Enabling LFE ouput on the Squeezebox 3

sn1009 · « **on:** 6 Feb 2007, 07:54 am »

Does anyone know of a mod to enable LFE output for a subwoofer on the squeezebox 3?

I have been browsing this and the slimdevice's forum without luck.

Thanks
sn1009

GBB · « **Reply #1 on:** 6 Feb 2007, 02:35 pm »

#1009 - please say a bit more about your requirements. Is this LFE output for a mono subwoofer? If so then you probably need a preamp that will sum left and right channels prior to going to the subwoofer.

If you can take stereo inputs to your subwoofer(s) then it simpler. You only need an extra set of RCA outputs for the subwoofer which can parallel the original outputs.

---Gary

sn1009 · « **Reply #2 on:** 6 Feb 2007, 03:11 pm »

This is the sub-amp:
http://www.frequence.dk/sites/ds4-0.htm

It supports both mono and stereo input.

Is it ok to parallel the outputs from the squeezebox using two standard phono Y-splitter or does this affect the sound quality?

jermmd · « **Reply #3 on:** 6 Feb 2007, 03:17 pm »

Try the RDES unit from AV123.RDES

machine · « **Reply #4 on:** 6 Feb 2007, 04:29 pm »

When I did this I used the Coax out to an external DAC and the Analog outs to my Sub.

I dialed in the subs crossover to fill in the low end.

Seemed to work good.

randytsuch · « **Reply #5 on:** 6 Feb 2007, 05:27 pm »

Quote from: sn1009 on 6 Feb 2007, 03:11 pm

This is the sub-amp:
http://www.frequence.dk/sites/ds4-0.htm

It supports both mono and stereo input.

Is it ok to parallel the outputs from the squeezebox using two standard phono Y-splitter or does this affect the sound quality?

Not a good idea. A y splitter is meant to split one output, to go to two different inputs.
You are trying to combine two signals, which you cannot simply do with a y splitter.

Randy

mca · « **Reply #6 on:** 6 Feb 2007, 05:59 pm »

How would the RDES help him out?

ctviggen · « **Reply #7 on:** 6 Feb 2007, 06:25 pm »

The sub amp already has left and right inputs, so just split the outputs of the SB, with one set going to your amp for your speakers and one set going to your sub amp.

The detriment to this is that bass will be produced by both the sub and the speakers. Unfortunately, the RDES system doesn't have a high pass output. This might be better:

http://www.hometheaterhifi.com/volume_8_4/outlaw-audio-icbm-bass-management-11-2001.html

sn1009 · « **Reply #8 on:** 6 Feb 2007, 09:07 pm »

Thanks for the input.

I was hoping for a cheap simple solution but judging from the answers in this thread it seems it is more of a hassle that I was hoping..

Does anyone know of a small recommendable crossover box which would allow me to extract the "lfe track" from the stereo phono output and feed to the sub. I would prefer if the lfe was not fed to my main speakers.

ctviggen · « **Reply #9 on:** 6 Feb 2007, 09:26 pm »

Just to clarify, the LFE (low frequency effect) signal is used for movies. Some people also use this term to mean any low frequency signal (which is what you're doing), but that can technically be incorrect. For instance, I have an active crossover that produces both sub outputs and an LFE output.

Unfortunately, your amp doesn't have an output. The thing I recommended (Outlaw ICBM) is near as cheap as it gets. I have an NHT crossover, but it's still around $250, if I remember correctly. Like this:

http://brandnamez.com/merchant.ihtml?pid=424&lastcatid=304&step=4&AffNo=492452167

Occam · « **Reply #10 on:** 6 Feb 2007, 09:35 pm »

Quote from: sn1009 on 6 Feb 2007, 09:07 pm

Thanks for the input.

I was hoping for a cheap simple solution but judging from the answers in this thread it seems it is more of a hassle that I was hoping..

Does anyone know of a small recommendable crossover box which would allow me to extract the "lfe track" from the stereo phono output and feed to the sub. I would prefer if the lfe was not fed to my main speakers.

I don't follow. Gary gave you an staightforward, simple solution. Buy 2 plug in 'y' splitters, one plugs into the right channel of your SB, the other into your left. Use 2 pairs of interconnects. One pair goes from each channel to the main amp. the other pair goes to your sub. Done. Admittedly, your main speakers are running full range. If you want to change that, you need to tell us what amp you're using. Then we can simply change the usual coupling caps on you amp to a smaller value so they function as a high pass filter.

Lordy, if you dole out information on a 'need to know' basis, the exchange of information is like a pulling teeth.
Are you using the SB for volume control?
What specific amp are you using?
What speakers?
What interconnects presently, or what would you prefer to use?
Can you solder and make a small diy project, if you want to avoid the use of splitters?

jermmd · « **Reply #11 on:** 6 Feb 2007, 09:55 pm »

Quote from: mca on 6 Feb 2007, 05:59 pm

How would the RDES help him out?

I thought it had a high pass out.
I guess the easiest way would be to split the signal as previously posted.

ctviggen · « **Reply #12 on:** 6 Feb 2007, 09:57 pm »

I thought it did, too.

DSK · « **Reply #13 on:** 6 Feb 2007, 10:05 pm »

Yes, the Y splitters approach is inexpensive, as easy as falling off a log, and works fine. I ran my SB2 this way into my main amp (47k Zin) and sub amp (30k Zin) for over 6 months.

ted_b · « **Reply #14 on:** 6 Feb 2007, 10:42 pm »

LFE does not exist in this SB3 2 channel world. LFE is a dedicated low freqency effects channel, available only in a 5.1 or 7.1 output. The SB3 doesn't support that. If it's subwoofer link you need, stop calling it LFE, and just do the simple y-jacks setup already proposed. No mods, no great rocket science, just a separate set of ic's to your sub(s). If you don't want the mains running full range, then send the signal to a crossover (either in the sub amp or external).

Occam · « **Reply #15 on:** 6 Feb 2007, 11:48 pm »

Hey Ted - I'm the only one allowed to unfairly ridicule new posters in the Lab Circle.

So the poor guy got the terminology wrong and wasn't able to read my mind..... Its probably a plus and indicates he actually has a life outside of audio.

ted_b · « **Reply #16 on:** 6 Feb 2007, 11:56 pm »

Sorry.

Wasn't meant as a ridicule, but my words could be misconstrued. I was more concerned that the thread would continue down a path that had him over-engineering this solution.
Thx

Ted

NewBuyer · « **Reply #17 on:** 7 Feb 2007, 07:28 am »

With the Y-adapters, you could also choose to use a pair of in-line passive hi-pass filters from ACI's website.

sn1009 · « **Reply #18 on:** 7 Feb 2007, 08:16 am »

Yep.. I think I will go for Gary's solution at first..

It just seems to me that randytsuch (#5) misunderstood my post #2 as I at first wanted to split the stereo signal but needed to know if it affected the sound quality..

As a reply to Occam in #10
Are you using the SB for volume control? Yep
What specific amp are you using? DIY icepower build into the speakers
What speakers? DIY, http://softica.dk/dk/webPages/passage/passage20_0.htm
What interconnects presently, or what would you prefer to use? Analog
Can you solder and make a small diy project, if you want to avoid the use of splitters? Yep. No problem. Just wanted a simple solution now for getting this up and running. I might try out another setup later.

Thanks for the input.

~sn1009

ctviggen · « **Reply #19 on:** 7 Feb 2007, 03:51 pm »

You might find that you like having bass both in the subs and in the main speakers. I ran my system for a while this way and didn't mind it. The benefit to sending low bass to the subs (and not to the main speakers) is that distortion caused by main speakers can be eliminated. However, if there's not much distortion from the main speakers, then it helps to spread the bass around the room, which can help to even out room modes that are activated. The detriment is that it can get a bit hard to phase align everything.