1098, 1068,1067, & 1056 owners, need you to test a bug.

[Kevin D]

I've found a DTS bug on a 1068 I was installing the other day. I recreated it on our store 1068, and even my home 1098. Rotel is looking into it, but I'm not sure how seriously. As people have time, if you could do a test for me I would appreciate it.

Play something in DTS. DTS music if you have it (maybe use credit music if you only have a movie). You need something that's dynamic and repeatable. If you don't have a center channel, good. If you do, unplug it. Play a bit of the track. Go into the menu and toggle the center channel from none to small.

What I have found is that with the center set to small everything sounds great. Setting it to none will collapse the soundstage and make the music sound like it's hitting a brick wall. The sound is less dynamic and not as much rear information is coming out. On my 1098 I had to set the center back speakers to none for the bug to arrise.

Short blurb: At least the 1098 and 1068 have a bug when you are not running a center channel or center rears where DTS tracks only are less dynamic and have no soundstage.

As you do the test, please reply with what model you have, what version it's at, and whether you get the same results.

1068
1.1.3
has bug

1068
1.1.7
has bug

1098
2.1.1
has bug

[Kevin D]

Not everyone jump at once...I'm having a hard time keeping up.

We wound up placing a professional mixer between the 1068 and the front 1080 at our customers house. Set the 1050 and the 1068 to have a center, and then mixed the center out back into the left/right. Everything sounds great now, no more "collapsing DTS soundstage" (Trademark Rotel, 2004)

Kevin D.

[GosonFletchy]

So it was not a bug then?

G.

:grab:

[Andrew Pratt]

Interesting. Whom did you contact at Rotel?

[Kevin D]

So it was not a bug then?

G.

:grab:

Untill they start coming with a $200 mixer when you have no center or center rears it's still a bug..

Andrew, I believe it was Shane/Shawn.. 2 Weeks ago they were going to try and reproduce it. I haven't had a chance to tell them it only occurs with no center-rears..

Kevin D.

[Tony]

Short blurb: At least the 1098 and 1068 have a bug when you are not running a center channel or center rears where DTS tracks only are less dynamic and have no soundstage.

I own a 1068 myself but I haven´t a DTS Sound bug. I listen to 5.1, so the Center back channel is set to ´none´ in the 1068 menu and everything sounds great. Is the bug only, if you have no center speaker? But who have no center speaker, if he owns a 1068 for surround sound????

Tony

[Kevin D]

Yup, the bug only comes up when you have no center or center rears.. Who doesn't have a center? Well at least me and my customer..

In my case, I can't afford the a center worthy of matching my CDM-9's yet and my customer is mainly a two channel guy that always sits on the sweet spot, but does want surround sound (but doesn't need a center to lock dialog to the TV)..

It's actually more common then you would think.. You can still test for the bug, all you have to do is disconnect your center wire and then toggle between no center and small center while listening to a DTS track.. You should easily here the entire soundstage collapse when ou set it to none..

Kevin D.

[DJDREW]

Hello Kevin,
Were your main front right and left speakers set to large or small, this makes a big difference? Also do you have a subwoofer in your system.

[Locutus2k]

It's actually more common then you would think.. You can still test for the bug, all you have to do is disconnect your center wire and then toggle between no center and small center while listening to a DTS track.. You should easily here the entire soundstage collapse when ou set it to none..

Kevin D.

Hi Kevin, i've tried to reproduce the bug with my 1098 but there was no "soundstage collapse", only the center channell on/off.
I'll give it one more try but, for the moment, i can say there's no such bug on my 1098 (firmware 2.1.3).
All the best,

Locutus2k

[Kevin D]

Hello Kevin,
Were your main front right and left speakers set to large or small, this makes a big difference? Also do you have a subwoofer in your system.

Drew,

My mains are set to small with a sub.. I'm don't have the bug (because I have center rears), I was just saying I can reproduce it..

I install this stuff for a living, so I promise you the problem is there.. It's understandable that the left/right will be a little more cluttered having the center information mixed in with it, but with no center nor center rears the sound hits a brick wall, theres just no dynamics to it.. Same thing on the rear outputs, they get louder and more dynamic. Mixing a center signal into the left/right shouldn't have an effect on the rears..

Locutus, thanks for attempting. Make sure the your center is unplugged, so you can concentrate on the fronts and rears alone.. I keep leaving the update cable at the office, I'll try to update to 2.1.3 and see if it goes away.

Thanks,

Kevin D.

[Kirby]

Hi Kevin. I have a 1056 that has the same problem. If I set the center to none the sound is terrible. If I set the center to none and set back speakers to small it is ok. Hope this helps. I don't know it Rotel really tries to find problems. I had an issue with video upconversion and they say they cannot reproduce the problem but I have seen the same issue on 4 RSX-1056s.

[Locutus2k]

Kevin: i've made more tests, asking for the help and ears of some audiophile friend. I can positively tell you that on my 1098 with 2.1.3 firmware the bug is not present, at least using the software i've used (a DTS movie and DTS cd of Sting Brand New Day).
Switching the center channel to normal/large/none doesn't produce any negative impact on the soundstage. I've made the tests with the center channel disconnected. My center back channel(s) is also disconnected (not present at all) as i've never used this feature.
Have you tried with new firmware?
All the best,

Locutus2k

[DJDREW]

I am no expert but if you have no center channel where there is center channel information and then on top of that you have small mains of course it maybe subject to sound bad.

Try changing your mains to large and tell me your findings. Anytime you select small speaker on a processor the main right and left spekaers will not sound full that why it called SMALL. Let me know what happens when you change them to large I am curoius if you have the same problem.

[Kevin D]

Drew,

I'll play around with large/small tonight (and up to 2.1.3 if I can remember that damn cable).. The large/small only has to do with bass management though, it will not have an effect on the high frequency dynamics.. That said since it only effects certain models at certain settings, changing them to large might also fix the problem.. I'll update tonight..

Kevin D.

[eelco74]

I have just been playing with the problems you find. I own a 1068 with 1.1.7 software.

I have tried with Cher's Farewell tour that has a DTS track
Normally I have a full 6.1 setup with all large speakers and a sub.

Now for the test,

All speakers large
No centre
No Surround back.

There is definately a change in sound, if it is dynamics or bass management I do not know. But the soundstage suddenely collapses if you change from "small centre" to "no centre".

There is also a big change in sound if you use the above setup( all large, no centre and surround back), and toggle between "surround back none" and "surround back large1".

This is definately a bug. I had to change back to all large to get the original sound back.

[Kevin D]

Yea! I'm not crazy... You've confirmed what I've found, enabling either a center or rear center (or both) will correct the problem..

Kevin D.

[Bob Knarly]

Hi Kevin. I have a 1056 that has the same problem. If I set the center to none the sound is terrible. If I set the center to none and set back speakers to small it is ok. Hope this helps. I don't know it Rotel really tries to find problems. I had an issue with video upconversion and they say they cannot reproduce the problem but I have seen the same issue on 4 RSX-1056s.

I could not have said it better,I have had several issues,Rotel has never solved ANY of them.These issues are on ALL Rotels I've tried,but instead of"if this is a problem lets fix it"I normally get the "never heard of it" routine.My 1056 does the same thing but its prolly my speakers/wire/electric etc..etc..etc..

[GosonFletchy]

I would like to say that I usually understand most of what I read on this forum. This thread has me lost though. I can not follow what is exactly going on here. What is the scenario where the problem is present? It sounds like you are trying to alter a surround mode and make the processor do something that no one would ever do. I am lost on this one. Can someone "dumb it down" for me and try and expain the setup again and why I would ever set it up this way.

G.

:grab:

[Kevin D]

A repeat of the short answer from my first message..

Short blurb: At least the 1098 and 1068 have a bug when you are not running a center channel or center rears where DTS tracks only are less dynamic and have no soundstage.

It's not a situation that no one would encounter. The only reason it's known is because my customer had the issue with his setup.

Kevin D.

[booktrunk]

I don't understand...

You expect it to sound the same without a centre.... and it doesn't it sounds worse...? Well ummm isan't that expected?

If you are saying that you don't like the way the processing within the Rotel handles the sound of say 4.1 or is it 4.0? as opposed to 5.1 or 6.1 .... then why not get a processor or amp that they prefer the sound of?

Different amps/processors will handle it differently, but to be honest to expect to loose the centre which a lot of people argue is the most important channel in a A/V Setup and expect it to sound the same is well wishful thinking to me.

Yes there are lots of good systems that sound good without a centre, but I bet they would be improved a lot with the inclusing of a good centre.

Steff

EDIT: OK improved a lot is an exageration, but improved they will be if they have a good matching centre.

[Kevin D]

I don't understand...

No you don't... No one expects the sound to be the same without a center channel. But to make it easier, disregard the left/right sound. The fact is having a center vs no center should not have any effect on what comes out of the rear speakers and it does...

There is absolutely no reason to post any more posts trying to argue the validity of the bug. Plenty of people run with no center channel and if Rotel doesn't feel like fixing or acknowledging it they need to remove the option of setting the center to none.

Kevin D.

[eelco74]

I agree with kevin,

I have tried it yesterday and there is definately someting wrong with the sound if you have no centre and no surround back. I would expect it to sound a bit less good without a centre channel that with a centre channel.

But we are talking about a major difference in sound. I tried it several times to hear the difference, because I could not believe my ears.

I am very happy with my rsp1068/rb981/rb985mkII. I have a full range 6.1 setup, so the bug does not affect me. But I can inmagine that for people without the front and rear centre the sound is unacceptable. I know not many people run without a front centre, so it is a rarity. But nevertheless it needs to be fixed.

[soundhound]

Rather than a "BUG" could this just be beyond the design spec? My Yukon does 125 mph forward, I am not going to tell G.M. they have a problem if it won't do it in reverse.

[eelco74]

Certainly not, since it was designed that way.

But you would complain if your brakes would work in all gears. But if you select 4th gear, you only have 50% brake power. Then you would complain for sure :-)

The option to select and configure your speaker configuration is pretty standard. It should not have such a major influence. Perhaps you should try the bug/problem/feauture yourself ?

[PewterTA]

So if I'm getting this right, there is little to no surround information sent to the rear speakers if you select to have no center and no center back speakers? I will test this out on Saturday/Sunday when I get my 1098...I'm just too curious about this..

It doesn't happen if you have the center enabled and no center back, correct and ONLY on a DTS 6.1 track (something like the new ROTK: EE is what I'll most likely try since that track is INSANE with rear information).

I love playing around, this will be fun to find and maybe figure out.

[GosonFletchy]

Ok. I got the new ROTK DVD as well. I will try this on Saturday and see if I can figure out what the deal is.

G.

:assimilate:

[soundhound]

eelco74, my only point is that I bought my Rotel 1068 for it's 5.1, 6.1, and 7.1 capability. If I only wanted 4 speakers I would purchase a "stereo" set up and amplify as needed, be it runing 2 speakers per channel in series. I would not go invest in a product known for it's 5.1, 6.1, or 7.1 processing capabilities. It may in deed sound terrible in 4.x, but I would bet that is not what the engineers were focused on when they conceived these. There may also may be mfgrs whose products sound fine in 4.x mode, but this could say as much about their "lack" of true "processing" capabilities as it does there processing capabilities.

[eelco74]

I tried it with Cher's DVD, wich only has a 5.1 DTS track, no 6.1. And I found the bug worked as well. So It does not seem to matter if it is a 5.1 or 6.1 sound track.

[DJDREW]

No you don't... No one expects the sound to be the same without a center channel. But to make it easier, disregard the left/right sound. The fact is having a center vs no center should not have any effect on what comes out of the rear speakers and it does...

There is absolutely no reason to post any more posts trying to argue the validity of the bug. Plenty of people run with no center channel and if Rotel doesn't feel like fixing or acknowledging it they need to remove the option of setting the center to none.

Kevin D.

Have you contacted Rotel yet with this problem? I would be interested on how they ignored it.

[Kevin D]

First call to Rotel was met with a little disbelief that they haven't heard of it (user error, understandable). They are aware of this thread and as of 5 minutes ago know exactly how to set it up and what models it effects.. I was told they would try and set up a sound room to test it out as soon as possible.

I'm sure that I was shuffled into the isolated problem, possible user error catagory. That's why I enlisted your help to know I wasn't crazy..

Thanks,

Kevin D.

[Wolfenstein 2k2]

OK, I just tested this issue on my 1098 (2.1.3 software installed) to find out whether I am affected by this "bug" as well.

I chose "The mummy 2: The mummy returns" DVD using German DTS 5.1 sound (track no. 20, end credits with score) and "Gladiator" using DTS sound as well (track no. 28 end credits with score). For a better comparison, I also tested the Dolby Digital sound tracks on these DVD´s as well as some other tracks showing various movie scenes. By the way, my setup consists of two Dynaudio 72SE as fronts, two Dynaudio 52SE as surrounds, the 122C as center speaker and the B&W ASW 750 as a sub.

1.)
This is my usual setup as follows:

FRONTS: LARGE
CENTER: LARGE
SURROUNDS: LARGE
BACK CENTER: NONE
SUB: MAX
As expected, everything sounds excellent in this case, especially DTS compared to Dolby Digital.

2.)
FRONTS: LARGE
CENTER: SMALL
SURROUNDS: LARGE
BACK CENTER: NONE
SUB: MAX
Everything still sounds great, same results as in 1.). A small amount of bass from the center channel is now missing as it is running in SMALL mode.

3.)
FRONTS: LARGE
CENTER: NONE
SURROUNDS: LARGE
BACK CENTER: NONE
SUB: MAX
You can immediately hear that there is a difference concerning the overall output level. You have to increase volume at least 6-8 increments to reach the former output level using setup 1.) + 2.). This wouldn´t be a problem at all if there weren´t other changes as well. Using this speaker setup, sound information from the center channel should be redirected to the fronts. So far so good. But what comes from the fronts now does not convince really. Some of the highs seem to be missing as if CINEMA EQ was activated, everything sounds a little bit flat as if a bigger part of the dynamics got lost. Maybe this is due to the fact that the sound tracks (DTS + DD) on both DVD´s (maybe all 5.1 DVD´s?) are just optimized for 5.1 setups and not for 4.1 puposes with no center running. Probably this is just a downmixing issue to less than 5.1 channels...All in all, setup 1.) + 2.) sound much better, no matter if you choose DTS or DD, music only or movie scenes.

4.)
FRONTS: LARGE
CENTER: NONE
SURROUNDS: LARGE
BACK CENTER: LARGE1/LARGE2/SMALL1/SMALL2
SUB: MAX
Very strange. Although I have no back center speaker physically installed, this setup sounds better than experienced in 3.). Some of the highs from the fronts and parts of the dynamics seem to be back now. At least, the overall output level definitely increases again and hence you might only "believe" that the highs and dynamics are back. Don´t know exactly at the moment. I definitely would prefer this setup if I had no center speaker physically installed (i.e. set BACK CENTER to LARGE/SMALL 1/2). Again, I experienced these changes with DTS and DD - so this is not a DTS-only issue.

5.)
FRONTS: LARGE
CENTER: LARGE
SURROUNDS: NONE
BACK CENTER: NONE
SUB: MAX
Sounds quite good, but no comparison to a real 5.1 setup, i.e. SURROUNDS channels are activated. Again, the overall output level is decreased when SURROUNDS are set to NONE vs. SURROUNDS are set to SMALL/LARGE. 5.1 or higher is undoubtedly superior to this 3.1 setup.

Conclusion:
Generally speaking, it seems as if the 1098 decreases the overall output level the less channels are actived (no matter if you use DTS or DD). Provided that you do not change the volume on your remote, 5.1 is louder than 4.1, 3.1 and especially the 2.0 downmix => possibly one merely considers higher ouput levels to be more dynamic if you switch between these modes from one second to another?. Having said that, maybe two speakers simply can´t play as loud as 4 or 5 speakers at the same time with the same volume. So, the alleged lack of dynamics when switching from 5.1 to 4.1 or even less speakers could be a result of mere acoustic aspects. Furthermore, I simply assume that our ears consider any other setup than 5.1 to be worse because it really sounds worse once you are accustomed to real 5.1 or higher. I mean if you have no surrounds, then of course sound stage is missing in the back. And when not using a center speaker, the sound information from the center is redirected to the mains, i.e the 1098 mixes 5.1 content down to 4.1 => possibly the "bug" is not a bug, but just a result of (a bad) downmixing / redirection of sound information from other channels. As I have no other preamp or surround amp available at the moment, I cannot describe how other amps will handle this issue.

Nevertheless, I have to confirm that the 1098 sounds much worse if no center speaker is selected and accordingly running in 4.1 mode (again, it doesn´t matter if you listen to DTS or DD / music or movies). 5.1 or higher sounds best on the 1098 without doubt, and it is not astonishing that people having no center speaker installed and hence are forced to use a 4.1 setup will be a little bit disappointed. At least I would be because I have a center speaker and can switch between the various modes. By the way: I haven´t dealt with this topic before. When I bought the 1098, I chose a 5.1 speaker setup in its menu and left it untouched until to today. Well, in the end I am really astonished how a non-5.1 setup sounds on the 1098.

EDIT 1: Just compare DD/DTS 2.0 DOWNMIX to 5.1 on your 1098 when playing DVD´s => the difference is amazing, 2.0 downmix sounds even worse than 4.1 (i.e. using fronts and surrounds only). IMHO there is no other way than using 5.1 or higher if you want to experience the "real" capabilities of the 1098 (and presumably the 1068, 1055, 1056, 1065, 1067?).

EDIT 2: I just ran the same bunch of tests, however using stereo CD´s this time. In contrast to the DVD´s I couldn´t reconstruct the worse sound experience when switching from 5.1 to e.g. 4.1. Almost every stereo CD still sounds good in 4.1 mode as if the fronts were running in pure stereo (bypass) mode and were additionally supported by the surrounds. There was no severe lack of dynamics, reduced highs, flat sound stage or something else detectable. Maybe the whole "problem" really only boils down to DD and DTS sound streams...

PS: Sorry for my bad English, I hope you guys understand what I mean by and large.

[Kevin D]

PS: Sorry for my bad English, I hope you guys understand what I mean by and large.

I just have to say that your message was easy to follow and your English was better than 95% of every other message I read on the Internet.. I think you can officially stop apologizing..

With that said, here's what I got from Rotel. I was only left a message, so I may not be 100%. Rotel closed early until Monday.

What I got from the message is that the processor can only handle so many things at once. Having the center be redirected to the mains while bass management is being applied will alter the sound. Setting the mains to large in the test setup will get the same output as if you had a center. Something to the effect that it can only compress so much into the outputs before sound quality is effected. So it appears that maybe the chip always has a 7.1 output and then has to mix 'none' items back in and mix the bass out. Mixing the center & center rears back in and mixing the sub out is too much for the chip. Take any one of those 3 out of the equation and it sounds fine. So not a 'bug', but a compromise to get the job done..

Not quite the answer I was looking for, but I'll talk with Shane when he gets back Monday just to make sure I understand everything correctly..

Kevin D.

[Andrew Pratt]

Interesting indeed.

[Wolfenstein 2k2]

First of all, it´s good to know that my English isn´t as bad as expected Writing so much in a language which is not your mother tongue is more challenging than just reading other people´s posts - certainly this is just a question of practice, too, and this forum gives me a good chance to improve my English. :T

Back to the topic:
In other words, the processor is "swamped" with its work under certain circumstances? So I wasn´t too wrong when saying that the "bug" could rather be a downmixing / sound+bass redirection problem? Hm, I wouldn´t even call it a problem, but an issue. As I said at the end of my last post, when playing stereo CD´s I could not detect such clear impairments of sound quality when switching from 5.1 down to 4.1 in contrast to DVD´s. And keep in mind, most CD´s are not primarily recorded for surround purposes. Well, the data stream coming from a DVD seems to result in "harder work" for the processor compared to the bits ans bytes on a CD...

By the way: I used both my DVD- and my CD-player for playing CD´s in this test (each connected both via analog and digital cables to the 1098 preamp) => no difference recognizable (except for the fact that my NAD 541i CD-player is significantly superior to my Pioneer DVD-player when playing CD´s in stereo mode ).

Furthermore, having all the new "facts" in mind, it seems as if the processor can´t handle properly the data it receives when playing DVD´s in DD/DTS 2.0 DOWNMIX mode. In this case, the processor has to redirect all channels to the fronts and cope with bass management simultaneosly. The result is an impairment of sound quality with limited dynmamics (I just watched the great battle in "Star Wars: Episode II"). I mean watching that DVD in 2.0 DOWNMIX mode really sounds horrible, the sound difference compared to 5.1 is more than obvious. Give it a try if you have a 1098 (maybe 1068 etc.) - listen and you´ll see (<= slogan sponsored by B&W ^^).

[Locutus2k]

Just a note: i've noticed that if i set center channel to "none", i still hear sound from the center channel unless, of course, i unwire it.
Is this normal? Setting the channel to none should mute it, even if it's not unwired.
?????????????

[Wolfenstein 2k2]

My center is muted when set to NONE. Except for the typical noise coming from the 1098´s processor there is nothing I can hear.

[Locutus2k]

My center is muted when set to NONE. Except for the typical noise coming from the 1098´s processor there is nothing I can hear.

Please, i need help: when i set my center to NONE it still works, with no differences at all. Maybe i do something wrong? I have front and center on LARGE, surrounds on SMALL, sub on MAX and NONE to back surrounds.
If i change the crossover settings i can hear something, but if i set to NONE one channell it continue to work normally. Firmware is 2.1.3
HELP!

[Wolfenstein 2k2]

I also have the front and center speakers set on LARGE, the surrounds are set on LARGE as well, the sub is set as MAX and the back surrounds as NONE. If I set any speaker to NONE, then there is no output one could hear. Very strange. Maybe you could reset your preamp to factory settings?

[Locutus2k]

I also have the front and center speakers set on LARGE, the surrounds are set on LARGE as well, the sub is set as MAX and the back surrounds as NONE. If I set any speaker to NONE, then there is no output one could hear. Very strange. Maybe you could reset your preamp to factory settings?

I've discovered that if you set the system decoding on LARGE on the advanced speaker menu settings (the one with crossover settings and Dolby, DTS, Music etc. settings), than you can't exclude the central or surround speakers. But if you set the system decodings on MASTER (and this is the factory setting), you can do that.
I can now confirm the bug: with no central speaker the soundstage is simply orrible.
Thx,

Locutus2k

[eelco74]

Any updates on this issue yet ?

[psych_o_pat]

Are the rsx-1055s have the same trouble?

I'm a new rsx-1055 owner, newbie to HT but senior to stereo...I'm now using a 4.0 configuration with:
Fronts: Large (powered by an external amp)
Center: None
Surrounds: Small (powered by the rsx-1055)
Center back: None
Sub: None

I cannot compare to a 5.1 setup so I 'may' be affected by the bug?
I plan to add a subwoofer soon but no centers (front nor back). Am I doomed to bad sound if I don't at least have a center with this Rotel?

BTW, I have bought this amp after listening a similar setup (4.0) but with the most expensives Arcam separates and better surrounds. I don't want to debate the issue of center channel vs no center channel, but I could say that from what I have heard in this setup the center channel wasn't missed at all.
I may went the wrong route (4.0 or 4.1) with the Rotel?

Any help appreciated, thanks

Pat

[Kevin D]

Any updates on this issue yet ?

No updates needed.. Not a bug, that's the way it is..

On the 1055, I have no idea if it's effected. Test it out and let us know!

Kevin D.

[SL Boy]

I have a 1068 with Quad 989 front speakers and no centre channel and no rear centre channels either. The sound stage on DD and DTS collapses compared to playing the same DVD via Dolby Prologic or playing a Video CD.

[gianni]

My RSX-1055 does the same thing with DTS.

This is very similar to what I found while listening to CD and selecting Dolby 3ST (w/ no center). Could this perceived increased dynamics be due to the increase in volume?

Also when making the switch especially to Dolby 3ST I notice a decrease in image focus and an overall more difused sound.