[dion]

I just got my Force XL. Haven't optimised the setting/placement yet but so far so good. I do have some basic questions:

1. Is it recommended to leave the power on or should we turn off whenever not in used
2. Is there any sound benefit of using spikes? I have carpeted floors
3. I'm using mainly for stereo music. Which sub configuration is best? I can use via power amp output or pre-amp output.

thanks,
Dion

[JLM]

Welcome dion,

1. Depends.  Is the home shared with irresponsible (most young) people that could get hurt or overload the sub?  My sub (different brand  ) has an automatic on/off feature which can be easily heard.

2. Depends.  Spikes are used to couple the device to the floor.  If the floor is flexible (wood framed) I'd leave the spikes off.  If the floor is stiff (concrete) I'd use them.  Try it both ways if you like.

3. Depends.  Routing your left/right channel speaker signals through the sub allows the subwoofer amplifier to "flavor" the sound going to all the speakers, providing a more uniform sound.  Purists detest the sound of most built-in subwoofer amplifiers and so would wire the left/right channel speakers without going through the sub.

[bpape]

1.  Personally, I'd leave it on.

2.  Spike it.  The idea is not just to couple to the floor but to keep the cabinet from moving so you get more impact from the driver instead of falling prety to the 'equal and opposite reaction' thing.

3.  Run from the preamp out if at all possible.   Even Mike D will tell you this.  The speaker inputs are there as a convenience if you absolutely have to use them.

Bryan

[Mike Dzurko]

Dion:

You've gotten good advice so far

Leave it on 24/7, it draws very little at idle, about 10 watts. We purposely eliminated "auto turn on" functions as they tend to be problematic.

The rule of thumb is you want to couple to the floor if it is solid, i.e. something over concrete.  You might want to consider decoupling, i.e. Auralex Subdude if you have suspended floors.

Preamp outs and line level are my first choice.  Enjoy!

[Dion]

thanks for the info.

Looks to me that I should buy some spikes or Auralex Dude between the sub and carpet floors. Any recommendation which one is better?

In terms of input, can you please elaborate why the pre-amp output is better than power-amp speaker output. My initial assumption is to use the speaker output as the sub can "read" the same signal that the speakers are receiving, hence better integration.

thanks again,
Dion

[dion]

one more question.

I'm looking at the high-pass filters on ACI website and am interested in trying them. I have a JM lab Micro utopia be - which frequency filter should I try (if any).

thanks again, Dion

[Mike Dzurko]

thanks for the info.

Looks to me that I should buy some spikes or Auralex Dude between the sub and carpet floors. Any recommendation which one is better?

In terms of input, can you please elaborate why the pre-amp output is better than power-amp speaker output. My initial assumption is to use the speaker output as the sub can "read" the same signal that the speakers are receiving, hence better integration.

thanks again,
Dion

The general rule of thumb is:
IF the floor is stable, I.E. concrete covered by carpet, tile, etc., then spike it.
IF the floor is suspended, like wood over joist, decouple it with something like the Subdude. 
As to the connections, my preference is generally to the most direct, least distortion prone hookup, I.E. the preamp level. The differences are usually very slight unless the main amp has unusual distortion characteristics. I've never personally had difficulties with integration either way. As in all things audio, experimentation is the key to Nirvana  

[Mike Dzurko]

one more question.

I'm looking at the high-pass filters on ACI website and am interested in trying them. I have a JM lab Micro utopia be - which frequency filter should I try (if any).

thanks again, Dion

Dion:

What does JM lab spec as the -3db freq? Is it ported and if so, front or rear. Thanks!

[Dion]

Mike, sorry for the late reply:

My JM lab micro utopia is front port speaker, 2 way, 50Hz at -3db and 40 Hz at -6db.

[dion]

Leave it on 24/7, it draws very little at idle, about 10 watts. We purposely eliminated "auto turn on" functions as they tend to be problematic.

Mike, I left 24/7 on (didn't turn down volume in sub) and after a while, when I touch the heatsink, it feels pretty warm. I'm not sure if this is normal, but at 10 watts, I'm assuming it shouldn't be warm at all. any thoughts on this?

Also, I'm wondering if you know the input impedance of the force sub. thanks,

[Mike Dzurko]

Mike, sorry for the late reply:

My JM lab micro utopia is front port speaker, 2 way, 50Hz at -3db and 40 Hz at -6db.

I'd use the 85Hz filters . . . . happy Friday!

[Mike Dzurko]

Leave it on 24/7, it draws very little at idle, about 10 watts. We purposely eliminated "auto turn on" functions as they tend to be problematic.

Mike, I left 24/7 on (didn't turn down volume in sub) and after a while, when I touch the heatsink, it feels pretty warm. I'm not sure if this is normal, but at 10 watts, I'm assuming it shouldn't be warm at all. any thoughts on this?

Also, I'm wondering if you know the input impedance of the force sub. thanks,

They are biased fairly high . . .  remember these are full range class A-B amps, not "chip" amps, so they will be warm to the touch. They are thermally protected, so unless they are shutting down at low levels, sounds like they're just the way they should be,
The input impedance at line level is approx. 10K ohms (10,000 ohms)

The input impedance with the Speaker Level adapter is approx. 24K (24,000 ohms

[dion]

thanks Mike. I knew it should be warm during use, but wasn't sure if it should be warm even not in use (but on).

I ordered the spikes and high pass filter. look forward to receiving them.

thanks,
Dion