Question for sub experts

[JimShaw]

I have a question for sub experts which I am not.

Right now my sub is tuned down to 20Hz and can go as low as 10Hz but
lowering tuning also reduces the maximum output of the sub (because it makes the driver work harder).

In your opinion, which is better: keep at 20Hz or will lowering the tuning as low as possible give me a better sound?

OR is the sound all subjective?

[Fors*]

Originally Posted by JimShaw

I have a question for sub experts which I am not.

Right now my sub is tuned down to 20Hz and can go as low as 10Hz but
lowering tuning also reduces the maximum output of the sub (because it makes the driver work harder).

In your opinion, which is better: keep at 20Hz or will lowering the tuning as low as possible give me a better sound?

OR is the sound all subjective?

IMO Jim, you should open up the crossover all the way to it's highest setting (opposite what you have it now) on the sub and then allow your Marantz to handle the responsibility of dictating the low frequencies by starting with a crossover or LPF of LFE of 120Hz. If this doesn't sound right to you still, then try adjusting the crossover in the Marantz to 80Hz. By setting the sub itself to just 20Hz, you are losing the LFE from 20Hz up to 120Hz. That's a significant loss of the LFE. By setting it up as stated above, this should give you a significant improvement in your bass response.

As far as the sound being subjective.....if it sounds good to you, then that is all that really matters in the end.

Here is Big Daddy's sticky on a Guide to Crossover Networks & Crossover Settings....

[JimShaw]

forsberg21

I thank you for the info.

I will start playing and testing today.

[Johk]

Hey Jim,

Are you talking about the subsonic (low pass) filter, which had the following settings:
- Sealed
- 10 Hz
- 15 Hz
- 20 Hz



If so, it's not the same as the crossover setting. The crossover should be set to off (you can put it to 120 Hz also).

For the subsonic filter, you can experiment with the different tuning but you need to insert the port plugs (the foam cylinders that came with your sub).
I think for your sub (refer to your manual to confirm):
- No plug: 20 Hz
- 1 plug: 15 Hz
- 2 plugs: 10 Hz
- 3 plugs: Sealed

Here are the graph for the different tunings from SVS:



From the graph, I would say that the 1 plug option seems to be a good compromise, but you need to consider other things...

In-room response will be different, as stated on the SVS site:

In-room extension, with corner placement, will typically yield 3-5Hz greater linear extension than shown. Results will vary based on room size, seat distance from your SVS sub, and subwoofer location in the room.

Information below 20 Hz, for most people bass under 20 Hz can not heard but it can be felt (as I'm sure you've felt it with your ultra ). As stated on the SVS site:

If you are willing to give up a few decibels in SPL capacity above 20Hz (and the PB13-Ultra has more "headroom" than most folks will use), then insert one, or even two port plugs, click over the subsonic filter knob to the corresponding 15Hz or 10Hz position and you are ready to move your home. Most users would experience strong output to around 15Hz with good placement in a typical room with a 20Hz setup.

Basically I would suggest that you try out the 15 Hz tuning on familiar material to see if you like it. Depending on the size of your room, the loss of headroom might not have any impact since the Ultra is a pretty powerful sub. If you can measure your FR using REW or simply plotting your response curve using test tones (and correction value for your SPL meter), then you will be able to see the effect of the filter.

Anyway have fun!

[Fors*]

I forgot about that...it is a very important question though...thanks for reminding me johk!

[JimShaw]

Originally Posted by Johk

Hey Jim,

Are you talking about the subsonic (low pass) filter, which had the following settings:
- Sealed
- 10 Hz
- 15 Hz
- 20 Hz

Anyway have fun!

Exactly what I was talking about, Johk

Thanks

[Johk]

Originally Posted by JimShaw

Exactly what I was talking about, Johk

Thanks

You're welcome!

If you haven't already, you can check out this post in the "official" SVS thread where I posted my curves for the 20 Hz and 16 Hz tuning on my Plus duo...