Rocket ULW-10 Audio Measurements
Pink curve = Rocket ULW10 without SOS
Purple curve = Rocket ULW10 with SOS
Yellow curve = ACI Force
With each sub placed in the same spot, I individually measured their in-room response. Using my True Audio TrueRTA, I measured the in-room response of the Rocket ULW-10 (with and without SOS activated) and my reference ACI Force ($799).
Now consider, that this is an in-room response and not the innate response of the sub itself. Nonetheless, since they were all measured at the same spot and using the same process the results are useful to explain comparative differences. Also, I intentionally measured the Force at a slightly lower level so the curves would show better, it is the relative differences that matter here.
The Force has a much more extended response, as expected. Its response is within
7db from 20 to over 60hz, not bad at all. If it were mated with speakers of a -3db point of 65hz or
lower (as most speakers are) the combined output would be fairly impressive, as far as in-room flatness
goes. My room would be troublesome with either subwoofer, if I tried to used speakers that rolled off
at a higher frequency.
The Rocket is fairly flat down to about 24hz and then drops sharply. This is outstanding performance at
this price point. Many budget units presume to call themselves subwoofers if they have an audible
response at 40hz
making such claims should be illegal. The curve (pink) without the SOS activated
has a tremendous hump between 32 and 49hz, which I would attribute to the 'resonant' and 'boomy'
qualities I describe further on in my listening tests. This however, is not a design attribute but a
room integration issue based on my room dimensions and the location of the subwoofer relative to my
primary listening position.
Relatively speaking and considering an inherent room mode between 32 and 49hz, the Rocket (without SOS)
had a larger hump than the ACI. After SOS, that hump almost completely disappears (purple curve), and
the resulting response is within 7db from 24 to 65 hz, very close to the ACI.