Comments Please! Does this solve the Bass Mgmt Dilemma?

[boa12]

""-Select the "Both" setting if you use a subwoofer and you want to mix the Main channel low frequency sound signals

with the LFE signals."

So in the both mode you do get LFE in the main speakers but you don get main speaker low frequencies in the

subwoofer therefore the mains have the potential to be producing low frequencies that are not being directed to you

sub because."

ej, actually I think its the other way around, as it is w/ most all processors/receivers - that is when you set both it mixes low bass from the fronts in with the LFE to the sub.

iow, unless you don't use a sub & select "main" which is the equivalent of sub:no, LFE always goes to the subwoofer only.

the wording by these makers makes it more confusing. such as denon's use of the term "fronts+LFE" you'd think the same. but its talking from the sub's perspective in that w/ this you get both low bass from the fronts AND LFE to the sub. LFE is only to the sub & doesn't also go to the front speaks.

so to get your hookup to work using the fronts preouts, you set it to "main" so that LFE is sent to the fronts preouts and not to the sub preout which you don't use.

this is basically the same effect as setting sub:no & wiring the sub in parallel to the fronts off the fronts speaker terminals.

what i'm talkin on the adjustable in my pre/pro is a combined high & low pass digital crossover in its dsp.

that is where i set it high passes all speaks set small at that point on up & low passes the sub out at that point on down.

so when i set it to 50hz & all speaks small, the speaks start getting cut at 50hz (instead of a fixed 80hz) on down at the adjustable slope rate, & the sub out/sub starts getting cut at 50hz on up at its adjustable slope rate.

as now looks like w/ all dsp, because i have sub:yes, all LFE channel (the .1 in 5.1) goes to the sub only & nowhere else.

of course i could set certain speaks large which disengages the high pass for those certain speaks, but i've found it sounds best using the high pass albeit at the 50hz mark.

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[Q-Man]

Boa & EJ,

You guys are confusing the hell out of me. I know that it doesn't take much to do that at times, so give me a break. I'm going to go read my manual again, but first I must say this. I think that on my RX-V3000 and my RX-V2092 when I select "Both" that the sub also plays the same lows that the mains are playing. The sub isn't just playing the LFE channel.

EJ, to conferm this play a CD that has a strong bottom end, some CD's and music don't have much below 45Hz. Now while playing this CD turn off the effects on the remote control, or on the front of the receiver. This turns off the front effect channels, rear surround channels,and the front and rear center channels. Another words this is how to lister to just stereo. Now on the front of the receiver turn off speakers "A". This will turn off the main speakers. Guess what? The only thing left playing is your sub. The sub wouldn't be playing if it wasn't receiving the same signal that your mains were or are. With two channel CD's there is no LFE channel or information being sent to the sub. This is why I keep my sub set at around 45Hz. I think it blends in nice with the Klipschorns around this setting, sometimes I use it at 35 to 40HZ.

Please comment on this, your making me loose sleep now.

Like I said, I'm off to read the manual for the hundredth time.

Q.

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Q-Man

[pierceb]

Losing Sleep! I'm also losing productive time at work!

Anyway, I thought I got it all figured out now, and all I figure I need is one y-adapter like Boa said and that's it. I will have to move my external crossover immediately next to my receiver (spelling??) because the y-adapter doesn't have very long leads.

However, I have one more question to Boa (or anyone else who can help). What output level do I set my external crossover at now (only filtering low bass from mains here)? Should I play regular two-channel music (with no LFE) and set the crossover output so it sounds balanced)? Then let the LFE go straight to the sub without any volume adjustment before arriving at the sub input? I guess I don't have much choice here unless I get a second crossover.

I will get another receiver (actually separates) with better bass management before I do that.

-PB

[boa12]

"I think that on my RX-V3000 and my RX-V2092 when I

select "Both" that the sub also plays the same lows that the mains are playing. The sub isn't just playing the LFE

channel."

sorry, but this is like a big puzzle for me. i know, i need a real life.

but no, looks like the yammy is just like every other HT receiver in this regard. that is the basic program in the dsp sends LFE to the fronts only when sub:no, or "main" setting in the case of the yammy.

its the wording in the manuals that makes it confusing:

-Select the "SW" setting if you are going to use a subwoofer. The LFE signals are directed to the sub.

-Select the "Main" setting if you do not use a subwoofer. The LFE signals are directed to the Main speakers.

-Select the "Both" setting if you use a subwoofer and you want to mix the Main channel low frequency sound signals

with the LFE signals.

notice for "both", it doesn't say where it mixes the two types of signals. where it is, is in the sub. the sub get both low bass & LFE, not the fronts.

as you know, low bass from the other channels & LFE are two totally seperate things. low bass is contained in the 5-7 other channels. LFE is a seperate channel (the .1).

i know i'm a bass mgmt freak, but hopefully this info is of value.

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[boa12]

"However, I have one more question to Boa (or anyone else who can help). What output level do I set my external

crossover at now (only filtering low bass from mains here)? Should I play regular two-channel music (with no LFE) and

set the crossover output so it sounds balanced)? Then let the LFE go straight to the sub without any volume

adjustment before arriving at the sub input? I guess I don't have much choice here unless I get a second crossover."

pb, you mean the crossover on your x-30? the output level is on your sub.

yes don't worry about the LFE. it's independent from your x-30 (when you run from sub out to sub). do as you said & set the x-30 cross where it sounds best to you on bassy 2-channel music.

& use the output on the sub to balance the sub level to your sys (best to use a sound meter & set that after setting the crossover on the x-30).

& be sure on your pw sub that its crossover is disengaged or turned all the way up to 120hz or higher from the start. otherwise its crossover will possibly cut LFE.

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[pierceb]

Boa, maybe your getting sick of this, but I thought I should clarify.

The sub is a Servo-15, hence is doesn't have any of the crossover options, etc. like the PW and PS series subs. All the subwoofer unit has is an output dial (like you said) and a line level input receptor plug. Thats it. All the other stuff is on the X-30.

On the X-30, there is a crossover setting dial (hz), a phase dial (degrees), and an output level dial. I can send high frequency material back to amp at 50hz, 80, hz, or 120hz.

In summary, I can control the amount of output from the crossover unit to the subwoofer (or can control the input level to the crossover unit). In essence, there are two volume adjustments to play with, one on the crossover unit and one on the sub.

So, if I had the LFE going directly to the sub, it could be at a different level (or intensity??) than the low bass being cut at the crossover unit. So I should adjust the output from the crossover unit to balance the LFE (I don't think this is possible).

So all I think I can do to set this thing up is balance the subwoofer (using the crossover) to bassy two-channel music, and leave it. If I need more total subwoofer volume, I can adjust the output on the subwoofer directly, this way the LFE and low bass are increased at the same level. Does this make any sense?

I'm starting to think I should get another receiver. This isn't a heck of a lot of fun. I really appreciate your help here, made me think pretty hard about what is really going on.

-PB

[boa12]

i haven't used your x-30, but it says it has its own variable crossover knob (in HZ). i would think you wouldn't use the high pass on it. to do that you run a connect from its output jack back into the receiver. you have nothing on the receiver to do that (no power in). so you don't use anything pertaining to the high pass output. since you don't run it back into your receiver, the high pass setting knob has no effect.

just run the receiver front preouts to the x-30 INPUTS & connect the sub (servo, sorry) to the sub output on the x-30.

so the only x-30 knob that applies is the variable crossover knob. that's what you set to where you want w/ bassy 2-channel stuff (probably somewhere between 40-60hz). set the phase switch on the x-30 the same as on the sub, whichever sounds best (probably 0 or normal).

so set the sub output level on the sub to where it balances w/ the other speaks & where you like the bass,

after you do the crossover on the x-30. if the servo sub has no crossover out/disable switch, then turn its crossover all the way up to 120hz or highest.

then the LFE will go on the other connection to the servo sub from the receiver sub out, when you set the receiver to sub:yes, "LFE only" & fronts:large. & the LFE will not be filtered by the servo sub's crossover.

don't worry about the LFE. set the sub output level to

the 2-channel low bass (or w/ a sound meter). then the LFE will about approximate your sub output, w/ +10db bursts in movies (that's good). your receiver has a seperate LFE control if you want to tweak that.

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[boa12]

pb, let me give you the steps in order.

on the servo, disable crossover or turn it all the way up.

on the receiver, connect the fronts preouts to the x-30

L & R inputs.

on the x-30, connect the sub output to the servo w/ Y-adapter.

on the receiver, connect the sub out to the other connection of the Y-adapter on the servo sub.

on the receiver, connect the fronts speaker terminals to the front speaks.

on the receiver, set fronts:large, sub:yes & bass control to "LFE only".

put on some bassy 2-channel stuff & play w/ the x-30 variable crossover to hear where it best jives between your speakers & sub.

on the servo sub & x-30, set phase the same to where it gives you the best bass quality.

(you may have to go back & forth some between the 2 steps above. many don't hear any real dif w/ phase setting & just leave it on 0/normal).

on the servo sub, w/ the sub output setting in your receiver at flat/0, use its output control to adjust it to your other speakers level (or maybe 5 db higher - best to use a sound meter).

on the receiver, when you're playing any 5.1 that has an LFE channel/content, you can tweak the LFE output level w/ the remote (may never need to do it).

that should be a start.

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[pierceb]

Thanks Boa,

I'm setting it up just the way you said, but there will be a couple of differences.

Forget LFE for a minute here, lets just talk how to control the low bass from the mains. My denon will accept an external left and right input signal. So when I send the left and right channels from the pre-out on the amp to the X-30 crossover, the crossover does 2 things. It cuts the low frequency material at whatever the dial is set at (35hz to 180hz) and sends this to the sub. Low bass taken care of. In addition, the X-30 has 3 sets of pre-outs to high frequency material (they are set at only 50, 80 and 120 hz, no other choices here. So I can connect the 50hz pre-out on the X-30 to the external in on the Denon. So the amplifier is only receiving 50hz and up signal. I will set the X-30 low pass filter at 50hz so that everything is taken care of.

I just got back from work, I have a new y-adapter and will try it right now. I'll let you know the results.

For the hell of it, lets open another can of worms. On a 5.1 (or 6.1 or 7.1) recording, is there much material below 80hz on the centre and surround channels? If so, I'm going to lose this information with this setup.

After all this, it may be best to only use the internal bass management in the Denon, and just cut everything at 80hz. Go figure.

-PB

[boa12]

pb,

"So I can connect the 50hz pre-out on the X-30 to the external in on the Denon."

wouldn't do that. now that i would think would create problems because you're running preouts back into the preamp. that would be a loop.

the ext in/direct inputs aren't like power amp inputs. they're meant to hook up an input device like a dvd-audio player. they bypass the dsp & dacs, but not the preamp. besides, to use those you'd have to switch to ext in which then doesn't use the dsp & dacs in the receiver. not good.

as for the other speakers, set them small. that then directs all their low bass to the front preouts/sub. you can try setting the rears large if they're big enough. then the bass from those channels goes there instead of the fronts preouts.

yes, there is a lot of low bass in the channels beside LFE for 5.1+ these days. but its a matter of whether the speaker can produce well down to 50hz or so, & what sounds best to you overall at your room, whether you do rear/surround on large or small.

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[pierceb]

Well Boa,

It doesn't work! Hooking up the sub out on the receiver and sub out on the crossover with a y-connector results in no LFE at all. Worked OK in two channel (although I know had some sort of ground loop type humming). I didn't like the way the highs sounded going through the crossover, sounded way too harsh.

Problem unsolved. Back to cutting it at 80hz with the Denon. I know what to look for when I upgrade. Thanks again.

I'm out. PB

[boa12]

pb, did you see my above? did you run the x-30 output back into the receiver. you don't want to deal w/ the highs thru the x-over. just the lows to the sub.

iow, you don't want to use the ext in on the denon unless you're connecting like a dvd-audio player or a dvd player using the analog outputs. (take it your dvdp is connected to a digital-input on the denon).

no argument here. it just may sound overall better setting all speaks small & using the sub out to sub. then you don't need the x-30 or the crossover on the sub. the receiver does all the filtering to the sub out.

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[boa12]

or another thing you could try is just not doing the sub out/sub & y-adapter.

run the front preouts to the x-30 & x-30 sub out to sub. (don't run the x-30 high out back into the denon & don't use ext in).

then set sub:no in the denon. the fronts will auto be set large & get lfe also thru the speaker connection. set bass control to fronts+lfe.

adjust the x-30 crossover w/ the bassy 2-channel stuff.

same as above. turn the crossover all the way up on the servo sub. everything else same as steps above.

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[pierceb]

Sorry Boa,

I didn't see your post re the external inputs. I think we were posting at the same time. Makes perfect sense to me now. What was I thinking?

Not going to use the X-30 now, it is disconnected.

Oh well, I guess I have to save for some quality equipment with better bass management!

I'd rather be reading this anyway, then what is going on in the General Questions forum.

-PB

[boa12]

pb, no doubt. actually rather these work arounds the best solution is something w/ an adjustable digital crossover in the dsp imho. that way the big speaks & sub aren't cut too high, & you get the LFE going to the sub only thru the sub out which i found creates much more dynamic LFE.

take a look at the denon 4802 or 5803, or the B&K 305 or 307.

i have a b&k ref 30 pre/pro & their receivers have the same bass mgmt- adjustable from 20hz on up in 5hz increments. plus even the slopes are adjustable. great sound w/ klipsch speaks too.

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My Home Systems Page

[erikjohn]

Boa/Q,

The low freq from the mains is sent to the sub in "Both" mode when and only when you are listening to a 2-Channel source. In which case it extracts the signal from the two channels ie it crosses it over and everthing below 90hz is sent to the sub. This is a no brainer as where else is it going to get the signal. I prefer to set the crossover setting myself at 120hz on the sub so I use the Main Pre out to feed the sub.

Ok now for when the source is 5.1... The amp is set to "Both" on the front and speaks are set to large. Now the fronts are getting all the normal signal from the front channels and the .1 LFE is mixed in. What do you get from the sub? As I would expect you get just the .1 LFE signal that it, that's all no more no less, not the same lows as are coming through the front because the front is getting a mix not the sub. The only way to get a mix in the sub is to set the fronts to "small" in which case you are not getting any bass out of the mains all from the sub.

Like I said before in my a previous post I can get the best of both worlds by using the pre outs. I also get the sub for 2-cahnnel stero listening ie not using any of the DSP's to simulate 5.1 and I can set my crossover levels at the sub above the 90hz which is fixed on the sub out of the reciever. The KSW-12 works overtime producing all of the bass between 120hz and 90hz that it would not get if I used only the sub out.

Now for the rest of the story.

Last night I configured the RX-V1 the way I have been planning on but just hadn't gotten around to. One point of interest is that as soon as I plugged into the Main outs I lost all signal to the Main speakers as the amp was wanting me to run a signal back into it in the Pre ins so I had to use my eq to complete the loop back into the amp which is fine because I wanted to juice up the signal anyway. I used the tape out on the back of the eq to the sub (both left and right channels into the sub). Immediately noticed a huge difference in the bass as I was getting the lows from the front above 90Hz to the sub. To be objective I also bypassed the eq controls and still had more bass. As I said before this setup is no different that how you would set up a sub on an old two channel amp theres nothing special about it.

IMO summary:

You can rest assured that the .1 channel output will cross over the signal at a set HZ unless your amp has bass management for the .1 channel. I would also say that probably 99.9% of all amps will not mix the front bass with the LFE to the sub in 5.1 mode because the .1 is a "discrete" channel", if it wasn't then why would you need six cables in for 5.1? You wouldn't you would only need 5 and the amp would figure out what to send to the .1 channel, the .1 channel is encoded in the signal. Also on all receivers when you use a DSP or Pro-Logic to create a 5.1 sound the amp is deriving the signal sent to the sub(.1 channel) from the mains and crossing it over at the setting you set the amp to or the fixed hz. Whats more, 99.9% of all recievers will not send a signal out of the .1 output when you are listening in 2 channel stereo mode.

Now I agree this thread has become very confusing but it's not rocket science folks. Even though some us have spent coultless hours behind a birds nest of wires configuring wiring and drawing diagrams to see if something will work only to get a huge ground loop that whats it's all about, it's fun to screw around with your stuff and learn more about it in the process. The best way to figure out how you want your setup is to expirement, if your satisfied with using the factory setup then thats fine too.

That reminds me back to the days when I was about 6 years old wiring up the old record players. Remember the ones that you could close up like a lunch box with a denim case. I would take those things and wire up as many speakers as I could get my hands on. I would collect pop cans which were 5 cent refunds in Iowa and turn them in for the cash. I would then go to all the garage sales I could find and buy up all the electronic junk I could find just to go home and take it apart and mess with it. Those were to good old days, all of that stuff was so interesting. Some things never change, the equipment just becomes more expensive and a lot more costly to repair if you screw it up. I would say alot of us here on this BB probably have similiar memories of their youth.

Anyway on a side note last night I also setup the RX-V1 for 4.1 stereo. I did this not by using a switcher on the Main speaker outputs but in a diffenerent way. If you have read this post you know I am now getting the sub in the mix on two channel stereo so thats the .1 of the 4.1. The RX-V1 has a out put for Zone 2 which is just another internal preamp that can be used to route any analog signal set into the amp to another room, recording device etc. and is completely unaffected by what the main pream is doing. I ttok the two channel out of the Zone 2, spilt it and fed it into the FL, FR, RL, RR of the 6.1 inputs. SInce I do not have SACD I am not using these inputs. I just set the Zone 2 out to whatever source I want to listen to and turn the amp to 6 channel input and whalla 4.1 and I am using 4 of the internal amplifiers to drive instead of having to use the B set of speaker outputs and all of the swithcing is done in the amp. No problem.

EJ

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89' K-horn's(Mains)

81' Cornwall's(Rears)

85' Heresey's(Centers)

KSW-12(Sub)

Yamaha RX-V1

61" Hitachi WIDESCREEN

Dish Net w/Opt Out

X-Box w/Opt & Comp Outs(DVD/CD)

JVC S-VHS

Sony Minidisk

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[boa12]

"The amp is set to "Both" on the front and speaks are set to large. Now the fronts

are getting all the normal signal from the front channels and the .1 LFE is mixed in."

this is where i degress. i think this the same as like "fronts+lfe" on any other receiver. that is its from the sub's perspective - IT gets low bass from fronts set large as well as ALL the LFE (no LFE goes to fronts).

only way LFE goes to the front speakers (terminals &/or

preouts), is when you set "Main" which is like setting Sub:No on most other receivers.

attached pdf is a good primer on LFE vs Low Bass.

"-Select the "Both" setting if you use a subwoofer and you want to mix the Main channel low frequency sound signals with the LFE signals.

keywords - subwoofer, mix, Main, low, LFE; that is the mixing is being done in the sub. not in the fronts.

I think yammy is confusing people by calling low bass "low frequency sound". but they don't mean LFE here. they mean low bass from the other channels besides the .1 (Low Frequency Effects). can be pretty confusin.

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This message has been edited by boa12 on 09-26-2002 at 01:56 PM

[boa12]

dupe

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My Home Systems Page

This message has been edited by boa12 on 09-26-2002 at 01:57 PM

[boa12]

hopefully to inform & not hassle or confuse, but better clear this up:

"You can rest assured that the .1 channel output will cross over the signal at a set HZ unless your amp has bass management for the .1 channel."

I think/hope you mean "sub output" in place of ".1 channel output" and "low bass" in place of ".1 channel". again, the dif between low bass & LFE (.1 channel). bass mgmt works w/ low bass. all bass mgmt works w/ really is low bass. as far as LFE, it either sends it to the fronts only (MAIN), OR to the sub only (the other two settings).

"I would also say that probably 99.9% of all amps will not mix the front bass with the LFE to the sub in 5.1 mode because the .1 is a "discrete" channel", if it wasn't then why would you need six cables in for 5.1?"

actually in 5.1 as well, about all do mix the front/low bass from other channels set small w/ LFE in the sub, & when your fronts are set large & you use the "Both" setting. the only way its true that the sub gets no low bass from other channels is when you set the speaks

large & the sub setting to LFE only (or the equivalent moniker by yammy).

"You wouldn't you would only need 5 and the amp would figure out what to send to the .1 channel, the .1

channel is encoded in the signal."

you have a point. but the bass mgmt dsp are configured

to send low bass to the sub as well as LFE, unless you want to run speaks large. but then many of us have found poor bass by doing that, especially on 2-channel music. guess they leave it up to the mixers to put most of the low frequency sounds in 5.1 in the .1 channel/LFE & sub only so as not to muddy up the sub w/ both. at least not both to the sub at the same time.

"Also on all receivers when you use a DSP or Pro-Logic to create a 5.1 sound the amp is deriving the signal sent to the sub(.1 channel) from the mains and crossing it over at the setting you set the amp to or the fixed hz."

.1 channel is LFE & is a discrete channel. the receiver/dsp does not derive it from the material. the .1 LFE is already encoded on the material as a seperate

channel. again, if you substitute "low bass" for ".1 channel you are correct.

"Whats more, 99.9% of all recievers will not send a signal out of the .1 output when you are listening in 2 channel stereo mode."

that's pretty true, but again i'd use the term "sub output" in place of .1 output. stereo material doesn't

have a .1 channel. when you use this mode on most it plays just the front speakers full-range. since you'd not want to use this mode w/ 5.1 material, i won't even get into that.

"Now I agree this thread has become very confusing but it's not rocket science folks."

I agree its confusing. But Bass Management is probably

the most complex issue in dealing w/ units & their dsp.

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[boa12]

"Like I said before in my a previous post I can get the best of both worlds by using the pre outs. I also get the sub for 2-cahnnel stero listening ie not using any of the DSP's to simulate 5.1 and I can set my crossover levels at the sub

above the 90hz which is fixed on the sub out of the reciever. The KSW-12 works overtime producing all of the bass

between 120hz and 90hz that it would not get if I used only the sub out."

ej, if you're using the front preouts to the sub instead of using the sub preout, i'd think you want the setting on "Main". that's the only setting where LFE (the .1 channel) is sent to the front preouts. if you set it to "Both" or "LFE" connecting this way, you lose LFE all together because its being sent only to the sub out.

& when you do it this way, i'd think you'd want to dial down the sub's crossover to 40-60hz. that way it jives best w/ the front speaks since both are getting the same low bass & you don't cut out all upper lfe because

its also going to your front speaks via the speaker connections.

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This message has been edited by boa12 on 09-26-2002 at 02:14 PM