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LFE vs High-level subwoofer connection, for FIDELITY

Simple as it sounds. What subwoofer connection method offers higher fidelity, and why? The LFE, 75 ohm unbalanced RCA cable. Or high-level, speaker wire to the binding posts of the amp. I am running 2 KEF KC92 subwoofers to a Soul Note A-2 Ver. 1 amplifier.
 

Grok Ai states it matches your speakers tonal balance, timing cues, and sonic signature, because it shares the same signal path through the amplifier that your speakers sound travels through. It’s also a great way to get tube or amp sound into your bass region. My LFE outputs from my Khozmo Acoustics pre-amp, bypassing the amplifiers elite and favorable sound.  The PS audio subwoofer had not been released yet or I’d have swoope those up, instead of the KEFs.

Also, has anyone heard that it is straining or damaging to a truly balanced, direct coupled amplifier to use high level inputs? This was mentioned to me and I can’t recall how reliable a source it came from. 

jbuddha882
thehybridvigor
16 posts
 

@bartsw The high level signal is already analog. Doing DSP downstream of this requires 2 additional conversions. Analog to digital and back to analog. It's possible but not best practice 

paducahhometheater
20 posts
 

People swear by a high level connection for 2-channel but the problem is that some popular subs that offer this literally just run it through a resistor and it's electrically connected to the low level input.  I just don't believe the hype if it's set up right.  For home theater absolutely not, you should never do this.  LFE always.  

paducahhometheater
20 posts
 

>> "If your crossover is below 40Hz it doesn't make a difference because you cannot localize it."

Technically that's more like 100 hz for localization but in actuality but the problem is that distortion artifacts and the fact that crossovers are not a brick wall has subwoofers producing stuff that's well over 100 hz.  

 

paducahhometheater
20 posts
 

>> "Thought some of the issue is that LFE is made for movies, it's an "effects" channel."

yes...but... 

Home theater mixes specifically include a separate LFE channel with a bunch of subwoofer effects that is completely thrown away if you try to use high level inputs and is inherently a really stupid thing to do in a home theater setup.  

However, for whatever reason, subwoofer manufacturers decided to simply label the low level inputs as "LFE".  I personally think it's dumb and misleading.  I guess their logic is that you have stereo inputs but only one, usually the left channel, is labeled LFE, which usually correlates to an LFE output on a receiver.  

bartsw's avatar
bartsw
274 posts
 

@paducahhometheater 

Technically that’s more like 100 hz for localization but in actuality but the problem is that distortion artifacts and the fact that crossovers are not a brick wall has subwoofers producing stuff that’s well over 100 hz.

Run some test tones, not real content producing full bandwidth. The limit where I cannot localize it is 37Hz and will vary by room. Also as @larryincmh mentioned being able to localize sub 60Hz in the right channel:

so I had to listen to that Soundgarden song on my system. As the song starts I hear the music only on the right channel which is the guitar solo.

As shown earlier, the spectrum from the music file confirms a sub 60Hz guitar solo in the right channel.

https://mega.nz/file/nUpgDRSR#zUWAdeA4LpDZaXdVsJ8HGblhy9q-z6UZ7Knz0SOJt8M

 

Home theater mixes specifically include a separate LFE channel with a bunch of subwoofer effects that is completely thrown away if you try to use high level inputs

This isn’t correct. Set Speakers = Large and Subwoofer = No. This sends LFE to the mains and subwoofer (using high level). Further subwoofer effect is mono. Directional (localizable) bass is retained using high level, or as Denon has done, they created ’directional bass’ for LFE to retain full range or high level performance.

 

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