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Dual sub setup

subfire91

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Joined
Aug 16, 2024
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Hi All,

Im thinking of going dual sub setup, and i would like your input.

I have read many contradicting opinions on how to connect a sub to the receiver. My stereo receiver (Denon DRA-900H) has 2 sub outs btw and its a stereo setup not surround.

Some argue that connecting via line in provides better sound and some go for LFE if your receiver has them. Whats your opinion on that matter?

Additionally in a sub setup is the volume of the sub turns up automatically when you crank up the volume of the receiver or you have to do it manually ?

Thank you
 
Most people go with Sub out connections. It is not necessarily just LFE (that is present only in material that has it e.g. 2.1, 5.1 etc. but not normal 2.0 stereo signal) that goes to the subs. Using bass management you can set the crossover between your LR and subs so that subs get the signal below the crossover point for LR plus LFE (if any). Crossovers are not brick walls but slopes so below the crossover frequency you will have overlap between the subs and LR as subs gradually kick in and LR phase out. Check what is default slope for LR and subs - but essentially it is what it is.

Not familiar with your AVR, but assume you have standard Denon bass management that works like above. LR bass will be summoned together with LFE and will become mono, which would generally not be an issue unless your crossover is high and bass becomes localizible. Newer Denon HT receivers have directional bass feature that could provide stereo bass in this scenario, but based on the quick glance, not available on your AVR.

Integration between the subs and LR can be tricky and in addition to bass management as above, people use EQ to facilitate integration. Subs tend to misbehave in the rooms and placing them correctly to complement each other for optimal frequency response, phase response and integration of both of these with LR can be tricky. People usually use REW to optimise their setup in terms of timing/phase. You might need additional tool to address frequency response, such as Mini DSP HD - to the extent you don't have EQ on your AVR and/or DSP on the subs.

I never did line level subs, so can't tell you much about that one, but not many subs have those connections nowadays (REL?). Another theoretical option is to use RCA splitter for LR outputs and feed that to the subs. This would give you "stereo" bass but you would need to manage the overlap which might be difficult unless you use tool like Mini DSP HD that might be the splitter and could EQ and align your LR and subs separately.

Sub volume is dependent on master volume, so yes, when you crank it up, sub will get louder as well. Manual adjustment of sub gain will need to be done upon the initial setup to integrate the subs with LR and between themselves. Once that is done, would not use the sub gain again. If you are connecting subs through LFE out, you should have LFE trim control on your AVR if you want to adjust the bass levels on the fly for different content.

Wellcome to the wonderful world of bass management - all the rewards come at cost though :rolleyes:.
 
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