Sub hookup (LFE question)

JSK2003

I apologize in advance if this has been posted elsewhere. I did browse briefly but did not find any answers.

I just setup a Polk PSW-550 sub using Polk's "recommended" settings. (Speaker wire method) However, my Denon owners manual suggests using the receivers LFE connection to connect the sub.

With the contradicting documentation I just want to be sure I'm setting things up for the best possible experience.

Thanks to all who reply,
-JSK

MxStYlEpOlKmAn

Ok, First Do the LFE hook up, see if u like it and it sounds good to u, and if ur curious - then try the Speaker wire hook up, see if u like it -- also....SCREW DENON! LISTEN TO POLK!

scottvamp

JSK, welcome to the club and congrats on the sub purchase.
I still don't get why Polk is suggesting the "speaker wire method".
Give me a little more info on the rest of your rig. I have never been impressed with the SWM. Go LFE off of your Denon - that is what it is there for. It is hometheater 101.
Once again I do not know why Polk is giving this as the perfered method on a sub like the PSW550. This is a common method with Passive sub/satilite systems. Anyway "typical HT setup" - go LFE.

scottvamp

also....SCREW DENON! LISTEN TO POLK!

Mx - see!!!!! Denon is his reciever/amp. How can u listen to Polks without a reciever. Denons are very good and the owners manual is correct over the Polk to boot. What are u talking about??????

JSK2003

Thanks for the responses.

I have been pleased so far using the speaker wire method however I'm going to try the LFE connection to see what I like best. I figure it wouldn't hurt.

-JSK

scottvamp

Sure - try'm both out and let us know which one u like best. With lfe u will have a db control on top of master volume and sub volume. U have to set all three properly. More control - better sound.

JSK2003

Okay, just got home with a Monster 400 subwoofer interconnect and now have things setup using the LFE connection. Set my front speakers to "small" and turned the subwoofer selection to "yes" on my receivers settings.

Popped in Star Wars AoTC and ran a few scenes to test things out. While there doesn't seem to be as much bass as before .. I do notice a much crisper and cleaner bass coming from the system.

I know I'll have some more tweaking to do but at this point I plan on staying with the LFE connection. Now I just need to read up on how to "tweak" the sub's settings for best performance for my setup.

Thanks again for the suggestions,
-JSK

scottvamp

JSK, great job -so far so good. Nice choose of cable also. Now that the sub is set to "yes" - when you do the db setup and it is sending pink noise to your speakers it should also send a signal to your sub. At that time u can adjust the db volume of it.

scottvamp

Popped in Star Wars AoTC and ran a few scenes to test things out. While there doesn't seem to be as much bass as before .. I do notice a much crisper and cleaner bass coming from the system.

That is correct because the bass IS quicker and cleaner - it will also be deeper and therefor you my FEEL more bass than you hear. This is ideal. If it is to low you can adjust the crossover on the sub to a higher point. Be careful not to over drive it with your recievers db boost.

swillis55

Originally posted by JSK2003
Okay, just got home with a Monster 400 subwoofer interconnect and now have things setup using the LFE connection. Set my front speakers to "small" and turned the subwoofer selection to "yes" on my receivers settings.

Popped in Star Wars AoTC and ran a few scenes to test things out. While there doesn't seem to be as much bass as before .. I do notice a much crisper and cleaner bass coming from the system.

I know I'll have some more tweaking to do but at this point I plan on staying with the LFE connection. Now I just need to read up on how to "tweak" the sub's settings for best performance for my setup.

Thanks again for the suggestions,
-JSK

I originally had my system set up this way. My only problem was when I played 2 channel stuff. (ie CDs, radio) No output from the subwoofer, only from the two mains set to small. Mind you, I could use pro logic II but if it's 2 channel, I generally would like to listen to it that way. I've heard if your DVD-A player does not have bass management, then you have full range of frequency sent to all speakers, regardless of the range it is capable of outputting. Just a thought.

Cheers,

Sean

scottvamp

On my Onkyo's the lfe plays through every source I throw at it.
Never heard of lfe only playing through DVD. Now DVDA gets a bit complicated. But I am just find with DD and DTS mixes.

swillis55

Originally posted by scottvamp
On my Onkyo's the lfe plays through every source I throw at it.
Never heard of lfe only playing through DVD. Now DVDA gets a bit complicated. But I am just find with DD and DTS mixes.

I guess the most logical question to ask you next is, when you play 2 Channel sources (ie. CD's) and have output through your 2 fronts/mains and your subwoofer, do you also have output from your surrounds? If not, I'm very interested in your Onkyo receiver because using the subwoofer out with my receiver (of course, subwoofer set to "yes") will only yield output through the subwoofer with 2 channel sources when set to surround mode. Stereo mode will only play through the fronts/mains. The only way for me to compensate for that (as stated in the polk manual) was to do the recommended sat/sub setup or use my surrond mode. DD and DTS no problems with LFE output.

Another question. Why would the bass sound any different whether JSK was using the subout versus sat/sub set up? No bass is lost because with the sat/sub set up, LFE channel would be sent to the "large set" mains. I know JSK said it sounded crisper and cleaner and less of it, but should you not be able to achieve this with a good sat/sub blend and using the built in filter vs. relying solely on the receiver.

You're probably thinking I should do a search to answer my questions, but I have, at length, and I've also read the various articles polk has on their website. I would just like to hear from folks who likely have more experience with this.

Cheers,

Sean

scottvamp

A sat/sub combo is just that. Usally a passive subwoofer is used or the amp on the sub that powers the sats. It is not designed to be used as a full HT system which incorperates lfe and bass management.

OK in a typical lfe HT setup. Playing a 2ch source such as cd's will always incorperate the subwoofer. In that situation anything not 2ch is considered a DSP. Digital Signal Processing. This allows different variations of surrounds to be used. I like 6ch sterio when I listen to music. No matter what the subwoofer is always in play. Use an HT to its benifits. A 2ch system is just that a pair of 3way speakers. Simply put. Doldy Digital Hometheater is what is called 5/6/7.1 sound. That (.1) stands for the lfe (subwoofer) you can only obtain this feature through lfe applications. Not with a sub/sat speaker line feed setup.

Dr. Spec

Look at Scott bringin' on the knowledge! Good deal! You've been tearing up the boards with great posts.

Ed

JSK2003

Thanks again for the wealth of information. I'm impressed.

I haven't really changed any settings yet with the receiver setup. I have left everything to the Denon defaults. As far as the PSW-550 ... I've set the Phase to 0, and the Low Bass and Volume knobs are both set at half. (As Polk recommends in the manual)

Just finished watching LoTR and I'm happy where things are. As a matter of fact, I may not change anything quite yet until I have a chance to test a couple more sources. (SACD, CD, DVD, etc.)

It's hard for me to gauge whether the bass sounds "right". After all, my old speaker setup consisted of just 2 Sony loudspeakers. I guess I'll just have to "Play it by ear" ... literally.

-JSK

scottvamp

I guess I'll just have to "Play it by ear" ... literally.

JSK, Enjoy - have fun. Tweak away.

Dr. Spec, Thanks - feeling the love!!!!!:)

swillis55

Originally posted by scottvamp
A sat/sub combo is just that. Usally a passive subwoofer is used or the amp on the sub that powers the sats. It is not designed to be used as a full HT system which incorperates lfe and bass management.

Doldy Digital Hometheater is what is called 5/6/7.1 sound. That (.1) stands for the lfe (subwoofer) you can only obtain this feature through lfe applications. Not with a sub/sat speaker line feed setup.

I have to disagree with you about this point. Using polk's website as a reference, they suggest that you don't lose your .1 channel/LFE with a sub/sat speaker line feed. Just because you're not using the subwoofer out does not mean this information is not used. The receiver takes this information and sends it to the your front left and right outputs, where you have your sub/sat speaker line feed setup.

You still have bass management with this setup because any speaker you've set to small in your receiver will have low frequencies (on mine below 100Hz) sent to the front left and right outputs rather than the LFE channel which was set to "no" or "off". All in all, all bass is still accounted for, according to polk's website. No channels are lost. So really, RM series can be used as a full HT system in a sub/sat speaker line setup with bass management.

Cheers,

Sean

Sumflow

Originally posted by swillis55
My only problem was when I played 2-channel stuff… No output from the subwoofer, only from the two mains set to small.

I thought the Bass only went to the mains when they were set to large?

I could use pro logic II

Sean does the Panasonic Pro Logic II send a separate signal to your subwoofer?

then you have full range of frequency sent to all speakers, regardless of the range it is capable of outputting.

Sean the idea is that if your source is sending the full signal out, either the Amp has to separate the Sub and send it to the woofer. Or you do the spaghetti wire technique, and let the Sub filter out the bass and send the rest to the fronts.

MxStYlEpOlKmAn

Ok, First Do the LFE hook up, see if u like it and it sounds good to u, and if ur curious - then try the Speaker wire hook up, see if u like it

Hay I took you advise. Pro logic with the spaghetti wire delivered no bass. Sub out on the Denon has plenty of bass anyway it is hooked up.

-- also....SCREW DENON! LISTEN TO POLK!

Polk needs cheerleaders like MxStYlEpOlKmAn as long as they keep selling owners manuals like the one on the 303. What I really have trouble with is taking Polk advise on speakers when there advise on setup makes so little sense.

swillis55

Sumflow,

When referring to the full frequency range being sent to all speakers, I was using DVD-A as my example. Many DVD-A players on the market do not have built in bass management and because you can only play DVD-A through 6 channel analog inputs, you bypass bass management in your receiver. As a result, your subwoofer will only receive the LFE channel and any speaker/channel you set or deem small will still receive full frequency range for that channel. Therefore, using the sat/sub line feed setup helps. An external bass management system (Outlaw?) comes in handy in these cases.

If my subwoofer was set up using the sub-out, prologic II would become active and send a signal to my subwoofer if my DSP was set to surround with a direct 2 channel source. Otherwise in DSP stereo mode, I only have output from the Left and Right fronts. Being as my fronts are sats, I need to use the polk recommended set up to get my low frequencies to come through properly.

Cheers,

Sean

TonyPTX

Originally posted by Sumflow

Polk needs cheerleaders like MxStYlEpOlKmAn as long as they keep selling owners manuals like the one on the 303. What I really have trouble with is taking Polk advise on speakers when there advise on setup makes so little sense.

True, and I'm not going to argue here, but the flaw in your logic is that you're doing your own analysis of what you "think" is right (i.e. using your knowledge of speaker systems and applying it here). For that same matter, consider if the instructions were for say, "how to assemble build a computer" or "rebuild a 4 bbl Holley carb," you would be a little less resistant to questioning the validity or accuracy of the instructions.

swillis55

Hey Tony,

How do you like your 6700's? I have the 6005 setup and I quite like them. Size was definitely a consideration when I purchased the system, but I'm wondering how you find the 6700's "sound". I've considered upgrading but would I hear the difference.

Sean

Dr. Spec

Originally posted by swillis55


I have to disagree with you about this point. Using polk's website as a reference, they suggest that you don't lose your .1 channel/LFE with a sub/sat speaker line feed. Just because you're not using the subwoofer out does not mean this information is not used. The receiver takes this information and sends it to the your front left and right outputs, where you have your sub/sat speaker line feed setup.

You still have bass management with this setup because any speaker you've set to small in your receiver will have low frequencies (on mine below 100Hz) sent to the front left and right outputs rather than the LFE channel which was set to "no" or "off". All in all, all bass is still accounted for, according to polk's website. No channels are lost. So really, RM series can be used as a full HT system in a sub/sat speaker line setup with bass management.

Cheers,

Sean

This is 100% correct - you don't lose the LFE channel with speaker level inputs.

Mains to large, sub to no, remaining speaks to small - it's all there.

I think what Scott meant was sat systems do not have full range speaks like towers and big centers/surrounds that can be set to large with the sub set to on/yes. In this case, the sub only gets the LFE channel, and all other speaks get a full range discrete channel.

Incidentally, this is not my preferred method of playback. I prefer all speaks set to small with an 80 Hz x-over to the sub through the LFE channel with the filter at the sub disabled/bypassed. I think much above 80 Hz and the sub can be localized too easily.

I do use "full range" speaks all around - more for their quality of sound and room filling volume capabilities than their supposed deep bass output or extension.

At 80 Hz on small, half the signal is being sent to the sub, and half is being sent to the other speaks. These are typically 24dB/octave filters, so all surround speaks will still see some sloping signal content down to about 60 Hz. Conversely, the sub will see some stuff up to about 100 Hz.

Try an 80 Hz x-over and LFE with sats, and you will have a mild depression in the FR between 100 and 60 Hz. This will go away with a 100-120 Hz speaker level set-up.

Doc

TonyPTX

Originally posted by swillis55
Hey Tony,

How do you like your 6700's? I have the 6005 setup and I quite like them. Size was definitely a consideration when I purchased the system, but I'm wondering how you find the 6700's "sound". I've considered upgrading but would I hear the difference.

Sean

I really like the setup now. It's taken me about month to be able to say that honestly. I was coming from a 2 channel world with full dynamic range speakers (JBL J325A's) to a sat/sub combo that needed tweaking and balancing to get it just right. Granted I hadn't dabbled in home audio in about 2 years, it was a bit of a learning curve to get to the point where I was able to understand what all the settings did and what had to be adjusted to get things to sound just right. I think when I do have the space for some larger fronts, I'll get them then. Biggest thing I've noticed is that the mid bass seems to be little bit thin for my tastes (but for some crazy reason, it sounds fine when I run full channel stereo. Go figure!)

My only regret know is "Why did I wait so LONG to get a 5.1 surround setup?"

scottvamp

his is 100% correct - you don't lose the LFE channel with speaker level inputs.

You don't lose it in theory. The lfe "signal" is now "mixed" in with other sounds produced by the mains. You are losing it as a seperate channel - seperate speaker. That is not have a true lfe channel. There are dsp modes out there that have a "3D soundfield" meaning you are getting "surround sound feel" with only a 2ch system. Now come on - is this really surround sound.
Anyway we sure like beating things to death on this forum - don't we. It is amazing that a simple question in audio and you could write an entire book to explain it all.
Bass Management will have more control with a seperate sub. Limits - Different db/frequency than what your mains are playing rather they are set to small or large.
Mains set to large "for example" will have a bass responce around 50-100hz where as your sub will hit at 50-18hz. So are getting a better spectrum of bass.

goingganzo

i have all my speakers set to small and my sub on. bass is non directonal so ifall your bass comes from one spot it is easer to get a good setup. i have ben told and experanced my self what is called a null when you have 2 bass sorceses that cancle each other out.