PB-1000 LFE vs line level inputs

[TankTop5]

I’m not sure if this is an issue or an observation but I had to make some major changes to my subs settings when I changed from my AVR to stereo. With the AVR I setup per SVS recommendation to volume gain at 50% and set crossover to 120hz to work best with my bookshelf’s. When I hooked up to my stereo receiver using CH B for line level inputs I had to reduce gain to about 1/3 and change crossover to 80hz plus put bass/treble on stereo to flat to get a constant rumble to go away. Just wondering if there’s something else I should take into consideration or if this is normal operation?


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[lovinthehd]

When using both L/R inputs on a sub you generally get a 6dB gain advantage over using a single input, so that you had to turn down the gain sounds fine. Crossover is actually employed with your sub (rather than just a low pass filter which is fairly common), so if using line inputs with a fixed high pass of 80hz and you dialed the low pass filter to same doesn't sound unusual either. I generally don't use bass/treble controls so making them flat sounds fine, too. Then again a lot is preference....

 

[Ed Mullen]

The low pass filter should be set to LFE for connection to an AV receiver, because the receiver is already sending a low-passed signal to the subwoofer.

When you refer to 'Channel B for the line level inputs' - do you mean the speaker level inputs (i.e. speaker wire and binding posts)?

The gain sensitivity of the speaker level inputs is different than the line level inputs - so yes, it's normal to need to adjust the amplifier gain to achieve a level match with the speakers. And you'll also need to enable the low pass filter on the subwoofer because the stereo receiver is sending it a full-range signal (unlike the AVR).

 

[lovinthehd]

He mentioned he moved the sub to an old 2ch receiver without bass management....altho he did say ch. B inputs line level which I took to be outputs but thinking about that not sure how many old units offered pre-outs for channel B vs speaker level outputs.

 

[TankTop5]

Sorry, I’m using the speaker outputs.


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[lovinthehd]

Sorry, I’m using the speaker outputs.


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Still just a gain difference between the sub's low level (line) and high level (speaker) inputs...but when I looked at the manual believe the high pass was specific to the line level only but Ed/SVS can confirm. Curious, what speakers are you using?

 

[Ed Mullen]

Still just a gain difference between the sub's low level (line) and high level (speaker) inputs...but when I looked at the manual believe the high pass was specific to the line level only but Ed/SVS can confirm. Curious, what speakers are you using?

The low pass filter on the subwoofer equally affects both line level and speaker level connections.

 

[Ed Mullen]

Sorry, I’m using the speaker outputs.


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OK thanks for clarifying - I figured as much when you said Channel B.

So to summarize - set the low pass to LFE when connected to the AVR and set the low pass to 80 Hz (or w/e frequency works best with your speakers) when connected to the stereo receiver speaker level outputs.

And adjusting the gain between inputs is normal - this is because the signal strength and the gain sensitivity is different for both inputs.

 

[TankTop5]

Still just a gain difference between the sub's low level (line) and high level (speaker) inputs...but when I looked at the manual believe the high pass was specific to the line level only but Ed/SVS can confirm. Curious, what speakers are you using?

Thanks for that, I will contact SVS and see what they have to say. I’m running the NAD705 and the Focal 706s I had previously talked about and another thread.


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[lovinthehd]

The low pass filter on the subwoofer equally affects both line level and speaker level connections.

I was referring to the high pass filter I mentioned originally from the manual (fixed 80hz)

 

[lovinthehd]

Thanks for that, I will contact SVS and see what they have to say. I’m running the NAD705 and the Focal 706s I had previously talked about and another thread.


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You realize Ed is the main man for this at SVS?

 

[TankTop5]

You realize Ed is the main man for this at SVS?

Hahaha, I was trying to figure out what you were talking about and then I scrolled up an inch and it all made sense.


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[TankTop5]

OK thanks for clarifying - I figured as much when you said Channel B.

So to summarize - set the low pass to LFE when connected to the AVR and set the low pass to 80 Hz (or w/e frequency works best with your speakers) when connected to the stereo receiver speaker level outputs.

And adjusting the gain between inputs is normal - this is because the signal strength and the gain sensitivity is different for both inputs.

I really appreciate you chiming in, thank you very much


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