Hz to 40Hz.   Enough talk.   Here is the data:

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Figure 1 shows the 2.83V @1m Sensitivity of a single Acoupower 18" in a multichamber bandpass box (solid), and a typical, smaller size club subwoofer box (dotted).   The Acoupower driven box happens to be 7.5% SMALLER than the standard club box.   The distortion reducing high end roll-off of the bandpass box is apparent, so is the low frequency extension.   Contrary to what many believe, this bandpass box has excellent transient response.   Much better in fact that the horn loaded box.   The lack of bumps in the response testifies to it's solid performance in both the frequency and time domain.   The single 18" horn loaded box has a typical response for this kind of box, as discussed above.   The 1/4 wavelength pipe resonance provides lots of boom at 50Hz, then the response drops like there is no tomorrow.   This particular unit is one of the most popular Single 18" horn loaded subs on the market, familiar to all of us in the industry.   This box has a rated sensitivity of 106dB at 1m and is claimed to have response to 30Hz.   Strange, but is looks like it is 87.5dB at 30Hz, not the 103 implied.   Hmmm, must be those darn marketing guys again.   Sadly, we have found most manufacturers of these boxes similarly exaggerate their claims.   While it is obvious that the Acoupower driven box has much more extension, it looks like you have to give up some output at higher frequencies.   Not at all.   See below.

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Figure 2 shows the Max Sustainable RMS SPL capability of both of the systems discussed above.   Both systems are using a single 18" unit, however, the Acoupower driver can handle four times the power.   The difference in output and extension can only be described as staggering.   The Acoupower loaded box has a mindblowing 15dB! more output in the last octave.   Again, the Acoupower driven system is slightly smaller that the horn loaded system.   The -3dB point has been extended 2/3 of an octave! The output is no less awesome when you actually do an A-B test.   One at a time, each person who experiences this output in person becomes a believer IMMEDIATELY.   The body shaking undistorted output can not be denied.

Please note that the incredible output capability of Acoupower drivers place increased demands on cabinet construction.   Seasoned professionals around the world have needed to build 2-4 iterations of their cabinets before they were not substantially limiting the output our drivers are capable of.   We are not in the cabinet business, but we are happy to provide you with information to help you make the best systems you can.   Please also see the information on the ports sets we have available.