Hello Hans,
Remember, connecting the 4 DEBRA subs is a bit different from hooking up regular speakers with regular spkr wire that has a pos. conductor wire and a neg.conductor wire combined side by side. With the Debra, you need to follow the procedure listed below:
The DEBRA’s supplied sub amp/control unit has dual speaker output terminals, labelled as A and B, and this thread details how the final sub cabling hookups are done in a series/parallel method:
Attach a single wire from the amp’s speaker A’s pos. output terminal to Sub#1’s pos. input terminal.
Attach a single wire from the amp’s speaker A’s neg. output terminal to Sub#2’s neg. input terminal.
Attach a single wire from Sub#1’s neg. input terminal to Sub#2’s pos. input terminal.
Attach Sub 3 & 4 using this series/parallel method on the amp’s speaker B’s output terminals.
"So after deciding on a cable management solution, should the rule of thumb be to determine the longest run of cable (to reach the farthest subwoofer) and use that length for the remaining three?"
"Am I assuming correctly that if multiple subwoofers are used, their cable lengths should be identical, as with the main speakers?"
Answers:
Connections are made using single conductor wire which is a bit different than regular speaker wire. To hookup the first pair of subs requires 3 single conductor wires: 1 wire is connected from the amp’s A pos.output to sub#1’s pos. terminal input, a second wire is connected from the amp’s A neg. output to sub#2’s neg. terminal input and a third wire is connected from sub#1’s negative terminal to sub#2’s pos. terminal. The proper length of each of these wires will depend on the distances between the amp and sub#1 and sub#2 as well as the distance between sub#1 and sub#2. You will not know these distances until you determine exactly where the amp will be placed in your office and exactly where sub#1 and sub#2 sound the best in your room.
The 2nd pair of subs also require 3 single conductor wires for hookup and you’ll need to determine exactly where sub#3 and sub#4 sound best in your room before the proper length of these 3 wires can be determined. I suggest you measure your room, decide where the DEBRA’s amp is going to be placed and then calll James Monteyn at Audio Kinesis in Utah to order your DEBRA and the 6 cables you’ll need for hookup. James will help you determine the length of each sub cable (with a bit extra added to allow for a margin of error in measurement accuracy) as well as the interconnects between your amp and the DEBRA amp and make them all for you at a very reasonable price.
I actually forgot exactly how we did this but I know James will walk you through the process and he may ask you additional questions and measurements. I think I just initially told him my room dimensions, where in the room the amp would be located and how I was going to route the 6 hookup cables and he did the rest. The cables will arrive with the subs and amp, so you’ll just need to route the cables, cut and strip the wire on one end of some of the cables to the proper length and make the connections. I’ll also help you through the whole process through installation, configuration and completion.
"What is the reason for the (temporary?) positioning of Sub#1 and #2 facing the ceiling? Not sure I understand how/why this helps to determine woofer placement."
This is called "the Crawl Method" and it’s just a proven effective process or ’useful trick’ for properly positioning each of the 4 subs in your room. This is the exact same method I used to locate my 4 subs and it was fairly convenient and works extremely well. You’ll just be sequentially and temporarily placing each sub #1 -#4, with each sub driver facing temporarily upward to let the bass soundwaves be launched into the room freely, so you can clearly hear it and determine exactly where the bass sounds best to you as you crawl on your hands and knees in a counter-clockwise direction around the perimeter of your room beginning at the front right corner of your room.
Once you determine the exact spot that sub#1 sounds best, you then screw in the set of three spiked footers into the sub’s bottom and reposition sub#1 upright to this spot with the 10" driver facing, and about 1-2 inches away from, the wall.
You then place sub#2 (with sub#1 continuing to play) face up at your listening position and continue to crawl around the perimeter of your room, beginning at sub#1, in a counter-clockwise direction until you discover the next exact spot the bass sounds best.
Once you determine the exact spot that sub#2sounds best, you then screw in the set of three spiked footers into the sub’s bottom and reposition sub#2 upright to this spot with the 10" driver facing, and about 1-2 inches away from, the wall.
This completes the ideal and permanent positioning of your front pair of subs connected to the "A" labelled left + right speaker outputs on the sub amp/controller. The next steps are to repeat this procedure to properly position sub#3 and #4 that are connected to the "B" labelled left + right speaker outputs on the sub amp/controller.
Once all 4 subs have been properly positioned and playing, sit at your desk listening seat and verify that the bass sounds exceptionally good to you. Also walk around your office and verify the bass sounds equally good to you throughout your entire office. If it does, you’ve successfully positioned all 4 subs and this stage is completed. If it doesn’t, you’ll need to repeat this procedure from the beginning. The lesson being to take your time and be precise in determining the spot the bass sounds best to you so that each sub is properly positioned.
The next to final step is to disconnect each sub’s cabling, reroute the cables so that they’re concealed optimally and then reconnect them.
Once all cables are optimally concealed, routed and reconnected, the final step is to play the music of your choice and enjoy the heck out of your system with the newly installed near state of the art bass system!
Enjoy,
Tim
