Originally Posted by bejoykr
For a long time, I had a PB1000 on a wooden floor and was happy with it. Then moved to new home and with the sub on the concrete floor, not getting the right bass. So been looking at my options
Let me just tell you straight up: you'll never be able to vibrate concrete like wood.
I've heard Full Marty's on wood (and concrete).
Even with my 29 subwoofers and 100kW I cannot replicate those vibs on my concrete floor.
vibs are vibs, and spl is spl. They are just not the same, and never will be.
That said: 29 subwoofers can pummel your body in ways that even 4 Full Marty's on wood can't...
You may be able to gain some of the vibs back if you are willing to make a raised floor, say: 2x4's placed sideways with OSB on top (~3" of height lost), or at least a few layers of OSB and whisper mat (<1.5" of height lost).
As for the subwoofers, yeah the HF/RF/HO/UM's are optimized for <40hz, while the PA is optimized for >40hz.
They will both do 10-200hz in the right box, but not optimally...
ULF requires high excursion and sometimes a high mass cone.
Mid-Bass requires a low-mass cone and doesn't need high excursion, it needs surface area and power handling and efficiency, higher ohms and an impedance peak in the mid-bass.
The difference between a 90db/w/m driver and a 100db/w/m driver is only 10db.
But ~10db is a ~10x increase in performance!!! It would take probably 8 RE-18's to equal the mid-bass of 1 B&C 18.
For the same SPL: increased impedance reduces current, current causes heat. (Watts also causes heat.)
In terms of heat and power consumption, using a 90db/w/m 0-4ohm sub for mid-bass is a bad idea, vs 8-ohm 100db/w/m.
Amplifier-strain is cause by two things: current (caused by too low of an ohm), or watts (caused by you cranking the knob too high). In both causes it causes heat or component overload, which makes a dead amp.
To get higher power into higher ohms, set the amp to bridge-mode (and buy a beefy amp, factor in that marketing people lie.
After fudge-factors, doubling up power only gets you 3db higher. There are limits.)
The NX and FP amps can output thousands and thousands of watts into 8-ohm, so getting the power it needs is not a problem; and at 100db per watt you won't need much watts to get loud anyways. 4 PA-460's can reach THX at 12ft back. An SVS cube won't be anywhere close to that, most subs show 3ft/1m figures which is a distance that nobody listens at. You lose 10db in the first 10ft.
If you want good <40hz and good >40hz, you need to use both driver types.
It's ok without either, just not optimal...
The PA will run out of excursion, and the UM will run out of thermal-handling.
Mid-bass doesn't have much excursion, so the cone just parks-and-bakes.
The best way to have good bass is to buy as many big cones as you can afford.
Excursion causes distortion.
It takes about 32watts to push 32 18's to 1mm, but it takes 3200watts to push 1 18 to 32mm. Both are the same SPL. The distortion will be zero vs gross.
The array will handling 32watts all-day, you can believe that. The single 18 won't last long at 3-4kW, seconds/minutes.
An array of subs can do things that singles can't dream of.
The more cones and boxes and amps and breakers you can afford, the better... There is no free lunch.