Attention all Denon 3803 Owners - Major Bass Management Flaw (1 Viewer)

[Mike Up]

Edward,

Calibrate all your speakers except the sub to Reference Level 75 dB with the internal test tones. Then run the test tone for the sub and set the sub level to -10 and then adjust the plate amp so the SPL meter reads 75 dB. Run a speaker-sub sweep with AVIA for each surround channel and then for the LFE channel only. Note the results.

I have done just that in my setup previously. I ran ovations sweep with my S&V disc. It's the same, S&Vs disc is a toned down version AVIA. I had very strong bass with the sweep in using DD.

I have a disc that has the subwoofer signals mixed in the front channels. So that when the speakers are set to small, the bass signals are sent to the subwoofer output. I calibrated all speakers, including the subwoofer to 75db. I then have Video Essentials where their test signals are all in 5.1 where the sub signal is the .1 channel. It matched perfectly. Since I was trying to get the best bass, I was experimenting for about a week with placement, as I said in the earlier message. I always referenced the LFE .1 signal against the directed bass. No matter which level the receiver's subwoofer level was at, they always matched. Also, I adjusted my subwoofer's internal amplifier at different times. I guess your calling the subwoofer's internal amp the plate amp? So last month, I essentially did everything your doing and I had no problems.

I think I know what your problem 'could' be. I had several problems in room location with my sub. I had cancellations and boosting all at different frequencies. The reason was directly related to the crossovers. "THE LFE CHANNEL WAS NOT AFFECTED!"

With a poorly placed sub that's suffering from cancellations or boosting related to timing errors with the main speakers, you'll have bass problems related to bass that was directed from small speakers, but the LFE channel bass will be unaffected since it's not affected by timing errors and reflections.

I suggest you move you subwoofer and try different placements. My AVR-3803 doesn't suffer this but that's because I tuned my sub placement to my room. The more I read your comments, the more I think this is your problem.

Good luck.

 

[Seth_L]

Edward,

See what I meant.

Seth

 

[Mike Up]

He hasn't been responding lately because of all the negative posts and problems people have been experiancing with this (among other ) units

Boy, I'm glad you know him personally, where he would tell you this. He surely didn't post a reason or tell the admin. why he's not posted lately.:wink:

To bad Yamaha never bothered with an audio rep, and their video rep. Bart Greenberg, didn't even stay the course.

I'm glad Denon has enough appreciation of their customers to offer support from their lead guy.

But we all know what a huge Denon supporter you are, and know you wouldn't come to a 'none related Yamaha' thread to bash the company you support so strongly.

 

[Mike Up]

See what I meant

If your referring to flames, I'm sorry that I don't have a problem as he does. Explaining to him that my unit works correctly is anything but a flame.

If it was a bug, my unit would also experience it, which it does not. Not saying that his problem isn't there, it's just not universal and perhaps is defective, needs a reset, or has poor sub placement. If what I said or anyone else's statement in this thread could be considered a flame, then someone's skin is definitely to thin.

 

[Jamey F]

It is my understanding that you can lower the level of the sub output in each input source also. The receiver should keep that in memory for each input AND type of source. This is a less than desirable fix IMO, but I believe I am currently using it.

I noticed the Bass was on the strong side while listening to LOTR, but I thought it was me. My Mains are set to -2 and my Sub is set at -3. If I understand all this correctly, my LFE channel would be default at 0. So, the LFE tracks would be 5db hotter than my mains? I turned down the Sub level to comensate for that, but I guess that is the incorrect thing to do. I guess I should lower my LFE channel level by 3-5 db also. Is this correct, and how do I do this. I have been through the setup menu and I don't see where to adjust the LFE level. I only see channel levels.

 

[Chuck Kent]

Jamey: The LFE adjustment is in the Parameter settings for DTS and Dolby Digital. (BTW, the LFE adjustment is not a bass peak limiter...just a level control. Denon only has bass limiters on their THX rated receivers.)

 

[Edward J M]

Mike Up:

My subwoofer is not poorly placed. At the listening position, I have no cancellation issues, I have no peaks, nor do I have any nulls. My in-room FR as determined with a 1/12 octave 10-100 Hz sweep is ruler flat (+/- 2 dB) from 11-100 Hz with one port plugged.

I appreciate your comments and suggestions. However, if my subwoofer placement does not change, nor does my high pass filter point, nor does the speaker size, nor does the position of the SPL meter, all of these items are eliminated as variables.

The ONLY thing I am changing is the Denon's internal subwoofer level, and then I am recalibrating to the same 75 dB each time. I know what I am hearing, and I know what the meter is reading.

I am just as certain this is a problem with my 3803, as you are certain it is not with yours. Another poster in this thread independently corroborated my findings with his Denon receiver and his own AVIA calibration disc, which sweeps both the low-passed bass and the LFE channel. Yet you failed to acknowledge his findings. Perhaps other Denon owners will chime in with their findings. I guess we can civilly agree to disagree at this point.

Chuck Kent - the 3803 does indeed have an LFE peak limiter circuit for DD and DTS playback, and the 3803 is not a THX certified AVR.

Jamey F - the long answer is listed somewhere above. The short answer is to keep the internal sub level setting the same as (or slightly higher than) the internal mains level setting. Then adjust the sub volume at the sub amp to obtain 75-78 dB on the meter.

Ed

 

[Lewis Besze]

Mike Up,
this isn't a room related issue at all,if you paid attention to the measured movie scenes,then you would realize,that when he raised the internal level on the sub output, and lowered the gain on his sub amp,the bass was measurably louder.If there was a cancellation of some sort,then he couldn't do anything about it the way he did.
What he says in short that the LFE level gets "screwed" as oppose to the low passed level,when the sub out is numericaly set lower internally.
This is somewhat the same situation,as what the Outlaw 950 does [in DTS ES Discrete only],though that pre/pro strips the LFE content completely.Thankfuly Outlaw already traced the problem to an EPROM,which can be exchanged easily.
I hope Denon will look into this as well for the sake of Ed and others who might come across with this problem.
Ed,
keep up the good work,this board need more members like you!

 

[Mike Up]

O.K.

Here's my findings:

Using Video Essential's Dolby Prologic speaker level test which uses the crossover of the bass management and has no LFE.

All Speakers: 75db
Subwoofer: 78db
Speaker levels:
Fronts:0db
Center:-4db
Rears:-4db
Back surrounds:-8db
Subwoofer:-7db

Using Video Essentials Dolby Digital 5.1 speaker levels which uses the LFE channel for the subwoofer level.

All Speakers:75db
Subwoofer:78db
Fronts:0db
Center:-4db
Rears:-4db
Back Surrounds:-8db
Subwoofer: -7db

It's obvious I have my subwoofer level 3db hot to my liking.

Since all my speakers are set as small, the bass level signal for the Dolby Prologic test was mixed into the front main channels and the bass management redirected it to the subwoofer output. It's level was +3db higher than the speakers output.

The Dolby Digital signal used the .1 LFE channel for it's subwoofer level and it again was 3db higher than the speakers.

Therefore the LFE bass level output equaled the bass management directed bass. Both have equal levels, as they should.

Readjusting internal subwoofer amplifier gain and then readjusting receiver subwoofer level gain made no difference from my previous findings. I just felt the need to document the numbers.

BTW, I have also found similar results using other DVDs but VE is a well respected disc and my favorite over ovation software derived Sound and Vision's tune up DVD.

Obviously, the AVR-3803 subwoofer level affects the LFE and redirected bass output equally and I would hope other's AVR-3803 receivers would do the same.

It's for this reason I believe that Edward has a defective receiver or it needs to be reset.

Ed, have you yet tried a reset? Chuck found that it cleared up an AL24 processing glitch that he was having. Hopefully it will do the same for you. Here's to hoping.

BTW, it's worth noting. The AVR-3803's internal subwoofer level signal seems to be hot by ~3db. Meaning that when using the internal test tones the subwoofer and speakers all equal 75db. With VE and other discs, the subwoofer level output is usually 78db making me believe that the receiver's internal test signal is a little high.

Also, since you guys are achieving 75db in your rooms while using the receiver's internal test tones with the main speakers calibration setting at -2db, that's pretty impressive. My room is 16' X 15' with 8' ceilings and my speakers are 89db sensitive Infinity RS towers. Listening position is 12' away. I have to adjust the main speaker levels up to +2 to achieve 75db in my room. Either you guys have high 93db sensitive speakers or smaller rooms(I surely don't consider mine large).

Also watched Reign of Fire today, and my buddy had to hang on to the couch for dear life.

Have a good one.

 

[Chuck Kent]

Edward: Respectfully, as long as you do not try the processor reset, I will remain unconvinced that your 3803 is acting as designed. I'm not saying that you may not still have a problem (your receiver could be defective), but as I stated before, it is clearly documented that if a Denon receiver has a glitch, the reset nearly always fixes it. (Years ago, Guide to Home Theater had trouble during testing of the AVR-5700's bass management. They did a reset and all was back to normal.) IMO, every stone must be uncovered in the search for troubles like these...

As for the 3803 having a bass peak limit setting, it does not. Download the 5803's (a unit that does have the limiter) manual and check the system setup section on the bass peak limit setup choice. The 3803 has no such setting. There is one comment in the 3803's manual that mentions bass peak level but it is an error. It is also well known that Denon manuals are often error prone. Such as in this case...

 

[Edward J M]

Mike Up: Based on your last post, your understanding of my problem is excellent, and you are clearly not experiencing the same problem I am. The level of your low passed bass and your LFE level are the same, even when your subwoofer setting is at -7. This is as how it should be and your Denon's bass management circuit is functioning properly.

That is clearly not the case for me, but your results are very encouraging. I will try a processor reset and reevaluate my findings and post them here when I am done. I'll write down all my speaker calibration numbers first so I won't have to go through that painstaking exercise again.

And yes, all of my speaker level settings for Reference Level (00) calibration at 75 dB at the couch are in the negative range. LF -3; C -4.5; RF -3; SR -3.5; SBR -1.5, SBL -1.5; SL -3.5. My room is 18 long, 12 wide, and 8 high and the couch is 11 feet from the mains.

Chuck Kent: When playing a DD or DTS source, hitting the Surround Paramter button pulls up a separate on-screen menu (page 60 owner's manual), which provides the user with (among other things) an "LFE" control.

This control has a range from 0 to -10 and allows the user to lower the level of the LFE channel if the subwoofer gets overloaded during DD or DTS playback. The setting of this control should remain at 0 for proper playback, and is not affected by the main menu subwoofer level setting, nor is it affected by the user's custom subwoofer setting in the DTS/DD mode.

Since this control is unaffected by any subwoofer level settings, and only works in DD/DTS playback mode, and is designed to keep wimpy subwoofers from self-destructing during high level DD/DTS playback, I think my description of this control was accurate. Some people call this an "LFE trim" control, some people call it an "LFE bass limiter", and some people call it an "LFE bass peak limiter". Perhaps the most accurate description of this feature would simply be an "LFE channel level control".

I wanted to avoid a discussion of this control up front, since mine is always set at 0 and I worried that including it into the discussion would muddy the waters and detract from what was already a difficult to describe problem.

Thanks to all!

Regards,

Ed

 

[jeff_coil]

Hi fellas I finally got off my lazy butt ran up to the store for a battery - left my meter on- and tested my 3803 as you guys did above.

Using Avia no LFE
All spkrs 85db
Sub 86
ch settings
FL -3
C +3
FR -2
SR -2
SL -.5
SW -8.5

LFE Sweep Right on other than my house curves
ch settings
FL -3
C +3
FR -2
SR -2
SL -.5
SW -8.5

So I would say mine is acting normal

 

[MatthewJ S]

Between this, the upconversion, and a few othewr problems, I don't think I'll be recommending this product to any of my customers soon...I think that some products from denon must be being rushed to market before all the bugs have been worked out.....

 

[Edward J M]

Jeff Coil - you didn't list the SPL for the sub on the LFE sweep. I'm assuming it stayed at 86 dB?

I will be doing the same thing with AVIA - I'll sweep the surround channels to the sub (low passed bass) and then I'll sweep the LFE channel - all at various sub level settings. I think I will use -10, -5, 0, +5, and +10 just to make sure I get a broad spectrum of data. I like to run my sub on the hot side, so I'll be using 85 dB for the speaks, and 89 dB for the sub (with AVIA), and 75 dB and 79 dB for the Denon's internal test tones.

I'll also compare the internal AVR 3803 75 dB test tones against the 85 dB AVIA test tones. Aside from the 10 dB difference in volume, the relative speaker levels should remain the same if the Denon's internal test tones are accurate.

I'll make sure to recalibrate at the sub to keep the same sub volume each time I alter the internal sub level.

This will take some time, but I'll post the data here before and after microprocessor reset.

FWIW, I'm using a B&K Model 2205 pro grade SPL meter that requires no bass correction factors. It was recently factory certified, and I also calibrate it regularly with the included calibration kit. I replaced the battery last night because it was running a bit low.

Regards,

Ed

 

[jeff_coil]

Hi Edward,
Yes it was ~86 on the LFE. My problem is I have some pretty big dips and valleys which I am aware of after some other exhausted testing. example I have a 5db dip around 90hz and a whooping 18db increase starting around 60hz and peaking around 18hz- When I first did the test I noticed that the internal tones are off from avia. Like you suggested I set all spkrs with the internal tones to 75 and they were cal'd in at 85 from Avia previously and I had to adjust all channels levels up to get 75db and it wasn't the same amount on all channels- I didn't record but they were definitely different but not really to surprising.

Like you I normally run my SVS hot but didn't for this test

Let me know what you find out. As I remember you just got your 3803 have you tried the up conversion? Any problems? I am lucky and in my system it seems to work great even though what i understand it isn't wide spread.
Jeff

 

[Chuck Kent]

Edward: Sorry if I misunderstood. I think we're on the same page.

I was concerned that while some may call it an LFE peak bass limiter or LFE bass limiter, it is important to not confuse the 3803's simple LFE level control with a true bass limiting control.

Here's to hoping the reset does the trick for you...

 

[Mike Up]

The way I take it is that the AVR-3803 only has a LFE level control, not a bass peak limiter. The THX AVR-4802 and AVR-5800/03 have the THX bass peak limiter.

The AVR-3803's LFE level control just gives the option of attenuating the LFE channel output.

A bass peak limiter allows the user to set up the highest subwoofer peak without distortion. Setup usually requires the user to steadily increase the bass peak limiter until audible distortion is present. Then back off just a hair before the distortion is present. That then would be the level that bass peaks would be limited to.

Simply saying the Bass peak limiter clamps the voltage output of the subwoofer output at a determined point before audible distortion sets in. I thought this was a THX only feature. I've never heard of it being in none THX products.

The manual seems to be in error stating that there is a bass peak limiter.

For me, a bass peak limiter wouldn't be necessary. My Velodyne subwoofer has an ANTI-CLIPPING circuit and OVER EXCURSION PROTECTION. I believe that essentially provides what the bass peaker limiter does or maybe even more.

That's the way I take it.

 

[Edward J M]

Jeff - No I have not tried the video upconversion. I have only one set of component video cables and I go straight from the DVD player into the HDTV. I figured going through the 3803 theoretically could result in some signal loss (however small), so why bother taking the chance? The only other video signal to the TV is a composite video output from the VCR.

Chuck/Mike - yes, it is the simpler LFE level control and presumably it affects only the LFE channel. It is not the more sophisticated "bass peak limiter" which would limit all bass regardless of the source (LFE or surround channels), and that's why I always attached the term "LFE" to that description. Still, the purpose of the control is to prevent overdriving the sub, albeit it accomplishes this in a much simpler manner than a true electronic bass limiter. Either way, an LFE level control or a true bass peak limiter can wreak havoc with the bass quality unless the user is aware of what they accomplish and how to properly use them (if at all). I have no need for either in my system.

Ironically enough, the sub level control in my 3803 is currently acting similarly to this LFE level control. It is allowing the high passed bass to remain at a set level and it is ramping down the LFE channel and creating a disparity between the two. Yes, raising or lowering the sub level control raises and lowers both the low passed bass and LFE bass, but the disparity between the two remains constant at any given setting. Preliminary sweeps have confirmed this (more formal data to follow), and I sure hope this processor reset does the trick. Perhaps the processor is somehow electronically merging the sub level control and the LFE level control, but this is pure speculation on my part.

Regardless, this has been a very useful thread for me, and I want to thank all of you for your great advice thus far.

Ed

 

[Edward J M]

Here is the follow-up to my 3803 Bass Management problems. I finally got around to running all the tests with Avia.

I calibrated all speakers (except the sub) to 75 dB C-Weighted Slow at Master Volume 00 using the Denon’s internal test tones, and my speaker settings are as follows:

LF: -3
C: -4.5
RF: -3
RS: -3.5
RSB: -3.5
LSB: -1.5
LS: -1.5

I then ran Avia at the same Master Volume setting 00 and was surprised to see the SPL only averaged 80 dB instead of the expected 85 dB. The relative speaker SPL stayed at 80 dB all around, which suggests the 3803’s internal test tones are accurate with respect to one another. However, if you trust Avia, true Reference Level for my system and room would be around +5 on the Master Volume setting providing the current speaker level settings remain unchanged.

For the subwoofer testing, I ran the Master Volume at 00, and calibrated the sub for each run off the Avia Left Front Low Passed Subwoofer rumble tone found in Chapter 7.3. High pass filter point was 80 Hz and all speakers were set to Small. Since Avia is Dolby Digital 5.1, I made sure the 3803 "LFE Level Control" was set to 0. All speaker level settings (except the sub) remained as listed above for the entire test.

The critical Avia test is found in Chapter 7.4, and is a six channel bass rumble tone that provides the level of the low passed bass in the 5 surround channels, and in the discrete LFE channel. According to Avia, the level should remain constant providing the bass management circuit is operating properly.

Here are my results for the Avia six channel bass pan test in Chapter 7.4:

Run #1:
3803 Sub Level Setting: -10
Sub Calibration SPL: 83 dB (Left Front Avia Chapter 7.3)

LF High Passed Bass Level: 83 dB
C High Passed Bass Level: 83 dB
RF High Passed Bass Level: 80 dB
RS High Passed Bass Level: 83 dB
LS High Passed Bass Level: 83 dB
LFE Channel Bass Level: 75 dB

Run #2:
3803 Sub Level Setting: -5
Sub Calibration SPL: 83 dB (Left Front Avia Chapter 7.3)

LF High Passed Bass Level: 83 dB
C High Passed Bass Level: 83 dB
RF High Passed Bass Level: 80 dB
RS High Passed Bass Level: 83 dB
LS High Passed Bass Level: 83 dB
LFE Channel Bass Level: 75 dB

Run #3:
3803 Sub Level Setting: 0
Sub Calibration SPL: 83 dB (Left Front Avia Chapter 7.3)

LF High Passed Bass Level: 83 dB
C High Passed Bass Level: 83 dB
RF High Passed Bass Level: 80 dB
RS High Passed Bass Level: 83 dB
LS High Passed Bass Level: 83 dB
LFE Channel Bass Level: 75 dB

I quit after three runs because my results were identical each time. I reset the 3803 processor and re-ran all the tests. The results were identical after the processor reset.

Data Analysis:

There was the expected 8 dB LFE channel deficit, but the deficit remained fixed at 8 dB regardless of sub level setting, which I did not expect. I also cannot explain the 3 dB deficit in the RF low passed bass level.

Subjective Findings:

Run #1:
3803 Mains Setting: -3
3803 Sub Level Setting: -10
Mains Calibration SPL: 80 dB (Left/Right Front Avia 7.2)
Sub Calibration SPL: 83 dB (Left Front Avia 7.3)

Subjective Bass Quality: Rotten - inconsistent within DVDs and between DVDs; weak at times, strong at others.

Run #2:
3803 Mains Setting: -3
3803 Sub Level Setting: 0
Mains Calibration SPL: 80 dB (Left/Right Front Avia 7.2)
Sub Calibration SPL: 83 dB (Left Front Avia 7.3)

Subjective Bass Quality: Excellent – consistent and robust within DVDs and between DVDs.

Summary:

Clearly there is something strange going on with the 3803 bass management circuit. Avia supports my subjective impression of an LFE channel deficit. But Avia shows said deficit to be fixed at any sub level, and does not support my impression that this deficit can be eliminated by setting the 3803 sub level to 3 clicks above the 3803 mains level.

With that said, I know my SVS 20-39PC+, and I know my DVDs, and anyone with half an ear can tell the difference between sub level –10 and sub level 0 with the same exact sub calibration level of 83 dB each time.

What works for me is this: If I run my sub 3 dB hot, then the 3803 sub setting has to be 3 clicks above the 3803 mains setting to get proper bass response.

I wish this were a tidy ending, but it isn’t. The Avia data only partially supports my position, but it is better to be honest and present the facts and my subjective impressions and ask for comments than it would be to cook the numbers for a happy ending. Comments are welcome.

Regards,

Ed

 

[Mike Up]

Edward,

Unfortunately, it seems you've confirmed it's defective. I'd exchange it, if you want to stay with the 3803.

From your description, it seems that the firmware that was loaded into the Sharc processor is corrupt. Since it's new, I wouldn't let them repair it. I'd exchange it.

Have you noticed any other oddities related to decoding, DSPs, and processing other than just in bass management? Since it looks as if the firmware is corrupted, I would have to think that everything related to the processor would also be affected.:frowning:

BTW, as far as SPL go, Video Essential's is said to be recorded at 75db. When calibrating with VE sound pressure level tests, I have to set my L/R speaker calibration to +4db to achieve 75db. With the Internal 3803 levels, I only have to adjust up to +2db. This obviously indicates that the 3803's internal levels are 2db high. The SPL internal levels from many receivers had been found to be slightly off, so this doesn't concern me. However, by your findings, to reach VE's 75db level, you'd have to turn your L/R speaker calibration up to +2db. That's only 2db off of my number. It seems you internal test tone levels are way off, which this would also be affected by the processor.:frowning: I'd exchange it definitely.

BTW, my listening spot is exactly 12' away from each speaker and 11 1/2' away from the center spot between the speakers. My speakers are straight firing, are not towed in. My speakers are Infinity RS2000.4 tower speakers with an efficiency of 89db. The speakers are 5' from one another and my room is 15' X 16' X 8' = 1920 ft3

Using the newest Radio Shack Digital Sound Pressure Level Meter CAT. NO. 33-2055 at my listening spot, to create 75db sound pressure levels with VE's tests, the R/L main speakers must be calibrated to +4db. With my speakers towed in, pointed directly at me, the main speakers must be calibrated to +2db. Having them towed in gains 2db at my small listening spot but then confines the sound-stage. I recently towed out the speakers, or positioned my speakers to fire straight ahead, and the sound-stage widened very significantly while doing no harm to the imaging.

Earlier you sited you had a listening spot only 1' closer to the speakers than me, and had a slightly smaller room at 1728 ft3(12' X 18' X 8'). While you'd obviously would gain more volume than my setup, 5db more(since had your L/R calibrated to -3db using 3803's internal test tones)seemed quite a bit given your setup specs were only slightly different than mine. If you had Klipsh speakers, than +5db would had seemed reasonable if not an understatement. Now it turns out your 3803's internal test tones are off by 5 db. If you used VE test disc, you should have 75db with your L/R speakers calibrated to +2db, only 2db less than mine. That seems much more reasonable for a closer listening distance and slightly smaller room.

I've only gone over this so if you do exchange, you'll have somewhat of a reference to go off of.

I think once you have a receiver that doesn't have defective processing, you'll be quite impressed.

Good luck.