@Rhythmdoctor
Yes, you need a stereo power amp and also an INFRA integrator to use the components you have listed as intended.
Background:
From the S18E-D datasheet:
It is a sealed box type enclosure optimized for use with the Bag End® Infra™ processors for extended low frequency response.
Frequency Response specs:
60 Hz to 2 KHz ±3 dB
8 Hz to 95 Hz ±3 dB with external Infra™ Integrator
Sensitivity is listed as 96dB 2.83V/1m at 80hz. 2.83V at 8 ohms is 1W...so this is the same as 96dB 1W/1m. AFAIK, the sensitivity will drop by 12dB per octave below approximately 80hz. The Infra Integrator provides 12dB per octave of corrective EQ, which is how they get essentially flat response to 8hz. However, for each 3dB of correction, you need to double the power; so you quickly hit the speakers power handling limit.
The S18E-R datasheet provides the following.
Maximum Calculated Continuous Acoustic Output:
Half Space @ 1 Meter
10 Hz - 89 dBSPL
20 Hz - 101 dBSPL
40 Hz - 113 dBSPL
80 Hz - 124 dBSPL
Even 124dB at 80hz is really not very loud. So the SPL a single cab can produce at 40hz or lower, is probably too low to be considered usable.
There is really little if any point in using an 18" sub the starts to cutoff at 60hz, especially when the sensitivity/max SPL is so low.
The way to get usable response to a lower frequency is to use multiple cabs. Each doubling of cabs gives approximately +6dB in max SPL when they are tight packed. For example, two doublings equals four cabs and allows you to add +12dB. Here are the new +12dB figures.
Maximum Calculated Continuous Acoustic Output (four cabs):
10 Hz - 101 dBSPL
20 Hz - 113 dBSPL
40 Hz - 125 dBSPL
80 Hz - 136 dBSPL
For the record, in the mid 90s I built a PA system with four S18E Compacts that had to be special ordered. The Compacts used the same drivers, but were half as deep as the regular single 18s. If I remember correctly this lowered the sensitivity rating by 3dB but had no impact on power handling. Each Compact had a dedicated 400W amp.
I had one of the original ELF 1 integrators that allowed you to customize the settings. If I remember correctly I experimented and set the LF cutoff at 40hz. Running the cutoff lower degraded the sound and further reduced headroom with no audible benefit that I could hear.
Even four of the Compacts were not massively loud IMHO. However this system was very compact and well liked for it's excellent mobility, and it stayed in service for over 15 years.
AFAIK the D10BX-N is
not designed to use the Infra Integrator.
Frequency Response specs:
42 Hz to 16 kHz ±6 dB
Impedance is 4 ohms.
Sensitivity is listed as 100dB 2.83V/1m. FYI 2.83V at 4 ohms is 2W. So consider the Sensitivity 97dB/1W.
The Sensitivity is 1dB higher than the S18. This cab will play lower than the S18 if you don't use the INFRA integrator.
