There is no reason to set a main speaker to large unless you have absolutley no subwoofer. True of False?

True in the pure techno sense. However, many, many,
exceptions.

old...

Think, setting a main to 'large' means that the channel's bass (NOT any LFE signal) will not be redirected to the sub (or other large-set output).

In other words (assuming there is a properly-set sub channel), the main output setting for 'large' or 'small' chooses whether to keep the entire frequency range in that channel, or redirect frequencies below the crossover frequency to another output. This has no impact on the LFE signal.

The LFE channel can carry the same low-frequency sound as the mains, or a completely independent signal that either complements the mains, or could be completely different. For instance, there could be explosion impact in the LFE channel while bass-heavy music is playing in the mains, with neither channel reproducing anything the other is. The LFE is mixed as a sixth (or seventh) channel.

So, the strict answer to your question depends on which speaker(s) you want the mains' lows coming from: the mains or the sub. Are the mains capable of reproducing everything you want to hear from them?

Larry
www.fineelectricco.com

Thinkly,

Let's look at the technical aspect first.

In an ideal world, every channel would have an array of thousands of individual speaker drivers, each independently amplified and carrying only a single tone. The fewer tones any driver has to produce simultaneously (and the less load on any amplifier), the better chance of reproducing beautiful, pure tones.

Unfortunately, this ain't gonna happen. The sheer cost and complexity makes this just about impossible. Not to mention the second aspect: The human ear probably couldn't appreciate the fidelity anyway.

The second best option: Each channel has an array of independently amplified drivers, but each driver must produce a range of tones, instead of a single tone. Most configurations would use three types of drivers, each optimized for a different range. A driver for the high range might commonly be referred to as a "tweeter," etc. This is still too expensive and complex for most of us.

Third best: Each channel has either a single driver or an array of drivers for each of three ranges: High, mid and low, with each range independently amplified. The exception would be the LFE channel, which -- although independently amplified -- would not need high or mid-range range drivers. Some of the very top-end audiophile speakers do precisely this, but it's still too expensive for most of us (sixteen channels of amplification for a 5.1 setup? Wow.) So we have to compromise a bit further.

More likely: Each channel has drivers as above, but only one amplifier driving all three ranges. The amplifier must be extremely powerful to drive all frequencies simultaneously at the required volume levels without distortion. Aesthetic considerations aside, it still costs too much for many of us to afford at least five (nowadays six or seven is common) full-range speakers and powerful amplifiers, plus the LFE amp/subwoofer. For many of us (including you and me, Thinkly) still more compromise is required.

Common HT setup: Some or all of the full-range channels divert their lower bass signals to the subwoofer, in addition to the LFE channel the sub is already carrying. This reduces the load (and price) of the amplifiers and speakers producing those other channels. It adds a corresponding load to the amplifier powering the subwoofer. Also the increased complexity of the multiple signals being sent to the single sub makes it more probable that the tones will not be as "pure," (the fewer tones per driver, the better, remember?) Unfortunately, this is the best many of us can afford.

The number of channels sending their bass to the sub depends upon the type and quality of each person's speakers and amplification! You send as much to the better components as they can handle.

For many people this means all small speakers and a big powerful subwoofer.

In your individual case (mains with 12" woofers, and an 8" sub): to me, it makes sense to let the 12" mains take some of the bass load off the 8" sub, assuming your main channel amps can handle the full frequency range load.

And in my case (mains with 15" woofers, twin 10" subs in a single cabinet, and good amps all around) I took the slightly unusual step of not using a dedicated LFE subwoofer at all. The whopping main woofers handle the bass from each main channel, plus they split the center's bass, plus part of the LFE. The 10" subs take all bass from the four (7.1) surround speakers (three channels), plus the rest of the LFE.

All the configurations above follow two technical principles: Let each driver handle as few tones as possible; and send the most bass to the speakers and amplifiers best equipped to handle it.

And finally, filter the technical aspects through the ergonomic and aesthetic rule: Which option sounds best? I tried at least three "bass routing" methods that I recall before finally settling on my present configuration. And if I ever get a really good subwoofer, you can bet the LFE goes back to it! :)

Hope this helped. I didn't mean to write a book...

-Bruce

This message was edited by Bruce Burson on 12/20/01 05:56.12.

Hey, nice book. And we didn't even have to pay for it. :)

Bruce; We meet again ol' chap.
1) In NOT disagreeing with you. I would say it would be dependent on what range the LFE encompasses. I have found in my case that how the LFE is directed & also the use of speaker size selection, creates a GREAT difference!
My best setting is LARGE & BOTH. Otherwise I notice a drop in the centre front "presence" & a Bass "hole in the middle, between R&L. Further, as I have seen offered on other threads there seems to be an advantage to having subs R & L to address the different channel's bass.
Therefore, with the Yam having the option of 3 LFE settings: Main/SW/Both, in chosing BOTH, I can then practically set all the rest of the speakers to LARGE & use the EQ settings to exclude frequencies (for other than the SW) below the lowest freq. response which each of the the speakers specs say they can handle efficiently? (or Mid or Hi for that matter.)
Comments?
2)[re your THX setup: I have come across several recommendations that in your case, optimum would be for you to use the small setting & send all the LFE to the SW(s) Which again brings us to the "A" vs "B" types of speakers. Mine are not "A's" like yours.]

Dougofthenorth

This message was edited by Dougofthenorth on 12/20/01 11:56.41.

Thanks again for the great info. So, if I understand correctly,I can have the mains set to large and the sub can still receive an LFE signal? All other bass frequencies below the receiver cutoff will be handled by the mains regardless of which channel we are talking about? For example if my receiver has a cutoff of 100hz than all frequencies below (not a brick wall) that frequency will be sent to the mains. Conversely if I have the mains set to normal than "all" frequencies below the cutoff will be routed to the sub along with the LFE ( LFE is a brick wall)? This leads to my next question....How does the sub crossover effect this distribution. I will suppose that it does not effect the LFE at all? I will also suppose that if my sub is set at 60 hz that only frequencies (again not a brick wall)60 and below will go to the sub. What happens if the mains are set to normal in this case? Will the high passed frequencies from the sub be redirected back to the mains, or are they lost? Also does a reciever's cut off frequency vary if the bass management is changed from large to small or vice-versa?

Think; For me to help this has to be a step by step question-answer string because each answer may allow or exclude the next step.
1) what is your Recvr's brand & model.
2) does it give the Sw/both/main option. (if no we end
there for that option!
also check out for a lot of answers: [Link: kenwoodusa.com]

This message was edited by Dougofthenorth on 12/20/01 12:38.51.

1. Kenwood VR 507
2. Yes I have sub output. (Can turn on or off) I can set speakers to large or normal. No both.


This message was edited by Thinkly on 12/20/01 14:27.46.

Think; The seting I was referencing was for the LFE setting to SW/MAIN/BOTH
NOT the LARGE/SMALL SETTING
What choices are your LFE settings?
Dougofthenorth

This message was edited by Dougofthenorth on 12/20/01 17:19.23.

Doug,
I have subwoofer On/Off. That is it.
After more research here is my decision and my reasoning. 1.Mains>Large. 2.Sub>On. 3.Center and Surround>Normal. 4.Sub Crossover> 80hz.
Reasoning: My sub is small. Also I can't shut my sub crossover off, so I set it to the highest setting which is 80hz. If I had the mains set to Normal then at the crossover for the receiver everything below 100 would go (not a brick wall)to the sub as a low pass. The sub crossover will block some of the frequencies between 100-80 hz. With the Large setting all of the bass 80-100 blocked at the sub will be redirected to the mains. I still get the LFE through the sub, atleast anything below 80hz. (brick wall) I have been lead to believe that a sub can reproduce the very low LFE better than any mains. Even a cheap sub at, say 20-30 hz, is better than a good set of mains at producing this band. Please evaluate my logic. Thanks

Think

Rule #1 If the sub out is set 'on', then the LFE signal goes there, period; if the sub out is set 'off, the LFE signal will go to whichever out is set to 'large'; if no outs are so set, the LFE will go nowhere. Gone. Kaput.

Rule #2 Any out (other than sub) that is set to 'large' gets the full frequency range of that channel (not any LFE, just normal bass). If you turn the sub out 'off', then see Rule #1.

Rule #3 Any out set to 'normal' (small) will have all frequencies below the receiver's cutoff sent to A) any out set to 'large', or B) the sub out (to be mixed with the LFE). If you turn the sub out 'off', then see Rule #1.

Rule #4 Any signal between the sub's 'low-pass' frequency and the mains' 'high-pass' frequency will not be reproduced at all. (If, on the other hand, the bands happen to overlap, they will be reproduced by both.)


You said:
"With the Large setting all of the bass 80-100 blocked at the sub will be redirected to the mains."

Not exactly; the receiver does not 'accept blocked frequencies to be re-distributed'. More accurately, "With the large setting, all frequencies from MAIN channels, NOT LFE, will remain in those channels (see Rule #2).

As long as the sub out is on, no LFE signals of ANY frequency will go anywhere else (see Rule #1). Any LFE signal blocked by the sub's crossover will not be reproduced at all.

Conclusion: the only way to not lose the 80-100Hz frequencies is to keep the mains set to 'large'.

Larry
www.fineelectricco.com

Wah-hoo!

Man, did this thread cover some ground while I wasn't looking! I'm going to have to compose this off-line, to make sure I don't miss anything.

From top to bottom, then:

Doug, bear in mind that Yamaha does things a little differently... Instead of a "Main/SW/BOTH" setting, most other brands set each speaker individually.

At the risk of duplicating Larry's comments: If the subwoofer is set On, it gets the LFE, all of it, period. For most "non-Yamahas," at least for the Kenwoods Thinkly and I own, there is no option to send LFE to any other speakers if the subwoofer is On.

If the subwoofer is set Off, the LFE will be divided among ALL speakers set to Large, whether Mains or not.

If the sub is Off and no speakers are Large, the LFE is lost.

When the subwoofer is On, the only remaining question is how many channels will add their individual bass signals to the sub on top of the LFE it's already getting, via setting those channels to Small (or Normal, or THX, or whatever the "Not Large" setting is called :) The LFE will still go -- only! -- to the sub, regardless of whether the other channels are Large or not.

Depending on the amp, some center channels can be diffused to help fill any hole between L&R, but that's another topic.

And on the subject of separate L&R subwoofers, that's REALLY another topic! Check out [Link: sonicdesign.se] if you're interested in more data on subwoofer placement and the use of multiple subs. In effect, that's what I'm doing with my main woofers, but the only way to send the LFE signal to them is by setting the amp to No Subwoofer.

Re "my THX setup." First, I need to clarify that I don't actually have a "THX certified" setup, precisely because of my "non-certified" speakers (and DVD player, and wiring, and...) As you have read, the most common THX setup consists of satellite speakers on all channels, freq cutoff at 80Hz, and all channels' bass below that PLUS the LFE going to a single -- extremely high quality -- amplified subwoofer. This is both because of the quality THX demands of their certified subwoofers and amplifiers, and because (as I mentioned above) the cost of amplifying ALL channels to those standards and buying full-range speakers for all those channels is out of many people's ranges.

=======

Thinkly,

Q: "I can have the mains set to large and the sub can still receive an LFE signal?"

A: True. Actually, the sub -- only -- WILL receive the LFE signal if it is set On. The mains setting has no impact on this.

Q: "All other bass frequencies below the receiver cutoff will be handled by the mains regardless of which channel we are talking about?"

A: No. If the mains are Large, the others small, and the sub is On, each main will handle only its own bass. The other channels will send their bass to the sub.

Q: "How does the sub crossover effect this distribution?"

A: Any frequency, regardles of channel, above the crossover will be thrown away.

Q: "I will suppose that it does not effect the LFE at all?"

A: No, it affects the LFE also. The LFE contains no frequencies above 80Hz, so if your crossover is set to that freq or higher you will not lose any LFE signal. But if you set it lower than 80Hz, see the previous answer...

Q: "I will also suppose that if my sub is set at 60 hz that only frequencies (again not a brick wall)60 and below will go to the sub. What happens if the mains are set to normal in this case? Will the high passed frequencies from the sub be redirected back to the mains, or are they lost?"

A: They are lost, as are the frequencies from all the other "normal" channels (see below).

Q: "does a reciever's cut off frequency vary if the bass management is changed from large to small or vice-versa?"

A: No. Strictly speaking, the receiver's cut-off frequency never varies. However... If a channel is Small, the cut-off is implemented (always at the same frequency); if a channel is set to Large, the receiver does not impose any cut-off at all!

So the RANGE of frequencies sent to the speaker definitely varies, but the cut-off -- when implemented -- is always at the same point.

======

"After more research here is my decision and my reasoning. 1.Mains>Large. 2.Sub>On. 3.Center and Surround>Normal. 4.Sub Crossover> 80hz." That looks pefect to my way of thinking, if your receiver also cuts off at 80Hz.

Thinkly, where did you find out that the receiver cuts off at 100Hz? Is that in the documentation somewhere? I couldn't find a manual for the VR-507 online.

As Larry stated, "blocked" frequencies will not be re-distributed. If you are stuck with a receiver low pass cut-off of 100Hz and a subwoofer high pass cut-off of 80Hz, you are losing any freqencies between 80Hz and 100Hz from every channel not set to Large.

And if this is in fact the case, I only know three ways to solve that. Fortunately the first one is free.

1) Set the Subwoofer OFF! This will force the receiver to divert the bass from all channels, and the LFE, to the Large mains. Since the mains don't drop the 80-100Hz range, and since they are now getting the bass from all channels instead of only their own, that will do it.

2) Replace the subwoofer with one that can crossover at or higher than the receiver cuts off.

3) Or, Replace the receiver with one that can crossover at or lower than the subwoofer cuts off.

Of course, you can also try to just live with the gap. Perhaps the amount of 80-100Hz information being sent to the small channels is not enough to matter if it gets lost...

-Bruce

Bruce; So I made a good choice in keeping my Yam!
Maybe that's why M'ONK called it a SWEET potatoe!
Also, I caught his post where he mentioned Yamaha's DSP (M'ONK I got the soap on the rope ready!)
Dougofthenorth (sweet potatoe- heh heh)

You guys are great. I finally get it. Bass Management = Large>reproduces all frequencies. Normal>redirects bass to sub. LFE always goes to sub. ALWAYS! ( I likely have a 80-100hz gap for ALL speakers set to Small with my sub on and crossover set to 80hz., correct?- this assumes the crossover frequency is 100hz)

Bruce, I am not positive that the 100hz crossover is the frequency. I was told that on another forum, but I can't verify it. Do you know how we can find this out? I am not going to call Kenwood because I don't want to lose my religion this close to Christmas. :) Thanks again Larry, Doug and Bruce. You guys are a Great Resource.

This message was edited by Thinkly on 12/21/01 10:32.59.