RSP1098 test tones

[DrBoom]

Just got my first 2 Rotel components, namely an RSP1098 and an RMB1075.
Very happy with both, even though they are severely being limited at the moment by my cheap Yamaha speakers which will be replaced with B&W (800 or 700 series) very soon.
Only 1 thing i can't get to work, the speaker calibration !
Every time i run the testtones i get different results, very incosistent.
I'm using the RS analog SPL meter, which has always proved me right, but this is getting downright ridiculous.
If i use the 75 dB calibration, setting all channels to 75 dB, i get almost NO subwoofer output what so ever, even though the speakers are set to small, sub to Yes and crossover to 80 Hz.
Then, i have to turn the sub up at least by 10 dB to get it up to speed with the rest.
The left speaker is at like + 6 dB, while the right is at 0 dB or vice versa, and the sound obviously comes from the left side, not in the center where it's supposed to be.
So either the testtones of the 1098 are horribly wrong, or there's something really wrong with my SPL meter :roll:
I'm going to borrow a Platinum DVD tomorrow, and see if that sets things right.
If not, i'm in the market for a new spl meter

[aud19]

Welcome Dr. Boom I wish it was under better circumstances though....

To start with I'd recommend a set-up disc like AVIA or Digital Video Essentials to fine tune the system with.

Does your subwoofer have it's own volume knob? (Most do.) I think it's preffered to leave the sub level set at "0" in the pre/pro and adjust the volume on the sub itself. If you have the volume set very low on the sub itself than no matter what you set it at in the pre/pro you will get low output.

Hopefully these suggestions will get ya on the right track

Jason




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[skipm]

Boom-

I've calibrated my 1098 with the internal test tones and with Avia and VE and in every case the channel levels were consistent except for the sub which actually was consistent, it was just consistently 8 to 10 db lower on the internal tones than with Avia and VE.

If I were you, and knowing what speakers you currently own, I would just use the internal tones and calibrate to 75 db except for the sub which I would increase to 8 to 10 db, whatever sounds more natural to you. You also know that with the 1098 you can adjust the sub level based on surround mode, which is really cool. Tweak it up for DD, a little lower for DTS, a little more for multi-channel, that's what I do. And then I would start saving my money for those B&W speakers. That will be one sweet sounding set up.

-Skip

[DrBoom]

Hi guys,

well yeah, like every other active sub mine has a volume control, but the thing is (and always has been) i have to set it all the way down, or it's out of range to further tweak with the level control on the 1098.
My guess, it's a very high gain subwoofer amp in the B&W ASW650.
And it doens't have a 0 setting, no numbers or lines what so ever.

Skipm, i think you're about right with the 8 or 10 dB shortage of bass.
Sounds like it's somewhere in that region.
Seems the normal channels are pretty consistent now, must've been tired or too excited yesterday so i screwed it up

One more thing, i've borrowed a Platinum Ultimate DVD for setup of the channels, but how do you permanently adjust the levels without going in to the test-tone menu on the 1098, thus activating the internal noise generator ?
I mean, i'm using the DVD test tones, then i want to correct the level to the appropriate setting, so i have to go into the test-tone menu where the levels have to be set right ?
The the sound from the dvd is cut, and the internal noise generator is started, so how am i supposed to do this thing ?
If you ask me, they should've put an on/off switch in that menu for the noise generator and allow you to change levels without that thing starting up.
Or is there another way ?

Kevin

[aud19]

Having the sub set all the way down can't be the answer. You should be able to set it to "0" at your pre/pro adjust the volume on the sub itself until it's at 75dB. This either requires a second person to adjust the sub volume while you sit in the main listening position with your spl meter or a lot of you getting up and down. Once you've got it set at the proper level then you can go set the sub levels for the respective surround modes + and - as Skip stated. Maybe -1 for DTS +1 for DD etc.

As for the internal test tones....I agree it's a bit of a pain not being able to turn them off when using a calibration disc. What I ended up doing was taking a reading based on the test disc and then noting that the level was either high or low would then go into the internal tones and raise or lower the level by a noch or two in the pre/pro and then go back and double check the settings on the disc. A bit of a pain but I don't think I had to go back and forth more than twice.

Jason




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[DrBoom]

I can't help but to think that Rotel configured it's subwoofer noise level too low.
One of the first software updates corrected the entire noise generator from - 23 dBFS to Dolby's standard - 30 dBFS which gives you a 75 dB calibration and with movies results in 105 dB maximum (0 dBFS).
One would start to think that they did the same to the subwoofer level, and set that to - 30 dBFS too, instead of the required - 40 dBFS since the peak level for a sub in a movie is 115 dB.
So in order to set the levels correctly, the test tone level for the sub should be 10 dB lower then the other channels, and normally we wouldn't have to worry about it because that's the way it's supposed to be.
Maybe Rotel requires you to calibrate all speakers to 75 dB and the sub to 85 dB ?
But I find that quite confusing, as with other receivers all speakers and the sub are calibrated to 75 dB, because of the 10 dB lower level of the sub test.
Did Rotel get sloppy here when programming the levels ?
Do they require you to set subwoofer level to 85 dB ?
Am i going nuts or are my perceptions of channel level calibration dead wrong ?

Has anyone else ever had this problem, or thought about it ?

[mazuly]

Hi,

I actually use the internal tone generator of the 1098 since the results I get are very close to results obtained using AVIA disk. I am not sure about the sub problems since I don't have a sub, but maybe I can help with the level setting using something like Platinum DVD or AVIA.

1) Set all the levels to 0 in internal tone generator.
2) Use the Platinum DVD to produce the test tone for you.
3) Adjust volume level until you read 75 dB on your left channel. Write the volume number down for reference.
4) Now adjust the center, surrounds and sub using the "Guide/CTR", "Search+/Sur" and "Search-/Sub" on the remote. Make sure you don't change the input or all those values are gone.
5) Copy those numbers to speaker setup menu.
6) Check those numbers with internal tone generator to see what kind of numbers you get and that if they are close enough. Make sure you set the volume to the number you wrote down before.

The only problem is that you can not adjust the right channel this way, but I have rarely needed to change this since the speaker setup for left and right is symmetrical and therefore you should be reading the same value for both. In my case they are usually off by less than a dB which I live as is.

Good luck,
Maziar

[Scarp]

I never had any problems with setting up the B&W ASW650 that I used to have. I usually had it set to a quarter to a half way.

My way of calibration I always used with the 1066 (and also 1098):
1) With the front left set to 0, turn up the volume (with the volume knob) of the Rotel until you get 75 dB.
2) Then adjust the other speakers to 75 dB also.
3) With the sub set its volume (with its own volume knob) at the lowest first and on the Rotel to 0 dB. The gradually increase the volume on the subwoofer, until it reaches about 72 dB. Since subwoofer signal are hard to calibrate it might be that it will fluctuate quite a lot. Thats why its best to leave some headroom. I think usually its prefered to turn up the values in the Rotel before turning up the volume on the subwoofer. So play around with +5 dB on the Rotel. This will leave you with enough headroom for a some lower volume or higher volume.

[DrBoom]

Scarp,

i did everything exactly the way you described it as this is the way it's supposed to be done
Started with left front, set at 0 dB, turned volume up to 75 dB, corrected all other speakers to 75 dB including the sub.
So there it is, playing a 75 dB test tone.
Next, i turn on some music, and the bass is at least 8 dB too low.
This is easily verified by switching the speakers to large, which gives me a lot more bass than with the speakers to small and bass redirected to sub.
I don't think i'm doing anything wrong, so i'm still not quite sure what's causing this.
Any way you turn it, the calibration level doesn't correspond with sub level during normal operation at all, no way that setting it to 75 dB is the correct value at this moment.
If i had to guess at the correct setting, i'd say 82 - 85 dB.
So that's pretty much the same thing as Skipm said, at least i'm not the only one.

[Andrew Pratt]

I've noticed the -10 dB LFE change as well.

[Scarp]

From what I heard and know, subwoofer are difficult to read out correctly. So that you dB meter reads something lower isn't a big suprise to me.

Otherwise I suggest setting it up more or less correctly and then modify from your own experience when listening to it. If the sub is too prominent it should be a bit lower, otherwise turn it up a bit.

Btw, you have the latest firmware?

[DrBoom]

No it's not the dB meter, because it has always been accurate, and the sub hasn't moved from it's location where it's always been.
So there is definitely something wrong with the test tones, and i'm gonna find out what it is too !
First thing on my list, email to Rotel, have them verify that the level is correct.

[Azeke]

I utilize 75db Rotel test tones for the speakers and 85 db for the Sub test tone, this is when Andrew and others first discovered the Sub level tones were incorrect on the 1098. My theory is that Rotel calculated the Sub test tones at 85 db and the others were calculated at 75db.

Just my quick thoughts,

Azeke

[DrBoom]

OK, i'm actually glad it's a known bug, would've been weird if i was the first guy to hear it
But if it's that well known, and has obviously existed throughout numerous software updates, why hasn't Rotel changed their manuals yet ?
They clearly state, and I quote: "Then, use the individual channel adjustments on the TEST TONE menu to adjust each of the individual speakers, including the subwoofer, to the same 75dB on the SPL meter."
Even the online version of the manual says this, the least they could do is change that one.
Or just plain fix it, to work when you calibrate everything to 75 dB.

Anyway, i'm very curious as to what Rotel's reply to my email will be regarding this "problem".

It's not a problem we can't overcome, but let's say you're an inexperienced user who happens to stumble upon Rotel (not likely but it could happen ), you follow the manual, and you're stuck with mediocre bass output all your life ???

Oh, one other quirck that i've started to notice, but i'm not sure if it's the 1098's nature or the interconnect i'm using.
It tends to have a slight echo or delay in the sound, doesn't matter which source, analog or digital, 2-ch, DD or DTS.
Sounds like a DSP program but it's in normal 2-ch mode as well.
I'm using the Van Den Hul D102 MKIII Hybrid as interconnect between the 1098 and 1075, and one 1 occasion i've read a review describing just this event with this particular cable.
So anyone else hearing a slight echo with the 1098, or is it just my cable ?

Thx

[Aussie Geoff]

Hi,

I've finally got round to testing my RSP 1098 (late November build) and the Sub level as per the Test tones exactly matches the DVD Platinum Test level (i.e. not 8-10 db down as experienced by some other users).

Now - here is a theory for you (as a software engineer at heart!) - Separate from the 1098 firmware there is processing code for the Cirrus DSP (Digital Signal Processor) at the heart of the 1098. Some RSP 1098s have DSPs with ( I think) V3.1 of the DSP code while others newer models have V3.2. For a while some of the beta firmware (1.1.5 I think) only worked with the V3.2 DSP code. They seem to have fixed this with the issued 1.1.6 firmware which (apparently) works with V3.1 or 3.2 DSP code. Anyway it would be easy for the firmware to provide correct test tones or bass levels with one version of the firmware and 10db out with the other. Especially as the relative levels test tones for the Sub need to be 10 different from all the others to meet Dolby specs where the sub reference level is 10db higher for the same encoded signal level to give more bass headroom.

Just a theory - but may well explain the apparently totally different results experienced by some RSP 1098 owners over the same setting.

Geoff Costello

[apotts]

I borrowed a dealer 1098 (see 1098 popping thread) and it was an old model (Aug 03) with 1.1.5 software, and it did indeed have this bug. But how about setting the sub using a better method.... your ears! Worked well for me.

I do have a question for the experts though. My sub (B&W ASW675) has an auto-power-on feature that is not very sensitive. It annoyingly switches off when listening at normal-quiet levels. So what I do is set the sub output on the proc to MAX and turn the sub volume knob down. No problem. But in the old analogue days, you always used an EQ to CUT levels, since increasing could distort. Does the same apply now? I guessed not (since why would Rotel have a setting that could distort the sound), but am I worrying about nothing?

[akopperl]

Does the -10db LFE change occur for all formats or just music? I was curious because I thought some formats have a +10 db boost for the LFE channel. In other words, if Dolby Digital boosts the sub 10 db - is the sub level correct for Dolby Digital and just too low for music.

Thanks.

[DrBoom]

I'm sure it affects redirected bass, and i'm reasonably sure it also affects LFE.
The redirected bass deficit can be easily heard by calibrating everything to 75 dB, set speakers to small and use a sub.
Listen to the amount of bass for a few seconds or minutes (or as long as you need) then switch the speakers to large and note the whopping difference
If i'm correct, there shouldn't be any (or not much) difference between a small speaker with sub, or a large speaker without sub in terms of bass quantity if properly calibrated.

As far as the LFE is concerned, I have the HT Tune up DVD at home, which I also used as a calibrating tool.
Now, the thing i'd need to know is if the "Subwoofer level" test is based on a pure LFE signal on the disc, or just a bass signal that's redirected through the Rotel's bassmanagment.
Too bad the HT Tune up DVD doesn't offer plain PCM stereo signals to adjust the redirected bass, but only DD and DTS test tones.
I have noticed that there is also a difference in DD and DTS tones, since I have to adjust the DD sub level to +1 dB, and the DTS to -3 dB but i guess that's normal.

Ofcourse if any format were to boost the LFE by 10 dB, where it shouldn't be boosted, then it will compensate, but that's like 2 wrongs making 1 right

[Aussie Geoff]

Dr Boom (and others),

It turns out I too have the LFE Issue! However I didn't realise it before (for reasons I'll explain). I also actually think it's a bass level issue NOT a test tone issue. That is I think the test tones are right but the actual LFE sub output is calculated wrong and is too low!

Net version: When I got my RSP-1098 I found that I needed to turn my sub volume way up (well past 3/4 If I was to run at 0 dB on the sub). I didn't like this much gain on the sub so I set my RSP-1098 Sub Level to Max (+10 db) and calibrated on that. I got a good relative match for the Aria DVD Platinum and the Test Tones, except that the volumes were different (75 db on the test tones is about 82 dB on the DVD).

Recently I decided to recalibrate my system and thought I'd try the RSP-1098 Sub Level of +0 dB again. Adjusted my sub volume control up and I was fine by the RSP-1098 test tones (75 dB all round). Did some listening and no deep bass!. Tried the DVD test and found I was -10 db on the sub.

Now I can crank up the bass either with the Sub’s volume control OR the RSP-1098 Sub level. It turns out that (for me) the difference in sub volume between the RSP-1098 Test Tones and the DVD relates to the difference in relative volume. For example, if I calibrate at +2 dB on the RSP-1098 Sub Level and adjust my sub actual volume to be perfect bass on the DVD, the RSP-1098 test tones show +8 db high. Conversely if I use the RSP-1098 test tones on +2db on the Sub Level and adjust my sub volume to be perfect on the test tones, then the bass on the DVD is -8db. I tried +4 db and got a 6 db mismatch!

You can fix the bass issue by any combination of the RSP-1098 Sub Level and the actual sub volume and this get the right actual sub output. But at 0 Db on the RSP-1098 sub level, there is a 10 dB mismatch between the real sub volume and the sub level generated by the test tone.

This is starting to make sense (to me). The RSP-1098 is my 3rd processor with the same Sub. For the first time I have had to turn the level well up (nearly ¼ turn) to get the same bass as I always had at a fixed setting before. I actually believe the RSP-1098 Sub bass level calculations to be wrong and too low by exactly 10db (remember the 10db difference in reference level for the Sub under DD and DTS) – but the Sub test tones are at right relative to the other test tones.

One other item of interest – As well as DD, DTS etc, my DVD test disk has Dolby Surround on it (no real sub channel) but it does the Sub test tone to test redirected bass. This had exactly the same problem.,,, But the corrected Sub levels exactly matched those for DD.

Tomorrow I’ll try the DTS and PCM stereo on the test DVD to see if they too have the problem (which I suspect they will).

PS – Andrew – do you know if this is fixed in the next firmware?

Geoff Costello

[Andrew Pratt]

No all I heard from Rotel was to adjust the sub output to your taste or use a calibration disc. I just have mine set using an SPL meter and a variety of test tones that i was using for my BFD eq. unit and its about 10dB higher then predicted...but it sounds about right and since its a set it and forget it type setting I'm not that concerned.

[Aussie Geoff]

Andrew,

Thanks. I will report this as a fault formally through the Australian Rotel Distributors and see what happens....

It's not fair on all those RSP-1098 users without a DVD test disk or trusting the test tones and needs to be fixed.

Geoff

[DrBoom]

My thoughts exactly Geoff, if you don't have a calibration DVD and you trust the test tones, you're screwed.
And besides, they should make it a bit easier to use external calibration, just a little option to turn the noise generator off/on when accessing the Test Tone menu would do the trick.

[skipm]

Since I've found the 1098's internal test tones to be spot on with Avia and VE, except for the sub, I calibrate all channels to 75dB with my trusty SPL meter range set to 70dB. I then change the SPL meter's range to 80dB and calibrate the sub channel to 85dB. Perfect speaker calibration in 5 minutes or less!

I do agree in that I wish they would make it easier to use external test tones since everyone seems to have their favorite.

-Skip

[skipm]

Since I've found the 1098's internal test tones to be spot on with Avia and VE, except for the sub, I calibrate all channels to 75dB with my trusty SPL meter range set to 70dB. I then change the SPL meter's range to 80dB and calibrate the sub channel to 85dB. Perfect speaker calibration in 5 minutes or less!

I do agree in that I wish they would make it easier to use external test tones since everyone seems to have their favorite.

-Skip