Rotel RSP-1066 Bass Management Report (1 Viewer)

[rodneyH]

Dre, I agree, the sound of this piece is incredible, I don't know if I have mentioned this or not, but I have 1 freind that owns a dealer and he could have ANY processor he wants, my father has another friend who works at a different dealer that sells Rotel along with TAG, Proceed, etc...

Both of these guys want to get the 1066 for thier own homes, it is THAT good. is it as good as anything outthere, probably not, but it is sooooooooooo close and for the $$, it is a great choice. My next pick would have been to Anthem AVM-20, but after hearing with and playing with my dads 1066 for a few weeks, I had to get one myself.

 

[Jeffrey Forner]

Dre;

Thanks once again for the report. I'm not exactly sure why you suggest I do everything I do in this latest edition, but I'm willing to take your word on faith and try it out sometime this week. As always, I'll let you know what happens.

 

[Cary P]

Thanks for the reassuring words, Dre.

It's good to know that the Rotel is generally such a strong performer, sonically.

I've been wanting to move to a separate pre/pro for home theater use for quite some time, and it's been a long wait for someone to offer a great sounding, up-to-date, fully functional HT pre/pro in my price range. I am really glad Rotel has decided to enter a market segment that so many other manufacturer's seem intent on ignoring (hello, Marantz?), so I hope Rotel succeeds in their efforts.

I really have high hopes for the 1066, which is why I was so disappointed to learn about the 1066's bass management problems on the multi-channel input.

I've read your reports on the workarounds for the bass management problems of the 1066, thanks again for your thorough and informative efforts. Hopefully, someone at Rotel has taken notice of the work you've done, so they understand the problem completely and can quickly devise a software solution.

My listening habits are primarily two channel music, and I have an Anthem Pre2L-SE with a HT bypass that I feed all of my two channel sources to directly, so bass management on two channel sources is not a big deal for me.

It's primarily the bass management issues on the multi-channel input of the 1066 that bother me. I am willing to set all of my speakers to small for Dolby Digital, DTS, and DPLII use, so I will have an acceptable workaround for movie and TV watching.

However, I am unwilling to purchase two ICBM's and twelve additional high quality interconnects in order to implement the ICBM sandwich solution you suggest for the multi-channel input. Unless Rotel can some up with a software fix, my multi-channel SACD and DVD-Audio listening will be compromised with the 1066. It's for this reason that I am reconsidering my pending purchase of the 1066.

Andrew reports that Rotel will fix these problems with their next generation pre-pro - anyone have any idea when this piece (the 1066's big brother) will be released? I imagine it will be substantially more expensive than the 1066 - and I bet it will be a THX Ultra II unit to help justify the increased cost. Maybe if I can get my dealer to assure me that I can upgrade to the next generation Rotel pre-pro when it is released, I will go ahead and get the 1066 now and hope for a software solution. Jeez, this sickness never ends - when will it stop?

Cary

 

[Chris Zell]

Dre,

Thanks for the interesting, and innovative suggestions for curing the bass management problems. I'm a new owner of a 1066, and am struggling with this right now. I have a couple of questions about how the unit operates and your solutions.

1. You state the problem in 2 channel analog where the speakers are large, and the bass is sent to the sub and is present in the mains. If this is a true analog passthrough, then the speaker setting large or small shouldn't matter - how would they cut off the low end in the mains if there is no crossover? It was my understanding that all crossovers were done in the digital domain. This would make the 2-channel analog a problem irregardless of large or small mains - smalls would act just like large. I could be wrong, and hope I am. But if there are analog crossovers, then why not use them also in the 5.1 inputs so bass management can be done there (like tha outlaw 950 - they have one set of 80 Hz analog crossovers for the 5.1 inputs).

2. I'd like to point out a reason for caution when choosing the solutions you propose where an ICBM is placed AFTER the 1066. Bass management can be problematic if implememted after time delays are inserted. Certainly, I would want to listen to see if this causes audible bass summing cancelations. May not be a big deal, particularly if the delays for a specific system are small, but people should be aware of the potential problem. Just in case, I like to avoid this potential problem if at all possible.

3. Most folks with subs do (or should IMHO) have all speakers set to small, so these bass mangement problems are minimized, and more easily solved. That is unless the small setting does not work, as I talked about in 1) above. I am currently solving the problem in the following manner. I have one ICBM for DVD-A, and am also utilizing the excellent, and extremely flexible crossover in my subwoofer.

Source: All 5.1 outputs from the source are connected to ICBM inputs.

ICBM: Set Fronts to LARGE, all others to small with appropriate crossover frequencies. Set bass to recombine (to send all bass to fronts).

Rotel 1066: Set sub to NO. Connect front outputs to sub inputs, all other outputs directly to amp inputs.

Sub: Set crossover frequency, slope, phase as desired. High pass outputs to main L/R amps.

This solution works for all cases as far as I can see. Please feel free to tell me I'm full of !$#@!@ if you see something that is wrong. The down side I suppose is if you want to listen to straight 2-channel w/o the sub. Then I would need to bypass the sub. Personally, I can't imagine wanting to disable the sub anyway. If I integrate it properly (which is a very time consuming task, but definitely worth it), I never want to be without it.

Just thought of another disadvantage of this solution - the inablility to adjust the subwoofer level for sifferent sources. Hmmm... that may be a problem in the long run. One way around it is to optimize the system for music, use the bass tone control for movies, where I am most likely to want a bit more impact, and abslolute accuracy is less important. After all, with Dolby Digital soundtracks, we are basically listening to MP3, and even the higher rate DTS has considerable compression. But I may want to tweek the sub level as I listen to other stuff too. Dang - I may need another solution!

Again, thanks for your solutions, and starting this interesting conversation.

Chris

 

[Dre J]

Jeffrey,

In a nutshell, you are doing what you did in the first installment. The difference is you are sending the LFE information from your DVD Audio through a clean un-summed channel pathe to the ICBM's LFE input. This clean channel is only avalable if you have a 5.1 set-up, which you do.

Dre

 

[Dre J]

Chris,
Thanks for taking the time to read the original Rotel RSP-1066 Bass Management report and additional device installments. It looks like it's been helpful to you, I hope. The bass management report characterizes the issues and the additional device control reports offer solutions for those willing to invest more money into their setups. I have mentioned other solutions will follow including low to no cost ones but they end up being limited. Since the ICBM offers extra flexibility with bass management, I decided to use them in the reports because of the great return on investment.
BTW: I can't and won't tell you that you are full of anything but happily firing neutrons in that brain of yours. I'll put a smiley face here so you can read the rest of the message in the context of fun and continued conversation on the topic.
My reply to 1:
I mentioned the 2-channel analog setting for small speakers still send a full range signal to the Left and right mains further up in this thread report but never updated my report to include the small setting didn't work for 2-channel analog. This is actually a good thing because Rotel did create a pure two channel pre-amp in the RSP-1066. All they need to do is fix the Subwoofer setting to act as "Yes" when set to "YES" and not "Max" when set to "Yes". This is what allows the use of the ICBM, or sub crossover, for two channel and the multi channel 6.1 input. A crossover consists of two parts. A high pass filter and a low pass filter. For two channel analog and the multi channel input, only the low pass filter is implemented and sent to the sub. Think of it as the 6.0 channels are being "Tapped" and the low frequency information is send to the subwoofer output. In the case of the multi channel input, the low frequency information is summed with the 0.1 channel and sent to the subwoofer output.
My reply to 2:
This concern is minimal and only for Dolby Digital and DTS, IMO, which you state lower as being less important to you. The amount of delay needed to cause a concern is extremely small with frequencies below 120 Hz. I think room acoustics (i.e.. reflections, cancellations) FAR outweigh any effect that you are cautioning about. Those time delays you are talking about can easily be tested by ICBM owners. All you have to do is go into the user menu of your Processor and change the timings. I'm willing to bet that you won't notice any more difference with the ICBM inserted than without, other than better optimized crossover points for your speakers from the ICBM. (Changing the timings with the ICBM in and changing the timings with the ICBM out.) Interestingly enough, the RSP-1066 only allows a timing adjustment in increments of 5 ms for the surrounds anyway. Furthermore, you are stuck with no delay if your center channel speaker is further away from the listening position than your mains, since it's based adjustment delays are based on the mains being furthest away. This is not the case for me, is it for you?
My reply to 3a:
Unfortunately, the optimal crossover points for my center channel and surrounds are not 80 Hz. 80 is on the verge of being too low for my surrounds and it's too high for my center, I'd like to try 100 Hz for my surrounds and 60 Hz for my center. I, also, don't want my sub involved in any 2-channel audio, DD, DTS, or L/R mains from DVD-A or SACD unless it's MUCH lower than 80 Hz. My mains are just plain faster and the option of using the Bass management features of the ICBM are a bonus.
My reply to 3b:
If you don't have the subwoofer output of the RSP-1066 connected to your sub, then you are doing OK. The only thing you're giving up is a more flexible crossover in the ICBM and the possible reduction of crosstalk, S/N ratio, and stereo separation due to the ICBM maybe being better in those areas that your Sub crossover.
It looks like you are implementing the top portion of the Dual ICBM sandwich by using the recombine function but turning on the crossovers for the center and surrounds during DVD-A playback and being content with the digital filters in the RSP-1066 for the DSP modes (DTS, DD, DPLII, etc.).
If you have the subwoofer output of the RSP-1066 connected, your shooting yourself in the foot and you will need to remove it. It wasn't clear if you do or don't. I'm assuming you don't have it connected.
Thanks for sharing your thoughts approach to the issue.
Dre

 

[Chris Zell]

Dre,

Thanks for the info contained in your detailed and informative reply. Nice to shoot the bull with someone so knowledgeable!

I suspected that the analog pass-through did not have a crossover at all for the fronts, regardless of large or small setting. I'm not sure if passing through a low-pass to the subs is a good idea, but that's the way it is. For low frequencies using the digital crossover in the 1066, I see no problem going through the AtoD, then LP filter, then DtoA. I doubt anyone could detect a loss of fidelity in the bass region.

You may be right that the summing after delay is not a problem, particularly if the delay's are not excessive relative to each other. I've never done a listening or measurement test, but I would want to if I ever go this route, just in case. I'll bet it won't matter much though, if at all.

Another thing about bass interference/cancellation - that is one of the reasons I think everything should be set to small in an HT system. Having multiple sources for bass, including the sub, is a nightmare to tune, just asking for cancellation problems. Also, the optimal location for the mains is never the best location for bass, so I much prefer to put the sub where bass works the best, the mains where they work best w/o the deep bass.

Concerning the use of the ICBM vs sub crossover: I WANT to use the sub (Revel B15) crossover instead of the ICBM. The ICBM obviously has the ability to perform bass management for a full 6.1 system, and is a relatively high quality unit. But for 2-channel applications, my sub crossover is MUCH more flexible, and I believe the electronics are higher quality. That's why I reduced it to a 2-channel system for the final crossover - I wanted to take advantage of the superior flexibility and electronics in the sub. Some of the flexibility advantages: the sub has finer frequency increments (10 Hz, not 20 ala ICBM), continuous phase (none for the ICBM), independently adjustable slopes for the high and low pass (12-24 HP, 24-48 HP), and independent LP and HP frequencies. I have had great success in the past using non-symetrical crossover frequencies (and slopes), surprisingly finding that sometimes a small gap results in a flatter response,and more pleasing sound. I designed a home brew active crossover where I can insert DIP plug-ins to vary frequency, slope(up to 6 pole - 36 dB)and type(Butterworth, Thomson etc) independently for LP and HP. After hours and hours of playing over the years, I have found that it is very nice to have as much flexibility as possible to optimally integrate a sub. I have built 2 of those crossovers, and I may pull them out to play with and experiment.

Yeah, I noticed the 5ms granularity in surround delays - one of the weak points of the 1066 for me.

I agree with you when you say you need different crossover points for surrounds/center, and the mains. I want 80 to 100 Hz for the surrounds and center, and likely 70 or 60 for the mains. That is another appealing thing about the setup I'm using - I can set the frequencies and other parameters however I want.

I'm curious what you mean by faster when you speak of your mains. I've never thought of bass as faster or slower, so I'm not sure I understand.

No, I'm not connecting the sub outputs of the 1066 to anything. Sorry if my earlier post wasn't clear on exactly how I set things up. You're right, if I did that the whole thing makes no sense and my foot would have a whole in it!

Last - could you tell us about your HT system? I always like to see what others have and can recommend, and maybe learn something that will help me also.

Thanks,

Chris

 

[Dre J]

Chris,
It looks like you have things under control and you are happy(the most important thing) with the setup you are using.
I'm a big 2-channel audio fan. So much so that I focus on 2-channel audio first , SACD/DVD-A second, and HT third. I believe that if you can nail down pinpoint imaging and a clean 2-channel audio setup, you have a critical piece of HT together.
When I say my mains are faster, I'm talking about the ability of my mains and Amplifier combination to have better control of bass in the 120 Hz to 30 Hz region. Since you have built Filters I'm going to assume you know what an impulse response is. I have observed certain bass frequencies that my Mains are able to reproduce much more accurately than my Subwoofer. This could be shown by thinking of a mechanical impulse response. The size of the Subwoofer cone and the amplifier driving it is more prone to the cone continuing to move after the signal is gone than the dual 8" drivers in my mains controlled by my amplifier.
As far as my set-up is concerned, you can look at my web site for a basic look at the equipment I'm using. I'll be happy to continue the HT setup information via e-mail if you wish. [email protected]
The part of my HT that's relevant to the topic is the addition of the Sony TA-P9000ES pre-amp. I'm still working on the report for this but it gives, IMO, the best option for individuals needing two (SACD and DVD-A) multichannel inputs. It's a clean analog pre-amp for the two 5.1 channels and has both a 5.1 by-pass (for the RSP-1066 5.1 outputs) and a 2-channel bypass (you can split the L/R main outputs from the RSP-1066 and remove the Subwoofer for 2-channel stereo. it has also garnered a stereophile class-A rating.
You can read about the Sony TA-P9000ES here.
Hope this is helpful
Dre

 

[Chris Zell]

Dre,

Thanks for the answer, and yes, I am familiar with impulse and frequency response. Looks like you have a high quality, fun music/HT setup. I'm especially impressed with how clean the setup looks - hard to make that huge mass of gear and wires asthetically pleasing. Nive Job.

I too am a music fan primarliy. Up to this point, I have watched less than 1 DVD/month on the average. Now that I have a slightly better TV and a new 1066, I'll probably view more, but I'll still 80-90% music. I used to be a 2-channel guy, then 2-channel plus sub. But after painstakingly choosing and integrating surrounds and center, I am now generally prefer multi-channel for music, even from 2-channel sources. Not saying I'm right - everyone has their own preferences that are equally valid. For me, one main key was to reduce the levels of the surrounds and center. They are not obvious sources for people when first sit down, but when I turn them off (particularly the surrounds), the sound flattens back to the front of the room is gets kinda boring for me.

The center is MUCH harder to properly set up IMO. Forget it if you don't have matching drivers etc. Even now, I occasionally turn off the center for certain tunes. EVERY HT setup I have heard that is playing music has the surrounds and center too bloody loud for me. They definitely screw it up, so I prefer 2-channel to that.

I am extremely interested in your impressions of the Sony TA-P9000ES pre-amp. I came within an inch of buying one a month or 2 ago. Please let us know when you've typed up your impressions. I am also interested in the low and no cost bass management solutions that you mentioned will follow.

Thanks,
Chris

 

[Dre J]

Link Removed
Updated 09/02/02 to include Small speaker setting note for 2-channel analog.

 

[AVspec]

Dre, I take it if all speakers are set to small and only digital inputs are being used then base management is a non-issue?

 

[Gregg_M]

I am looking at upgrading my electonics. First of all I have spendor bookshelf speakers for fronts and rears and a spendor center chanel. I love the Rotel 1066 but this bass issue has me worried. Is the Bass issue only regarding large full range speakers? Will I run into the same issues with my not so full range bookshelf. I would like to run these speakers as full as possible. Ny sub is a velodyne 10". I am also upgrading dvd, cd etc. I do want the ability for all formats. DVD A SACD etc. Thanks for your help.

Gregg

 

[Dre J]

Mark,

That would be correct except for the LPCM. You will need to set the sub to "NO" in order to completely avoid the double bass.


Gregg,

My first post, in this thread, has all of the information I have collected with links to all the reports. I think you will find the answeres there. Further up the thread you will find that I'm still fond of the RSP-1066. However, I want Rotel to fix the Yes/Max issue AND the bass summing on the multi-channel inputs.

 

[Dre J]

FYI:
Firmware version 1.45 also has the same Bass management issues stated in 1.42/1.43.

Dre

 

[Dre J]

Poor mans solution (Non-ICBM)
Note: This fix will not help the 6.1 multi-channel input. you will need to use one of the other solutions listed in my original post or purchase a TA-P9000ES analog preamplifier.
RSP-1066 settings:
Speakers->
Setting Mains to Large
Subwoofer to No
Center to Small
Rears to Small
Backs to small
Set the subwoofer crossover to the value for your center and surrounds.
Just like I've reported in my other ICBM fix threads, do not use the subwoofer output!
You will need to have a subwoofer that has a built in crossover OR an external crossover like Paradigm's X-30.
If you read the Rotel RSP-1066 Bass Management Report, you will understand why this will work. It eliminates the 0.1 channel from the configuration. As stated in my other fix reports above, the Rotel 1066 redirects DTS and DD LFE information to the Mains defined as large when the subwoofer is set to "NO".
The Left and Right Main outputs will go to your Subwoofer OR the x-30. The high-pass side will go to your Amplifier for your mains. The subwoofer will handle the low frequency information. (X-30 users will send the low frequency output to your subwoofer amplifier.)
This configuration will work for all modes except the 5.1 multi-channel input.
The downside of this arrangement is the extra LFE information bundled with the L/R mains. The crossover will only send LFE information below the cutoff frequency. The Mains handle any LFE information above the cutoff frequency.
The other issue is the debate of use of a subwoofer for music if you have capable Mains. (In my case, the mains outperform the sub on proper tonal characteristics and impulse response for music.)
Hope this helps
Dre

 

[rodneyH]

actually wouldn't that send ALL Low freq info to the Mains and LFE to the sub as well-giving you double bass (but since you have it crossed over,it will only play what you have it set at)??

Maybe you should do the same set up, BUT put the mains as "small", then set the crossover at 60Hz (or is the lowest 40Hz??) (so in reality, it really isn't a very "small" speaker at all) and set the LFE as yes??

 

[Dre J]

Rodney,
No. Please read the
Link Removed and the Rotel RSP-1066 plus Outlaw ICBM Bass Management Fix Report
in my original post. The links are there. After reading them You will understand why this works. The Bass Max issue is with the 0.1 channel. This channel is eliminated in the configuration I've proposed.
Dre

 

[Bill Blank]

The best thing for Rotel to have done would've been to provide fully independent setups for each input. I can't believe that the 2-ch analog signal still gets sent to a subwoofer if one is connected (mine is not as of yet). I have main speakers that have very usuable output down to 31.5 Hz and I'm going to have to "work-around" Rotel's oversight! That's a shame and I'm sure there's nothing a firmware upgrade can do to solve the problem.

The only thing I need a friggin sub for is HT which I'll use 20% of the time!

At $1500 I thought I'd gain flexibility over most $500 receivers but that's obviously not the case. "2-CH DIRECT" should be EXACTLY THAT, NOT 2.1!!!

Bill

 

[rodneyH]

bill, I agree, In the meantime, I just set my 2 channel analog input Subwoofer level to the lowest DB possible, I can bearly hear it/if I hear it at all. btw, I listen to a lot of 2 chan

 

[Dre J]

Bass Management for the LPCM, 2-channel analog inputs, and the 6.1 Multi-channel analog inputs are not fixed as of yet. It is broke for everything but the DSP modes.

I thought Rotel said this was a Priority.

I'm starting to feel cheated with a device that does not meet the features outlined in the manual.

This is becoming very disappointing.

We were told that this defect would be a priority. However, the lack of response indicates this issue will not be addressed because they are not willing to take care of customers that have invested in one of there product offerings. I am beginning to think that I have been told a lie to pacify my displeasure with the bass management.


I'll be happy to talk to anyone at Rotel, again, about the broken bass management controls.

Dre J
e-mail: ill-dre (at) fuse (dot) net