Safe to connect both sub pre-out and front speaker out to subwoofer?

[Fodox]

Until now i have been using only 2 speakers and a sub, that was set up using the subwoofer crossover (reviever -> sub -> frontspeakers), but i just got some new speakers that i want to use in a surround, so that i can get the full experience when watching movies with 5.1 tracks.
I thought it would be a good idea to let the receiver handle the crossover, so i rewired the system.
Now the system is connected as shown below:

• Reciever — (RCA) —> Subwoofer
• Receiver — (Speaker cable) —> Speakers

When i listened to music with the old 2.1 setup it sounded MUCH better since the subwoofer also blended in, but i was missing the surround channels in movies and games.

My 4.1 hardware setup:
Receiver: Marantz SR4500 - crossover set to 100 Hz
Speakers: Scandyna Minipod (SB)/The Drop (Front)
Sub: SVS PC12-Plus (old version/525 W RMS BASH amp) - crossover set to max.
Sources: Computer (toslink), PS3 (Toslink), Airport Express (minijack-RCA stereo)

Source output settings:
Computer audio card: Set to output DD5.1/Dolby Pro Logic/Dolby Digital Live
PS3: Set to output DD5.1

The problems:

• The sub is only activated when the receiver is fed with a DD/DTS 5.1 signal.
• If the receiver is fed with 2.0 track, then the sub will not be activated

What i would like:

• To listen to music in stereo/multichannel stereo and also have the subwoofer playing (by using the crossover in the sub)
• To be able to listen to a DD/DTS 5.1 track from the computer/PS3 without missing out on the 0.1 channel
• Maybe be able to use the 7.1 inputs in the receiver for PCM HD audio in the future if i should upgrade my soundcard at some point (Not a requirement, but could be nice to have)

My solution/theory/question
My theory is that to get the best from both worlds (stereo and surround) is to let the frontspeakers go through the sub LPF/HPF to blend in the sub in stereo AND connect the sub pre-out on the receiver to RCA input on sub to also be able to get the LFE channel in DTS/DD5.1 and then set the receiver to “Large Fronts, Small Surround and Subwoofer enabled” in the setup menu.

Is it safe to connect it this way? Is there a reason why i shouldn’t? I really don’t wan’t to break anything by connecting it wrong

 

[lovinthehd]

What happens when you set your fronts to "small"? Not all receivers use bass management for the stereo mode, yours may be one of them.

 

[TLS Guy]

I have looked at your manual. If you have selected a sub and set the crossover in the receiver and set the speakers to small, the sub should always handle the lower frequencies regardless of input.

There should be no problem. Your receiver definitely does use bass management in 2.1 stereo mode, is the speakers are set correctly in the set up menu according to your user manual.

You can not connect it as you describe.

 

[j_garcia]

One of two things are going on: you either have it set to "source direct" which bypasses bass management in stereo mode or you have your mains set to large. Both of these will not send signal to the sub in 2ch playback.

 

[Littlefoott]

The problems:

• The sub is only activated when the receiver is fed with a DD/DTS 5.1 signal.
• If the receiver is fed with 2.0 track, then the sub will not be activated

the subwoofer is only getting the .1 lfe channel from movies

under bass management set it to lfe only
lfe and mains aka double bass aka plus is all rubbish for people who just like loud noise

and lower your crossovers to 80hz or 60hz (80 recommended) to the sub isn't so directional

 

[Fodox]

Thanks for all your answers and being slow to reply in my own thread, but it has been a busy week for me so far.

About my the receiver speaker configuration:
Fronts are set to small, Subwoofer is enabled.
I just only seem to be able to get it activated when listening to DD5.1/DTS5.. Else i have to set Surround mode to CS2. Even them it sounds pretty weak and it sounds somewhat like a computer satellite surround setup. I really don't like the sound in that mode.

I have however changed the wiring back to my old setup, where I connect the speakers through the subwoofer. The crossover is set to 70 hz on the sub and it blends in nicely with the speakers i think.
In the receiver the speakers are now set to Large, the subwoofer is disabled, and now it sounds WAY better IMO instead of when just using the sub pre-out (RCA).
Since most think it would be a bad idea to connect my system the way i suggest, I think i'll just keep my current setup as it is now, so I guess I'll just have to live with not being able to get LFE when i want to use the 7.1 input in the near future.

Thanks again for spending your time answering my question

Here are some relevant pages i also found in the manual for the curios

 

[TLS Guy]

I think you must have your sub output set too low from the receiver. The manual clearly states your sub will be active in 2.0 if your speakers are set to small and sub enabled. You are doing something wrong or your receiver is defective. It is 2005, so you are due for an update.