Rotel 1560 audio calibration issues

[grit]

I'm trying to calibrate my 5.1 Era speaker system, powered by my Rotel 1560 and sourced by my Oppo BDP-83 bluray player. All interconnects are quality HDMI cables.

I've used the Rotel test tones as well as the AIX audio calibration bluray, measured on my trusty Radio Shack SPL. Here's what happened:

The two source materials give wildly different calibrations. The AIX bluray has me lower the center and raise the rest. The Rotel has me drop the fronts by 1db and increase the rears by 1db. The sub... is a real problem. Keep reading.

When watching either TiVo (i know its a different source) or a movie via the Oppo, the AIX makes the center channel sound much lower than the rest. Unfortunately, the Rotel calibration creates another problem - subwoofer balancing.

The sub can be used with either the built-in crossover, OR it can be bypassed and let the Rotel set the crossover. Nifty. Unfortunately, Rotel does NOT obey its own crossover information when playing the test tones. Thus, the sub measures around 85db while the center measures around 65db. I tried activating the cross on the sub, but I'm not convinced this is the best way to measure the sub, since its really only getting LFE info and 80Hz and down. I'd think a dedicated, 40-120 Hz signal would be best for measuring it rather than the Rotel pink noise.

So, what I really want to know is if someone can recommend a good audio calibration disc with a dedicated LFE channel track. I'd really prefer the Dolby and DTS HD audio tracks for this. The AIX disc seems perfect on paper, but the results don't sound properly balanced at all.

[carlsen]

funny thing about that centre channel

I cant recommend a good test disc, but after I calibrated my system using the rotel test tones and an audio meter, I found the centre channel to be way too low. Now, my center channel is exactly the same as my main fronts, its 220pounds in weight and over five feet across ( the mains five feet high of course ), so with exactly the same speaker subject to the same test tone it rally surprised me that the volume would constantly come out so low in real world viewing experience.

This was the same whether I used a dvd player ( rotel ) or my bluray ( pioneer ). The centre was just too low. I havent got around re-calibrating the unit until I figure out a better way to do it but I do use the temporary calibration reset buttons on the remote to boost the centre now every time before I start viewing. Not sure but I though I read somewhere else about someone mentioning the centre soundin glow even after calibration with their 1560. Wondering if anyone else has experienced this?

[grit]

I've got a little more insight now, and I suppose, a different question.

First, for those of you playing with your 1560's calibrations, you might want to pull the power plug on your receiver. I finally had an issue where the subwoofer only worked with the Rotel test tones, then not at all. A quick pull of the power plug fixed the whole thing. I first tried just turning the receiver off via the power switch, but that didn't work. Probably just a firmware glitch.

After "rebooting" the receiver, the two calibrations were relatively close (off by +/- 1db). However, the sub was still WAY off. I figured out WHY, but not which is correct.

The Rotel built-in test tones are closer to being a full-spectrum test tone. The AIX LFE channel test tone is probably a 80 Hz (or similar) sound. To balance the Rotel test tones out, I turned ON the subwoofer crossover, so only sounds 120 Hz and lower were processed.

So now, the two tones were closer in frequency. However, the AIX disc and Rotel are still off by over 10 db. So which one is correct? My guess now is that my room acoustics are creating a null zone for the 80 Hz range or, making frequencies above that sound louder. Any suggestions on how to test for this?

[madmac]

Re: Calibration and test tones

Hello,

Firstly, I would absolutely go with the Rotel test tones. Hearing is very subjective so once done, do minor adjustments to you're personal taste if only absolutely nesessary . Secondly, I recommend doing any sub adjustments using music as a guide rather than movies. Jazz is a good choice because the bands are usually minimal and the bass is defined. Set the sub volume so the bass sounds real and does not dominate the sound. Once done, the bass intensity via the sub is by and large correct for all sources. Also, be advised that the Rotel allows you to customize the sub volume for EACH source so if you like more bass for movies for example, this is easily done in the sub menu.

I would always advise a SPL meter and using the Rotel pink test tones. SPL does not lie and if it is telling you that your speaker volumes are properly calibrated, I would advise by and large that you stick with that because it is truly correct.

It's kind of like being in a band and each person has their own idea of what is in tune and using their ear to tune their instruments. NOT A GOOD IDEA!!. Tuners do not lie....neither do SPL meters !! Ears do because everyone has their own bias in regards to sound!.

[ray5]

I cant recommend a good test disc, but after I calibrated my system using the rotel test tones and an audio meter, I found the centre channel to be way too low. Now, my center channel is exactly the same as my main fronts, its 220pounds in weight and over five feet across ( the mains five feet high of course ), so with exactly the same speaker subject to the same test tone it rally surprised me that the volume would constantly come out so low in real world viewing experience.

This was the same whether I used a dvd player ( rotel ) or my bluray ( pioneer ). The centre was just too low. I havent got around re-calibrating the unit until I figure out a better way to do it but I do use the temporary calibration reset buttons on the remote to boost the centre now every time before I start viewing. Not sure but I though I read somewhere else about someone mentioning the centre soundin glow even after calibration with their 1560. Wondering if anyone else has experienced this?

Same experience here but with a Rotel 1570. Mine is 2db higher than the Fronts. I used to do it on the fly as needed but I saw that I consistently did so then went into the menu and now that is default. It works fine now.
Also, after I changed my amps from Rotel to Classe the vocals became clearer and the bass tighter. I am not a audiophile and noticed the difference.
Ray

[madmac]

Strike me dead if I'm wrong but, don't Rotel amps use Classe amplification components?.

[srb]

R.I.P.

Steve