Sub wiring help, high level speaker terminal to RCA line level Sub inputs

@millercarbon I see what you mean. One thing is why would any possible distortion be present through the pre-outs but not through the speaker outs? I don’t think the power amp is doing anything to make the signal out of the pre-amp cleaner. I figure it’s just amplifying, which whether done through the RCA outs, or eventually through the power amp and speaker terminals, it’ll still be there. Unless the argument is based on the the Y-adapter itself causing the distortion, not the pre-out signal.

One other thing that I was thinking about is the effect on the audio signal after being amplified multiple times over if using the Speaker level outputs. So the pre-amp is slightly amplifying the signal, which is then fed to a power amp that is again amplifying the signal even more, which then in this case would be sent to a 3rd amplifier which would be amplifying a signal that had to be lowered by resistors in between, before finally reaching the Subwoofer itself.

Just in a logical sense to me going though that cycle seems like it has the potential to introduce more distortion to the sound than going one straight shot to the power amp.

One other thing that I was thinking about is the effect on the audio signal after being amplified multiple times over if using the Speaker level outputs. So the pre-amp is slightly amplifying the signal, which is then fed to a power amp that is again amplifying the signal even more, which then in this case would be sent to a 3rd amplifier which would be amplifying a signal that had to be lowered by resistors in between, before finally reaching the Subwoofer itself.

Just in a logical sense to me going though that cycle seems like it has the potential to introduce more distortion to the sound than going one straight shot to the power amp.

Both approaches are capable of providing excellent results in many systems, and both approaches have their potential pitfalls. Some of my previous posts in this thread have described pitfalls that can occur in each of those cases.

As I’ve mentioned earlier potential pitfalls of the preamp-to-sub approach include the fact that the signals that are reproduced by the main power amp and the main speakers can under some and probably many circumstances be adversely affected by the input impedance of the sub’s amp, or by the capacitance of the cables connecting the preamp to the sub, or by both, notwithstanding how counter-intuitive all of that may seem. Although it appears those issues probably won’t occur with your particular equipment.

If all potential pitfalls are avoided, or do not apply to a given system, driving a sub via the power amp outputs has the potential advantage of providing the closest sonic match between the signals that are provided to the sub and to the main speakers, as was mentioned early in the thread.

Regards,
-- Al

Bring back an old thread from 2019 to get clarification.

I am researching the viability of adding a pair of Rythmik L12 subs to my system that is based on shortest signal path.  I run a DAC directly into mono amps that sit at the base of my speakers.  No preamp, no LFE or subwoofer connections in my system.  My speaker cables are only 12” in length.  I prefer high level input connections.

Miller Carbon suggested a solution to connecting a subwoofer to high level signal source when a high level signal source input is not available on the subwoofer.

The clarification I am looking for is the “Parts Express” LOC, that is mentioned earlier in this thread.  It states that it has a 30 watts max rating.  If my amplifier is rated at 400 watts, what reliability concern is there due to the vast differences in ratings?

Hopeful the Electrical Engineers and millercarbon will chime in and provide clarification on why the difference in ratings would not be a potential reliability issue.  These electrical concepts are above my pay grade.

Thanks in advance for sharing your wisdom.
 
Neil

@nsm1979

Hi Neil, the last time I checked, Rythmik did offer an amp option that contained a high level input. I would contact Rythmik with your questions.

The clarification I am looking for is the “Parts Express” LOC, that is mentioned earlier in this thread. It states that it has a 30 watts max rating. If my amplifier is rated at 400 watts, what reliability concern is there due to the vast differences in ratings?

Of course max wattage rating matters, otherwise they won’t state that specs. For example, the Russound ADP-1.2 Speaker-level to Line-level Adapter is rated 250watts rms/ 500watts peak by using 1/2watt and 1watt resistors. If you apply power higher than the rated power to the LOC, its resistors will burn out!

https://images.crutchfieldonline.com/ImageHandler/trim/1736/1129/products/2008/543/x543ADP12-f.jpeg

BTW, be very careful using high level connection for subwoofer if your amplifier speaker negative output is not grounded (balanced, BTL or some class D amplifier), best to confirm with your amplifier manufacturer.
If your amplifier has floating speaker negative output, a Jensen Transformers speaker to line converter is one of the solution.

https://www.cs1.net/pic/jensen_transformers/SC-2NR_manual.pdf