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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
patrickalston
183 posts
 

I have Martin Logan CLS 1, a full range electrostatic, and dual  Martin Logan Dynamo 10 subs.  I use the balanced output on my preamp which is run to a JL audio CR-1 active crossover that splits the signal around 50 Hz for both the mains in the subs.  It works well and blends the subs and the main speakers seamlessly.

I was advised not to connect using subs using the speaker terminals (I use dual mono tube amps)

paducahhometheater
20 posts
 

>> "The range in question is near 40Hz-100Hz and speakers, particularly full range, are best suited in this range. Many subwoofers crack above 150Hz."

This is two different conversations.  I'm talking about generally speaking, not your guitar solo, the idea that you want to send powerful 6 hz sine waves to your mains with a high current external amp, at the levels anywhere near what it was intended to be to pull off the effect properly, is daft, for multiple reasons.  

funnychap
32 posts
 

I use LFE for my 2 direct servo Rythmik F12G subwoofers.

https://youtu.be/WBpDJ38shtk

bartsw's avatar
bartsw
274 posts
 

@paducahhometheater 

Notice that peak at 82 hz?  That’s a low E.  If you cross reference the guitar tabs, you’ll see that they play an open E string sometimes.  That’s as low as this guitar is going to play on this track.  The stuff below it is just junk, it’s registering as low as 1 hz on the intro, just not reality... distortion artifacts or something,

This just showed up on my feed that could explain how a combinations of high notes creates a low note. It looks like another reason why you can't theorize the lowest notes of an instrument and justify it for your setup needs. https://www.youtube.com/watch?v=Sn07AMCfaAI&t=326s

paducahhometheater
20 posts
 

>> "could explain how a combinations of high notes creates a low note"

I can't watch it right now but it sounds like you're describing basic intermodulation distortion, which yeah is a thing, and is also a huge reason not to send subwoofer frequencies to your mains lol.  

A good example is using 50 hz and 230 hz, you're typically going to see things like:

F1 + F2 = 280 hz
2x F1 + F2 = 330 hz
F2 - F1 = 230 hz

F2 - 2x F1 = 180 hz

I haven't seen a situation where intermodulation distortion actually produces frequencies lower than F1, which seems to be what you're claiming.  

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