line-level or speaker-level?

blinboom

I know this will likely cause "controversy", but i am looking for the pros and cons of each. I currently run the Sony ST-DE575 receiver with a set of RT600i's for fronts, a CS245i center, two "older" (they will eventually be updated) bookshelf rears, and a seperate Velodyne CHT8 subwoofer with options for line level or speaker-level and a switch for direct/internal x-over.

I don't believe that I can turn off the built-in x-over on the receiver. It seems I can only alter the signal sent to the Sub by setting speakers to "small" or "large" which activates Sony's bass redirection circuitry.

I am looking for a solution that will give me the best possible "clean" output for DVD, yet will still give me the depth in my music (without sounding like I am inside a giant woofer).

Any suggestions will be greatly appreciated! Thank you to all!

-Brad

mantis

The sub line level out is always a good choice,
thats how the system was designed.For movies its a direct lfe channel to the sub,and a bass management for all speakers ran in small.Adjustable crossover's in receivers is so valuable.I think all receivers should have this feature.Most of the brand new models comming out have this feature.
Music it's alittle harder to do.Its slightly not that cut and dry.
OK,
when you setup your system for theater playback, your suppost to set the speakers and sub to the same level..75db.This doesn't always workout in most room unless the sub is in a perfect place.the sub always seems to get to loud.I find that taking the sub down about 5 db works more the most part.Thats so you can play both music and movies with slightly older processors.I mean like 6 months or so.
Music I can see why you want to run speaker level to the sub.It's a shame that not all sub's can process both line level and speaker level at the same time....Rel can but not many other can.in Rels setups you can run the LFE to the sub taking care of all the theater's needs, set the level at the sub and away you go.
Then at the same time, running speaker level with the provided balanced cable, you hook the leads to the mains positive side and share the ground,at the sub side you can now setup the mains with the sub to extend the mains low's.With a independant input on the sub.How cool is that????
For your setup it's going to be slightly harder.Try only line level from the LFE out andLeaveing the sub's crossover at exaclty what the receiver puts out(I don't think your sub had a unfiltered lFE input does it,if it does use that and bypass the internall crossover in the sub.)Run just music that you know very well and try to blend the sub in so it sounds like the music is just comming from the mains.(there more to that but start there first).

Aaron

Music I can see why you want to run speaker level to the sub......Try only line level from the LFE out andLeaveing the sub's crossover at exaclty what the receiver puts out(I don't think your sub had a unfiltered lFE input does it,if it does use that and bypass the internall crossover in the sub.)

If you can see using speaker level connections for music, why can't you see it for HT? What's the difference? Using this method will bypass the double filter problem you're going to have with the line level connections unless you use the L&R preouts. Why use line level connections???

Aaron

mantis

Aaron,
you can use speaker level,Some subs could put a unessary load on the amp,line level doesn't cause any load.The way the receiver's are designed,the LFE output is the way to go.
Double filtering can be a problem,sub's all should have a unfiltered input, but not all do.Polk now uses these inputs on there sub's.The last I checked on Velodyne they do not,they should.BUt leaveing the crossover at exaclty what your outputing to the sub will defeat the double filtering effect to a degree.
Speaker wire can carry the signal to the sub,but you have to run the mains in large and pull double duty.Some speakers don't react well in large, I heard many **** because they had to much bass info.Lfe tracks are very dynamic,most main speakers have trouble with that.
I would try both ways and see what works best for your system.Speaker level might be the better way,but all the systemsI have put together I use line level.

blinboom

As I said in my original email...yes, the velodyne DOES have a switch to bypass the internal crossover, (which I am currently setting to direct, which is an unfiltered input).

What I can't figure out from my manuals is whether or not their will be a loss in signal (LFE...etc...) if I use speaker level connections. I am guessing this method would be more beneficial for playback of music...but I don't want to give up a solid, clean HT. The towers (RT600i's) work nicely alone for music...but I just want to be able to tweak in the bass ever so much to be able to add that richness and fullness that the sub provides.

Alright... let the debate continue...:) Any and all suggestions/comments welcome.... Thanks in advance for the replies!

-Brad

Aaron

Man, I don't know what I was thinking. I thought this was a different thread.....disregard my comments; they're wrong.

Aaron

Dr. Spec

My $0.02:

Use line level LFE jack to unfiltered input on sub. Use quality cable.

Set your speaker settings to "small" on the receiver.

Set your sub level and all your speaker levels on the receiver to 0 dB on the individual volume controls.

If you have an LFE bass adjustment control turn it off.

Set your sub master volume at the halfway mark.

Get a Rat Shack SPL meter for $40 and run your test tones. Use the C-weighted and slow response setting on the meter.

From your listening position, turn up the master volume on your receiver until your center channel test tone runs 75 dB.

Then individually adjust the electronic volume controls for the mains and surrounds on the receiver until they also are running at 75 dB.

Then individually adjust the electronic sub volume at the receiver until the sub is running at 78 dB on the test tone. If you cannot achieve 78 dB within +/- 3 dB on the receiver's individual sub volume control, then physically increase or decrease the master volume at the sub (not the receiver) until you can.

Your speakers and your sub are now properly calibrated for HT and music. Adjustments for individual tastes should not vary by more than 3dB from this baseline.

If when watching DVDs you drive your system loud enough to hear a pronounced "clack" from the sub on bass-intensive DVD tracks, your overall master volume is set too high and you are overdriving the sub. At this point you have two choices, turn down the volume or buy a better/bigger sub.

Spec

mantis

So why set the sub louder then the rest of the system?

Dr. Spec

The human ear is less sensitive to SPL at low frequencies as compared to the higher frequencies. Adding 3dB of SPL on the sub is a good starting point to compensate for this.

gidrah

Hearing sensitivity: This is why manufacturers starting adding a LOUDNESS switch. I don't know if this equalization is carried over to the LFE out, but I doubt it. Good call Doc.

There has been much talk around here about Sony with Polk speakers. The general concensus makes me think to use the sub's internal amp.

Dr. Spec

Gidrah:

My receiver (Kenwood) actually has the fancy equivalent of a loudness control for the LFE and bass channels - it's called "Cinema EQ". Supposed to "enhance bass and blend the mains and the sub" according to the owner's manual. How it exactly accomplishes that is a mystery - the spec page for the receiver is silent on this issue. Only works in 5.1 mode, whereas the conventional stereo bass control is bypassed in 5.1.

I find Cinema EQ is helpful to me when my speakers are all set to "large", but is completely unnecessary when they are set to "small".

Beware though, some people have a "Cinema EQ" function on their receivers (Sherwoods for example) that limits dynamic range and reduces harshness during 5.1 playback and is completely unrelated to bass and the LFE channel. So clearly this term is not universal.

Spec