After returning from a 6-mos Engineering Assignment in Japan (so NO Apartment payments), in 1971 I bought a pair of ALTEC Voice-Of-The-Theater Speakers (smaller 800 Hz Xover Horns in "Flamenco" design w. Triple-Wide Cabinet). When I retired (the 1st time) in 2002 , I eventually got tired of Sectoral Horn's somewhat distorted mid/treble (despite a diaphragm/speaker coil replacement), so I decided to use them ONLY as a Sub-Woofer PAIR (Yes, TWO is much better than ONE to minimize Room Modes), driven by my old Marantz 250 Amp ("Arc Welder" dims the lights when powered up) and a 1/3-Octave Band Equalizer, tweaked (with the ports CLOSED for better Transient Response) using R-S Calibrated Microphone in their SPL Meter and TrueRTA Real Time Analysis Software displaying Spectrum Levels while playing a PINK Noise sound track...whewwwwww...and then I had to go around the room and place small pieces of foam on the back of SOME pictures, a few in the ALTEC's to prevent loosening Grill Cloth from flapping and weather striping around the Hall Closet door to keep it from rattling. [I LOVE all KINDS of Music....incl. Pipe Organs.) [PS: Last time I checked, my ALTEC's were worth about $600, intact or sold as parts.]
My son and I bought enough of the above speakers to rebuild my Rears and five NEW ones for him.....if he ever gets some time off from work and fixing things on the house he recently moved into. Rears are same 6-in DIY Rear speakers I built about 1972-ish, designed using the then NEW Thiele/Small measurement & design procedures (per subscription to Audio Eng. Society Journal) ...now on their THIRD set of (now Cerwin-Vega) drivers...each time with a different length for the Tuned Port...and of course now using readily available FREE SOFTWARE to do the calculations.
Fronts use Bi-Amped (separate Amplifier for highest Damping Factor and speaker interaction) DIY Sealed Boxes with 10-in Woofers that my son used at College in his "Boom-Car" [he once won a "Best Sound & Freq Response" award]....still thinking about 12-in upgrade, but it would need to use a stepped out front to fit under the Monkey Pod Table the UDTV sits on. Mids (800-8 kHz) are Bohlender-Graebener Neo-8PDR Planar Magnetic with NO BACK for Bi-Polar Radiation (same Neo-8's as some of the less expensive Martin-Logan's) and Super-Tweets are closed back Dayton-Audio Pt2 Ribbons that cover the range of freqs I doubt I can even hear anymore. My goal was to have nearly instantaneous Response to Transients...which I have certainly achieved other than perhaps the 44-yo magnets in the ALTEC Sub-Woofers. Center Speaker had to fit under the UDTV's Table, so my DIY design uses a pair of 7-in plus PT2 and Neo-8PDR in a SEPARATE Closed sub-section.
I've been using some form of Bi-Polar or Di-polar Speakers for like FOREVER...same time I was listening to DISCRETE SURROUND via 8-Tracks and playing with early Matrixed & Directed Logic QUAD-SOUND. I started with R-S Piezo-Electrics tied across the ALTEC terminals pointed up and back....FILLS in the sound space so it sounds more REAL, rather than relying on the delayed, reflected path to give your ears a not-quite-right resemblance of sound coming from JUST than the point source speaker. In the early days of THX Speaker Certification, ONLY Bi-Polar Stereo speakers earned their approval (e.g Infinity Electrostatics, Magnaplanars, Bose (Bletch!!!!) and a few others)....later on they caved to pressure and changed to the current recommendation of Bi-Polar Speakers on the REAR....but I disagree (backed up by listening to DOZENS of high-end speakers at AES, NAB & elsewhere)....and ROLL MY EYES at the dozens of speakers required for Dolby Air system to effectively do the SAME THING (you KNOW users will use Matrix Delays rather than recording discrete tracks from a bunch of microphones):
Speakers: Bipole vs Dipole -
A Guide to Bipolar, Dipolar, & Direct-Radiating Monopole Surround Speakers (PART I) - Blu-ray Forum
Here's an old photo (with my FIRST, 42-in HDTV) taken just after I swapped in the DIY Center Channel (replacing the small DIY Box under the Chair....just one more thing we lined up for Duty Inspection when we returned from Japan). Some CECB's and my Original HD-OTA Tuner with Adaptive Antenna Array I/F normally occupy the "Hole" below the Table. Marantz 250 Amp (2x125 Watts RMS), Behringer 1/3-Octave Band Equalizer and old Sony Pro-Logic Amp (Bi-Amp for 10-in's) is hidden on the floor to extreme Left but are now stacked on top of Left ALTEC. Pioneer SACD/DVD-Audio/DVD/CD Player on Right was replaced by OPPO BD-93 and Sony AVR was replaced by Pioneer VSX-1050 (7x100 Watts) with MOSFET Transistors (require LESS Feedback for better Transient Response). Box above Sony AVR is I/F Box for old HDTV with JVC D-VHD just above it, which is fed by the IEEE-1397 Capable Cable Box on top (with SACD leaning against it). Old HD-DVR below HDTV is still used for when there are TOO MANY shows at the same time...plus a Multi-Room HD-DVR that can pull also shows from the MR HD-DVR in the other room that my wife watches (so up to SIX simultaneous DVR recordings....I actually NEEDED FIVE just the other night):