What frequency rate do you set your subwoofer at?

[Rufus Almasy]

I set mine at the lowest possible, 10 hz. Any higher than that and it rattles too much. I don't like subwoofers that have higher frequency rates than that.

 

[norton9478]

Your speakers go down to 10hz?

 

[Rufus Almasy]

Sorry man, I thought they did. It's actually read at 60 hz which is kinda cheap then. At least it can go up to 200 hz and not 120 like those cheap ones you find on some stores.

 

[Xian Xi]

I usually set mine to cut off at about 80hz, nothing higher, only lower.

What is "phase" btw? And what is it good for? The last 2 subs I had had this setting.

Smokehouse?

 

[smokehouse]

It depends on your setup. I normally look at the freq response of my speakers and of my sub. Example: My mains/surrounds/center roll off at around 55Hz (going down)…My sub rolls off at around 100Hz (going up). A good spot would be to cross over my sub at 65Hz…not too low for the mains, not too high for the sub.

As a rule of thumb, you don’t want you sub doing anything over 100Hz (yes, I know what THX says about this…they can go fuck themselves). Any decent speaker should be able to do 100Hz without distortion or breaking a sweat. 100Hz for a 10”/12”+ etc drive is much more difficult giving the Fs of that driver and the Fb of the enclosure.


Bla, bla, bla…long story short, most systems will be fine at 80Hz…as a matter of fact, many lower end receivers automatically do this anyway.




Phase is normally one of two things, 0 or 180. Lets say you have two speakers. One will be wired correctly (pos to pos, neg to neg) and the other the opposite (pos to neg and neg to pos). the second speaker would be wired “out of phase” with the other meaning that when one speaker is moving forward, the other will be moving 180 degrees out of phase…or backwards. Take your two hands and put one away from you, the other close to you and start moving them in a “away, towards, away, towards” fashion. This will emulate the throw of two drivers out of phase. In phase speakers will move in and out in unison with each other. Speakers wired out of phase will cause a strange diffuse sound field…not pleasant. Do it intentionally and see what I mean (a calibration DVD would really help out with this one).

The ability to switch the phase on a subwoofer can sometimes be useful. Sometimes switching it to 180 will help with room coloration. Bass is tricky and although a room may not interfere with the main speakers too much, it might really mess with the bass.

Personally, I feel sub placement is everything. I don’t ever dick with the phase setting as I think it’s lame and a band-aid or sorts. If you sub is experiencing room cancellation, move it around (if possible). I’ve had to do this many times and it works. Granted a decent calibration DVD and SPL meter are EXTREMELY helpful when doing this.

 

[smokehouse]

I set mine at the lowest possible, 10 hz. Any higher than that and it rattles too much. I don't like subwoofers that have higher frequency rates than that.

There are very few subs that will even do 10Hz…most that can cost more than some cars…


As for the 50Hz comment, that’s not bad for a bookshelf speaker. As a matter of fact, that’s all you really want your average 4-6” driver doing anyway. My B&W’s cut off at 55Hz and they are considered decent speakers.

 

[Rufus Almasy]

My subwoofer is only great for movies, but for music it's not that bad.

 

[ttooddddyy]

What is "phase" btw? And what is it good for? The last 2 subs I had had this setting.

Smokehouse?

0 deg phase is for subs positioned with the same direction as the main fronts and center speaker, 180 deg is for a sub positioned at the rear facing the fronts and center, otherwise you will get a nulling effect - that sounds lousey, just like getting the phase wrong on the main front speakers in stereo mode.

 

[norton9478]

Just a question...

If i set my receiver crossover at 80 hz, then should i just turn the dial on my sub all the way up ???

 

[smokehouse]

Just a question...

If i set my receiver crossover at 80 hz, then should i just turn the dial on my sub all the way up ???

That will work. Your sub will only work with what it receives so if your receiver is doing it's own LFE crossover, there's no need to have a redundant crossover working in the sub so turning it up to the highest available point is fine.

Not to get on a soap box, but this is why I started building my own custom subs. You're paying for a bunch of shit you do not need. Artificial "bass boost" switches often just distorts the sound, the majority of people do not understand phase and there's rarely a need to use that switch anyway (a little sub placement goes a long way) and figuring that most people have a receiver with a built in LFE/bass crossover, most of the crap other than the volume control is a waste of time.

I use stand alone amps (which are FAR better than plate amps) and some LFE processing like the Outlaw Audio ICBM...than add a passive sub and you have a 100% customizable system that will sound far better than most all-in-one subs.

 

[Xian Xi]

0 deg phase is for subs positioned with the same direction as the main fronts and center speaker, 180 deg is for a sub positioned at the rear facing the fronts and center, otherwise you will get a nulling effect - that sounds lousey, just like getting the phase wrong on the main front speakers in stereo mode.

What if my sub is behind me but facing left?


So it would be like:

[Left]------------------------------------[Right]

------------------[Center]----------------------



---------------[Seating Area]------------------

[LR]-----------------------------------------[RR]
[Sub, cone facing <----]

 

[ttooddddyy]

I would say 180 deg out of phase would be optimum for that set up. It depents on the shape of the room, try it out. This is not an exact science, there are so many factors to be taken in to account.

What if my sub is behind me but facing left?


So it would be like:

[Left]------------------------------------[Right]

------------------[Center]----------------------



---------------[Seating Area]------------------

[LR]-----------------------------------------[RR]
[Sub, cone facing <----]

 

[Xian Xi]

How do I do a 180 degree phase, it just says phase on and off?

And the room is square 10' x 10'

 

[smokehouse]

How do I do a 180 degree phase, it just says phase on and off?

And the room is square 10' x 10'

You're not going to want to hear this but this is the best way for you to set up your subwoofer. Buy a digital SPL meter from Radioshack:

http://www.radioshack.com/product/i...&cp=&sr=1&origkw=spl&kw=spl&parentPage=search

Buy this calibration DVD here:

http://www.amazon.com/Sound-Vision-...3-3376900?ie=UTF8&s=dvd&qid=1193579650&sr=8-3


And use the subwoofer calibration tools to help you correctly setup the level and phase of your sub. You can fiddle with the sub all you want but I'm telling you, this would be the correct (and cheapest) way to do it.

 

[ttooddddyy]

How do I do a 180 degree phase, it just says phase on and off?

And the room is square 10' x 10'

Phase off = 0 deg.
Phase on = 180 deg.

 

[claymin]

smokehouse,

can you place sub-woofer in the middle? between left and right facing towards the seating area? Would it cause cancellation with both rear ones? I'm very curious.

 

[Xian Xi]

You won't get good bass response with it being in the middle of the room. From my experience it works best when in a front corner of the room.

 

[smokehouse]

smokehouse,

can you place sub-woofer in the middle? between left and right facing towards the seating area? Would it cause cancellation with both rear ones? I'm very curious.

Placing a sub in the corner will augment the sound...now, with that said, making it louder does not mean better or more accurate, corner placement can mean distorting the sound. Like I've said before, a good SPL meter, calibration disc and some time spent on placement will work wonders.

 

[Xian Xi]

I had that SPL meter and for my setup the sub facing the corner has the best SPL reading, although when the sub is facing me in the corner the SPL the reading was a hair higher but I couldn't hear that much bass.

 

[smokehouse]

I had that SPL meter and for my setup the sub facing the corner has the best SPL reading, although when the sub is facing me in the corner the SPL the reading was a hair higher but I couldn't hear that much bass.

You also have to take into consideration freq response. Player a 100-10Hz sweep and watch for hot spots in the dB response, placing it in the corner can augment certain frequencies (often around 40-50Hz but it varies on sub/room shape).

 

[ttooddddyy]

Im curious as to why you would require that config. If you have fronts and rears and a center, why not place the sub somewhere near. Is this hypothetical ?
It is not critical.

smokehouse,

can you place sub-woofer in the middle? between left and right facing towards the seating area? Would it cause cancellation with both rear ones? I'm very curious.