LFE, subwoofers and interconnects explained - Page 13

Originally Posted by arbitrage000

Yep, boosting the entire SW channel is not the same as boosting just the LFE part of the SW channel and will make all redirected bass from the other channels 10dB too high. (3x too high).

Originally Posted by yampan

..... I have the speakers now set to "small" and the sub setting to "subwoofer only"

Now I have to keep the volume on the sub pretty low, even if I have the sub setting on the receiver to 0db as it gets boomy pretty fast ......

Setting the test tones to what sounds equal to the front and center speakers is invariably too much bass in general and I have to lower it, whether or the receiver or on the sub.

Originally Posted by yampan

O.K. I read the OP and sort of understand the principles, but I get lost on the specifics. I wonder if one of you who understands this better than I could give me some advice for my new Christmas setup.

Currently I have tired 15 year old Advent Prodegy fronts and a 10 year old Infinity 8" sub, all of which I am replacing with Polk Audio RTi8s and a Polk Audio PSW12.

I have a Yamaha RX-V750 which can control the SW output by db or test tone, plus or minus. It can also control the LFE output from 0db downwards. I have the speakers now set to "small" and the sub setting to "subwoofer only"

Now I have to keep the volume on the sub pretty low, even if I have the sub setting on the receiver to 0db as it gets boomy pretty fast--perhaps because it isn't such a good sub, perhaps because it is downfiring onto a hardwood floor, perhaps both reasons. Setting the test tones to what sounds equal to the front and center speakers is invariably too much bass in general and I have to lower it, whether or the receiver or on the sub.

Anyhow, though I realize it is up to me to determine my final settings, I am a bit confused about where I should start. I have no calubration discs. I judge everthing by what tv or dvd or hd sounds like, whether the bass sounds balanced, overpowering, or lacking.

The new sub is not downfiring, which hopefully is good. The new speakers are much larger, but does that mean I should set them to large?

1. Would setting the subs volume control to about 50% be a good place to start?

2. Should I set the new fronts to large?

3. Should I set the sub setting to "both", allowing the fronts to handled any lows they can? Or should I still keep it on "Sub only"?

4. Should I leave the LFE to 0db and presume that is correct? (all audio is transmitted to the receiver by either toslink or coax from DTV, DVD, and HD DVD) How would I know if that needs separate adjustment?

Just thought it would be nice to know I am headed in the right direction for the new stuff. Any help would be greatly appreciated. Thanks in advance.

Originally Posted by Sonic icons

I think the first thing you should do is get a Radio Shack or similar Sound Pressure Level (SPL) meter

Originally Posted by cnickersonjr

I went through a similar tweak. See my findings at this link.

Originally Posted by yampan

Believe it or not, I have a 30 year old Radio Shack Sound Pressure level around somewhere. It's just been through 5 moves and is hiding somewhere. Problem is, I found out years ago that the SPL doesn't always yield satisfying results even though it theoritically should. Maybe it just me. Thanks for the thought, I should really try to find it just to see what's what.

Originally Posted by krabapple

Not quite. The "LFE" is content put in the disc's .1 channel, in the mixing studio. If you set speakers to 'Large', only the LFE is output to the subwoofer. Meanwhile, any bass that was mixed to the front left/center/right or surrounds in the studios, stays in those channels and goes to those speakers. But if you set the speakers to 'Small', the LFE plus the bass from the 'small' loudspeakers, is blended together and output to the subwoofer.

Originally Posted by Scott_R_K

You are , of course , correct . My bad . I assume you've had the upgrade done on your '74 ?( I'm still waiting )

Had you noticed any previous problems with the "Auto" selector for Audio ? I've changed the Audio to Optical from HDMI in my PS3 but the '74 will lock onto HDMI instead of Digital . Video is HDMI switched through the '74 . Do you know if that is still a problem after the update ? I can change it manually each time .

Originally Posted by RyanA3

Hello mates, Pioneer VSX-82TXS owner here. Lub this receiver. But I recently upgraded my dvd player to HD-DVD. And I got some 1.3 hdmi cables. My receiver is not 1.3.

Also, I am missing some low end punch.


This thread is amazing (Pioneer VSX-84TXSi/VSX-82TXSi(VSX-AX4ASi/VSX-AX2ASi): latest USA firmware apparently fixes - with this, +10dB analogue SW boost also affects HDMI. New units may not have this firmware)

Found this : http://www.pioneerelectronics.com/PU...+A+V+Receivers
Firmware avail.

But I wonder.... I bought my receiver in early summer 2006. HDMI video and video switching is flawless. Only issue is LFE. Should I get the firmware update? Or is it there already, and I need to make a setting change (doubt this).

Originally Posted by EWL5

Sounds like you need the firmware update. Call Pioneer for the closest compatible service center. With any luck, it should be driving distance. Here is my take on the before/after update concerning watching HD movies on the Pioneer VSX-84TXSi:

Before firmware: 6/10 (legacy DD/DTS gets real old after a while)
After firmware: 9/10 (hello TrueHD, DD+, DTS-HD MA core!)

I couldn't watch HD movies with lossless tracks as there was absolutely no impact in the LFE and brought me back into reality instead of immersing me.

Originally Posted by RyanA3

6/10 + 9/10 ???



1. power off receiver.
2. hold down the power button + standard surround buttons at the same time.
3. ignore the first series of info. as per pioneer.
4. write down the second series of info. this is the pertinent info.

My reciever was purchased in late March 2007!
I had no issues with hdmi or hdmi switching.
However, since adding a HD-DVD player, my LFE if missing in action.

My 2nd series of coding was: D1.003 H.005

Originally Posted by EWL5

RyanA3, you might be better off following this thread:

http://www.avsforum.com/avs-vb/showthread.php?t=787551

The 82's latest firmware should be:

M1.002 F0.503
D1.003 H1.005
HOST**
f1.004 s1.001

Check your 82 firmware again.

6/10 = 6 out of 10 rating before firmware
9/10 = 9 out of 10 rating after firmware

Originally Posted by RyanA3

I hope some of the "pioneers" of this thread/issue/fix are still with us... so they can help the n00bs through??????????


I am about to unwire my receiver and drive 90 minutes.
Are you sure I don't need the LFE update.
My firmware is:

M1.002 F0.503
D1.003 H1.005
F1.004 S1.001

Which one of these is applicable to the LFE issue with hddvd/hdmi.
My hdmi (video portion) is ok.

If it's ok firmware. What do I need to do to fix the issue with the receiver.
I don't hear any sub since connecting an hddvd player.

Originally Posted by lovingdvd

As you may recall I did some tests a week or so ago with a Yamaha RX-V1700 and concluded that it did not seem to have the LFE issue. I now have a Yamaha HTR-6090 which I'll be testing over the next couple of days for the LFE issue. Since the 6090 is very similar to the 1700 I'm hopeful it'll test out ok. Will post my results back here shortly.

Originally Posted by Rash1

Sorry for such a basic question, but is it normal for the LFE brackets on my Pioneer VSX-82 to blink on and off during a program on HDMI connection?...and could a fault in the process result in occasional sound cuts of a fration of a second?? Having trouble finding the source of the cutting sound...

And didn't have time to read all 13 pages of posts here...sorry, thanks for the input...

I'm quite new to this setup and don't have much knowledge so far...

Originally Posted by rabident

I have an 84txsi with the firmware that lets you manaul add +10db. The problem is it doesn't appear to only apply to the LFE channel. All bass output is boosted, even the test tones, so MCACC detects the bass as 10db too high and calibrates it out.

Is their a firmware release that fixes the issue entirely, or is the front panel boost workaround as good as it gets?

Anyone know if the new 9 series has the problem as well? i.e. VSX-94TX

Okay, what level should the subwoofer output be? If it were just the LFE track, then you'd expect it, as discussed above, to be 10dB lower than the other channels to fit the 10dB higher maximum LFE output.

But if the player is performing bass management, then the subwoofer output also has to contain redirected bass; this extra signal could push the signal back above its nominal limit. To prevent overloading their output, or the receiver's input, players with bass management conventionally lower the SW output by a further 5dB. (This 5dB value is specified by Dolby, see references). Sometimes this 5dB drop switches in and out depending on whether bass management is being performed (ie if any speakers are set to SMALL).

The final SW output will typically be:

SW = LFE
or:

SW = Lower5dB(LFE + Lower10dB(Redirected bass)) = Lower5dB(LFE) + Lower15dB(Redirected bass)
So, in those two cases the SW output from the player will be respectively 10dB or 15dB lower than the other channels. A receiver should offer the ability to specifically boost the SW input on its multichannel analogue interface to compensate.

Originally Posted by msulinski

... what about the BD30? Does that mix the redirected bass and LFE bass correctly, and does it output -15 or -10dB?

Originally Posted by Mupi

1) I thought I read that the LFE track is already recorded
10db louder than the other channels.
So if I just play the disc and if the receiver isnt doing any
boost and if I am not changing the subwoofer level, does it
mean that the LFE is playing 10 db louder than the rest.

or

2) is it true that the LFE is not recorded 10db louder so
to make it play louder I have to boost the LFE on my
receiver either using the LFE level control or the
subwoofer level control or both.


If 2) is correct and if there are AVR's that provide both
LFE level control and subwoofer level control, then why
are people asking for the AVR to apply the 10db boost
by default.


I know there is a lot of stuff already. I tried reading all the
articles but I am having a hard time understanding. I guess
if I clear my misconception and read further I may understand
better.

Originally Posted by scsiraid

Its the other way around.... LFE is recorded 10db LOW and needs to be boosted in the amp. Since the intention is that the SW be capable of going 10db louder than the other channels... and that LFE is transmitted over the same type of 'transport' (PCM or analog)... it needs to be recorded 10db low so that it wont overload the transport when it reaches full output levels. A 10db boost in the amp then restores the level. Note that if you have any speakers set to small... it needs 15db cut and boost instead of 10db. This is because you are adding even more bass info into SW channel and have to reduce it further to keep it from overloading at full output.

If you are sending bitstream to the receiver... all should be fine. PCM is a bit more iffy but many if not most/all receivers can apply various boosts to LFE/SW to compensate. Analog is a mixed bag.... recent receivers seem to have the capability but older ones dont.