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Spl calibration


Diesel

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8 hours ago, JohnA said:

 

No, and 75 db doesn't really matter/mean anything. 

 

Sure it does, because Audyssey pulls test tones down 10 db, so calibrating to 75 db with an external microphone is actually calibrating to 85 db which is considered reference. :)  People don't seem to consider this.  Had they bought a third party test disc and done this it would be different but the internal test tones are purposely dinged 10 db, at least on Marantz and Denon.  Onkyo may be different for some reason but I thought that was an Audyssey thing not an Onkyo thing.  

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The method I use to balance my speakers is as simple as possible.  The front left and right are most important to me, so I start with them.  I, too, use a Radio Shack meter.  Since the speakers are being set to match, the actual volume setting is not that important.  My place is pretty quiet, so I usually use 65 dB when balancing them.  This is with the test tone produced by the AVR.  Louder than that means the occasional blast, and it's not any more effective.  I set the front left and right at 65 dB, then go right around the other four speakers (front centre, rear centre, surround left and right.  It's a 6.1 system.) setting them at 65 dB as well.  As another member mentioned, it can be helpful to raise the volume of the front centre speaker by 1-2 dB to make the dialogue easier to hear.

 

To set up the sub, I use a test disc that goes from 200 Hz down to 5 Hz.  I try for a smooth response in the range from 25 Hz. (the lowest my sub will do) to 200 Hz. with dips and peaks minimized as much as possible.  This can take a dozen runs or more, taking notes each time.  That was when I was using a separate equalizer for the subwoofer.  Now, the AVR can show the profile and allow some tweaking of the sub's frequency response through its range.

 

Once that's all done, the volume balance should be good for effective surround sound.  A bit of tweaking may be needed, maybe raising or lowering the volume of the surround speakers a bit, but it gets you started.

 

The AVR I use, a Yamaha RX-A2060, can do this automatically with its own microphone, but I'm not always satisfied with what it comes up with.  However, it can be used to set the time balance of each speaker, so each has the correct delay according to its distance from the listening position.  Once that's done, then the volume of each speaker can be set.

 

I should have mentioned that first, but that shows that it pays to read to the end of the post.  The AVR can do its settings, then switch to Manual and balance the speaker volumes to my taste.

 

I'm not clear on the 0 reference level idea.  Usual listening level settings for me are -32 to -50, except when listening to vinyl, which calls for volume settings in the -12 to -18 range, due to the lower output of the turntable's cartridge.  Max volume I listen at is in the 90-100 dB range, and 70-80 dB is more typical.  I've never turned my system up to 0 dB, because that would be at the severe pain level, probably over 120 dB.  That's what happens when using auditorium gear in a living room.  The front speakers are fed by a pair of 1000 watt amps, one for bass and one for treble, connected directly to each driver, since the crossovers are disconnected and replaced by the Dx-38 processor that does all the EQ before the signal gets to the amps.

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10 hours ago, Islander said:

The method I use to balance my speakers is as simple as possible.  The front left and right are most important to me, so I start with them.  I, too, use a Radio Shack meter.  Since the speakers are being set to match, the actual volume setting is not that important.  My place is pretty quiet, so I usually use 65 dB when balancing them.  This is with the test tone produced by the AVR.  Louder than that means the occasional blast, and it's not any more effective.  I set the front left and right at 65 dB, then go right around the other four speakers (front centre, rear centre, surround left and right.  It's a 6.1 system.) setting them at 65 dB as well.  As another member mentioned, it can be helpful to raise the volume of the front centre speaker by 1-2 dB to make the dialogue easier to hear.

 

To set up the sub, I use a test disc that goes from 200 Hz down to 5 Hz.  I try for a smooth response in the range from 25 Hz. (the lowest my sub will do) to 200 Hz. with dips and peaks minimized as much as possible.  This can take a dozen runs or more, taking notes each time.  That was when I was using a separate equalizer for the subwoofer.  Now, the AVR can show the profile and allow some tweaking of the sub's frequency response through its range.

 

Once that's all done, the volume balance should be good for effective surround sound.  A bit of tweaking may be needed, maybe raising or lowering the volume of the surround speakers a bit, but it gets you started.

 

The AVR I use, a Yamaha RX-A2060, can do this automatically with its own microphone, but I'm not always satisfied with what it comes up with.  However, it can be used to set the time balance of each speaker, so each has the correct delay according to its distance from the listening position.  Once that's done, then the volume of each speaker can be set.

 

I should have mentioned that first, but that shows that it pays to read to the end of the post.  The AVR can do its settings, then switch to Manual and balance the speaker volumes to my taste.

 

I'm not clear on the 0 reference level idea.  Usual listening level settings for me are -32 to -50, except when listening to vinyl, which calls for volume settings in the -12 to -18 range, due to the lower output of the turntable's cartridge.  Max volume I listen at is in the 90-100 dB range, and 70-80 dB is more typical.  I've never turned my system up to 0 dB, because that would be at the severe pain level, probably over 120 dB.  That's what happens when using auditorium gear in a living room.  The front speakers are fed by a pair of 1000 watt amps, one for bass and one for treble, connected directly to each driver, since the crossovers are disconnected and replaced by the Dx-38 processor that does all the EQ before the signal gets to the amps.

Reference refers to calibrating a system to THX's industry standard for MOVIE recording and playback.

If a system is calibrated to this standard then the volume of 0 is reference, meaning a maximum peak output of 105db from main channels and 115db from the lfe track.  Again that is peak.  

 

The movies are recorded, and then played back in theaters so that 85db is the average ouput.  That leaves 20db of dynamic range for dramatic effect, i.e. gunshots, crashes, screaming, or anything the audio engineers want that loud.   The lfe track is again referenced to 95db and then peaks at 115db, 10db higher because engineers have proved low frequencies (under 120hz but more specifically under 40hz) is "heard" by ours ears similarly to 10db less at higher frequencies....they are making it sound balanced.

 

Because home settings have walls that reflect sound and are close together the test tones a system uses to calibrate are 75db instead of 85db.  But even with this, the calibration is still set to 85db, it just is easier to deal with at 75db for setup than 85db.

 

Now until recently with the advent of 5 channel and 7 channel recorded and remastered music, music has NEVER had a standard for recording and playback levels.  One recording is completely different than another and especially as you go further back in time, few systems even had the ability to play at reference levels and many recordings were done to sound good in the average listeners setup or even in a car, which is how the engineer would try to make it sound good for most people.  That is why when listening to different music recordings you may sometimes choose to turn up or down the bass...it is because every music recording can be different based upon the engineers choices.

 

Reference for some cant be achieved with their speakers and avr....i.e. dome tweeters and a low watt avr.  Klipsch are so sensitive, most in the 90s some even in the 100s that reaching reference levels is easy even with a low power avr.

 

Most people dont listen to music at 100db levels for long, and also few watch every movie at reference.  Its too loud for most peoples ears and further, in a room that is not well treated and large like a theater, there are resonances and huge peaks and dips in the frequency response that can make a reference peak of say 105db actually as much as 120db or more at the resonant frequencies.

 

Many music listeners get used to these resonances and learn to like how the bass punches so hard and thats why....their room has particular characteristics they like.  Likewise movie fans that for the first time calibrate their theaters and use a tool like Audyssey that smooths out the frequency response and sets the range to sound flat...freak out because they think all their bass is gone.  

 

Commercial theaters are quite large where all the walls are far from the listener, the walls and ceiling are treated, and the playback is calibrated to have a very good response without resonances in most seats.  That is why most people can handle a movie in a theater being so loud.  Home theaters are usually in a living  without those characteristics and so there are many harsh peaks in the playback that make reference unbearable.  Even in a well treated room few people want to watch everything at reference, its justs too loud and stressful.

 

A good Klipsch system like yours can play way beyond reference.  If calibrated that would mean the volume goes over 0db to say +10 or +20.  The fact that it can has no bearing on whether it should.

 

Before THX and really before the commercial release of the first Star Wars, few movies were recorded with a standard and fewer had sound engineers that were given material and told to truly wow audiences with the audio.  That is why so many movies from before 1980 and really even 1990 have soundtracks that are not impressive.

 

Lucas and his young sound engineer for Star Wars, just out of audio school, literally changed the world of movies and audio playback.  Lucas' Skywalker Ranch is even today considered the very best place to record movie audio.

 

Music engineers around the world have built their own state of the art studios to improve the recordings of music today.

 

We have been fortunate to live through the birth of high fidelity audio 👌

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12 hours ago, MetropolisLakeOutfitters said:

 

Sure it does, because Audyssey pulls test tones down 10 db, so calibrating to 75 db with an external microphone is actually calibrating to 85 db which is considered reference. :)  People don't seem to consider this.  Had they bought a third party test disc and done this it would be different but the internal test tones are purposely dinged 10 db, at least on Marantz and Denon.  Onkyo may be different for some reason but I thought that was an Audyssey thing not an Onkyo thing.  

 

Audyssey is a little different animal. 

 

I cannot imagine any scenario where the system SPL had any effect on *relative* level calibration.  OK, maybe if you had a 'dozer running next door.

 

If I set my master volume at 0 while running the test tones the level would be ~100 dB, maybe more.  I'm unwilling to tolerate that; I don't want more tinnitus.  It is also very unnecessary to set the *relative* levels for each speaker.  That appears to be what the OP originally asked. 

 

My Integra only has a calibration range of +/- 10 dB on each channel.  Far too little to cut system output to 85 dB at 0 db on the master volume.  Also an arbitrary, relative setting.  When watching a movie, my normal setting is about -20 to -15.  No one will stay in the room above that.  With the sensitivity of my Klipsch and power amps, that have no input attenuators,  I get loud early and cannot change it.  Ultimately, I will listen to movies at the SPL I like and would not subject my neighbors to "Revenge of the Fallen" at theater levels at 9P. 

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Strange.  I have jubilees and can calibrate it however I want. :)  

 

Still don't understand this though:
 

2 hours ago, JohnA said:

It is also very unnecessary to set the *relative* levels for each speaker.

 

Maybe I'm misunderstanding but I can't wrap my head around that statement.  Level matching of different speakers is pretty basic and very important.  Surely we're talking about different things.  

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15 hours ago, Islander said:

I've never turned my system up to 0 dB, because that would be at the severe pain level, probably over 120 dB.  That's what happens when using auditorium gear in a living room.  

 

0 db (which is supposed to be reference level) means diddley doo unless it's calibrated properly.  A setting like -20 is supposed to mean 20 db below reference.  It's a standard.  Without calibrating to this point it means nothing.  I have jubilees and four 18's in a 15x20 room and it's set right.  -15 is plenty loud but there's no way it's at the levels that you guys are talking about.  -50 as mentioned would literally mean that a standard conversation would be at like 35 db or something.  You're at least 20 db off most likely.  

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Read this: "Audyssey FAQ Linked Here"

Unlike most manufacturers'  manuals, it is crystal clear.

 

If you are going to use Audyssey (which I strongly recommend) don't use the test noise in your AVR, because that noise does not pass through the filters Audyssey has assigned.  In some (good) rooms it won't make much difference, and in others, where Audyssey had to provide a great deal of correction, setting levels with the AVR supplied pink noise will give you levels that are way off.  If you must "check" Audyssey levels after calibration, use a test DISK which, because its signal goes in through the BD or DVD or CD input of the AVR, WILL pass through the Audyssey filters, and will be a valid way to check levels.

 

The ONE level that most Audyssey users change after calibration is the subwoofer.  Most people want more bass than what "flat" provides.  There are many reasons for this, especially the Harman curve.

 

 

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4 hours ago, vasubandu said:

Just out of curiosity, why do people rely on a microphone and an algorithm instead of their own reactions? I am looking for my microphone and wondering why.

when a pro installer sets up a theater they rely on measurements and best practices

why rely on what u think is good when u may find out a properly calibrated setup may be far superior?

 

our ears get used to almost anything.  it takes a few weeks to adjust to something new imo

if you have never measured a room...not speaker levels but the full frequency response and decay, you have hardly scratched the surface

 

to compare its like saying why go to a high end restaurant when you are already a good cook?

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On ‎1‎/‎27‎/‎2018 at 10:24 AM, RoboKlipsch said:

We have been fortunate to live through the birth of high fidelity audio 👌

Great write-up and couldn't agree more. I rarely play a cd and my Music collection is Multichannel. :) Oh, yeah, the setup listed in my sig is pretty good for movies too. 

 

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1 hour ago, Zen Traveler said:

Great write-up and couldn't agree more. I rarely play a cd and my Music collection is Multichannel. :) Oh, yeah, the setup listed in my sig is pretty good for movies too. 

 

Your system is honestly a connosieurs dream in Klipsch.    Am I reading correctly that you have 2 pair of unicorns for surrounds? 👍

 

Thank you for the kind words

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On 1/26/2018 at 3:01 PM, JohnA said:

Adjust the sub calibration to 3 or 5 dB higher than the mains.  The RS meter is less sensitive at low frequencies. For my setup, 5 extra db sounds good, 5 more is "impressive". 

 

 

I've been reading up on this lately.  Actually, because the RS meter is less sensitive at low frequencies, the reading displayed by the meter is lower than the actual SPL.  

 

So, if for example, the sub's test tone is a 40-80 Hz rumble, and one calibrates to 75 dB along with the other channels, the sub will will actually be 1-2 dB hotter than the other channels.  So, if one wanted to calibrate the sub and other speakers to the same level, the sub level would need to be reduced 1-2 dB.

 

These articles get into this:

https://www.svsound.com/pages/faqs#faq__frequency-response-measurements

https://www.powersoundaudio.com/pages/spl-meter

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9 hours ago, JJkizak said:

Two movies come to mind when thinking about huge glorious sound levels, "Shane" and "Patton".

JJK

 

Both are excellent movies.  Shane was released to most theaters in icky 1953 optical mono, but a lucky few got Western Electric 3 channel stereo.  That implies that the original music elements, the original dialog elements, and the original sound effects elements were recorded on a magnetic format.  I hope the Blu-ray made use of these magnetic tracks.  Since you used the words "huge glorious" I think it did.

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