[jimdgoulding]

Targa loaned me his Hsu Research.  Looks like an 8" driver and it's down firing.  I have several questions and hope I can get your help.  I know nothing about using a sub.  Had one once but it was in a bigger room than I have now and a long time ago:

There is carpet on my floor.  Could it be beneficial to fire the sub up instead of down?  Or at my listening position?  The -3db figure for my main speakers is 37Hz.  Is there a general rule for where the sub should chime in?  I presently have it set around 42Hz.

There is a 0 and a 180 degree phase switch.  How does one of the other play with the sound?  How should I set it.

I didn't place it a corner, I placed it 1' or so from a side wall and about 3' out from the front of my room.  Any rules of thumb regards?

I have found so far, today is the first day, that using it my analog bass sounds better than my digital bass.  The digital is a litte tighter, and maybe quicker, but doesn't seem to be going as low or is as full and warm.

Thanks for your advice.  Really.

[Letitroll98]

I'm no expert on subs, but I found that using a Radio Shack SPL meter, any decent test CD with frequency sweeps, and some graph paper to make a world of difference in integrating my sub.  I was quite surprised on how non-intuitive the settings I ended up with were.  I also just set my sub at the speaker's low frequency cut off and turned up up the level until I could hear it.  When I ran a frequency sweep I ended up with a frequency setting much higher than I thought it should be and a level much lower than I thought it should be.  The sound became magical, beautifully integrated.  My GF (in whom ears I trust) said, "You can't hear it, like you can't tell you have a subwoofer, but you can 'hear' it in the music."  I judged this to be a well integrated sub, and this is with Magneplanars.

As I understand the phase switch, you set it to the phase that has the most loudness in your room.  As far as placement, lots of folks round here have been elevating their subs on a strong box or platform.  I like my sub well away from room boundaries and as close to directly midway between the speakers as possible.  I hope this helps and I don't get flamed too bad from the real subwoofer experts here.

[bpape]

Down firing is fine and gives floor boundary reinforcement.  Good deal on not being in a corner.  Where exactly will just take some trial and error.  In my experience, I've found that staying with prime fractions of room boundaries works well so maybe 1/7 or 2/7 of the room width from side wall to center of driver and 1/5 of room length from front wall to center of driver.

Will you be using an active xover to cut off the mains or will they still be full range and this is just overlap/fill-in?  If no xover, then probably bring it in around 40-45 Hz with mains that cut at 37Hz.  If an active xover, then may be 60ish and use steep slopes on the external xover and disable the xover on the sub.

Bryan

[jimdgoulding]

No active crossover, mains are running wide open.  Sounds like I'm in the ball park with you guys.  Last night, spun Rachmaninoff's Symphonic Dances thinkin I'd get more bass from the tympani whacks but didn't seem to tho I didn't A/B it.  No need to do that on Crosby's If Only I Could Remember My Name.  Phil Lesh's bass guitar definitely went lower and didn't woof up or become discontinuous.  Maybe a tympani just doesn't go that low to begin with tho I believe I detected more weight.  I'll revisit that. 

[bpape]

Forgot to expand on the phase thing.  Once you find the best place for the sub, play a tone where the xover point is set. Switch back and forth for whichever is louder as previously stated. 

Bryan

[K Shep]

No active crossover, mains are running wide open. 

I recently made the move from full range speakers to 2 way + sub.  I would recommend trying a crossover.  I borrowed a Behringer CX2310, then took it a step further with Velodyne's SMS.  If you are intending to get the best out of this experiment please try an x-over.  Here is the Behringer unit I initially used available from Amazon - $81.53 before tax & freight.

http://www.amazon.com/Behringer-CX2310-Stereo-Frequency-Crossover/dp/B0002Z82LM/ref=sr_1_1?ie=UTF8&s=musical-instruments&qid=1279814648&sr=8-1-catcorr

[jimdgoulding]

Thanks, fellas.  Shep, if I add this or any sub permanently or ever go to something like Reference 3A Dulcets on stands where there would be no if, I will.  Thanks 

[ctviggen]

Forgot to expand on the phase thing.  Once you find the best place for the sub, play a tone where the xover point is set. Switch back and forth for whichever is louder as previously stated. 

Bryan

Wouldn't you then have to adjust level?  Or do you do this before level is set? 

[BrianP]

If your main speakers go down to 37hz, an 8" sub probably won't give you much useful extension below that. A 12" or 15" might. Ideally you want an F3 below 20Hz, to cover that last octave.

[Letitroll98]

I recently made the move from full range speakers to 2 way + sub.  I would recommend trying a crossover.  I borrowed a Behringer CX2310, then took it a step further with Velodyne's SMS.  If you are intending to get the best out of this experiment please try an x-over.  Here is the Behringer unit I initially used available from Amazon - $81.53 before tax & freight.

http://www.amazon.com/Behringer-CX2310-Stereo-Frequency-Crossover/dp/B0002Z82LM/ref=sr_1_1?ie=UTF8&s=musical-instruments&qid=1279814648&sr=8-1-catcorr

Note that this unit has only XLR connections as it's a pro unit.  But yes, either an external crossover or using the high level (speaker wire) inputs will help all subwoofers integrate with the mains, and improve the quality of the main speakers as they don't have to produce the lowest frequencies.  I've heard that many subs with high level connections don't have effective crossovers, e.g. they are only low pass filters and don't have the benefit of relieving the mains from reproducing low frequencies.  I don't know much about internal crossovers in subs so perhaps one of the experts can comment?

[K Shep]

Note that this unit has only XLR connections as it's a pro unit.  But yes, either an external crossover or using the high level (speaker wire) inputs will help all subwoofers integrate with the mains, and improve the quality of the main speakers as they don't have to produce the lowest frequencies.  I've heard that many subs with high level connections don't have effective crossovers, e.g. they are only low pass filters and don't have the benefit of relieving the mains from reproducing low frequencies.  I don't know much about internal crossovers in subs so perhaps one of the experts can comment?

Great point.  I purchased XLR to RCA adapters which worked well for my exercise.

[bpape]

Wouldn't you then have to adjust level?  Or do you do this before level is set?

At this point, all you're trying to do is set phase.  Just look for which position is louder (less phase cancellation).  Once you get the position and phase done, then yes, you'd want to adjust level accordingly.

Bryan

[jimdgoulding]

Well, later, I don't seem (no pun intended) to get things seemless or maintain timbre across the board.  I've tried changing the sub's location and it's crossover point and it still seems recording dependant.  But, I've got two weeks to fool around with it until its master returns from overseas.

[jimdgoulding]

My room is small, 15x12x8'.  On some recordings the sub is obvious and intrusive, no matter what I do.  I get respectable bass without it.  I'm forgetting it.     

[decal]

My room is small, 15x12x8'.  On some recordings the sub is obvious and intrusive, no matter what I do.  I get respectable bass without it.  I'm forgetting it.   

Now we're getting somewhere!!