Questions about setting up SubWoofer with my HiFi stystem

[lreinstein]

Hi,

Forgive me asking what may be basic questions:

I would like to hook up my Velodyne SPL10 Subwoofer (SW) to my HiFi system. (I mostly listen to Jazz and Classical).

My system consists of a Marantz PM7001 Integrated Amp (IE) and a pair of KEF XQ40 floorstanding speakers.

1. The IE has a Pre-Amp Out Left and Right. If I use these to drive the SubWoofer, should I use the Left, Right, or use a Y connector?

2. The Velodyne SW has an LFE L and R input. Does it matter if I use the L or R or should I use an additional Y connector at this end?

3. Note that the Velodyne SW has its own internal crossover network. Since the speakers response (within 3 db) is down to 45 hz, should I set this for a value of 40hz, 50hz, or just do it "by ear"?

4. The Velodyne SW also has L and R output connectors (line out). Would it be better (or even possible) to connect the music source (my DAC) output to the Velodyne SW line inputs, and then feed the Marantz IE with the line outputs? Would the crossover network remove the low base so that it would NOT be sent to to the Marantz IE?

5. Finally .... How do I judge what volume to set the SW volume at? Is this just a matter of taste?

Thanks very much .

Larry

 

[everettT]

Yes use the main preouts, I'd start with 90hz on the crossover and use a y splitter it's fine, as for volume unless you use an spl meter your gonna have to play it by ear. Does your intergeated provide pink noise for level matching? You wanna start at least an octave higher, crossovers are not a brick wall and you want it to blend

 

[Latent]

1. The IE has a Pre-Amp Out Left and Right. If I use these to drive the SubWoofer, should I use the Left, Right, or use a Y connector?

2. The Velodyne SW has an LFE L and R input. Does it matter if I use the L or R or should I use an additional Y connector at this end?

keep it stereo from pre-out to sub as this is the reason for having two inputs on the sub. The sub is very flexable and will accept a mono signal as well but it works just as well with a stereo signal and internally sums the two inputs to generate a mono sub channel to amplify to the internal driver.

4. The Velodyne SW also has L and R output connectors (line out). Would it be better (or even possible) to connect the music source (my DAC) output to the Velodyne SW line inputs, and then feed the Marantz IE with the line outputs? Would the crossover network remove the low base so that it would NOT be sent to to the Marantz IE?

This method you suggest may work but it has a big limitation as the volume control of the amp does not effect the volume of the sub which means you would have to do all volume level adjustment on the DAC or source and keep the Amp at a fixed calibrated volume to match the sub level. This turns your integrated amp into a straight power amp with only one source available and a fixed gain.

Also it is up to the sub maker to choose if they want to add a high pass filter to the line outputs or not with some units doing it and some may not. Doing some research on this model may give you the answer.

EDIT: one other idea is to go pre-outs from the Amp to the sub and then sub outs back to the Amp Main inputs (which are next to the pre-outs) Then you have to switch the switch on the back labeled "SEPERATE" to ON which directs the amp section to pull its signal from the Main input terminals instead of the internal pre-out. The only downside is main signal path now goes though the analog lowpass/highpass filter in the sub and it may degrade your speaker signal a little depending on the quality of the SUB's circuitry.

5. Finally .... How do I judge what volume to set the SW volume at? Is this just a matter of taste?

A SPL meter may help but in the end of the day what sounds best to you should be the main factor.

 

[lovinthehd]

From looking at the manual (for SPL 800, 1000 & 1200 that comes up on the Velodyne site for SPL series) it has a fixed high pass filter of 80hz.

 

[lreinstein]

Yes use the main preouts, I'd start with 90hz on the crossover and use a y splitter it's fine, as for volume unless you use an spl meter your gonna have to play it by ear. Does your intergeated provide pink noise for level matching? You wanna start at least an octave higher, crossovers are not a brick wall and you want it to blend

Thanks,

No pink noise in IE, but have sources of pink noise. I don't understand how to use it with an SPL meter. Do I look for equal volumes of SW and of AMP? not sure how to Mute Amp but keep SW signal.

L

 

[Dan Madden]

I'd use 2 RCA cords from the stereo pre-out and send both the left and right signal to the subwoofer (Since it accepts them). I'd set the sub crossover to 80hz and adjust the main sub's volume manually by ear. Set the sub's volume so that it compliments your main speakers and not dominates them. Remember also that sub placement in the room is very important as to how it will perform.

 

[lreinstein]

I'd use 2 RCA cords from the stereo pre-out and send both the left and right signal to the subwoofer (Since it accepts them). I'd set the sub crossover to 80hz and adjust the main sub's volume manually by ear. Set the sub's volume so that it compliments your main speakers and not dominates them. Remember also that sub placement in the room is very important as to how it will perform.

I may be wrong ... but I think I see in the Velodyne Manual that it combines the left and right signals together. so, 2 RCA cords is probably a good idea.

 

[PENG]

I may be wrong ... but I think I see in the Velodyne Manual that it combines the left and right signals together. so, 2 RCA cords is probably a good idea.

If your Velodyne's line out are in fact filtered (high pass), then your option 4 modified version, is a good option but be sure to do it as Latent described in his post#3 in the "Edit" paragraph. Apparently some Velodyne sub offers high pass settings, if you listen relatively loud, try 90 Hz instead of 80 Hz, again I refer to Latent's "Edit" version of your 4).

If you listen loud and watch lots of action moves, the PM7001 may approach the clipping points during peak demands so it should help (a little) by letting the subwoofer do more.

 

[markw]

You need to both the right and left channels to the corresponding inputs on the subwoofer. Bo NOT use a backwards "Y" splitter expecting to combine both channels into one

You can either use the outputs on the sub to return the signal to the main amps. I don't think the subd high pass filter is adjustable. You're stuck with what it's set to.

Alternately, you can continue to run your mains full range and manually blend the sub (using it's crossover and level controls) with your mains naturally fall off. This is what I do.

 

[TLS Guy]

You need to both the right and left channels to the corresponding inputs on the subwoofer. Bo NOT use a backwards "Y" splitter expecting to combine both channels into one

You can either use the outputs on the sub to return the signal to the main amps. I don't think the subd high pass filter is adjustable. You're stuck with what it's set to.

Alternately, you can continue to run your mains full range and manually blend the sub (using it's crossover and level controls) with your mains naturally fall off. This is what I do.

You are absolutely correct. The pre outs are never buffered, so using a Y connector would make the whole system mono. The sub inputs are buffered when combining the right and left inputs.

 

[lreinstein]

Reading the Velodyne Manual carefully it looks like the SW itself basically combines the L and R inputs

 

[TLS Guy]

Reading the Velodyne Manual carefully it looks like the SW itself basically combines the L and R inputs

That is exactly whatIi told you in the post above!

 

[lreinstein]

That is exactly whatIi told you in the post above!

yes.
thanks