Originally Posted by jchong
Hi craig, would you take a stab at writing a commentary about how you think those 3 subs would sound based on the measurements? I'm curious to see how such a commentary would look like.
I could certainly do this, but I am going to pass on this request for 3 reasons:
1. IMO, the graphs speak for themselves. I chose these graphs as examples of different FR's only, not to make "examples" out of any of these subs.
2. There are many owners of these subs on the forum. I don't wish to offend any of those owners. More importantly, I don't think the point of this thread is to discuss the SQ of individual subs.
3. The graphs speak for themselves.
The OP said:
Flat Frequency Response
Low Distortion, (especially as output levels rise, and at the lowest frequencies).
In other words Low, Loud, Flat, Clean
I posted graphs showing extension, (Low), output, (Loud) and FR, (Flat). IOW, everything the OP asked for except distortion, (Clean), graphs, (which are nonetheless available on the Data-Bass website.)
"sound signature" of each of those subs can be gleaned from the graphs. Nonetheless, how any specific sub will sound in any particular room will be a function of the room, the listening position and the optimization efforts the owner/installer has gone to to optimize the "transfer function" of that sub to the LP. Even a marginally performing sub can be made to sound good by installation optimization. However, NO sub can go beyond it's performance capabilities and physical limitations, and these will always be determined by the "baseline" outdoor, GP measurements.
For example, a sub with a -3 dB point of 25 Hz will never have deeper extension than 25 Hz, no matter how it is installed in a room. Even if you add multiples of that same sub, the combined response will still have a -3 dB point of 25 Hz. The maximum output at 25 Hz will go up, but the roll-off below that will stay the same. If you want deeper extension than 25 Hz, you need a subwoofer with deeper extension, pure, plain and simple.
I will also state that I think the difference in "transient response" between sealed subs and "vented" subs is clearly audible. For example, here is the transient response of the SVS PB13 Ultra in sealed mode:
and here is the response of the exact same sub in 15 Hz "ported" mode:
The LF roll-off is obviously different, but the decay time difference is, IMO, going to be much more audible than the LF roll off. The LF roll off can be compensated with an LF boost, (i.e., a Linkwitz transform circuit.) The slow decay time can not be compensated for with any current technology, and that slow decay will muddy the sound of the bass, and interfere with the response all the way up into the midrange.