Hi all... I am posting this in the section that seems to have the most activity and for general help. I bought a 950 preamp on the ebay outlaw store and love it. It sounds flat out amazing but it's got one quirk. I have to turn the LFE channel up to like +8 to get any kind of decent output out of that channel. Is this normal?

this system is a 2.1 music only system with marantz monoblocks for the amps and energy RC-70 speakers which I have bi-amped (so I have 4 monoblocks and I split the L and R feeds with a y-cable for the amps that run the highs and lows). I am crossed over on my L and R fronts at 60hz, I am using digital bass management (not bypass mode) and my mains are set at 0 db gain. I am using an optical cable to connect my Sony multi disk CD player to the 950 on optical input 1.

Anyways.. for the LFE, I also have to use a y-cable to split the LFE channel so I can get any kind of decent output out of it even at +8 on db gain on that channel. With that setting I still have to have the sub gain knob at least at the 2pm position to get good bass out of it.

Should I try setting my mains at -5 and then the LFE channel at +3 to kind of offset this or is there something else I can do? I have tried 3 different subs and they all behave the same way.

any and all input welcome.


EDIT: http://www.avsforum.com/t/748147/lfe-subwoofers-and-interconnects-explained
http://www.gearslutz.com/board/post-prod...fe-channel.html

I wonder if this 10db thing has something to do with it. Most LFE channels are boosted +10db to balance out the LFE with the other channels but that seems to be what I am lacking here.. I didn't want to max out the trim to +10db but that seems like what I need to even things out. Is it safe to do that? does it increase distortion? (decrease sound quality?)

Why is it that you have a Y connection on the LFE channel? Do you have two subs? Are your mains set to large or small in the 950? If set to large the LFE channel will not get a signal at all. Since your system is a music only system I would not expect big bass effects as there are not many recordings that have much bass below 60hz. The LFE channel is used mostly in movies for explosions and other sound effects and is allowed to go much higher in volume IF a signal is present. Make sure your mains are set to small if you want the sub to do the heavy lifting below 60 hz.

Thanks for your reply.. I have my mains set as small, otherwise I would get nothing from the SUB channel... but I respectfully disagree with your comment about there not being a lot of music out there with signal below 60hz... just about all of my music has my sub pumping out bass like crazy, and not just the electronic music. Heart, ELO, Loverboy, and other old rock has bass below 60hz.

Anyways, that issue aside, I thought it was odd that I had to boost the SUB channel to +8 to get a good signal out of it. I am using a y-splitter on the LFE cable because it's a trick to increase the signal strength with some subs. Rather than plugging into the single LFE rca input you use a splitter and connect both right and left inputs.. it really worked well for my Velodyne impact-10 so I tried it on this sub when I had the weak signal and it did help quite a bit.

So it's working and it does sound good so I think I am just going to set this issue to rest.. I did see one other thread about a 950 with weak LFE output from like 2003... so I am not the only person to notice this.. maybe something unique to a couple of units? who knows..

Thanks again for your reply though, I wasn't sure if I would get one.

EDIT: I want to note that I ran my polk PSW505 on the 950 for a long while and before I had it on two different Pioneer receivers, both of which I played a lot of stereo only music from with the sub active and I had the gain at like -2 (0 was a little too bassy)... so it's not the sub for sure. I also didn't have to use the y-cable trick on those setups.

EDIT: if anyone wants to hear good LFE from a song, pick up Lorde - Pure Heroin and listen to the track 'Royals'. I am thinking 25hz on that one.. it gets under your feet and shakes our whole house..

Guys,

I think there us some misunderstanding about about the SUB channel and the LFE channel. The LFE is ONLY activated when it is present in the mix, such as in DD or DTS. It is used to accentuate very low frequency info from effects such as crashes, etc. There is NO LFE channel in any other recordings. The SUB out channel takes any info that is below the crossover settings when you set your speakers to SMALL, and sends it to the SUB. When you are watching DD or DTS movie, the unit adds the low frequencies below the crossover settings and the LFE - when present- together and send them to the SUB (S). I can't speak to your Velodyne setup, but there really is no reason on most subs, to use both L and R RCA inputs with a Multichannel Preamp with a single sub out. Sub info is MONO and Using a "Y" adapter in this case WILL reduce the output volume.

Thanks very much for the clarification. I guess I generalize LFE being the sub output, but they are two different things as you say.

for the y-adapter trick, it really works... if you have low signal coming in on the single channel that plugs into the single sub rca jack on the sub, using the y-cable and plugging into the stereo inputs on the sub (if it has them) boosts the input level. It works for my velodyne, my polk and the SVS sub I am auditioning now. I realize it's splitting the signal into two thereby reducing the signal that goes to each leg of the y adapter but having signal coming in on both channels seems to boost the overall input level on the sub. My ears don't lie.. It works and that's all I can say.

BTW - here's the really old thread I found that seems to confirm someone else noticed this also
http://ubb.outlawaudio.com/ubbthreads/ub...ite_id=1#import