# Toshiba Bass management?



## slidell (Jan 23, 2007)

Hi All,

Anyone using the analog outs to your non HDMI AV receiver? My Yamaha claims no bass management when input on the back analogs..that it's up to the player to provide bass management to the sub and provide crossover for same.

Are you happy with the A2 set up and results?

TIA


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## bobgpsr (Apr 20, 2006)

The HD-A2 has no multichannel analog outputs -- hence no bass management. The HD-A1 and HD-XA1 do have and the bass management works ok -- but you need to externally do the industry standard +10 dB boost on the LFE channel. The HD-XA2 currently has a bug in its bass management and needs a future firmware update from Toshiba to do it correctly (only when speakers are set to small does the problem arise).


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## slidell (Jan 23, 2007)

bobgpsr said:


> The HD-A2 has no multichannel analog outputs -- hence no bass management. The HD-A1 and HD-XA1 do have and the bass management works ok -- but you need to externally do the industry standard +10 dB boost on the LFE channel. The HD-XA2 currently has a bug in its bass management and needs a future firmware update from Toshiba to do it correctly (only when speakers are set to small does the problem arise).


Thanks, I guess I better call Yamaha. My HTR-5960 has two level controls for LFE, 0 to -20 cut and a second non calibrated volume slider. Nothing in the worthless manual touches on external bass management, what I need may be there.


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## Otto (May 18, 2006)

Well, if the A2 has no analog outs, you will have to go in digitally to the Yamaha. In that case, you shouldn't have to worry about this other stuff. Start with both "LFE Cut" and "Sub Out" levels at 0. Set your levels by using an SPL meter or any built in cal stuff your Yamaha may have (or by ear if all else fails).

Are you crossover frequencies and channel levels set up OK for everything else?


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## slidell (Jan 23, 2007)

I guess I miss understood bobgpsr, the A2 and the XA2 are the same? I need to download the manual and see just what my options are.

Thanks Otto


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## Otto (May 18, 2006)

Not sure.... Which unit are you using?


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## Snatcher (Jan 8, 2007)

I have an HD-A1 and a Yamaha RX-v1700 receiver, and have that particular player connected via the analogs (my Loewe Aconda has no HDMI in, and the player won't output component video when HDMI audio is enabled).

You will indeed need to compensate for the 10 dbs on the LFE channel from the Toshiba. The Onkyo I had before (the 604) did compensate for the 10 db, but the Yamaha doesn't and there is no option to do so, even using the Receiver Manager Software. I had to calibrate everything with the volume on the sub 10 db hot and the Receiver at -10 for the sub, and the Toshiba at its own levels.

Bass management does work, but the Yamaha would do a way better job so I'd recommend you switch to HDMI whenever possible.


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## slidell (Jan 23, 2007)

OK, thanks guys. I haven't bought yet so testing the old waters. The A2 price has come down that I'm close to buying even without the HDMI on the receiver. I need to do my homework a bit more...


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## bobgpsr (Apr 20, 2006)

slidell said:


> I guess I miss understood bobgpsr, the A2 and the XA2 are the same? I need to download the manual and see just what my options are.


No they are not. The A2 does not have multichannel analog outputs -- most users use either HDMI multichannel LPCM or the Toslink digital audio. NO bass management needed in the player -- you use your AVR/Pre-Pro bass management for those interfaces. 

Whereas the HD-XA2 does have 5.1 multichannel analog outputs and attempts to do bass management -- but it needs fixing. 

The HD-A1 and HD-XA1 (gen 1) players are ok in this area -- their b.m. works and they both have 5.1 multichannel analog outputs.


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## bobgpsr (Apr 20, 2006)

We have found that the audio will work fine on the 5.1 analog outputs and the bass management works with 1.6 firmware. The trick that we have learned is that you have to set the XA2 SPDIF output to PCM in order to have the bass management work on the 5.1 audio analog outputs. A goofy XA2 bug/workaround. :coocoo:


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## Vader (Jul 8, 2006)

One thing to bear in mind here. With Ed Mullens help, I just got my sub bottoming problem solved, and it is a direct result of the bass management bug in the Toshiba (A1 in my case, don't know if it also plagues the 2nd gen). Essentially, it fails to give the industry-standard 10dB "kick" to the LFE prior to sending it out over the analog channels. That can be corrected for with no problem, but the kicker is that the _redirected bass_, which never was 10dB too low to begin with, is now _10dB hot_. As a result, my subs were getting the LFE info at the standard level, and the redirected stuff off the charts. For the time being (until Toshiba fixes this in a firmware upgrade), I switched back to bitstream, and will let my AVR do the bass management stuff, and do it right... I will miss the awsesome clarity of TrueHD, but I would rather have my bass mixed and balanced properly...


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## MACCA350 (Apr 25, 2006)

The industry standard in relation to the LFE boost required at the AVR is:

10db when speakers are set to LARGE in the player(when there is no redirection of bass)

15db when speakers are set to SMALL in the player(when there is redirection of bass)

This is to allow headroom because of the addition of the redirected bass to the LFE channel.

cheers


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## Vader (Jul 8, 2006)

MACCA350,

I didn't know about the 15dB for speakers set to small (which mine are), but it makes sense. I stand corrected. The way I understand it, then, is that the redirected bass never needed that boost in the first place, so it was actually 15-25dB hot (assuming that HD-DVE still has the 10dB problem in the LFE tone - so I calibrated to 82dB for the sub - and I gave it a 15dB boost at the AVR). Thanks for the correction...


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## MACCA350 (Apr 25, 2006)

Vader said:


> MACCA350,
> 
> I didn't know about the 15dB for speakers set to small (which mine are), but it makes sense. I stand corrected. The way I understand it, then, is that the redirected bass never needed that boost in the first place, so it was actually 15-25dB hot (assuming that HD-DVE still has the 10dB problem in the LFE tone - so I calibrated to 82dB for the sub - and I gave it a 15dB boost at the AVR). Thanks for the correction...


Are you applying the boost before or after calibration? Since you have the HD-DVE you can use its tones to calibrate correctly. I've got a copy of that on its way from Amazon, so I'll then be able try it on my XE1.

cheers


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## Vader (Jul 8, 2006)

MACCA350,

I am applying the boost before calibration, using my AVR to boost the EXT IN sub channel by 15dB. Based on the article you found, if the Tosh is failing to provide the 15dB boost before it does the BM, and assuming that HD-DVE has the same LFE problem as the SD version, my redirected bass is 15dB too hot. So, if there is a lot of bass in the mains that gets shunted to the sub, its not a wonder that it bottomed, but that it did not do so sooner...


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## Sir Terrence (Jun 8, 2006)

MACCA350 said:


> The industry standard in relation to the LFE boost required at the AVR is:
> 
> 10db when speakers are set to LARGE in the player(when there is no redirection of bass)
> 
> ...


This is not really the industry standard. Once the LFE channel is boosted at the decoder level, there is no more boost in the LFE channel. When all speakers are set to small, there is an electrical boost of 15db going to the subwoofer, not to the LFE channel itself. There is a -15db cut as each channel is redirected to the subwoofer, and that takes care of overloading the sub inputs.


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## MACCA350 (Apr 25, 2006)

Sir Terrence said:


> This is not really the industry standard. Once the LFE channel is boosted at the decoder level, there is no more boost in the LFE channel. When all speakers are set to small, there is an electrical boost of 15db going to the subwoofer, not to the LFE channel itself. There is a -15db cut as each channel is redirected to the subwoofer, and that takes care of overloading the sub inputs.


It seems we have two threads on the same topic.

If you run a Digital optical/coax connection from the player to the receiver then the receiver will perform the proper channel adjustment. When you connect with the multichannel analogue from the player you will need a boost for the LFE/SW channel. If there is no BM at the player the boost needed is 10db, If there is BM at the player the boost needed is 15db

Here is what Roger Dressler(Director of Business Development for Dolby Laboratories) said about how BM is performed.



Roger Dressler said:


> The LFE signal is recorded 10dB lower than the main channels. The process of bass management usually means the bass from the main channels is mixed with the LFE, then presented to the subwoofer. The signal level in the LFE channel is permitted to reach full scale, so in order to mix anything with it, additional headroom must be provided, even when the other 5 channels are being scaled down 10dB to achieve the correct relationship relative to LFE. The amount of additional headroom provided is 5dB. The bass from the main channels is attenuated 15 dB and the LFE is attenuated 5 dB before mixing.
> 
> This means that the bass signal levels coming out of a “fixed level” player is -15dB wrt the main channels. Most AVRs are able to use this level correctly, as they apply the same "scale by -5dB" process when performing bass management internally.


cheers


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## Vader (Jul 8, 2006)

> It seems we have two threads on the same topic.


... which is my fault. Actually, this thread is where this discussion belogs (which I am learning a great deal from!), and I derailed my own thread concerning the re-mixing of Dolby Digital Plus and TrueHD. My apologies.


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## Tommy (Apr 20, 2006)

Not sure if this will help this problem or not but here is info on the most recent firmware update v 2.2

Firmware Update Version: 2.2

Applicable Models: HD-XA1, HD-A1 and HD-D1.

Overview:
This firmware update adds support for certain anticipated network delivered content in future HD DVD discs, improves certain video and audio processing capabilities, as well as addresses certain disc playback and HDMI/DVI related problems identified by Toshiba.


http://www.tacp.com/tacpassets-images/notices/hddvdfirmware.asp


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## Vader (Jul 8, 2006)

I wish the problem had been addressed, but Toshiba has yet to even acknowledge such a problem exists. Maybe in FW update 3.0 (the one with DTS-HD....)


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## Tommy (Apr 20, 2006)

I believe the insides have mentioned it on another board so I think they are aware of it...


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## Vader (Jul 8, 2006)

Well,

After a great deal of reading on the subject, and taking boatloads of SPL measurements, I have reached the following conclusion about the bass management in the A1: it's busted...

I found that, for some reason, the TrueHD and DD+ pink noise is exactly 5dB colder than the DD or DTS counterpart. I calibrated the speakers to 75dBC/85dBC on both SPDIF and analog using DVE, and then compared the TrueHD signal (downmixed to DTS on SPDIF) from HD-DVE, without changing anything. It is almost exactly 5dB cooler, at 80dBC (for _both_ SPDIF and analog). I am not sure why this is, but DD/DTS measures fine, and so do all of the satellites. Maybe because of the increased dynamic range offered by DD+ and TrueHD (I find that DD+ is also cooler by about the same amount by comparing the SPL of the "beethoven flyby" in the Swelltone demo on DVE/HD-DVE)

So, even when using SPDIF, the LFE is shy by 5dB, and there I can do nothing about it there. Since I never had a problem before I re-calibrated using the TrueHD tone (which is 5dB colder than DTS), I am gonna go back to analog and re-calibrate back down to 75dBC/83dBC (using the DTS tone, or 78dBC using the TrueHD tone). That represents a whopping 7dB headroom gain over when I had calibrated the TrueHD to 85dBC!!! Assuming that the TrueHD tone is indeed 5dB cold, that would mean that my redirected bass would only be 5dB hot, and I have more than enough headroom to handle that. When someone is calibrating anyway, could you do the same comparison and let me know if you find the same 5dB difference - between TrueHD (downmixed to DTS) on SPDIF and TrueHD over analogs? More importantly, anybody care to guess why?


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## bobgpsr (Apr 20, 2006)

I am confused with what you are saying...that the analogs (all 6 of them with a 5.1 system) are 5 dB down or just the LFE. My experience would agree that the analogs come out at a lower level than when using a S/PDIF connection. The volume just needs upping when using multichannel analog input or have the AVR do a boost on all 6 of the analog channels together for just the 5.1 analog multichannel input. Many AVRs will do that (just adjust the multichannel input) and not change the S/PDIF overall level calibration.


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## Vader (Jul 8, 2006)

Bob, 

Just the LFE is 5dB down - on both analog and SPDIF. All of the satellites (F/C/R/Surrounds) are fine, and measure at 75dBC any way I come at them. The LFE measures 85dBC when using DD/DTS from DVE, and 80dBC using TrueHD from HD-DVE. And nothing else changes in my setup between tests - just the source....

You are not the only one who is confused at this point (I don't have much hair left to pull out). The only other thing I can think of is that the HD-DVE test pink noise is recorded only 5dB hot (as opposed to 10dB).... At least that would explain why there is a 5dBC drop on _both_ analog (TrueHD) and SPDIF (TrueHD downmixed to DTS)...?

:wits-end: :dontknow: :wits-end: :dontknow: :wits-end: :dontknow:


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## MACCA350 (Apr 25, 2006)

I have a heap of Data from testing both AVIA and DVE which you can see in this thread. In addition to that I have tested using both Denon 2200 and Toshiba XE1. Tests were setup, as per the other thread, with room EQ off and calibrated to 75dBC with the receivers internal test tones. The Receiver and both players, 2200 and the XE1, were setup the same(all speakers-small, Xover-80Hz). Here are the results in regard to the 2200 and XE1.

AVIA................2200 Dig+Ana.....XE1 Dig.....Analog
Left channel.........81dBC..............81dBC......81dBC

Left ch HF............81dBC..............81dBC......81dBC
............LF...........80dBC..............80dBC......80dBC

DVE
Left channel.........72dBC..............72dBC......72dBC

LFE channel..........83dBC..............83dBC......90dBC

DVE-HD
Left channel................................72dBC......72dBC

LFE channel.................................85dBC......90dBC
.....................DRC turned off......*80dBC.....*85dBC

After all this testing I noticed I had the DRC turned on in the Toshiba XE1, so I turned it off and rechecked the 'DVE-HD LFE channel' tones, you can see the difference it made in the numbers with the *. I will re-check the other XE1 tests with the DRC off over the weekend.

One other thing, has anyone noticed that DRC in the receiver does not work when using the SPDIF connection and playing a TrueHD track, although it does work when playing a simple DD track like those on a SD-DVD? it seems that when the player has to re-encode the audio for the SPDIF output it looses or doesn't add the DRC information into the DD bitstream that is output from the SPDIF connection. A little bit annoying for late night viewing.

cheers


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## Vader (Jul 8, 2006)

MACCA350,

Your results seem to confim I am not completely crazy, as there is exactly a 5dB dip on both SPDIF and analog LFE when DRC is turned off (I have it disabled both in my AVR and in the Tosh). This weekend, I'm gonna try the same tests, but disable the Tosh BM. I'm betting that I will get my 5dB back over analog, but not SPDIF (obviously). Thanx for your measurements!


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