Actually, the title was a disguise for my DBT of D'Addario vs. D'Angelico light gauge bronze strings on my HD28LSV...
This concerns the best theoretical panel location for (4) 10" subwoofer drivers within their enclosures; here are the details:
• 1.7cf sealed enclosures
• HWD 24.5 x 10.25 x 19.25”
• Active crossover estimated 60 Hz
• Dual matching 10” drivers per sub
• L/R mono subs are also main speaker stands
• Main speakers have excellent power response 70+ Hz
• Confirmed -3 dB low bass cutoff in-room is 30 Hz or lower (anechoic 40 Hz)
• All sub panels 1.25” MDF, full-width window brace, SoundCoat/BH5 lining
These drivers were quick, musical & transparent when previously employed in the intended fashion; these qualities to be exploited in giving up the first ½ octave (may be filled in later w/ a single larger sub in addition to this proposed small pair).
After considerable thought I believe this is the best potential sighting for the four 10” sub drivers in the above system only; this choice may well sound terrible in other venues; proposals should apply to only this system.
All drivers mounted as close as possible to the base w/ the following variations:
L channel:
One 10” forward-firing
One 10” fires L on the side panel
R channel:
One 10” rearward-firing
One 10” fires L on the side panel (yes, fires the exact same direction as the opposite sub, explained below)
The goal is to average/minimize the few audible bass modes I’ve so far experienced in this room, HWD 7-7” x 16-7” x 25-9”. Toward this goal fully-symmetrical driver arrays for the two mono subs, regardless of the driver locations, would detract from sound quality by increasing the room mode effects in the bass range below 70 Hz. The four prescribed driver locations are each unique, non mimics the other. The greatest averaging of all boundary effects via different path lengths to the walls is the final result. The wavelengths below 60 Hz are long enough to mask the different path lengths to the ear, especially between channels. But I’m inviting contradictions before I cut the holes.
With binding posts on the base facing down, the prescribed driver locations will also allow either sub to be swiveled around 180-degrees. In this fashion both channels could be forward or rearward firing, w/ mirror-imaged side-firing drivers. Both subs could then be fully symmetrical in case that sounds better.
The following are considerations from industry professionals followed by my own:
One of the world’s best speaker designers Yoav Geva of YG Acoustics believes rear-mounted sub drivers require too-great spacing for proper integration; he is so firm on this position that he avoids it in his designs. In this case there is about 6’ spacing between the front wall corner & the proposed sum-total single rear woofer, so this consideration seems moot.
Pierre Sprey of Mapleshade suggests mounting the sub drivers on the two side panels opposing each other, & tapping the pole pieces to accommodate a threaded torque-cancelling bar. This idea has great potential force-cancelling benefits w/in the enclosure & driver-vs.-driver, but I believe there is more potential gain to be had by spreading/averaging the room modes via my proposed driver locations. In other words, the room mode force is greater than the driver torque reaction force. Besides, in the prescribed locations a torque bar could be inserted between each driver & its opposite speaker panel, achieving most of Pierre’s recommended benefits.
Fire away...but remember, the D'Angelico's always won the DB/ABX test!!!!!!!!...
