[gregorio]

Yes. What I said applies to getting vaguely accurate LFE in a home. Vaguely...that's the trick.

Yes, it depends on how vaguely you mean by "vaguely". With an SPL meter most consumers would end up calibrating the sub out by 4 or 5dB and that's without any FR issues.

G

 

[bigshot]

Last night I tried subtractively applying the correction (-7dB to the mains, center and sub) It worked better because it put the overall volume level into the normal listening range I generally use. (It was hotter before and I had to lower the overall volume.) The Dolby track has the exact same problem as the DTS. I didn't have a chance to check the two singles (Penny Lane & Strawberry Fields) or the lossy version on the DVD. I'll get around to checking that this weekend. It turns out that I had the sub dialed back a hair because my dog was getting anxious during a horror movie the other night and I hadn't returned it to the saved settings. No need to raise the bass in the mix. It's perfect once the overall correction is applied.

The big news though is that the Kraftwerk 3D The Catalog box set arrived yesterday. It is the best multichannel mix I've ever heard. I don't have 3D or Atmos, but even flat with 5.1, it blew me away. The set consists of eight concerts shot in art galleries around the world where the band plays 8 different albums in their entirety. The video incorporates experimental computer animation in 3D and blurs the line between the band performing on stage and the synthetic environments in the computer generated backgrounds. Fascinating and very entertaining. I've never been a huge fan of Kraftwerk. They always struck me as Devo without a sense of humor. But presented in this context, it's clear they have their own unique vision.

However the most amazing thing about this set is the sound. It is totally immersive with elements that move around the listener in a circle, diagonally across the room and out into the middle of the room. The placement is absolutely perfect with no dips or bumps as the sound gets handed from speaker to speaker. I've heard placement like this as parts of recordings before, but this set uses sound field placement throughout the whole program. It's very dimensional. They play with synthetic ambiences too. Parts sound like a lid has been placed on the room and other parts sound like a huge cathedral. There is a 3D headphone mix too, but I haven't checked that out yet. Frequency response is all the way out to the edges of hearing, with super deep sub bass and mosquito sounds alll the way at the top. The dogs definitely got a plenty of special canine-only frequency content with this blu-ray.

The big box set is pricey, but there is a cheaper single disc version too. If you have any interest at all in new uses of home theater technology, you owe it to yourself to check this out. Unfortunately, I can't do Atmos because my listening room has a peaked roof, but I am tempted for the first time to upgrade my projector to a 3D model. Even if this is the only thing I have to play in 3D, it still would probably be worth it.

 

[bigshot]

I pulled out the trusty SPL meter and checked my levels this weekend. I was a little less than -2dB in the rears. So the imbalance is likely more in the range of 5-6 dB rather than 7.

 

[pinnahertz]

I pulled out the trusty SPL meter and checked my levels this weekend. I was a little less than -2dB in the rears. So the imbalance is likely more in the range of 5-6 dB rather than 7.

I've found many "trusty" SPL meters off by +/- 3dB (I own a calibrator). The Radio Shack meters, for example...not as trusty as one would hope.

 

[bigshot]

Then the best way to know for sure is to listen to it yourself and try some settings until you find the one that sounds right. 1 to 3dB is right around the just detectable threshold for differences in sound level in music, so it's as close as dammit.

 

[pinnahertz]

Well, the best way

Then the best way to know for sure is to listen to it yourself and try some settings until you find the one that sounds right. 1 to 3dB is right around the just detectable threshold for differences in sound level in music, so it's as close as dammit.

I understand what you're saying, but the "best way" is to use accurate measurement systems and proper technique to verify complete calibration of the room, including level and EQ. I don't use a cheapo SPL meter to do any of that, even though my meters are all calibrated. Measuring band-limited pink noise with an SPL meter of questionable accuracy and ignoring EQ won't get you there.

 

[bigshot]

I didn't spend $900 on my SPL meter, but it isn't a cheap one either. It cost about $70 (if you can really judge quality by price, which I doubt.) It does the job I need it to do.

The problem with audiophilia on both sides- the true believers of snake oil and the super-scientific skeptics- is that they both get totally lost in minutia. Horse sense is greatly lacking. Precision in calibration is a good thing, but it isn't the destination, it's just a start. Any real world listening room has strengths and weaknesses and balancing your compromises can emphasize the strengths and reduce the weaknesses. That means (gasp!) tweaking your calibration a bit. Precision is great if you have a perfect system, perfect speakers and a perfect room. But that's the domain of recording studios whose business it is to be in perfect calibration. At home the goal is a little different- to get the best sounding music possible in the space you live in.

I've seen people walk down this road before....

Your equipment isn't good enough > Your system is good but it can't sound good unless it's properly calibrated > The meter you used isn't precise enough > Your meter was precise enough but your room might be messing up your reading. Try EQ. > EQ is a crutch. You need to do room treatment. > Your room treatment didn't correct all of your problems. > It's impossible to be truly 100% calibrated. > I give up. I'll just buy more expensive equipment. (return to beginning)

I believe in a broad strokes approach. I take what I have to work with and I optimize it as best I can, addressing the big problems first. If you dive straight down to the detail level, you never get close to what you're trying to achieve. First things first. When it gets to the point where you're almost all the way there, sit down and listen to some music and remind yourself what your REAL goal is.

By the way, my system is VERY carefully EQed. That's the factor I'm most attentive to tweaking because it can make the greatest improvement. I've arrived at a very satisfactory compromise that makes the response at various points in the room as good as it can be- tempered by the capability of the 5 band parametric equalizer built into my AVR. Is it perfectly calibrated to one main listening position? Not completely, but it sounds good in my room in all the places people sit when they listen to music.

Good sound in the home isn't a strict formula or recipe. It's the art of balancing within the constraints of your particular situation. Absolutism is no fun and it doesn't get you the best sound either.

 

[pinnahertz]

I didn't spend $900 on my SPL meter, but it isn't a cheap one either. It cost about $70 (if you can really judge quality by price, which I doubt.) It does the job I need it to do.

I own several SPL meters, some about the same as yours, and one much more expensive. For rough level setting, any of them work fine. For calibration, none would be adequate.

The problem with audiophilia on both sides- the true believers of snake oil and the super-scientific skeptics- is that they both get totally lost in minutia. Horse sense is greatly lacking. Precision in calibration is a good thing, but it isn't the destination, it's just a start. Any real world listening room has strengths and weaknesses and balancing your compromises can emphasize the strengths and reduce the weaknesses. That means (gasp!) tweaking your calibration a bit. Precision is great if you have a perfect system, perfect speakers and a perfect room. But that's the domain of recording studios whose business it is to be in perfect calibration. At home the goal is a little different- to get the best sounding music possible in the space you live in.

Then there are those of us who have been trained as professional calibrators. We know about acoustic strengths and weaknesses, as well as compromises. However, the first tool is good data. You get that with precision measurements and proper measurement data processing (not just an SPL meter, and not just an RTA in the LP). I'm not going to take the time to outline the whole procedure, but I guarantee getting "lost in minutia" would loose me money, and so I don't do that.

But I can confirm that while a useful tool, the SPL meter is not what we use to calibrate systems.

I've seen people walk down this road before....

Your equipment isn't good enough > Your system is good but it can't sound good unless it's properly calibrated > The meter you used isn't precise enough > Your meter was precise enough but your room might be messing up your reading. Try EQ. > EQ is a crutch. You need to do room treatment. > Your room treatment didn't correct all of your problems. > It's impossible to be truly 100% calibrated. > I give up. I'll just buy more expensive equipment. (return to beginning).

Yep, I've seen that taken to extreme. How about a system built up with $400K of gear placed in the worst acoustic environment possible? Yes, I was there. The challenge wasn't in calibration (which was almost impossible), it was in convincing the owner of what he had to do next.

BTW, I've found there is no system...NO system...that cannot benefit from precision EQ. The trick is now you perform the analysis, and how you respond to it.

I believe in a broad strokes approach. I take what I have to work with and I optimize it as best I can, addressing the big problems first. If you dive straight down to the detail level, you never get close to what you're trying to achieve. First things first. When it gets to the point where you're almost all the way there, sit down and listen to some music and remind yourself what your REAL goal is.

Part of a good professional calibration is, in fact, listening to well known test material, and at several points along the way. We also start with broad strokes, but then use smaller and smaller brushes. The last tool is the recognition of the point of diminishing returns, and stopping short of hitting it head on.

 

[bigshot]

I can understand going to that degree for a recording studio that needs to be able to send work to another studio and have it sound exactly the same. But why would anyone need that sort of degree of precision to adjust a home stereo system? My AVR only has half dB steps and it's only a 5 band parametric equalizer. Even if I could get more accurate readings, how is that going to make any difference at all to the settings on my AVR? I feel like we're talking about two different things here.

To recap... I noted that the rear channel was way too low on the new Beatles 5.1 mix. You said I should eliminate the possibility that my levels may be set incorrectly. I did that. Now you say my SPL meter isn't accurate enough. I feel pretty safe saying that it's accurate to a dB or two. I need to calibrate my living room like it's a recording studio to be able to discern a 6dB imbalance? I can hear that clearly with my ears with no SPL meter at all!

I really should put this in my sig file. It's become a mantra in audio forums...

Your equipment isn't good enough > Your system is good but it can't sound good unless it's properly calibrated > The meter you used isn't precise enough > Your meter was precise enough but your room might be messing up your reading. Try EQ. > EQ is a crutch. You need to do room treatment. > Your room treatment didn't correct all of your problems. > It's impossible to be truly 100% calibrated. > I give up. I'll just buy more expensive equipment. (return to beginning)

 

[castleofargh]

I have this totally not professional definition that guided pretty much all of my audio adventure.
good enough: when it stops pissing me off.

^_^

 

[pinnahertz]

I can understand going to that degree for a recording studio that needs to be able to send work to another studio and have it sound exactly the same. But why would anyone need that sort of degree of precision to adjust a home stereo system?

The THX motto is "What the creators intended". To do that you need to have a system that matches as well as possible the system on which the original was created. That's not impossible, but you can't achieve that goal by picking your favorite speakers, dropping them in a room and setting levels with an SPL meter. Even if you EQ, there are a few additional significant things to do. Now, perhaps the typical home doesn't need to replicate "what the creators intended", but in this case you're making a qualitative judgement of what the creators did, and without much detailed attention to matching your system to the standard. We still don't know if their system hit a standard either, but one would hope....

My AVR only has half dB steps and it's only a 5 band parametric equalizer. Even if I could get more accurate readings, how is that going to make any difference at all to the settings on my AVR? I feel like we're talking about two different things here.

Equipment limitations are always a problem. You need to be able to respond to detailed measurements. The typical AVR can't do that just with 5 bands of parametric EQ, but some have way more than that, and there are other methods and external devices.

To recap... I noted that the rear channel was way too low on the new Beatles 5.1 mix. You said I should eliminate the possibility that my levels may be set incorrectly. I did that. Now you say my SPL meter isn't accurate enough. I feel pretty safe saying that it's accurate to a dB or two. I need to calibrate my living room like it's a recording studio to be able to discern a 6dB imbalance? I can hear that clearly with my ears with no SPL meter at all!

...and you calibrated your ears with an ear calibrator?

Please understand I'm not suggesting your observations are incorrect. I'm suggesting that without carefully matching your system the same standard that which the creators used, your conclusions could be in error.

 

[gregorio]

@bigshot out of curiosity, how are you calibrating your sub? What levels do you use?

G

 

[bigshot]

Gregorio, it's a 12 inch Sunfire True Sub by Carver. It came with its own built in calibration system which I used once to set it up. Since then, I've just adjusted level, not EQ. I'm not as concerned about EQ below 80Hz as I am in the core range like the upper mids. I just make sure that descending bass patterns that are supposed to maintain consistent volume level stay consistent- and they have. The hand off between mains and sub are nice and smooth. I pay very close attention to that.

Pinnahertz, I have absolutely no interest whatsoever in pleasing the creators. I listen to music for myself in my own house with my own equipment. I've had hundreds of people in my room to watch movies and listen to music and just about everyone has commented that it sounds better than what they hear up at Universal City Walk or at the Chinese, which I'm sure are THX calibrated. I've been to screenings at the Frank Wells Theater at Disney, and my system compares well to that. That's the room that inspired me to make a theater in my house in fact. My system was set up by one of the engineers who worked on creating the THX standard. He said he could certify it for me, but if I wanted that, it would basically be just paying for a piece of paper to hang on the wall. He helped me set up the room and choose some of the equipment. He got everything set up and balanced. It made me very happy and I didn't have space on the wall for a certificate so I skipped that. About a year later I had an engineer friend come by with his test equipment and run tone sweeps to verify that it's OK, and I've run Spears & Munsil occasionally to keep everything fine tuned. It's as close as I can get with the EQ in my AVR and the capabilities of my projector. That works fine for my purposes.

By the way, several people over at the Home Theater Forum have tried boosting the rears on Sgt Pepper and they all agree that it appears to be mastered too low. The range they all seem to be arriving at is around a 5 to 7dB boost. That's probably just due to the variations in how amps display level changes. Mine is in half dB ticks, but I doubt it's exactly a half dB. I'm pretty confident that my system is close enough that I can discern if two channels are attenuated by 5-7dB without having to jump through hoops and split a bunch of atoms. Close enough for government work.

 

[pinnahertz]

Pinnahertz, I have absolutely no interest whatsoever in pleasing the creators.

That's not what I said. If you want to hear what they heard, and it is your option if you don't, you need to calibrate to the same standards. You've already pleased the creators if you bought their product.

 

[Strangelove424]

Gregorio, it's a 12 inch Sunfire True Sub by Carver. It came with its own built in calibration system which I used once to set it up. Since then, I've just adjusted level, not EQ. I'm not as concerned about EQ below 80Hz as I am in the core range like the upper mids. I just make sure that descending bass patterns that are supposed to maintain consistent volume level stay consistent- and they have. The hand off between mains and sub are nice and smooth. I pay very close attention to that.
[/SIZE]

What's your crossover setting? I've been on the fence, moving up and down, for years. Can't find one I'm set on. And by any chance, have you experimented with 4.1 sound? The more I use 5.1, the more I question the utility of the center speaker, which has awkward dispersion characteristics due to horizontal arrangement, and lack of dimension due to being a single speaker. It's fine for handling dialogue in movies, but I really don't think center speakers deserve to carry as much lyrical content as is usually mixed into them for music. I've even got into the habit of disabling the center speaker, allowing the receiver to divert the information to L/R channels. Additionally, the surrounds are often under-utilized. A typical surround setup has floor standers up front but bookshelves for rears since they only need to handle ambients/effects. Mine's like that. But in 5.1 music those rear speakers are used to deliver a lot more harmonic content. Wouldn't it make more sense to have rear floor standers there too? This is what brings me back to 4.1, or quadraphonic + a sub. If a phantom front center can be created by mixing between L and R, then rear center could be achieved the same way, as well as left and right sides. Like 4 sided stereo. And you can basically turn any modern day 5.1 receiver into a quadraphonic setup in a minute. I truly believe quadraphonic might be able to achieve a more cohesive soundstage than typical 5.1 or even 7.1. The problem is I don't have the funds right now to experiment with additional floor standers in the rear. And it's a gamble, so if it turned out to be a cacophony of reflection and phase cancellation, I'd have wasted the cash and be stuck with speakers I didn't know what to do with. I've heard quadraphonic died due to being too early for its time essentially, but don't remember any detractors from an audio perspective.