Do you think you need a subwoofer?

I think this is one of the most important threads on Audiogon for all to read and understand.

I have purchased a Velodyne DD15 (should arrive in about 4 weeks), and when funds allow I will try adding another for true stereo low freq. I'll experiment with crossing over my Dynaudio S1.4s ~80hz and see how that goes.

Questions: What is the difference between high-pass and low-pass? Also - on the DD series, there seems to be a graphic EQ as well as a parametric EQ. The parametric EQ has a Q value that can be modified. Is that parametric EQ something that I would want to fiddle with, or should I be able to accomplish everything with the more simple visual EQ? The velodyne documentation is a little light on describing what the purpose of the parametric EQ is relative to the visual EQ.

Thanks,

Todd

Dear Todd: Congratulations for your choose !!. The high-pass filter is the one that do the crossover for the frecuency range that will handle for the main speakers, example: frecuencies from 80Hz and up; and the low-pass is the filter that send the frecuency range to the sub, example: 80Hz and down.

The parametric EQ allow to perform adjustements with a specific frecuencies, that's it that the filters in a parametric EQ are variable and with a variable Q ( broad band ). In a graphic EQ the frecuencies and the Q are fixed.

Maybe you will have to use both of these EQ. You can know it when you try to do the integration to your system/room.

Regards and enjoy the music.
Raul.

What does it sound like when running strictly a subwoofer or two below 80Hz?

And what should I listen for when adjusting phase?

I finally got a decent amp for my pair of passive subs, a Samson Servo 550 (275wpc). It's a pro/live amp used in clubs/bars/etc.

Anyway, I feed my subs via a Paradigm X-30 active subwoofer crossover with line-level inputs.

I am currently feeding the X-30 directly from my cd player's "fixed" outputs and my monoblock tube amps from it's "variable" outs while rebuilding my passive transformer volume control.

Anyway, last night while playing assorted jazz, classical, and rock I would intermittently turn the volume down on my main speakers to listen strictly to the subs output.

I expected to hear distinct, clear-cut, drum strikes or the clean resonance of standup bass strings, but that isn't what I got. Everything was rather muted in a undefined way. It certainly fleshed things out when mixed in with the mains speakers, but I expected more attack, I guess.

The best description would be a line that an audio reviewer once used - the subs recreate the trailing edge of a note rather than the leading edge. More resonsce and decay than strike.

I've tried varying the x-o frequency from ~60Hz-120Hz.

Does this seem right?

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Great thread guys; thanks for sharing the great information.
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Rgds,
Larry
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Dear Darkmoebius: What you are hearing is right: "Everything was rather muted in a undefined way. ".

For the low bass reproduction has " means " for our " ears " it has to be working with the midrange sound, other way ( 80Hz and down ) you will heard what you already heard.

Regards and enjoy the music.
Raul.