I want my cake and eat it too: LFE AND Line Level

Erik Tracy

So, my fellow Polksters and gurus - I run my HT rig for both music and movies.

For music, I prefer putting my avr in Pure Direct so I can take advantage of better DAC performance of a dedicated CDP and also listen to LPs with the least amount of sonic manipulation.

But, when I put my avr in Pure Direct the sub shuts off because this is a 2-channel mode only that bypasses all circuitry for analog connected devices except for the amp section.

I could re-wire my system so that the sub is either connected via speaker or line level outputs to the fronts, but then I would loose bass management for when I want to watch all those cool BD releases with lossless audio and the fearful LFE effects that could damage my diminuitive RTiA3s - especially at reference levels and the strain that puts on my Carver.

Does anyone have any ideas for having it both ways via a switch or simple IC swaps at the sub (easily access to the rear in my rig)?

I'd like to be able to go to Pure Direct for 2-channel listening and still have the sub on, but I'd also like to switch back to a bass managed configuration via the avr when watching BD movies.

Any thoughts or ideas - much appreciated!

pearsall001

Check your Yammie's settings, there should be one for both sub on & sub off for 2 channel. My NAD T765 has Analog Bypass that shuts everything off & is a pure direct analog signal. Then with the Stereo setting all digital settings are off except for bass management. I'm sure you can configure it the same way with the Yammie. The setting names might be different though.

Erik Tracy

pearsall001 wrote: »

Check your Yammie's settings, there should be one for both sub on & sub off for 2 channel. My NAD T765 has Analog Bypass that shuts everything off & is a pure direct analog signal. Then with the Stereo setting all digital settings are off except for bass management. I'm sure you can configure it the same way with the Yammie. The setting names might be different though.

I've been in contact with Yamaha service and hanging out on the avs forum with other Yammie owners. From what I've been told the only mode that stays analog all the way thru the chain is the Pure Direct.

There is a mode called "Straight" and it does bypass the DSP effects, but analog inputs still get converted to digital on the input and converted back using the AVRs DACS - something I was hoping not to do to still have the sub on and keep the signal analog all the way thru.

My RTiA3s can kick down some decent bass - pretty surprising, to my ears at least, but for that final low end response and hit - they need the sub even for music.

I've done some extensive a/b comparisons with a recent audition CDP player and definitely prefer the CDP's DACs to my AVRs - just am frustrated at loosing the sub in Pure Direct.

sigh...:(

disneyjoe7

My old Onk had a Pure Direct mode which I perfered, but it also had a stereo mode which turned on the sub LFE output along with the L / R outputs.

joeparaski

How about a Y-connector at the main outs from your AVR?

Joe

Mike21

Hi Erick

My Onk 805 does the same thing, even in stereo mode.

You might try driving the sub out of the L/R analog preouts for Zone 2 (if your avr has Zone 2).

If you try this, please let us know if it works.

Mike

okiepolkie

This may not be exactly what you are looking for, but REL subwoofers do this internally, and do a very good job doing it: http://www.rel.net/index2.htm

Basically, it combines the front channels lfe to create a more seamless bass response in movies and music.

obieone

I'm in the same situation as you Erik. The only ideas I've had are:

A: Get 3 way flr. speakers w/ pwrd sub, i.e. LSi25 and run the R/L out to the sub's, and leave a/the dedicated subwoofer to the LFE.

B: Get a 2nd sub woofer, like a Velo SPL-800 and run the R/L to that for music, and have the primary sub for HT.

Both are limited to SPACE and $$$:o

Erik Tracy

obieone wrote: »

I'm in the same situation as you Erik. The only ideas I've had are:

A: Get 3 way flr. speakers w/ pwrd sub, i.e. LSi25 and run the R/L out to the sub's, and leave a/the dedicated subwoofer to the LFE.

B: Get a 2nd sub woofer, like a Velo SPL-800 and run the R/L to that for music, and have the primary sub for HT.

Both are limited to SPACE and $$$:o

Hmmm...I do have my first PSW303 in the garage doing nothing.

I suppose I could fiddle with that by using "Y"s from the avr pre-outs to feed my Carver and the PSW303 and have the PSW303 on when I go Pure Direct, and turn it off when in HT mode to feed the Valor via LFE.

Or I could run "Y"s from the avr pre-outs to my Carver and the Valor at the same time I have the Valor hooked up via LFE.

I could connect the pre-outs via the "Y" to the Valor when listening Pure Direct, then disconnect them and use the LFE connection for HT mode.

Not elegant, but doable.

I was toying with the use of multizoning - but I think in Pure Direct, multizoning doesn't work so the sub would again shut off.

Hmmm....

disneyjoe7

Why couldn't you do that and keep the 303 on? Just re-balance it in the system, its not any different then a 'Full Range" speaker which didn't need a sub to support the lower bass.

mmadden28

Erik Tracy wrote: »

....There is a mode called "Straight" and it does bypass the DSP effects, but analog inputs still get converted to digital on the input and converted back using the AVRs DACS - something I was hoping not to do to still have the sub on and keep the signal analog all the way thru.


...I've done some extensive a/b comparisons with a recent audition CDP player and definitely prefer the CDP's DACs to my AVRs - just am frustrated at loosing the sub in Pure Direct.
...

I was under the impression that an AVRs DACs are only used if you input a digital signal to it. And if you have a CDP to a DAC to your AVR (analog in) that the AVR does not use its DACs.

Somebody please correct my thinking if I am wrong. If that were the case then it would seem that an external DAC would really only be useful if you run to a pre then to an amp and not use an AVR at all in the chain.

Erik Tracy

mmadden28 wrote: »

I was under the impression that an AVRs DACs are only used if you input a digital signal to it. And if you have a CDP to a DAC to your AVR (analog in) that the AVR does not use its DACs.

Somebody please correct my thinking if I am wrong. If that were the case then it would seem that an external DAC would really only be useful if you run to a pre then to an amp and not use an AVR at all in the chain.

Here is the signal block diagram for the yammies:


I've been told this applies to the V1800/V3800 as well.

The Pure Direct path for analog inputs stays analog.

I've posted the question if the Yamaha "Straight" mode will keep an analog input as analog, but was told no, it will still go thru the ADCs, will still have EQ and bass management applied, but will skip DSP, and then use the yammies DACs.

Any other experience or definitive answers that counter this welcomed.

So it would seem for the Yamaha avrs, Pure Direct is the only true analog path for analog inputs - but no sub if connected via LFE.

And the advantage of an outboard DAC would be defeated if you use anything other than Pure Direct - and again - no sub.

rhulett

Not familiar with your sub, but most newer subs will apply a 80hz crossover when running them at speaker level. Instead of hooking the wires to your speakers, hook them to your sub in, run new wires to the speakers from the sub, set the front speakers to large. You can then run pure direct without any problems and still have a sub, although you will have to play with the subs high pass crossover to get some of the boominess out of the sound.

Erik Tracy

rhulett wrote: »

Not familiar with your sub, but most newer subs will apply a 80hz crossover when running them at speaker level. Instead of hooking the wires to your speakers, hook them to your sub in, run new wires to the speakers from the sub, set the front speakers to large. You can then run pure direct without any problems and still have a sub, although you will have to play with the subs high pass crossover to get some of the boominess out of the sound.

Both my Valor and Polk sub have, what I think, are LOW pass crossovers with an upper pass freq of about 120Hz.

I originally had my first sub hooked up via speaker level from the avr to the sub then from the sub to my front mains (aka 'the Polk way').

The problem with this is that you loose avr 'bass management' and the fronts must be set to Large.

So, in this configuration, I can have my cake (Pure Direct with Sub) but I can't eat it (no avr bass management via LFE out).

But....since I actually do more 2-channel listening than HT movies (about a 65/35 split) - I may just go back to the "Polk Way" and walk the dangerous edge of no bass management, scary harmful LFE effects to my tiny RTiA3s, and the strain it will put on my Carver M-1.0t mkII (rated only at 400 watts @ 8ohms)

I'm such a rebel....or dummy....maybe both...;)

rhulett

Erik,
I'm not sure I understand. If you hook it up the polk way, and set your fronts to large, then there is bass management still taking place. It would be routing your center and surround low signals to the fronts(sub). Hooking up line level, now your sub would take over the high/low pass of the signal, and in theory, only send 80hz and higher content back to your mains. It takes some extra speaker wire, but half the fun of this hobby is tweaking.
Rob

Erik Tracy

rhulett wrote: »

Erik,
I'm not sure I understand. If you hook it up the polk way, and set your fronts to large, then there is bass management still taking place. It would be routing your center and surround low signals to the fronts(sub). Hooking up line level, now your sub would take over the high/low pass of the signal, and in theory, only send 80hz and higher content back to your mains. It takes some extra speaker wire, but half the fun of this hobby is tweaking.
Rob

I guess I don't understand either. Neither my Polk or Epik Valor 'high pass' the speaker level outputs from my amp or avr. They only have a low pass xover that sets the upper pass frequency for what the sub will respond to.

I've not heard of subs that apply a high pass to mains hooked up via speaker level inputs. Do you have any specific models you can point me to? Sounds interesting.

But yes - you are right - I can still have bass management to my center and surrounds by setting the fronts=large and sub=off and hooking up the lines to the sub first then to the mains, or I could do this by using "Y"s off of the avr pre-outs for the fronts as well.

The more I talk about this, the more I think I'll go back to the "Polk Way".....

rhulett

Erik,
Both of the SVS subs that I've had, filter out anything above 80hz at both the speaker level and rca level outputs. I'd check with Epik and polk to see if this is also the case.
Rob

Erik Tracy

rhulett wrote: »

Erik,
Both of the SVS subs that I've had, filter out anything above 80hz at both the speaker level and rca level outputs. I'd check with Epik and polk to see if this is also the case.
Rob

I just checked with Polk support - it does not 'high pass' the audio when using speaker level connections. It does a 'pass thru' of full range audio.

I suspect the Valor is the same but I've got a question in to them as well.

THanks,
Erik

Log1x

Does your Yamaha have a setting to change your speakers to Small and Large? If so, set it to Small and that should fix your problem...at least it did on my Pioneer.

Erik Tracy

Log1x wrote: »

Does your Yamaha have a setting to change your speakers to Small and Large? If so, set it to Small and that should fix your problem...at least it did on my Pioneer.

Actually, what I want to do is use the memory settings on my Yamaha to hold two configurations:
1) HT mode with speakers=small, LFE/Bass=Sub, xover=80Hz. I will use this for watching movies (sub is connected via Subout on avr to LFE input on sub)
2) Pure Direct mode fronts=large, LFE/Bass=Fronts, no xover, surrounds are don't care cuz in Pure Direct I only get front outputs anyway - it is a 2-channel only mode

But what happens is for #2 - the sub turns off.

I prefer the Pure Direct because I have analog components with DACs that sound better than those in my Yamaha. If I put the Yamaha in any other mode, the signal gets converted via the ADCs and uses the avr's DACs.

I'm noodling out a configuration that will allow me to have both.

The trick is figuring out how to get the sub hooked up to work in both settings.

I may opt for either:
1) a manual swapping of connections at the sub for LFE connection and/or Line Level - depending if I'm watching HT or listening Pure Direct
2) give up bass management and run line level only to the sub and run my fronts=large so I can have the sub on in Pure Direct
3) dust off my PSW303 and hook up two subs: 1 for HT and 1 for music

SuperG

Hi Erik,

One option would be to use channel A and channel B if you have this option with your avr.

Hook up your mains via channel A and your sub via channel B (the polk way) and also with LFE.

When listening to music, set your main speakers to large, sub no and use speaker channels A and B. This way, you will have your sub playing through channel B the polk way.

When listening to movies, set your main speakers to small, sub yes and only use channel A, turn off channel B.

The only problem is that you might forget a step and have both LFE and channel B going through your sub at the same time...not sure of the impact but it is not recommended.

Erik Tracy

SuperG wrote: »

Hi Erik,

One option would be to use channel A and channel B if you have this option with your avr.

Hook up your mains via channel A and your sub via channel B (the polk way) and also with LFE.

When listening to music, set your main speakers to large, sub no and use speaker channels A and B. This way, you will have your sub playing through channel B the polk way.

When listening to movies, set your main speakers to small, sub yes and only use channel A, turn off channel B.

The only problem is that you might forget a step and have both LFE and channel B going through your sub at the same time...not sure of the impact but it is not recommended.

Hmm...the Yamaha V1800 that I have does not have 'channel' outputs.

There are Zones where the V1800 can drive a source to other 'rooms'.

But I checked the manual - this only works for analog inputs. Zone outputs won't work for Digital or HDMI connected devices.

Ok - that might still work for CDs and Phonos - which I want to be analog - but I think that when I put the V1800 into Pure Direct that the Zone ouputs will get shut off as the unit goes into a 'minimalist' mode for 2-channel only.

I've got a question posted over on avs - the manual doesn't really explicity say what the unit does in Pure Direct at the Zone outputs.

If the Zone outputs do stay active in Pure Direct, this may be a work around....stay tuned.....this was first proposed by Mike21 above - he may be onto something...but I've got a nickel that says in Pure Direct all outputs shut off except for Front L & R.

Erik Tracy

Follow up...

I contacted Epik about simultaneous connections and was told you can, but the signal connections would be summed - so if I connected my Valor sub via LFE from the AVR sub out, and at the same time, connected the line level inputs, from the AVR front L/R preouts, the sub would sum the two - which is not what I want for the two different listening 'modes'.

Chad at Epik said that for my rig, what I would have to do is cable swap between LFE and Line Level.

Kinda what I figured.

I guess I have to deal with the Yamaha V1800's limitation of having only one true analog pass thru mode for Pure Direct and either get two subs (one hooked up LFE, the other as Line Level) or manually switch between LFE and Line Level on one sub.

If other AVRs don't have this limitation and really do have a mode to synthesize the .1 bass signal from a pure analog path that doesn't digitize analog inputs - I may just consider an AVR upgrade.

Or just not have a sub when listening Pure Direct if I want to listen to outboard DACs or direct signal from my phono....

Yeah...I'm a tweaker and a 'purist'....

cabbiepimpin

I have the Denon 1909...I use the analog outs on my CDP to hook up to the Denon in order to use the CDP's DACs, and run the Denon in Pure Direct Mode.

Denon's menu gives the option of choosing "yes" or "no" for subwoofer for 2ch Direct/Stereo listening (and, somewhat counterintuitively, one must choose "LFE+Main" as opposed to just "LFE" under SW Mode in order send an LFE signal to the sub).

I wonder: does this bass management convert the analog signal into the digital domain? Is it possible to leave the analog signal as is, while only directing the low frequencies elsewhere, thereby still bypassing the Denon's DACs?

I have to say that my CDs have never sounded better, so whatever the answer is, something's working right.

Erik Tracy

cabbiepimpin wrote: »

I have the Denon 1909...I use the analog outs on my CDP to hook up to the Denon in order to use the CDP's DACs, and run the Denon in Pure Direct Mode.

Denon's menu gives the option of choosing "yes" or "no" for subwoofer for 2ch Direct/Stereo listening (and, somewhat counterintuitively, one must choose "LFE+Main" as opposed to just "LFE" under SW Mode in order send an LFE signal to the sub).

I wonder: does this bass management convert the analog signal into the digital domain? Is it possible to leave the analog signal as is, while only directing the low frequencies elsewhere, thereby still bypassing the Denon's DACs?

I have to say that my CDs have never sounded better, so whatever the answer is, something's working right.

Not sure.

It could be that what you are hearing is a dual DAC 'effect' where your CDP DACs feed an analog signal to the AVR, then this gets digitized, bass management applied, .1/Sub synthesized from the 2-channel source, then converted back to analog by the AVR DACs and sent to your speakers?

I've done some direct comparisons with my CDP and DVD player DACs in a Pure Direct and also feeding a digital signal directly to my AVR and letting the AVR DACs do the final analog conversion.

I can hear a difference in the DACs (:eek: I hope the audio atheists don't chase me down).

I think my AVR DACs do an admirable job - great for movies, but for 2-channel they just seem to be a tad recessed or 'lazy' for my tastes.

I can't explain how any AVR can synthesize the .1/Sub channel from a pure analog input and have that signal *remain* analog all the way thru the AVR.

Maybe someone smarter than myself - and that shouldn't be too hard - can explain that.

cabbiepimpin

Erik Tracy wrote: »

Not sure.

It could be that what you are hearing is a dual DAC 'effect' where your CDP DACs feed an analog signal to the AVR, then this gets digitized, bass management applied, .1/Sub synthesized from the 2-channel source, then converted back to analog by the AVR DACs and sent to your speakers?

I've done some direct comparisons with my CDP and DVD player DACs in a Pure Direct and also feeding a digital signal directly to my AVR and letting the AVR DACs do the final analog conversion.

I can hear a difference in the DACs (:eek: I hope the audio atheists don't chase me down).

I think my AVR DACs do an admirable job - great for movies, but for 2-channel they just seem to be a tad recessed or 'lazy' for my tastes.

I can't explain how any AVR can synthesize the .1/Sub channel from a pure analog input and have that signal *remain* analog all the way thru the AVR.

Maybe someone smarter than myself - and that shouldn't be too hard - can explain that.

Yes please...someone in the know please answer this. Can/does the AVR (specifically, the Denon 1909), while in Pure Direct mode, create the .1/Sub channel from a pure analog input and still keep the signal completely analog?

Seems to me that since the 1909 actually gives the option of selecting a sub line in the direct mode menu, that it somehow synthesizes the .1/sub channel while staying in pure direct/completely analog mode.

To think that just a year ago I thought I knew everything there is to know about this stuff...

Erik Tracy

So my order from Audio Advisor came yesterday: 2 RCA splitter/adapters (the metal version), and 2 Audioquest Black Thunder II Sub cables.

I rewired my rig with the RCA splitters on my external amp so that a set of AQ Black Mamba IIs run back to my avr pre-outs and another set runs to the line level inputs to my Valor sub....my avr is just too crowded in the back to get the splitters on at the source - but this setup is equivalent.

With this setup I can now switch my AVR to Pure Direct and listen to a direct analog signal all the way from source to speakers with no additional A/D-D/A step in the avr just to keep the sub on.

I still have a AQ sub-x cable running from my AVR Sub out to the LFE input on the sub - and it is a bit clunky to have to disconnect either the LFE cable or the Line Level cables from the sub when I switch between HT/movies and music.

I did have to dial in the sub xover when connected via line level because this passes the full audio signal to the sub - but once dialed I can leave it alone because when I recable for HT/Movies at the LFE input - the xover it bypassed anyway.

With an uncorked Bordeaux I sat down for some 'serious' 2-channel listening and some dialing in of the xover setting on the sub.

After some experimenting I got the sub dialed in and meshed well with the fronts.

I then switched the sub cable back for LFE connection and reverted back to bass management mode with the AVR doing its additional A/D-D/A even for CDs and LPs.

For me, for my rig, for my preferences - I gotta say I really prefer the line level mode for music. Yes - more steps to recable the sub, but I think I get a better meshing of fronts to sub with the continuously variable xover control on the back. If I need 62.56778Hz as the high cut-off for the sub, I can do that. I can't on my avr - which only has 20Hz increments of granularity for changing the sub xover.

I heard much better bass resolution and clarity for my setup and room config/acoustics. And the Valor really came to life at higher volumes....not boomy at all - I actually had it set to less than 50% on the rear volume control.

The whole reason for this experiment was to see if I could get just a bit more musical enjoyment for my setup. The constraint was the loss of sub in Pure Direct with the sub connected via LFE and my preference for the sound of my CDP DACs and a direct analog path from my LPs.

I suppose if my AVR had a mode, like others reportedly have, where the sub is not turned off AND analog signal stays analog all the way thru the AVR - then this extra effort would not be needed - or if my AVR had better/same DACs as my source components.

Still....the ability to have finer control of the meshing of sub to fronts is something I need to consider - I really think this does the better job as opposed to fixed increments on the avr, but that's just me - a hopeless 'tweaker'