Amplification for Clonewheel: Subwoofer or bass amp?

[smanzella]

"The unit itself has a 100hz crossover point which is actually the bottom of the SS3's range."

 

If that's true (I can't find definitive specs), then this speaker is useless without a sub. A 100Hz high-pass filter for keyboard applications is ridiculous. The low C on a B3 is 30 Hz. You lose that note, and the next two Cs..more than 2 octaves, gone!

 

I don't think 100hz is the absolute bottom of this amp. It starts to taper there. You would never hear that low C on any speaker if what you said were true as even most bass cabinets are not rated below 40 to 45hz. But you can still hear the notes since no speaker cuts off completely at their rated low end frequency. Also, the second C (65.406 hz) and the third C (130.813 hz) sound just fine through a SS3 without a sub.

[cedar]

I don't know if this is helpful regarding the crossover point, but this is what Aspen has on his FAQ page (in an area discussing how best to use the Behringer with the SS):

 

be careful to keep it (the hi pass filter) under 125Hz tops, even better may be 80-100Hz and also not too much level (just enough to feel it). When I run the sub after the SS3 it's easy to plug and unplug the sub and judge the difference. Basically, it's just the under 100Hz LF that needs support.

[smanzella]

I took Aspen's advice and it works well.

[WesG]

Bass amps generally are flat (within +/- 3dB ... for good units) down to 40 or 45Hz. "They are rated for" is meaningless. The speaker's response is simply not as good at, say, 39 or 44Hz. There is no cutoff.

 

Having a crossover or HPF implies something like a 12- to 48-dB-per-octave cutoff. This is dramatically different than merely observing a non-flat response.

 

Thanks for the math catch, I meant to multiply 30x2x2 and somehow did 30+30+30.

 

Point still stands. Play an organ's low C on any decent keyboard amp, and you will hear something. Now put a 100Hz high pass filter on the channel. Totally different experience, for all intents and purposes, the note will be gone.

 

Wes

[cedar]

One advantage of the subwoofer approach is that typically a subwoofer has controls that allow you to tune the unit to the rig and the room. The Behringer has controls that allow me to tune the high cut frequency which can vary from room to room.

 

Re-reading this thread again and just wondering whether anyone can comment or amplify (no pun intended) on this advantage of the subwoofer.

 

How important is this ability to tune the high cut frequency" to the room?

 

As I continue to research the subwoofer/bass amp choice, I'm getting the impression that those who advocate the bass amp approach are usually playing left-hand bass on a separate keyboard. At the moment, my left-hand bass-playing is strictly on a Mojo, so maybe the bass amp makes less sense in that context.

[WesG]

I don't have any experience with this hardware, so take this with a grain of salt....................but if your goal is to get a flat response, then your crossover setup will not vary from room. If your goal is to compensate for variations in the room, then this likely will not involve just increasing a hump in response around 100-120Hz; you will want to be able to use an equalizer.

 

If I was running a Mojo into a SSv3 with a sub, I would put a dbx DriveRack PX or something like that between the two, to act as a crossover and equalizer. This way you can tune the crossover to give a flat response, then use the graphic equalizer to apply a boost (bass? treble? whatever floats your boat). You could also use the GEQ to tune for the room, or if there is a really bad room mode you could notch it out with the PEQ.

 

Wes