Subwoofer settings with RSX-1067

[gstellenberg]

Stumbled across this forum a couple of weeks ago after upgrading from a Denon 3802 to an RSX-1067. Thanks for creating such a fabulous resource on Rotel equipment. I've read through many of the past threads concerning the 1067 and subs but still have some questions.

I have the RSX-1067, RDV-1050, B&W 703 (fronts), B&W HTM7 (center), B&W 705 (rears), and M&K MX-105 sub. The 1067 is configured with large fronts and a sub.

1) The speakers are great for music without the sub. Listening to mostly dvd-audio's, should I simply disconnect the sub channel from the DVD player?

2) Using the 1067's test tones, I calibrated the speaker levels. When calibrating with Digital Video Essentials, the sub is way too low. To make DVE level's appropriate, I had to adjust the DD, DPL, and DTS subwoofer levels in the 1067 to 9 or max. It seems weird to need to adjust them this much. Is this normal?

3) Assuming the sub levels needed to be adjusted because the level is low when going through the dolby decoding logic, should I expect the adjusted levels to be appropriate for my DirecTV signals, which will go through either DPL or DD? I can't get test tones from the DTV receiver.

Note - I also played the test tones from both sides of the 1812 Overture DVDA. This confirmed that for DTS I need the 9 adjustment, and if I leave the sub channel connected for multi input, 0 adjustment is needed.

4) Why would I not want to set my crossover to 40 Hz? It seems like I should use my speakers as far down as they reach and then crossover to the sub. Using DVE, I can hear the speakers kick in around 33 Hz.

Thank you.
- Gerry

[Andrew Pratt]

1) The speakers are great for music without the sub. Listening to mostly dvd-audio's, should I simply disconnect the sub channel from the DVD player?

No leave the sub connected to the subwoofer out on the 1067 and we'll deal with stereo in a moment.

2) Using the 1067's test tones, I calibrated the speaker levels. When calibrating with Digital Video Essentials, the sub is way too low. To make DVE level's appropriate, I had to adjust the DD, DPL, and DTS subwoofer levels in the 1067 to 9 or max. It seems weird to need to adjust them this much. Is this normal?

That's a known quirk in how Rotel set's their subwoofer test tone. Typically you set the main speakers to the test tones and then set the subwoofer to a level that's 10 dB higher then the rest. DVE will work as well but its got a faulty subwoofer test tone as well which might result in incorrect subwoofer levels as well. Still your 9 dB boost sounds correct so you likely did it right.

3) Assuming the sub levels needed to be adjusted because the level is low when going through the dolby decoding logic, should I expect the adjusted levels to be appropriate for my DirecTV signals, which will go through either DPL or DD? I can't get test tones from the DTV receiver.

yes once things are set up properly the levels will be correct for all inputs.

Note - I also played the test tones from both sides of the 1812 Overture DVDA. This confirmed that for DTS I need the 9 adjustment, and if I leave the sub channel connected for multi input, 0 adjustment is needed.

Sounds right given the known issue.

4) Why would I not want to set my crossover to 40 Hz? It seems like I should use my speakers as far down as they reach and then crossover to the sub. Using DVE, I can hear the speakers kick in around 33 Hz

There's a big difference between how low a speaker can play and what the cross over should be set to. The rule of thumb is to set the cross over at a point that's twice as high as the "F3" point of your front speakers. The F3 point is the frequency at which the speakers output has dropped by 3 dB from flat. Many manufactuers will post their F3 values but typically just list it as the lower response point so you'll often see it shown as 45 Hz- 18 Khz etc. If that case i'd recomend 80 Hz as your crossover point esp for movies. Now here's where the power of the new Rotels come into play. For movies you really should set all speakers to SMALL with a cross over of around 80 Hz regardless of how large or front speakers are. There's a few exceptions but for the most part even "full range" speakers don't extend low enough for movie bass in todays soundtracks so let them do what they were designed to do and leave the rest to the subwoofer. Now for music a good number of us with larger front speakers prefer to run our speakers as full with no sub when listening to music. To do that what you do is go into the subwoofer setup and for Stereo set the sub to off. Doing that will make your fronts full range with no sub for stereo.

[gstellenberg]

Thanks for the response... lots of great info.

No leave the sub connected to the subwoofer out on the 1067 and we'll deal with stereo in a moment.

Actually I was referring to the multi-input connector for the sub from the dvd-player. Based on your answers, though, I'll leave it connected and turn the sub off for multi-input music playing.

For movies you really should set all speakers to SMALL with a cross over of around 80 Hz regardless of how large or front speakers are. There's a few exceptions but for the most part even "full range" speakers don't extend low enough for movie bass in todays soundtracks so let them do what they were designed to do and leave the rest to the subwoofer.

What's the difference between setting them all to small versus setting the fronts to large and the subwoofer to 'max'? Is it better to let ONLY the sub get the low frequency stuff?

Now for music a good number of us with larger front speakers prefer to run our speakers as full with no sub when listening to music. To do that what you do is go into the subwoofer setup and for Stereo set the sub to off. Doing that will make your fronts full range with no sub for stereo.

In the speaker->advanced menu, I can specifically set the stereo mode to 'large'. I'm guessing I should do this in addition to setting the subwoofer to 'off' in the sub settings->stereo menu item.

[Andrew Pratt]

What's the difference between setting them all to small versus setting the fronts to large and the subwoofer to 'max'?

Setting the sub to MAX means that all the subwoofer LFE tones will be duplicated on the front channels as well...unless you like over done bass this isn't a good choice for most setups.

Is it better to let ONLY the sub get the low frequency stuff?

Yes as it makes it far easier to calibrate. Ideally though you'd own 5 very large speakers that wouldn't need subwoofers but that's exceptionally rare for a variety or reasons

In the speaker->advanced menu, I can specifically set the stereo mode to 'large'. I'm guessing I should do this in addition to setting the subwoofer to 'off' in the sub settings->stereo menu item.

Yes that's correct.

[gstellenberg]

Ok, got it. Thanks Andrew!