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LFE vs. RCA Subwoofer input question

NiagaraPete

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I'm considering buying a single, 8" sub, frontrunners being SVS 3000 Micro and Cambridge Audio Minx X301. Gotta keep it small due to space limitations.

I'm not entirely sure I understand the first question. I thought the crossover was set through the subwoofer itself? My setup is:

[Audio sources] --> Rotel RC-1572mkii Preamp -XLR-> Rotel RB-1552mkii Amp --> ELAC DBR 62s

The Preamp has 2 dedicated sub outs and single pair of rca pre-outs. The XLR outs go to the power amp.

I'm assuming I could hook up to a Subwoofer via either of the dedicated sub outs or via the unused rca pre-outs. Bad assumption on my part? If not, is one better than the other (LFE vs. RCA)?
I’ve owned the svs mico 3000. It’s easy to integrate and I wouldn’t get to caught up in the hi pass filter issue. With the svs spp it’s easy to blend the sub to your mains.
 

Chrispy

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Strictly speaking LFE is only the ".1" channel in content that has such. AVRs can give you the option of using the sub just for LFE, but generally you use the bass management feature. Some even double it up by using a double-bass feature...
 

Chrispy

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FWIW I prefer to high pass my speakers, even on only a 2ch rig. In this case with a small sub like the one you have, you're not gaining a whole lot with the blending thing IMO. I prefer more capable subs myself, and like to take the load off my speakers (many of which are more capable of bass than those Elacs, too).
 

NiagaraPete

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On the back of the micro you have 2 rca inputs. One is marked to be used with a single lead from your LFE.
 

Kal Rubinson

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On the back of the micro you have 2 rca inputs. One is marked to be used with a single lead from your LFE.
1. The OP does not have an LFE output.
2. The input on the sub marked LFE also serves as a the right channel line input. The two functions can be switched with the SVS app.
 
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REK2575

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When you say LFE "doesn't include the regular bass in the other channels" -- that's very surprising to me. Doesn't one want the 'regular bass' signal sent to the subwoofer? "LFE" makes it sound like only the quite low 'effect' frequencies from AV content -- explosions in movies and the like -- are getting channeled to the sub, and your stereo speakers are left to carry the 'regular bass'. Is that correct?

And if it is, isn't that an argument for using the RCA pre-outs from the preamp to a subwoofer?

I am still curious about @DVDdoug 's statement about LFE 'not including regular bass in the other channels'. For someone using a subwoofer for critical listening of music rather than movies/tv, that sounds like an argument for using L/R RCA connection rather than single LFE. But maybe I'm misunderstanding something - (very possible!)
 

Chrispy

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I am still curious about @DVDdoug 's statement about LFE 'not including regular bass in the other channels'. For someone using a subwoofer for critical listening of music rather than movies/tv, that sounds like an argument for using L/R RCA connection rather than single LFE. But maybe I'm misunderstanding something - (very possible!)

LFE channel is one thing, redirected bass another, and they can be combined (with the right processor) as far as signal sent to the sub. The LFE input on a sub is a poor name for "bass management done elsewhere". The use of the L/R inputs is particularly suited to older 2ch gear that has no sub pre-out (mono signal), where you can let the sub sum a stereo signal to mono instead. Some subs do provide for an actual high pass for speakers, tho fairly rare these days....
 
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REK2575

REK2575

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I appreciate all the informative posts in response to my question. Thanks everyone.

Wondering if anyone has thoughts about / experience with the two small subwoofers I'm considering, SVS 3000 Micro and Cambridge Audio Minx X301.

The SVS clearly offers more, but it's also about $400 more expensive than the Minx X301. Anyway, thoughts welcome.
 

Chrispy

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If you really are that limited by box size, I'd rather have the SVS....they're slightly different designs but I'd give the edge to the SVS on the performance side, don't know if the expense makes it worth it to you, tho.
 

Slayer

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he SVS clearly offers more, but it's also about $400 more expensive than the Minx X301. Anyway, thoughts welcome.
If space and money are your main factors and this will be used mainly for music listening.
I would go for TWO RSL speed woofers. You'll be far better off.
 
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REK2575

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If space and money are your main factors and this will be used mainly for music listening.
I would go for TWO RSL speed woofers. You'll be far better off.

Thanks for the RSL recommendation. I wasn't aware of this brand. The new 10S MkII looks outstanding at a very attractive price-point. But at 15 sq. in. it's probably too big a footprint. Really need something in the cubic foot max. size, and definitely can't do dual subs; single only. Still, I'm going to keep these on my radar; they look like they're a little hard to get a hold of at the moment.
 

Slayer

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they look like they're a little hard to get a hold of at the moment.
Yea, that applies to most things these days. As far as size goes, they really aren't that massive. They have sales regularly, and with independence day coming, rest assured they will be on sale. As far as value to performance goes, they are excellent.
Last year I installed a big screen for my sons buddy, he had two, needless to say, I was impressed. Had I not already had two monoliths, I would probably have gotten the RSL's, for a music only system, their that good of a value.
 

Chrispy

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Generally takes bigger footprints for better subs.....curious, do you have one particular location in mind or is that flexible?
 
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REK2575

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Generally takes bigger footprints for better subs.....curious, do you have one particular location in mind or is that flexible?

Space and placement are rather strictly limited due to arrangement of living room furniture and location of my stereo. Equally if not more important, I need something low profile that will not attract the critical gaze of my loving wife ;)

I might be able to get away with a 10" sub, but I'm mostly looking at 8" because of the need for small form-factor. I am intrigued by the RSL that @Slayer pointed out. It's same price as the Minx X301 (which by now has been on the market for many years and is not new tech). 15" cubic in. footprint is absolutely max I could try to pull off; the RSL fits that bill, but it might simply be too massive in the eyes of aforementioned wife...

EDIT - actually, strike that. The RSL is listed at $100 less than what the Minx X301 is retailing for over at Crutchfield... Just became an ever more attractive option...
 

KMO

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When you say LFE "doesn't include the regular bass in the other channels" -- that's very surprising to me. Doesn't one want the 'regular bass' signal sent to the subwoofer? "LFE" makes it sound like only the quite low 'effect' frequencies from AV content -- explosions in movies and the like -- are getting channeled to the sub, and your stereo speakers are left to carry the 'regular bass'. Is that correct?

DVDdoug is describing the LFE channel in a recording.

Receivers do not have LFE outputs - they have subwoofer outputs. That subwoofer pre-out contains both the LFE track, and if the crossover is enabled for any main channels, the bass from those channels too.

When using a receiver subwoofer output, you need to find the input and/or mode on the subwoofer that they tend to label (for reasons best known to themselves) "LFE". I guess if you had just an actual LFE track, you would send it there, but you can also send it a combined LFE plus crossed-over main channel bass signal.

In practice "LFE" (input or mode) on a subwoofer just means "assume preconditioned subwoofer-appropriate signal - mono with low-pass filtering already performed". As opposed to "stereo signal that needs combining and low-pass filtering".

And if it is, isn't that an argument for using the RCA pre-outs from the preamp to a subwoofer?

The subwoofer output is RCA, usually? I guess you mean left and right? But no, you should always use the subwoofer output if you have one.

It's actually the other way around - you don't (normally) get the LFE from any other channel. If you downmix to 2.0, the LFE is normally thrown away - it's only output to subwoofers.
 

Chrispy

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Space and placement are rather strictly limited due to arrangement of living room furniture and location of my stereo. Equally if not more important, I need something low profile that will not attract the critical gaze of my loving wife ;)

I might be able to get away with a 10" sub, but I'm mostly looking at 8" because of the need for small form-factor. I am intrigued by the RSL that @Slayer pointed out. It's same price as the Minx X301 (which by now has been on the market for many years and is not new tech). 15" cubic in. footprint is absolutely max I could try to pull off; the RSL fits that bill, but it might simply be too massive in the eyes of aforementioned wife...

EDIT - actually, strike that. The RSL is listed at $100 less than what the Minx X301 is retailing for over at Crutchfield... Just became an ever more attractive option...
Sub positioning in room for best performance doesn't always match up with aesthetics/desired location, fwiw....rooms below Schroeder can be funky. The RSL is a better sub IMO than either the SVS or CA, and is one of the better values for subs. You might like this review https://www.audioholics.com/subwoofer-reviews/rsl-speedwoofer-10s .

My brother has a pair of large RSL bookshelves from version 1 of the company from a very long time ago (think at least 30 years now), try and pry them out of his hands :) (version 2 of the company is somewhat a revival with the son mostly running things). RSL has some nice home trial deals, such as including return freight should you not be satisfied with the sub, don't believe that Crutchfield offers (altho believe Crutchfield's restocking fee is reasonable). Same for SVS, awesome customer service package, including round trip on freight should you not be satisfied....
 

Chrispy

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FWIW was just going thru emails and RSL indicates pre-orders for the Speedwoofers will start June 3 at noon, they're expecting delivery of them June 30. They advise they sell out quickly. I also see they charge a $25 return fee now (within the 48 continental states).
 

muslhead

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if you want a high pass filter on a small, powerful sub that lets you adjust crossover and look no further than the kef kc62. Look at its specs and flexibility and compare to your svs and / or minx. Its pretty easy to see which one stands above the rest. Of course, all those features, flexibililty and power come at a higher cost.
 

phoenixdogfan

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"LFE" is "strange terminology"... LFE (low frequency effects) is normally the "point one" channel in surround format and it doesn't include "regular bass" in the other channels. The LFE gets routed to the subwoofer ONLY so if you don't have a sub you lose the LFE.

AVRs have a built-in crossover and "bass management" options so the bass from all channels can be mixed and routed to the sub. And of course that includes regular 2-channel stereo sources. Usually that's called a "small speaker" setting, and it's the most common home theater set-up because most people don't have room for 5 or 7 (or more) full-size speakers that can reproduce bass.

Usually the easiest & best solution is get an AVR, which will have the full crossover with high & low pass. Or, many people just run full-range into the main speakers. You can also buy an active crossover or a MiniDSP. But, you still need a proper surround decoder and bass management if you want to get the LFE from surround tracks and mix it with the regular bass.
Anyone know exactly how to implement the LFE channel in JRiver? Does it involve setting up a shelf filter in parametric eq to bump up lows 6-10db below 100-140hz? For that matter, how is high pass implemented on the mains. Can that be done in room correction or does it also need to be a filter done with parametic eq? Finally, under Output Format screen there is a drop down box for setting the low pass filter, is that to be used or can it be set in room correction?

I have used JRiver for years, and I'm still not exactly sure I'm getting the LFE channel done properly. Moreover my Dirac filters seem to indicate that even though I instruct JRiver in the Room Correction screen to send all low frequencies to the sub below 100 hz (which seems like it would be setting a high pass filter to me) my center and LS 50's are still active down to 40 hz (per my Dirac Live measurements) even though I'm implementing the 100 hz cutoff at 24db/octave.

So, I would like to definitely figure out how I can set JRiver up exactly as a 5.1 surround receiver would work, with satellites high passed at 100 hz and all their bass sent to the subs, and the sub lowpassed at 100 hz with all bass including the LFE channel sent to it.
 
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