Why does Audyssey XT32 insist that subs be -10db even after setting gain?

[HTfreak2004]

What?

What?

 

[William Lemmerhirt]

What?

Did you see what I quoted? I don’t follow what you were trying to say.

 

[HTfreak2004]

Did you see what I quoted? I don’t follow what you were trying to say.

I wasn’t trying I wrote that in plane English

 

[William Lemmerhirt]

I wasn’t trying I wrote that in plane English

Is that horizontal? Or air...
Plane that is.

 

[lovinthehd]

According to reference 85 db is the average playback at 0 with 20db (105max) headroom for satellite channels and 30db (115) for the sub that has been bass managed.

When bass from satellite speakers is redirected to the sub in addition to the .LFE signal the sub will play up to 10 db hot vs any other channel!(big demand not many subs like)

If trimmed -10 db within the processor or AVR this restores the sub playback volume to that of the other speakers.

It’s now become common practice to add more subs to increase the SPL above 105 without placing all that effort on a single sub!

Yes, that's the general definition of movie reference level.

The LFE channel is simply 10dB higher level for reference than the speaker channels. Adding bass-managed channels can indeed raise the total output level of the sub.

If you trimmed the sub back 10dB after calibration, it would no longer be setup for movie reference levels, tho, so I wouldn't want to do that.

You can either use more capable subs if that's your issue, or more of them if needed, to obtain reference levels. That's not the question in this particular instance as far as initial setup goes, tho.

 

[VonMagnum]

Like the others have said. One thing is that the 120hz setting for LFE is not a crossover, it's merely a LPF on the LFE channel, and it's nominal setting is 120hz as that is generally the limit to LFE channel content. Setting my subs to -10 is pretty much what I aim at myself, and only raise the levels in the avr (nice to have a more precise way of doing it, and one you can revert to base level any time you want....not so easy with most gain controls on subs).

One thing to consider, however is if you run your bass hotter than normal. I've found most people actually prefer bass 4-8dB higher than "flat/reference". So, if you have your sub turned up after Audyssey is run, it's also raising that 120Hz limit up higher as well and may not sound quite as good in that range as in the 20-80Hz range (at least I find upper mid bass too high annoying, but there's almost no such thing as too much 20-40Hz bass. That is one reason I run the LFE channel LPF at 80Hz instead. That lowers the upper curve lower to help compensate for the sub being turned up 4dB above flat (with my "sub" setting set to punch it up another 4dB on demand without having to adjust the optional levels). Thus, there's more bass at 20-80Hz, but then it starts ramping down so that 81-120Hz in the LFE channel isn't too high (and of course the regular 80Hz crossover does the same for the main levels).

Hmmmm, I don't think the newer Marantz units have the separate sub setting under 'Audio' though anymore as people apparently found that setting confusing whereas I find it quite useful with some soundtracks and bass shy record conversions, etc. to kick the bass up a fair amount with adjusting levels).

 

[lovinthehd]

One thing to consider, however is if you run your bass hotter than normal. I've found most people actually prefer bass 4-8dB higher than "flat/reference". So, if you have your sub turned up after Audyssey is run, it's also raising that 120Hz limit up higher as well and may not sound quite as good in that range as in the 20-80Hz range (at least I find upper mid bass too high annoying, but there's almost no such thing as too much 20-40Hz bass. That is one reason I run the LFE channel LPF at 80Hz instead. That lowers the upper curve lower to help compensate for the sub being turned up 4dB above flat (with my "sub" setting set to punch it up another 4dB on demand without having to adjust the optional levels). Thus, there's more bass at 20-80Hz, but then it starts ramping down so that 81-120Hz in the LFE channel isn't too high (and of course the regular 80Hz crossover does the same for the main levels).

Hmmmm, I don't think the newer Marantz units have the separate sub setting under 'Audio' though anymore as people apparently found that setting confusing whereas I find it quite useful with some soundtracks and bass shy record conversions, etc. to kick the bass up a fair amount with adjusting levels).

How does the LPF limit change with level? Never heard that before, got a source? Or are you talking about the effect of some eq in connection with using a higher sub level? Are you talking about LFE content alone?

 

[VonMagnum]

How does the LPF limit change with level? Never heard that before, got a source? Or are you talking about the effect of some eq in connection with using a higher sub level? Are you talking about LFE content alone?

Yeah, I'm the source (actually there was a quote by someone somewhere that verified what I was saying, but I'm not going to hunt for it. Besides, it's common sense). LFE is already limited to 120Hz cutoff and regular bass is being trimmed off the sub at 80Hz in most setups. But if you turn up your subwoofer say 6dB above reference level (because it sounds so much better in the deep bass region),you've ALSO turned up the subwoofer to play 6dB louder at 120Hz, which may not be desirable at that frequency (because higher frequency bass sounds MUDDY) (i.e. you want it FLAT as possible above a certain frequency, which I think is right around 80Hz to start quelling it down). However, the LFE is unaffected by the regular sub crossover so you now have +6dB at 100Hz and +6dB at 110Hz right up to wherever and whatever they do to cut it off in the signal itself (you don't know). If you set the LFE to 80Hz, however. It will start rolling off the LFE off at 80Hz.

I forget what the curve is on that setting, but let's assume it's a fairly standard 12dB/octave and you have it set to 80Hz instead of 120Hz. That means at 120Hz, the level is now 6dB less (80 -> 160Hz is one octave, so 40Hz added to it is 1/2 octave or 120Hz). So what have you effectively done in that scenario? You've lowered the bass at 120Hz by 6dB in the LFE channel. It's now FLAT relative to the source material while 80Hz and below are +6dB higher. Between 80Hz and 120Hz, it now has a downward curve towards flat. This limits how much "muddy bass" you get when you turn up the sub above reference levels.

Now if you use flat subwoofer levels (0dB),you aren't affected by high 81-120Hz LFE levels since you never turned it up in the first place. It's just even. You probably want to keep the 120Hz point, although technically speaking, 120Hz is typically regarded as somewhat directional so I'd personally want to limit its output anyway as I don't particularly want my attention drawn to my subwoofer anyway. IMO, they should have cut the LFE off at 80Hz or perhaps no higher than 100Hz to begin with. I assume they've probably baked some curves into LFE material to join up already, but you never know.

 

[lovinthehd]

Yeah, I'm the source (actually there was a quote by someone somewhere that verified what I was saying, but I'm not going to hunt for it. Besides, it's common sense). LFE is already limited to 120Hz cutoff and regular bass is being trimmed off the sub at 80Hz in most setups. But if you turn up your subwoofer say 6dB above reference level (because it sounds so much better in the deep bass region),you've ALSO turned up the subwoofer to play 6dB louder at 120Hz, which may not be desirable at that frequency (because higher frequency bass sounds MUDDY) (i.e. you want it FLAT as possible above a certain frequency, which I think is right around 80Hz to start quelling it down). However, the LFE is unaffected by the regular sub crossover so you now have +6dB at 100Hz and +6dB at 110Hz right up to wherever and whatever they do to cut it off in the signal itself (you don't know). If you set the LFE to 80Hz, however. It will start rolling off the LFE off at 80Hz.

I forget what the curve is on that setting, but let's assume it's a fairly standard 12dB/octave and you have it set to 80Hz instead of 120Hz. That means at 120Hz, the level is now 6dB less (80 -> 160Hz is one octave, so 40Hz added to it is 1/2 octave or 120Hz). So what have you effectively done in that scenario? You've lowered the bass at 120Hz by 6dB in the LFE channel. It's now FLAT relative to the source material while 80Hz and below are +6dB higher. Between 80Hz and 120Hz, it now has a downward curve towards flat. This limits how much "muddy bass" you get when you turn up the sub above reference levels.

Now if you use flat subwoofer levels (0dB),you aren't affected by high 81-120Hz LFE levels since you never turned it up in the first place. It's just even. You probably want to keep the 120Hz point, although technically speaking, 120Hz is typically regarded as somewhat directional so I'd personally want to limit its output anyway as I don't particularly want my attention drawn to my subwoofer anyway. IMO, they should have cut the LFE off at 80Hz or perhaps no higher than 100Hz to begin with. I assume they've probably baked some curves into LFE material to join up already, but you never know.

I thought you were saying the limit was raised (i.e. somehow raising the sub trim level raised the frequency cutoff to 150, 200 etc). Of course when you raise sub level you're changing things from flat. How you want to tweak in between is up to you afaik. The rest of it I'll have to read fresh later. What source materials are you talking about particularly, tho?

 

[VonMagnum]

I'm saying IF you want to raise your bass levels above reference (flat), you might want to consider lowering the LFE low-pass setting if you don't want bass levels above 80Hz to go up the same amount (think of it as LFE compensation). I only want bass BELOW 80Hz above flat. But this goes contrary to the advice I keep seeing that says NEVER TOUCH the 120Hz setting there. I had a link somewhere at some point where a professional echoed the same advice. Over 50% of people run their bass hot (above flat), so it's something that should be considered to avoid "boomy/muddy" bass which I only perceive as such above 100Hz and hence the 80Hz recommendation that I use if you're going to raise your sub level to 4-8dB above flat.

 

[lovinthehd]

I'm saying IF you want to raise your bass levels above reference (flat), you might want to consider lowering the LFE low-pass setting if you don't want bass levels above 80Hz to go up the same amount (think of it as LFE compensation). I only want bass BELOW 80Hz above flat. But this goes contrary to the advice I keep seeing that says NEVER TOUCH the 120Hz setting there. I had a link somewhere at some point where a professional echoed the same advice. Over 50% of people run their bass hot (above flat), so it's something that should be considered to avoid "boomy/muddy" bass which I only perceive as such above 100Hz and hence the 80Hz recommendation that I use if you're going to raise your sub level to 4-8dB above flat.

I'm not really that concerned with content of the LFE channel, whether I limit it a bit or not isn't that consequential during most movies, but I prefer to have all of it rather than limit it. Besides, I cross at 110/120 anyways currently so little difference between LFE and bass managed content anyways. I tweak my way, you tweak yours

 

[SwedishChef]

Thanks to everyone for the responses and discussion.

I think I understand what’s going on a bit better now. I won’t worry too much about the number on the screen, but will do some testing to see whether I enjoy a boost of a couple db for the subwoofers. I haven’t needed to boost the center channel. Maybe it’s relatively fine as-is. A few answers to other questions:

• I had problems in the past with another, older sub waking up properly, so I know what you mean (and it was loud doing so, too), but both the Hsu seem to be great - come on silently (or close enough for me) and regularly.
• I do have the fronts set small with 80hz crossovers currently. I’ve done some reading that indicates there’s a whole host of potential issues lurking if you start setting even large speakers to large. I’ll do more reading, and experiment a bit, but I suspect 60 or 80 is the right way for me to go, at least while I'm working to establish a solid baseline to experiment against.
• I’m interested to learn that LFE+Main will still send a subwoofer signal in pure direct. One of the gaps in my understanding is around whether the signal below 80 hz will EVER be sent to the main towers by the receiver after this configuration. For example, when listening to two-channel stereo content from a disc, when streaming 2-channel, etc.. It seems like a potentially annoying side effect of the proper movie settings that music could potentially be compromised (For example, if the receiver sent the content below 80hz to neither the front speakers nor the subs. Perhaps that's why the receiver does still use the subs in 2-channel modes.).

I feel like I’ve lost some resolution and treble clarity in two-channel music listening since I moved the speakers to their new location. Unfortunately, I didn't test at each step. I’ll have to check position, room correction, and a few other possibilities, since I changed a lot at once.

 

[lovinthehd]

First, a crossover isn't a brick wall (there's a roll-off slope involved, it's literally a crossover point between two roll-off slopes....the sub and speakers are both receiving signal at a reduced level at a given rate of dB per octave. See picture below (slopes not necessarily matching yours)

What you call resolution and treble clarity can mean a lot of different things....personally I don't like LFE+Main, some do.....go with what you prefer in the end whether it is "correct" or not.

 

[HTfreak2004]

You really have to love psycho-acoustics.

On one side we have the scientific read outs and the other side our ears.

To tweak or not to tweak the $64000 question.

Too bad it wasn’t as simple as science. Damned ears can’t really play low frequencies well anyways. Good thing our Skull gets a good sense of low frequencies though

 

[VonMagnum]

I'm not really that concerned with content of the LFE channel, whether I limit it a bit or not isn't that consequential during most movies, but I prefer to have all of it rather than limit it. Besides, I cross at 110/120 anyways currently so little difference between LFE and bass managed content anyways. I tweak my way, you tweak yours

It's not really limited if it's at reference (bass is raised so LFE is flat at 120Hz). It's a slope not a brick wall.

 

[HTfreak2004]

It's not really limited if it's at reference (bass is raised so LFE is flat at 120Hz). It's a slope not a brick wall.

Interesting.

Let’s see if your slope is 12db per octave. 80-160 is down -12 db and at 1/2 octave 120hz -6db

Now if one ran the sub 6db hot -6db slope they wash each other. Over the 1/2 octave! From 80-120

The real problem your concerned with is muddy/boomy bass as well as localizing you sub which you stated was more likely above 80hz

Maybe relocating your sub or listening seat could alter that equation slightly!

Not a perfect solution but a possibility non the less!

 

[VonMagnum]

Interesting.

Let’s see if your slope is 12db per octave. 80-160 is down -12 db and at 1/2 octave 120hz -6db

Now if one ran the sub 6db hot -6db slope they wash each other. Over the 1/2 octave! From 80-120

Yeah, that's what I'm saying. That's WHY I use 80Hz for LFE because I tend to run bass 6dB hot. That keeps it flat from 120Hz onward and slowly ramps up to +6dB by 80Hz where I like more bass (from 80Hz down). This just keeps the LFE limits the same as the regular bass (which already crosses at 80Hz too).

The real problem your concerned with is muddy/boomy bass as well as localizing you sub which you stated was more likely above 80hz

That's just from playing with bass levels over the years. Below 80Hz, more bass sounds better with no extra boom. If I increase bass above 80Hz, it's starts sounding boomy or in some way less desirable to my ears.

Maybe relocating your sub or listening seat could alter that equation slightly!

Not a perfect solution but a possibility non the less!

I think it's pretty good where it's at (+/- 1.5dB from 22Hz to 180Hz and +/- 2.5dB from 20Hz to 200Hz)

 

[VonMagnum]

As you can see, the average bass level is about 2dB higher with my default bass setting (I have the "sub" setting in the Marantz menu set to raise it 4 more dB at the push of a button for a total of 6dB up). Reference mode lets the high frequencies drop off above about 8.5kHz (flat creates a bit of a peak I don't like, even though it evens the response to 20kHz). There is a room dip around 700Hz that Audyssey can't contend with, but it's not horrific. I'd have to find a room treatment that works in that region. Everything else is about +/- 2.5dB without the dip to 8kHz.

Full response with Audyssey on (Reference, not Flat) Def Tech PF-1500 + PSB T-45:

 

[HTfreak2004]

I prefer to leave all my settings flat. I don’t have a graph of my room nor have I gone to your extent to flatten the largest frequency spectrum but source material differs quite a bit from one recording to another!

I do believe that the xo points matter and subs should or ought to be dedicated to frequencies 80hz and below.

The real intention of a roll off slope should be to reduce the double bass gain from to many speakers covering the same frequency range from amps that have different gains.

My sub integrated well with my other speakers. It’s crossed at 60hz relative to my mains & 80hz relative to my centre and surrounds. .LFE is set at 120.

I’m not a fan of adding bass gain just because the source material may lack some kick. Boosting a signal doesn’t change the frequencies only there perceived loudness.

As far as I’m concerned if the recording studio intended for the source material to be boosted they should have amplified that material so I needn’t colour it myself!

I prefer source direct. Soon as I fumble with a gain I’ve introduced more draw from my amps that is difficult to account for by ear alone especially when boundary gain is factored into that fumble!

Anyway I respect your experience and point of view. This topic has been quite good actually so Koodos to everyone who participated today!

 

[NINaudio]

Too bad it wasn’t as simple as science. Damned ears can’t really play low frequencies well anyways.

What kind of upgrade did you get that your ears play any frequencies at all?!