Subwoofer?

[craizedmanic]

I am thinking of adding a second subwoofer to my system. Before i went to spend the money I borrowed my brothers subwoofer and hooked it up. I have an outlaw 12 inch sub which is down firing dual ported (ports on bottom of sub) and his is a 10 inch down firing single port (port faces front toward listener). I was wondering if the difference in ports would make the bass sound different. Because I think that is sounds worse with the second subwoofer added. After all the research I have found that one option is to place one sub on top of the other. And that is what i did to try things out because i didn't want to take the time of finding oposite corners to make them match. I though that since both subs were in one location spreading the sound in the same direction that this would help smoothe out the bass and keep my outlaw from bottoming out which it has done from time to time. In some movies when i think the bass should be rattling my seat it seems to fall off or disappear. I was hoping that a second subwoofer would help to take a little bit of off the outlaw and give a more balanced over all bass sound. But that was not the case there was no improvement and I believe that it was actually worse. Any thaughts or ideas would be appreciated because i am at a loss on how to get the sub to continue to hit with out bottoming out. Would an amp instead of a second sub be of more help?

[Favelle]

I am thinking of adding a second subwoofer to my system. Before i went to spend the money I borrowed my brothers subwoofer and hooked it up. I have an outlaw 12 inch sub which is down firing dual ported (ports on bottom of sub) and his is a 10 inch down firing single port (port faces front toward listener). I was wondering if the difference in ports would make the bass sound different. Because I think that is sounds worse with the second subwoofer added. After all the research I have found that one option is to place one sub on top of the other. And that is what i did to try things out because i didn't want to take the time of finding oposite corners to make them match. I though that since both subs were in one location spreading the sound in the same direction that this would help smoothe out the bass and keep my outlaw from bottoming out which it has done from time to time. In some movies when i think the bass should be rattling my seat it seems to fall off or disappear. I was hoping that a second subwoofer would help to take a little bit of off the outlaw and give a more balanced over all bass sound. But that was not the case there was no improvement and I believe that it was actually worse. Any thaughts or ideas would be appreciated because i am at a loss on how to get the sub to continue to hit with out bottoming out. Would an amp instead of a second sub be of more help?

Port length, width, and whether or not they are flared all contribute to the "tuning" of a sub. And the tuning of said sub contributes to its efficiency at certain frequencies. Playing a frequency outside of the subs tuning can result in bottoming, clipping, and general distortion at high levels.

If the sub is bottoming out, it has reached the max (xmax/xmech) that the driver can output. More power isn't going to help. However, amp clippage and driver bottoming often sound similar.

With the sub-sonic frequencies now on a lot of Blu-rays (and even DVD'S) the subs of old simply don't cut it. It use to be a good music sub that cut off at 30hz was also a good home theater sub. Not so anymore.

[craizedmanic]

This sub is rate to go down to 18 hz and when it is not bottoming out it just doesn't seem like it is always putting out were i think it should. I don't have an amp on the sub or my system yet. Thank you for your help all is greatly appreciated.

[LordoftheRingsEE]

First, adding a second subwoofer in any room's size is always beneficial.

Second, you need the exact same type of sub. It's just the same with speakers, you simply don't mix the front left with the front right, right?

Third, it takes some time and fine tuning to balance the two subs together.
The Phase must be the same, the Gain must be the same. The Low-Pass Filter should be set in both to its highest position, or Bypass mode if available.
And because you have now two subs, I recommend setting their Gain (Volume level) in both to about 1/4 to 1/3 at the very max., from their rotary knob position.

Quatro, you're much better off positioning them at different places in your room, than stacking them on top of each other. One in each front corners is always a good place to start.

That's about it to start putting you in the right ball park.
Work on that, and you'll see that almost no matter where you sit in your room, the bass will become more even and balanced.

Cheers & Merry Christmas,
Bob

[Favelle]

This sub is rate to go down to 18 hz and when it is not bottoming out it just doesn't seem like it is always putting out were i think it should. I don't have an amp on the sub or my system yet. Thank you for your help all is greatly appreciated.

How are you powering the sub without an amp??

[Favelle]

First, adding a second subwoofer in any room's size is always beneficial.

Second, you need the exact same type of sub. It's just the same with speakers, you simply don't mix the front left with the front right, right?

Bob

Generally, but not always. Many people have a single low-tuned sub to cover the low end, and then a "boomy" sub to fill out the 40-80hz range. Eases the transition as you approach the crossover. Its not a bad idea and has proved successful. But, corner loading 2 identical subs gives you a 6dB increase in loudness. 3dB is doubling your volume so 2 identical subs gives you 3X the volume as 1 does!

[TheGreenDude]

Generally, but not always. Many people have a single low-tuned sub to cover the low end, and then a "boomy" sub to fill out the 40-80hz range. Eases the transition as you approach the crossover. Its not a bad idea and has proved successful. But, corner loading 2 identical subs gives you a 6dB increase in loudness. 3dB is doubling your volume so 2 identical subs gives you 3X the volume as 1 does!

10 dB is double the perceived volume, not 3....

+/- 3 dB is what you need to have a perceived "flat" response

[LordoftheRingsEE]

Adding another similar sub gives you about 5db more in dynamic range.

* But the greatest benefit is more balanced low frequencies in more parts of the room.

[TheGreenDude]

Adding another similar sub gives you about 5db more in dynamic range.

* But the greatest benefit is more balanced low frequencies in more parts of the room.

Well 3 dB is double the SPL, so I'm curious how adding a second similar sub could more than double the SPL. Rather the goal when doubling up on subs should be to achieve less distortion at the same volume.

[craizedmanic]

First my sub is powered. I was playing CODMW2 and ask my wife to check and see if anyone had responded. When she read to me what it said I gave her a response, but she misunderstood me, but it is powered. I think my problem is the bass on the upper side of things around the 40 to 80hz range I say. When I run my speakers in full range the bass seems more smooth and even. However when they are not in full range it seems find when it is rattling the house but then when things ease up and it isn't quite as low it seems to be missing something. I so confused and do not know enough about it to be sure that that is what is going on. But that is the best way I can explain what I am experinceing.

[TheGreenDude]

So... leave your speakers set to full range..

Hsu makes a dedicated midbass sub too if you're interested.

[Favelle]

Corner-load it. Run an EQ to bump the 40hz+ range.

[craizedmanic]

That is a good idea there GreenDude, but I thought I needed to stay with the same brand on the subs just like with the speakers.

Favelle what do you mean corner load it. If you mean place it in a corner then it is all ready done. That was the best place for it after the subwoofer crawl. If you mean something else when you say corner load then I do not know what you are talking about.

Also, I have been looking at the Velodyne's SMS 1 from Outlaw to add for my subs. Do you guys think this would be a good idea.

[Favelle]

Corner loading is a well-known home theater practice of a sub placed on the floor in a corner to enhance the efficiency due to reinforcement of the immediate reflections from the walls and floor, which is not available for a free-standing sub. Basically free SPL's for doing nothing....much like porting a sub. Watch the freq. spikes though. EQ-ing will still be necessary.

[Blacklac]

Adding another similar sub gives you about 5db more in dynamic range.

* But the greatest benefit is more balanced low frequencies in more parts of the room.

Well 3 dB is double the SPL, so I'm curious how adding a second similar sub could more than double the SPL. Rather the goal when doubling up on subs should be to achieve less distortion at the same volume.

I have always understood it as, adding another sub (equal power) would add roughly 3db. Doubling amp power *could* also add 3db. Just from my car audio days, my mind could be a little rusty.