Understanding why this is important

During the sub calibration there are two tones. One is a higer frequency while the other is bass. So what bass in this case? A,B or C? As far as I can tell, my receiver sends the same bass signal to the mains as it does the sub for this test. This is regardless of if the mains are set to large or small. I can get the lw test tone to match the high one but only if I turn the 'Cinema EQ' feature off on my receiver. For some reason, the Cinema EQ feature on my Kenwood VR507 receiver, renders this sub matching test useless. My receiver manual does state that there will be no LFE sent to the sub with the front speakers set to large, however if it is in Cinema EQ mode than the sub will be used. I like the large mode better because my cheapie Aiwa 8'' doesn't sound as good alone as it does accompanying the 12" woofers in the mains. Anyway, I concluded that I can't get the front left to match the sub with the Cinema EQ mode enabled. I can with it off. However the overall sound is terrible with Cinema EQ off. So I decided to just calibrate the bass tone to 85db (+10 over my other channels) During the frequency sweep on the sub set up, with my fronts set to large and cinema eq set to on, by sub and and the woofers in the mains seem to be carrying the same signal until it hits the crossover frequency at which point, the sub takes over. Does this sound right? It seems to be what is happenign with my setup.

Larry, many on here have said that you should calibrate your system at a given volume or "reference" level. Most have also said that you should stay at this reference level to be assured that all channels are still matched. I thought that if you strayed from this volume setting, that your channels are most likely no longer matched. For example, if I calibrated all of my channels to 75db at a volume control setting of -27db, than I should always have my overall volume set to -27db while viewing a DVD. You are saying that I could set my volume control 10db higher to -17 db (this is how my volume control works, #'s get lower the louder it gets with -00 being the lowest and 00 being the max.)and I would now be listening to 85db. Isn't this contrary to what most people preach on here?

Think, I was suggesting that the channel matching difficulties you began this thread with might be helped by boosting the five channels to the 85dB you could bring the sub level to, then reduce the main volume, THEN get your 75dB overall level. I was trying to help you with channel matching, not overall volume level; that's a personal preference. You should calibrate at the volume at which you will be listening.

In other words, boost the other channels to match the sub, then reduce your main volume knob to, if necessary, -37dB, which will give you back the original 75dB overall (assuming your knob's dB markings are accurate).

Also, the 75dB reference level is not an 'etched-in-stone' mandate. It's a suggested target for those looking to get a movie-theater envoironment in the home. It certainly does NOT mean that you can't set the volume to a level that suits your own ears and the material you're viewing.

Most quality equipment will maintain channel-matched tracking when varying the main volume, so an initial channel calibration should not need to be redone just because you change the volume. However, if you move speakers or furniture, or something that will change the relationship between your speakers and ears, then you should recalibrate.


Larry
www.fineelectricco.com



This message was edited by Larry Fine on 12/17/01 18:42.01.

Thinkly,

First, always bear in mind that goal number one is to make the system sound good to you, regardless of technical standards. With than in mind...

Let's talk about Kenwood Cinema EQ for a second. The Cinema EQ setting is designed for Small front speakers. (I'm quoting from their brochure entitled Home Entertainment 2001-2002) "Cinema EQ Mode Delivers Powerful Sound With Small Speakers. When using small spekers, it's difficult to reproduce low-range sounds, particularly the rich, deep tones required when watching movies. No problem. Just switch on the Cinema EQ mode, and mid- and low-range frequencies are boosted to provide a dynamic sound that's balanced with subwoofer output for more movie viewing fun."

So, we've found the culprit, as you already guessed. With Cinema EQ enabled, the Kenwood is sending a boosted mid and low freq to your main speakers, including the Avia test tone. To make it worse you are sending the boost to Large speakers with 12" woofers, so your bass is REALLY emphasized! No wonder you couldn't get the 8" sub to keep up...

You'll have to keep Cinema EQ off while setting the sub's level. Theoretically, it should be kept off all the time anyway since you don't have small front speakers. But that's only the theory, do whatever sounds best to you.

In reference to your "frequency sweep" observation: If your mains are set to Large, there is no crossover freq at which the sub "takes over". The mains are full-spectrum at the large setting. However, since the signal to the subwoofer (a) consists of bass from all the channels not set to Large (b), plus the low bass from the LFE channel (c), that's a lot of signal. It may very well sound louder to you during the sweep than left and right mains which are each only carrying one personal channel bass signal.

Finally: At the risk of boring you, let me re-emphasize Larry's post about overall volume level. The suggestion to balance at a high level and then reduce the overall volume was an attempt to address your specific problem with "too much subwoofer." You will normally want to match the speaker levels at the overall volume level you want to use when listening! Watch the Avia disc's tutorial on listening at reference levels again, it's got good stuff.

Regards,

-Bruce

This message was edited by Bruce Burson on 12/18/01 05:27.46.

Thanks a lot guys. It is nice of you guys to bend over backwards to help a rookie. I appreciate it. I will try and experiment with the Cinema EQ turned off. One last question. Guy Kuo from Ovation is quoted in one of the above posts saying, "During the calibration of your subwoofer level, you usually don't have an ability to independently adjust the strength of bass coming from each main channel. This can mean that you find the SPL reding of subwoofer tests vary depending on which channel is being tested. The most common reason for this is a difference in how the bass is being processed (one channel is large while the other is small). Since you can't independently adjust each, it is reasonbable to either average for the front three channels or simply concentrate on gettng the front channel right since that one carries the most work in a movie soundtrack."
Is he talking about the center channel speaker when he says "front channel"?

Think, yes, the 'front', singular, would mean the center, as in dialogue, as well as music and sounds common to the front mains, unless the discrete mix intentionally excludes any of this from the center channel. That's one of the 'advantages' to discrete multi-channel sound.

have you ever noticed the gross difference in center-channel output when listening to music, and switching between 'stereo' and 'pro-logic'?

Larry
www.fineelectricco.com

Ok, Just spent a couple of hour playing. I have come up with yet more questions. I take your advice Bruce to use settings based on preference, however, I want to have every thing set to specs or at least as close as possible. The Cinema EQ mode sounds great, maybe too great. With this mode enabled there seems to be more mid range frequencies played whereas with it off there seems to be more highs and lows. I presently have my system set up with ALL speakers set to normal and the sub on. I have all levels set to Avia's standards. Am I now more pleased with the sound? I am not sure... I am pleased knowing it is calibrated correctly. It is just a different sound than before. I conclude that if you intend to run any reciever in Cinema EQ mode than you should toss the Avia DVD out the window if you want to use it to calibrate audio. With Cinema EQ enabled it is impossible to match the individual channel levels with the sub. For example, on the left channel the bass was always too high. The center channel had no bass at all. The right was like the left and the surrounds had no bass like the center. Would it be fair to say that the Cinema EQ mode would be more suited to someone that didn't calibrate their system with the Avia CD? Would it also be fair to say that it is 'better' to calibrate everything to the Avia CD standards than to use something like Cinema EQ which appears to be a mode in which frequencies are distributed in a manner intended by the manufacturer to compensate for average home theater weaknesses? I understand that the term better is subjective, but my goal is to most accurately duplicate a movie theater in my home. Hence the term, home theater. ;) I know people that turn their rears up as loudd as they will go just because it seems like a novelty to them to show their friends, "hey look i have sound coming from the back of my room!" To them that sounds "better" than having them set to Dolby specs. I compare this to using Cinema Eq where my sound is more attention getting, but my sub is never matched to my other speakers because I am unable to calibrate it in Cinema EQ mode. What do the pros think?

Think, my opinion is that the short answer is: non-EQ'd setting is 'more accurate', whether it pleases or not.

Larry
www.fineelectricco.com

IMHO: Well, I ain't no pro, but... You're pleased that it's calibrated correctly. Me, too! It's a great feeling when I finally got mine all put together. Then, I use that as the baseline and start playing.

To paraphrase Larry's comment, any deviation from that calibrated baseline will not be as technically accurate. But just as I didn't calibrate at 85db because I don't listen at 85db, I may decide to play with the tone controls, too. So if I decide to turn on the loudness contour, or compress the signal, or boost the midrange with Cinema EQ, whoopee! Whatever sounds good. And, of course, I can always return to my baseline whenever I like.

So don't throw away the Avia. Use it to calibrate your system (with Cinema EQ off, naturally :) just so you get the good feeling from the knowledge that it is technically accurate. After that, put the Avia away, stick in a movie, and have fun tweaking.

BTW, Now that it's calibrated, do you want to start ripping things apart and rewiring them again (grin)? Here's how I finally ended up configuring my system, which is similar to yours (better woofers in the mains than the subwoofer has). I have no dedicated subwoofer anymore. I'm now using the subwoofer as part of a satellite-subwoofer rig with my L&R Surround speakers, with the sub poitioned behind the listener. So, "Subwoofer Off," "Mains Large," "Center Normal," "Surrounds Large"(sat-sub), "Rear Surrounds Normal." The mains are reproducing all the front bass, any bass on the surround channels is coming from the rear of the room, and I cannot tell by listening where the LFE is (but the room is shaking, wow!)

-Bruce ;-)

This message was edited by Bruce Burson on 12/19/01 10:34.22.

Shouldn't I calibrate it with Cinema EQ on? If I calibrate it with Cinema EQ off and then switch it on and go back and check the 5 channel matching, than I find my center and surrounds are way off. They are off as much as 5-10 db each. I can match all of the five channels in Cinema EQ but not the sub. It seems like it is like this.... I can either have the five channels matched or I can have the sub matched or I can have everything matched and turn the Cinema EQ off. It just lacks a lot of the punch that it has with Cinema EQ on. I am trying to contact Kenwood and get a more thorough explantation of what Cinema EQ should be used for. It is almost like I wish it wasn't ever thought of. If it wasn't on my receiver I most surely wouldn't miss it and everything would be calibrated correctly. However, now that I have heard it, I like it. All would be well if I could just get the sub matched. It seems a little boomy in this mode but it seems very 'drab' with it off. With it off there is like no mid range and little bass. I have tried to raise the level of my other channels and simply reduce the overall volume, but I can never catch the bass tone on the Avia disc. For example if I raise my left front to +10 db than my bass tone seems to rise proportionatly. One last question. When using the sub matching software provided by Avia. What specifically is on each tone? More specifically what is on the bass tone? I know that this has already been addressed here but I still am not clear. On the bass tone is there bass from only the specific channel being tested and is the LFE also present? Or is this only LFE? I think this would be a lot easier to understand if it weren't for the way that Cinema EQ effects my setup and subsequent tests.

Shouldn't I calibrate it with Cinema EQ on? If I calibrate it with Cinema EQ off and then switch it on and go back and check the 5 channel matching, than I find my center and surrounds are way off. They are off as much as 5-10 db each. I can match all of the five channels in Cinema EQ but not the sub. It seems like it is like this.... I can either have the five channels matched or I can have the sub matched or I can have everything matched and turn the Cinema EQ off. It just lacks a lot of the punch that it has with Cinema EQ on. I am trying to contact Kenwood and get a more thorough explantation of what Cinema EQ should be used for. It is almost like I wish it wasn't ever thought of. If it wasn't on my receiver I most surely wouldn't miss it and everything would be calibrated correctly. However, now that I have heard it, I like it. All would be well if I could just get the sub matched. It seems a little boomy in this mode but it seems very 'drab' with it off. With it off there is like no mid range and little bass. I have tried to raise the level of my other channels and simply reduce the overall volume, but I can never catch the bass tone on the Avia disc. For example if I raise my left front to +10 db than my bass tone seems to rise proportionatly. One last question. When using the sub matching software provided by Avia. What specifically is on each tone? More specifically what is on the bass tone? I know that this has already been addressed here but I still am not clear. On the bass tone is there bass from only the specific channel being tested and is the LFE also present? Or is this only LFE? I think this would be a lot easier to understand if it weren't for the way that Cinema EQ effects my setup and subsequent tests.

Think,

Reference "Shouldn't I calibrate it with Cinema EQ on?" I think you answered your own question: "I can either have the five channels matched or I can have the sub matched or I can have everything matched and turn the Cinema EQ off."

What's your priority? If you want to be technically accurate, you have to use the Avia test tones as designed: That is, with all settings as flat as possible. You will have to keep the Cinema EQ turned Off during the calibration process. That's the way it is. And don't bother trying to check the calibration matching with the Cinema EQ On later, it will never match. It's not DESIGNED to match that configuration, only an "untweaked," flat setting with no special additions from your receiver. If you want to be "technically accurate," you're there!

What that setting actually SOUNDS like is another thing. If your goal is to have a system that sounds good to your ears, stop worrying about technical accuracy and start playing with the buttons and knobs.

If you sometimes want one or the other, or you want to compromise between the two ideals, do what I suggested earlier: Start with a fully technically accurate calibration. Afterwards -- with full knowledge that you are now deviating from "technical accuracy" -- then change anything that you like until it sounds good.

BTW, many people don't like the flat response. It's not like you are alone or anything.

-Bruce

This message was edited by Bruce Burson on 12/19/01 11:32.50.

I'm new to HT. Can you tell me exactly what the AVIA CD does. Is this something I should get for my HT system? If so, where do I purchase this CD and what is the cost? Thanks!!

On 12/11/01 12:28.49, Thinkly said...

Bruce,

What is the brand of your sub and your mains? What is your power source for the mains? Just curious as I have not seen many mains that can keep up with a good sub in terms of bass reproduction and level....Tony


Happy Holidays!!

Hackney,

The Avia test dvd is a top notch audio/video calibration device for home theatre. IMHO it is a must have for the serious installer/tech head or homeowner that is interested in their technology. It will DEFINATLY make your system sound and look MUCH better than it does now! Actually, the video tweaks are extremely easy to learn and master and will have your TV looking like film instead of video in about 1 hour of tweaking time.

Get it now and don't delay, it's the best 30 bucks I've ever spent. Get it at amazon.com or go to www.ovationsw.com and check it out!