PD.2150 vs PDN.2151 graph thoughts?

Im building a soundsystem designed to be compact, impactful, with exellent sound quality and bass extension down to 30hz. I intend to use this system for high sound quality and deep bass for smaller crowds, rather than being mainly concerned with getting the highest volume levels possible out of the drivers for bigger ones.

With all this considered the sub cabients im going to build are the Cubo Subs (tapped horn / bandpass hybrid believe) with 21 inch drivers (4 in total). They can go down to 30hz, are compact, and although they may not give the same volume levels as say the Hog Scoop 18s that is not my main concern, they are also the only subs i have space to store.


I was originally gonna use the PDN.2151s but after comparing the graphs to the PD.2150s im not too sure. Heres the graphs:

PDN.2151:


PD.2150:




As you can see the PDN seems to roll off and have lower output around 30hz, should i be corncerned about this given my goals for the system? The PDs are cheaper too but weigh more than the moon, wondering if the graph differences are enough to justify getting the 2150s, or going for the much lighter but more expensive PDNs.


As far as im aware PD subs are highly regarded but are they any other 21 inch drivers that are all round better?

Here is a link to both drivers i meationed with all specs:

www.precision-devices.com/Product-Details/PD2150

www.precision-devices.com/Product-Details/PDN2151

First I would forget about looking at driver plots for anything below 200Hz. The type of enclosure used will dictate how the low end behaves.

Second I'm not sure I would want to use any of the drivers you mentioned if your aim is the highest fidelity. If you choose a 3 meter front loaded horn then the driver selection should be based on rigidity and parameter preferences, but in a tapped horn the sound of the driver is also important.

Check out some of the offerings from B&C, Beyma or 18 Sound if you want to hear nice things going on in the LF region.

Also how long is the horn path in the Cubo you are going to build. If its under 2.8 meters then you are not going to hit 30Hz.

Personally I would be building single 18" reflex cabs for your application and use multiples.