What happened at this site?

[GranteedEV]

Now I'm certain I have never clipped my 500 watts pf power to the bass speakers, reproducing these types of sounds, not even close. I suspect there is the attempt to drive the sub too hot to cover the lacking elements.

Not as far as I can tell. Then again, I'm letting the Audessey auto setup set the sub trim level here on its own. Past that I`ve got an ~18hz high pass filter on a sealed sub with a tapco J2500 amp driving it. Again, it's an 89 or so db sensitive driver, and I'd assume the loudest a movie LFE out should ever get would be (115db-at-seating-position reference level minus 10 to 8db listening level minus room gain which I've never measured plus distance loss). Perhaps it's just the size of my room, but I've definitely seen the clip lights come on.


The cars-exploding-in-a-chain-scene in Iron Man 2 being a notable one. A possibility I've considered but haven't quite explored is that the Auto-EQ may have been engaged and adding low end boost to try and get flat response down to 20hz (anechoically, my subwoofer should be about 8db down at 20hz and I really have no idea what room gain is like as I lack the equipment to measure it but I assumed it should naturally give me flat response... perhaps i'm wrong and there is boost being added that I'm unaware of?)

Do you by any chance have the LFE channel at -10db? I've read that when the LFE channel is redirected to the mains, its magitude becomes 10db lower than if it is actually output via LFE Pre-out. How is your setup, again?

The only other explanations for my clip lights would be

- Clipping pre-amp outs being recognized by the amp as a clipped waveform and hence the light
- An unusual gain structure that I don't fully understand

But as far as I can tell, the balance generally feels right, with the exception of those one or two scenes which trigger the red clip light.

Now one of the best tests are the canon shots in Master and Commander. I have actually heard 18th century canon fired. For this movie they actually recorded 18th century English canon, and very accurately too.

To reproduce these shots correctly you need the whole enchilada in proper balance. When the right balance is achieved the result is terrifying. I have had visitors grip the arms of my theater chairs for dear life, without bottoming a driver.

I don't doubt it one bit. I've never seen that particular movie or scene to be honest. It's on my list

I really don't think the demands of music are very different from HT or even at all. Both require realism. I would point out that music is a big part of every movie.

Well, when I listen to music, I like an average level anywhere from 70-80db with dynamics as loud as 95-100db (however so the recording should call, of course.) Now with respect to movies, it's moreso a matter of the recording calling for dynamics in that 105-110db range. That's where the demands of music and HT differ. Beyond that I understand what you're saying.

Not only that natural speech and the accurate reproduction of the familiar sounds of everyday life really enhances the telling of a story more than the ability to reproduce the odd earth shattering explosion. In any event I personally believe earth shattering explosions are of more import to the HT buff than family and friends being in a theater that can produce sounds that really draw them into a movie.

Indeed. As far as movie special effects, it wasn't the bass that has impressed me most about my speakers. It was actually a different scene where the glass shatters. The dynamics can take your breath away!

Ultimately I just.. at the end of the day, don't want to bottom or clip an amp or hear distortion. One approach to this is soft clipping I guess.

A speaker system with shouty reproduced speech (common) really detracts from the average viewers enjoyment. Natural intimate speech really draws them in far more then if the ground and walls shake. What I getting at is the creating of believable atmosphere and acoustic environments.

I agree with this %100. Shouty speech can ruin one's day. It gives an awkward and unnatural "inside your head" feeling.

So I don't think there is either or here. But I truly believe passing up a speaker with a nice smooth response and excellent balance to buy a sub that rattles walls is not the right trade off. So yes, the last octave is nice to have, when accurately reproduced and blended in with the rest of the system in an unobtrusive way, but in my view it is not part of the basics.

In that sense, I would I agree with you. But as far as budgeting is concerned, I just (personally) feel that weak subs aren't even worth the time of day. I'd rather run no sub than a wimpy sub. I guess my opinion of subs is that they're worthless if all they're doing is essentially the same thing as your mains. The point of a sub to me is to reproduce what the mains can't. In essense that's the LFE Channel which tends to be 10db hotter and thus requires more power, the 20-50hz range that my ears can barely hear and my mains don't quite reproduce. And the 50-65hz or so range where my mains have a good bit of port output contributing that I'd rather not (hence why I cross them at 80hz, not 60hz). But past that, for music I feel the blend is seemless, and for some (read: not even most) movies I definitely think the subwoofer and amplifier are being put through the paces. Compared to some of my favorite music, it's not even close. The subwoofer driver barely even <i>moves</i> for even the most gut wrenching of music. But movies can definitely get notable excursion out of it to the point where getting a second would even be worthwhile. There's a clear divide.

I don't think it's my subwoofer being run hot, but rather the signal being innately hot.

 

[Pyrrho]

I agree that that is the ideal. But in the real world, people operate with various budgets, and the question becomes, what do you sacrifice in order to stay in budget? Do you give up the deepest bass for better midrange and treble, which will affect every piece of music you listen to? Or do you make everything sound worse in the midrange and treble in order to have deeper bass? These are real world questions that people should think about in making their decisions.

This quote is of me, not of GranteedEV that you have listed in your response.

This thread has turned into one of the best discussions we have had for a long time.

I don't think you have quite posed the options correctly.

Any loud sound effect even one such as a cannon shot or explosion has enormous energy out of sub range. Even for these sources there is far more energy in the mid, and upper bass and mid range, then there is last octave content. There is also nearly always significant HF contribution.

The accurate reproduction of these effects, still requires everything in correct balance.

Now I'm certain I have never clipped my 500 watts pf power to the bass speakers, reproducing these types of sounds, not even close. I suspect there is the attempt to drive the sub too hot to cover the lacking elements.

Now one of the best tests are the canon shots in Master and Commander. I have actually heard 18th century canon fired. For this movie they actually recorded 18th century English canon, and very accurately too.

To reproduce these shots correctly you need the whole enchilada in proper balance. When the right balance is achieved the result is terrifying. I have had visitors grip the arms of my theater chairs for dear life, without bottoming a driver.

I really don't think the demands of music are very different from HT or even at all. Both require realism. I would point out that music is a big part of every movie.

Not only that natural speech and the accurate reproduction of the familiar sounds of everyday life really enhances the telling of a story more than the ability to reproduce the odd earth shattering explosion. In any event I personally believe earth shattering explosions are of more import to the HT buff than family and friends being in a theater that can produce sounds that really draw them into a movie.

A speaker system with shouty reproduced speech (common) really detracts from the average viewers enjoyment. Natural intimate speech really draws them in far more then if the ground and walls shake. What I getting at is the creating of believable atmosphere and acoustic environments.

When my rig reproducers really accurate distant thunder far outside the side wall of this room, and someone say we going to get a thunder storm, I know there is true realism.

I guess the comments I so often get from people who come to watch a movie, isn't about the big sounds, but about intimacy and really being drawn deep into the story by realistic believable soundscapes.

So I don't think there is either or here. But I truly believe passing up a speaker with a nice smooth response and excellent balance to buy a sub that rattles walls is not the right trade off. So yes, the last octave is nice to have, when accurately reproduced and blended in with the rest of the system in an unobtrusive way, but in my view it is not part of the basics.

I think you must be misunderstanding what I stated. I did not say that home theater and music were essentially different; I said that when one is on a tight budget, one must make sacrifices. Deep bass is one of the things that one can choose to sacrifice. One could instead choose to get less good reproduction of the upper frequencies.


I agree that a great system will sound great with either music or movies. After all, both involve the reproduction of the signal that is recorded, and your speakers and other gear do not care what it is that the signal is. (And one might also add, most of the sound in a typical movie is music.)

As for dialog being clear, that is extremely important, and that is one of the reasons why it is a bad idea to scrimp on speakers. Dialog occurs in virtually everything except silent movies, and so that will pretty much always matter. Not every movie has significant deep bass, and so that will only matter in some cases. This strongly suggests that sacrificing deep bass is probably a better option, as it will be irrelevant in many cases, whereas the midrange always matters.

Also, you are obviously right that canons are not just a matter of the very deep bass.

 

[Pyrrho]

... I've read that when the LFE channel is redirected to the mains, its magitude becomes 10db lower than if it is actually output via LFE Pre-out. ...

There is a lot of confusion about this that one can find online. The LFE originated for 70mm film, and it was recorded such that it was to be played back at 10dB louder than the other channels in order to be able to have greater headroom with the bass without affecting the other channels. You can read about this at:

http://en.wikipedia.org/wiki/Low-frequency_effects

http://www.dolby.com/uploadedFiles/zz-_Shared_Assets/English_PDFs/Professional/38_LFE.pdf

Now, with home gear, it is set up to properly deal with all such issues without you bothering about it. In other words, just follow the directions in your owner's manual, and you will get the proper balance of bass.

This is one of those cases where a little information is a bad thing, as people get confused and then start doing bad things with their levels as a result.

 

[TLS Guy]

This quote is of me, not of GranteedEV that you have listed in your response.

Sorry about that! I seem to be first class at creating those sort of mix ups.

 

[TLS Guy]

Do you by any chance have the LFE channel at -10db? I've read that when the LFE channel is redirected to the mains, its magitude becomes 10db lower than if it is actually output via LFE Pre-out. How is your setup, again?

No, I do capture the LFE signal because of the flags.

It is quite complicated to capture and introduce the LFE signal to a full range speaker.

[URL="http://www.drmarksays.com/?cat=9"]You can follow the set up here in my review of Audyssey[/URL].

If you listen to LFE signal there is not much there and nothing of any detail. So it is frequencies above sub range that really define the event.

I agree poor subs get you further behind and that's the rub.

 

[TLS Guy]

New stuff for you guys to pour over here... http://www.data-bass.com/blog

Extensive new testing data that will be updated with new products as time goes on....

Lots of clicking to see measurements of all the systems... look around

BTW, take a look at the THD's on the different products.... -- very interesting and quite enlightening IMO.

Subwoofers to me are just as intimate as speakers are to the many masses, and you may scoff at the powers that I have chosen to implement - rather then efficiency but there are reasons I chose that path...

I don't think scoff is the right word, incredulous comes to mind.

Even allowing for poor sensitivity and efficiency, I can't envisage using that much power in the last octave with any semblance of balance.

Granted you have a low sensitivity system, and I have a system that couples well to the space and really connects. However except for very brief moments there really isn't much down there. In any case the event is defined to a much larger extent by the frequencies well above sub range.

No sub can have "fast bass" that is an oxymoron. What gives the appearance of tight bass transients is a low Q bass system superbly integrated to a powerful clean system in the upper bass, mid range and HF. Then you get the appearance of tight bass transients. A sub by itself can not do that, as it has such a narrow bandwidth. Bags of reserve need to be built into the speakers and amps carrying the upper bass and the mid range. That is where the vast majority of the power bandwidth is, even in an earth shattering explosion. Cracking the latter nut is a much tougher proposition than the sub design. The relative expense is also commensurate.

 

[Swerd]

... And frankly, I think he is right, that many want to have exaggerated bass from their subwoofer, just like a lot of people complain about not having enough sound from their surround channels. They paid for those speakers back there, and they want to hear something from them! It is like those people who want to fill their screen with picture, no matter what the aspect ratio of the original source is. They paid for the whole screen, and so they want it filled. Never mind that in doing these things they will frequently distort the picture and sound.

So true! I have both done the same (in the past ) and witnessed it in others.

 

[jp_over]

So true! I have both done the same (in the past ) and witnessed it in others.

I too am guilty of this apostasy in a "before audioholics" life.

 

[Shock]

So true! I have both done the same (in the past ) and witnessed it in others.

Why movie screens and tv screens don't use the same aspect ratio is a question no one is able to answer. Even if they try to, they're wrong.

 

[Pyrrho]

Why movie screens and tv screens don't use the same aspect ratio is a question no one is able to answer. Even if they try to, they're wrong.

The answer is that movie aspect ratios are not standardized, and so it is impossible for any particular screen aspect ratio to match all films. In the case of movie theaters, very often they use curtains to cover the portions of the screen that are not used for the film being shown, so the screen looks like it fits all of the films that they show, when the reality is that they cover more or less of the screen with curtains to give that illusion (which is a good idea, as the screen is more reflective than the curtains, so there are less unwanted reflections). You could do the same thing at home with your TV, if you wanted to cover the parts of the screen that are not being used for a particular film that you are showing, which, in fact, would be a good idea, but it is more trouble and expense than most people care to do.

Something different but giving a superficially similar appearance can also be done in the projector, as they have something called an "aperture plate", which is basically a piece of metal with a rectangular hole in it that is placed on the opposite side of the film as the light source which restricts the size of the image that comes out of the projector. Ideally, the aperture plate will be the right size for the image desired by the filmmaker, though in actual practice a projectionist might alter this, either due to ignorance, not having the correct aperture plate, or a desire to willfully alter the image.

 

[mtrycrafts]

.... Have people gone completely mad here?

Maybe it is the "Full Moon Effect?"

 

[Shock]

The answer is that movie aspect ratios are not standardized, and so it is impossible for any particular screen aspect ratio to match all films.

This was pretty much what I was getting at.

 

[BoredSysAdmin]

I like turtles