Hi & welcome to Audioholics!
Hello. I have a Denon AVR-1911. It was hooked to a Sonance 10-150 subwoofer which either stopped working, or never worked. I dinked around with AV receiver settings, but nothing seemed to bring the subwoofer to life. I next bought and plugged in a new powered, Klipsch subwoofer, which worked immediately. I have a few related questions, please...
Does "line in" on the Sonance "match" the "PRE OUT (Subwoofer)" on the AV receiver? Those are the same thing?
Yes, 'line in' on a subwoofer and "Pre Out' or 'Preamp Out" on your AV receiver are meant to be connected to each other.
Any audio system makes use of a wide range of signal voltage levels. The signals coming from a microphone or phonograph pick up are very low, and the voltage levels coming from a receiver's amp section are boosted high enough to drive speakers. For convenience, these different signal levels are divided up into several ranges:
Line Level – The voltage level coming out a typical sound source, such as a CD/DVD/BR player, FM tuner, tape recorder, TV, etc. For the most part, any line level source can be plugged into any line level input jack on an AVR.
Pre Amp Level – Line level signals adjusted by volume and tone controls of the pre amp section of a receiver. They also get moderately boosted by the pre amp section of a receiver. The differences between Line and Pre Amp level voltages are close enough so they can often be interchanged without trouble.
In most receivers, the Pre Amp and Amp sections are contained in the same chassis. In very expensive audio systems, the Pre Amp and Amps are separate boxes connected by the usual audio interconnect cables with RCA plug terminals. Some more expensive AVRs do have Pre Amp output jacks for all the audio channels, allowing you to use the AVR as a pre amp for external amplifiers.
Speaker Level – Is the signal level coming out of an amplifier that goes directly to a speaker.
What's the difference between the subwoofer PRE OUT on my AV receiver and the Zone 2 PRE OUT? Possibly, that's the same question as: what's the difference between sending a PRE OUT signal with one cable versus with two (i.e., L and R)?
Pre Out for a sub woofer sends low frequency audio signals from your AVR to a sub woofer. It uses Pre Amp level signals because the sub woofer has a built-in amplifier. In movies & TV with the audio in one of the typical Dolby or DTS surround sound formats, there is a separate channel for a sub woofer. There are ways you can adjust it in the set up menu of your AVR.
Those Zone 2 Pre Out jacks allow you sent 2-channel audio from your AVR to another external 2-channel amp that you must provide. For example, it allows you to listen to music in another room, while using your existing audio sources along with your AVR as a pre amp for the second zone.
Denon provides online version of the manual for the AVR-1911. You can download and save it as a pdf file. It will help with all your questions.
Is my original subwoofer likely just bad, failed? Do subwoofers fail fairly often?
It's built-in amp probably failed. That is known to happen, especially in the cheaper sub woofers. If it has a fuse in it, check to see if the fuse blew.
Is there a good video I can watch, or book that I can read, to educate myself further? I don't understand "direct", "crossover", "gain", "low pass", "phase", "LFE", etc.
All those are addressed in the AVR's manual. But you may find the manual has less 'what is it info' and more 'how to info'. I don't know of a good book or video to recommend. Maybe others can help with this?
