Originally Posted by photobyfriend
First post. I just replaced a single REL T7 (8" driver/10" passive) with two SB12-NSDs because the amp died after 5 years. I am a two channel guy and have a integrated amp with no bass management. I connected the subs with the pre-amp out and just do not understand how to set this up. The sound is very underwhelming. My previous subs (the REL and before that a HSU vtf10 mk2) crossovers were set at 45hz and the gains have always been set very low (never past the 9 o'clock range) so that it just barely filled in the background. My mains are Magnepan 1.6s.
I have spent countless days scouring Google, AVS and audiogon for set up tips. Nothing seems to work. Either they are bloated or not there. I tried them in each front corner and also staggering them front to rear. Honestly, with the last two subs I just threw them in the corner and they sounded good with minimum placement. It seems that I have to run one 180° out of phase to get some bass. My room is 15x22x7.5. dry-walled, in the basement with carpet and pad over concrete. Ceiling is not finished but is filled with Roxul. I do not have a door hung yet but have a 36" doorway at the back (probably acting like a port).
Does anyone know what each hash mark on the crossover represents? It shows 30 htz or 150 htz. The gains are set at 12 O'clock on both SB12s with the crossover around 9 o'clock (I think around 45-50 htz?) Phase is 180° on one and zero on the other.
I have a radio shack analog sound meter but all I have found is instructions using the pink noise generator that I do not have. Although, I do have a CD that will play a pink noise. Do I put both subs in the listening spot and do the crawl?
Any help would be appreciated before I send these back.
Since sub for music is the same principle, as a multichannel system. You have to start with the basic, here a few.
-First find the best location for them. The crawl technic work well for many (you put the sub at your listening position, crawl on the floor around the room, to find where it sound louder).
-The gain on your subs, been a 9 o'clock, are very low. I would raise them to 11 o'clock.
-To adjust the phase on each sub, turn one On (after you put those subs at best location for your room), and the other Off.
Use your radio shack analog sound meter (also need test tone, if not available on your system, some CD are available on line, a quick google search should do), to find what phase setting play the louder, on that first sub. Then you do the same for the second sub with-it ON and the first one Off (one sub at the time). And record what level you get from those readings, for might need to be know later.
-Then using your radio shack analog sound meter again. Check the sound level with both subs On, to make sure you have no cancelation between them, if you do the overall volume will be lower than one sub On only.
-If having cancelation between the two subs. This is where it get complicated. Leave both subs On, and choose on sub to play with different phase setting's, until the overall level of bass goes-up.
Also having both subs at equidistance to your MLP (Main Listening Place), help a lot to reduce cancellation from the subs.
But all depending of your room, best placement.
This thread may help you understand, how sub work within different environment, and more a proper place to ask;
Guide to Subwoofer Calibration and Bass Preferences