Originally Posted by schnikes55
I can't get enough volume to the subs
- OPPO BDP-105D
- NAD 275BEE
- Ascend Sierra Towers w/raal
- Rythmik L12 Subs (2)
. I have the LFE signal from the OPPO split going out to each sub. I have the Sierra Towers set to Small and I've tried both Left/Right downmix as well as Stereo downmix. I've played with Crossover between 40Hz and 80Hz. I've played with controls on the L12s and have their volume up all the way. I've even streamed some bass heavy music (Bassnectar, Bass 305) to make sure it wasn't the music.
Start with the basics: Make sure you are cabled to the Sub output of the OPPO, and not to, say, the Center channel output.
Make sure you are connecting to the LINE LEVEL inputs of the Subs. Some Subs have both speaker level and line level inputs. The speaker level inputs expect higher voltage (you would connect the output of a speaker power amp to those). The output from the OPPO is intended to connect to Line Level inputs on your 2 subs.
Also make sure you are connected to INPUTS on the Subs. Some Subs also offer a separate set of Output jacks to pass a signal through the Sub to speakers.
If you are using either the RCA pair or the XLR pair from the Dedicated Stereo Analog outputs to hook up for your main speakers, and also want the OPPO to do Crossover processing for you, then you must use Stereo Signal FRONT LEFT/RIGHT. This is a DIFFERENT setting from the Down Mix setting found in the multi-channel Analog Speaker Configuration menu. Setting Stereo Signal to FRONT LEFT/RIGHT configures both pairs of Dedicated Stereo outs to act just like the normal LF/RF pair from the multi-channel set -- i.e., the Dedicated Stereo pairs will respond to all the settings that normally apply to that multi-channel LF/RF pair. In particular, this means you can get Crossover processing.
To get Crossover processing, whether or not you are using those Dedicated Stereo outs, you then set LF/RF to SMALL in the OPPO's Speaker Configuration menu.
If you plan to play multi-channel content, you can also set Speaker Configuration > Down Mix to STEREO. Again, this is a separate setting from the Stereo Signal setting just mentioned above.
IMPORTANT NOTE: When you change Speaker Configuration > Down Mix to STEREO, the OPPO will turn the Subwoofer output OFF as a side effect, so that you are configured for 2.0 output. So after changing the Down Mix setting, go back into the Subwoofer settings and turn the Sub back ON as needed for 2.1 output.
Now use the built in Test Tones in the 105D to insure you are getting output on LF/RF/Sub. If you are getting output on the speakers but not on the Sub, go back into the steps above and check all of this once again.
Once the Test Tones demonstrate that you have good Sub output, now set the required Sub boost using the Volume knob on each Sub. (Leave the Sub Volume Trim in the OPPO at 0dB.) The idea is to have the pair of Subs produce the same output level as each of your two main speakers.
Now check your music again. Check with a CD first. Adjust the Crossover frequency setting in the OPPO to best match the characteristics of your room. If you are not sure about that, set it at 80Hz.
If necessary, temporarily disconnect the main speakers to be sure you are getting bass at a reasonable level from the Sub. Note that for most music, the Sub output is not supposed to be very loud. In addition, the very lowest bass frequencies are felt, rather than heard.
If the output from the Sub appears right on its own, but still appears anemic when you play it along with the main speakers then the most likely answer is that you have the Sub's Phase set incorrectly. (Some Sub's will offer adjustable Phase; some will only offer a 2 position Polarity setting.) What's happening is that the Main speakers and Subs are playing identical bass content at the same time through the octave below the Crossover frequency. If the Sub is out of phase with the Main speaker you get cancellation.
Since you are using TWO subs, it is also possible they are not in correct Phase with each other. The procedure to fix this is to power one Sub at a time and adjust its Phase to best match against the Left Front speaker. I.e., play some stereo or monaural, bass heavy content, and adjust Phase to get the maximum perceived bass at your seating position.
Then power just the other Sub and adjust its Phase. When both Subs are, individually, in-Phase with Left Front, then they are also in-Phase with each other.
Note that if you are playing SACD discs or DSD media file music, Crossover processing can only happen if you have SACD Output set to PCM in the OPPO. (No audio processing is possible when DSD-Direct-to-Analog conversion is in use.)
Also note that if you are playing content into the USB DAC Input of the 105D, Crossover processing is never available. The DAC Input goes straight to the DAC's in the 105D, bypassing all processing.