Please, help me get a feeling of what reference level is

[cribeiro]

Hi!
I intend to buy an spl meter, but in the meantime I'd like to know how loud is the reference level. I have a Yamaha rx-v530 amp, and maybe another owner of the same gear knows at which level of the amp he gets the reference. I know that it also depends on the signal and the sensibility of speakers, but I only want a rough estimate. BTW, my speakers are rated to be 91 dB, although I wouldn't believe it much...

edit: I have just realized that also room size is an issue... There is so much in the game!! Well, it is about 6x4 square meters, and about 2.5 meter height.

 

[RobDickinson]

Go to a THX certified cinema. That'll be reference level...

IMO well to loud for home.

 

[cribeiro]

Ok, you have proved that I am stupid... Never thought about it!
I have been a couple of times in a thx certified cinema, actually for The Lord of the Rings, and I must admit it is loud. But I must also say that it didn't disturb me. I think it is simply right like that, because I had never before felt so inmersed in a movie like then. You may remember there is a scene in the second part where one of the animals that orcs ride looks directly at you and bites... I jumped back on my seat, trying to save my testicles!! I promise it is true!
Thanks for the idea!!

 

[bobgriffiths]

I was amazed according to the THX web site there are only 11 THX certified cinemas in the UK

Cambridge Picture House
39-39 St. Andrews Street
Cambridge CB2 3AR
United Kingdom
Screens: 1

Cheshire Oaks
Site Offices, Stanny Lane
Ellesmere Port
South Wirral L659CB
United Kingdom
Screens: 1

Curzon Soho
99 Shaftesbury Avenue
London W1D 5DY
United Kingdom
Screens: 1-3

Greenside II
Greenside Place
Edinburgh
United Kingdom
Screens: 3

Liverpool Picture House
FACT Centre
88 Wood Street
Liverpool L1 4DQ
United Kingdom
Screens: 1

Stratford Picture House
Salway Road Stratford
London E15 1BN
United Kingdom
Screens: 4

Warner Bros West End
3 Cranbourne St
London WC2H 7NA
United Kingdom
Screens: 5

Warner Village Plymouth
Barbican Leisure Centre
Shapters Road
Coxside Plymouth PL4 0LG
United Kingdom
Screens: 7-9

Warner Village Portsmouth
Gunwharf Quays
Portsmouth P01 3TA
United Kingdom
Screens: 3

Warner Village Star City
Star City
Heartlands Star Park, Watson Rd.
Nechells
Birmingham B7 5SB
United Kingdom
Screens: 1 & 19

York Picture House
Coney Street
York Y01 9QL
United Kingdom
Screens: 1

NOT one in the UK's third largest City Manchester!!

 

[cribeiro]

He, he... There is even one in my home town, Naron (Galicia, Spain), which has even less than 50 thousand souls!
48 in Spain, although this in my town doesn't appear in the web... (it is very new)!
Yes, amazing about uk... Germany has 54...

 

[bobbypunk]

I thought reference level on a home amp is 0 db
maybe i'm wrong and completely off the mark though.

 

[cribeiro]

Ok, without entering in details, the dB scale is logarithmic, and such scales (as actually any other, but we are so used that we don't realize) need some reference, i.e., a measure unit. 0 dB means that you have exactly a measure unit.
An example: you measure in meters (well, not you in uk...), and 1 meter is your measure unit. If you say "this tree is 10 meter high", you know what you talk about, because you know how much 1 meter is (well, not you in uk... ;-) ). Now imagine that instead of meters, you measure in Log(x meters/1 meter). In that units (which are actually dB), 10 meters is 1. Funny, right? And one meter is 0, i.e., reference.
I hope I didn't mess it up too much... I tend to do so... But I promise I know what I am talking about!!
PS: I admit, I have no idea of how big one foot is... except mine )

 

[buns]

i agree with the guy saying it is too loud...... at reference in my room my ears will get sore simply from talking. With an explosion i could all but blow the windows out (if you care to investigate some of my earlier posts, i have before managed to crack one....)

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[Malky1903]

I have a Pio 912 and when I run the MCACC, the amp automatically turns all the speakers down to a muted -18db. Would that be reference level for my amp?

 

[buns]

so it is muted at -18db...... you cant hear anything?

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[Malky1903]

Originally posted by buns
so it is muted at -18db...... you cant hear anything?

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Correct! The only sounds you hear are the test tones from each speaker. Once the set up has finished, the volume automatically goes back to where it was before the auto set up started.

 

[avanzato]

cribeiro: My Yamaha AX630 is -29db when calibrated with the Avia DVD to 75db. This is certainly loud enough for me and I wouldn't really want to try 85db reference level. I think the speakers are 87db efficient so you can work your level out from there... maybe?

 

[buns]

oh...... i misunderstood, the signal is muted but the test tones arent! makes sense now! The test tones are simply being set at -18db, i imagine 0db should be reference

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[bobbypunk]

the vsxax3 set itself to 0db to run it's tests
om MCACC

 

[bobgriffiths]

Sorry its off topic

criberio In the UK we use and are now taught centimetres ,metres ,kilometres at school and not taught feet and inches but we still have road signs in miles?! .
In the Uk you buy speaker cables by the metre and i think its illegal to sell speaker cable without telling you how much it is a metre and displaying only how much it is in feet and yards!

No wonder kids are confused.

11 THX cinemas in the UK is a disgrace we have tons of crud sounding multiplexes.

I personally have only heard one cinema in my local area which sounds "much" better than my home system and that was at the Printworks IMAX in manchester

 

[buns]

I still have trouble seeing past the size (sorry hearing) of the real cinema. Although my sound is better, it can be just as loud, it can do most things, but it cant mimick a room 5 times the dimension, the volume is correspondingly 125 times more..... for this reason I think its hard to actually compare cinema and home cinema.... refernce level really doesnt cut it for me as far as making the experience more cinematic

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[bobgriffiths]

your right buns the amount of detail, the quick transient response at home makes it sound better.than most multiplexes but it is hard to compare as the room makes all the difference.
The most important "reference" level is getting your levels set correctly to the same output level with a SPL meter .
The actual volume level you play it at isnt really the isssue i listen to my system at a comfortable level and when a loud action sequence occours it has enough impact to make me jump and shake the sofa.
People get obsessed with how load it is . a pneumatic drill is loud but i dont want to listen to one all night .Quality has to come into the equation.

 

[zaphod]

With regard to the earlier post by RobDickinson just because a cinema is THX certified does not mean that it plays at reference level. Most cinemas I have come across do not play at reference level including the THX screen I have seen. Most seem to play with the level set to about 5 where reference level on Dolby kit is 7. The reason being that they get complaints that the sound is too loud from some members of the audience so they reduce the level for the rest of us.

Zaphod

 

[Smurfin]

Originally posted by bobgriffiths
I was amazed according to the THX web site there are only 11 THX certified cinemas in the UK

Cambridge Picture House
39-39 St. Andrews Street
Cambridge CB2 3AR
United Kingdom
Screens: 1

Cheshire Oaks
Site Offices, Stanny Lane
Ellesmere Port
South Wirral L659CB
United Kingdom
Screens: 1

Curzon Soho
99 Shaftesbury Avenue
London W1D 5DY
United Kingdom
Screens: 1-3

Greenside II
Greenside Place
Edinburgh
United Kingdom
Screens: 3

Liverpool Picture House
FACT Centre
88 Wood Street
Liverpool L1 4DQ
United Kingdom
Screens: 1

Stratford Picture House
Salway Road Stratford
London E15 1BN
United Kingdom
Screens: 4

Warner Bros West End
3 Cranbourne St
London WC2H 7NA
United Kingdom
Screens: 5

Warner Village Plymouth
Barbican Leisure Centre
Shapters Road
Coxside Plymouth PL4 0LG
United Kingdom
Screens: 7-9

Warner Village Portsmouth
Gunwharf Quays
Portsmouth P01 3TA
United Kingdom
Screens: 3

Warner Village Star City
Star City
Heartlands Star Park, Watson Rd.
Nechells
Birmingham B7 5SB
United Kingdom
Screens: 1 & 19

York Picture House
Coney Street
York Y01 9QL
United Kingdom
Screens: 1

NOT one in the UK's third largest City Manchester!!

That list is incorrect: the UGC cinema at Ipswich has its premiere screen THX certified, and at least Screen 6 (which, quite honestly is awesome).

Dolby reference level IS too loud for most people, I used to think that with my Lex MC-1 I was listening to most stuff at around -05db, but in fact their test-tones were 3db out from Avia's. On the whole not alot in my room goes above -8db as it's simply too loud (even at -8db it's as loud as any movie I've ever seen at the cinema). Then you have the extremes of badly recorded DVDs such as Underworld, where I found above -20db was uncomfortable....

 

[bobgriffiths]

i got the list direct from THX web site.
As i understand it you have to pay for regular certificates and check ups to be a THX certified theatre.
but i am most probably wrong!

maybe it was (and still is )a THX certified cinema but they havent paid there subs(pun sadly intended) or is it a new cinema?

 

[Smurfin]

Originally posted by bobgriffiths
i got the list direct from THX web site.
As i understand it you have to pay for regular certificates and check ups to be a THX certified theatre.
but i am most probably wrong!

maybe it was (and still is )a THX certified cinema but they havent paid there subs(pun sadly intended) or is it a new cinema?

Definately not a new cinema...

 

[cribeiro]

Avanzato, thanks for the numbers... Now I see that it is really loud... Only one more question... How big is your room? That also matters...

Bobgriffiths... I didn't intend to hurt with my comments, I only wanted to make some fun out of that... But your points are very interesting. I didn't know about that. Thanks!

Thank you all for your comments!

 

[avanzato]

Originally posted by cribeiro
Avanzato, thanks for the numbers... Now I see that it is really loud... Only one more question... How big is your room? That also matters...

It's 5.7m long by 3.4m wide and 2.75m high. Just the right size for THX Select.

Smurfin also makes a good point about the differing recorded levels on DVD's. Some you have to turn up and some down. Presumably THX specced ones are at least standardised and accurate?

 

[cribeiro]

Ok, that means it is approximately same size as mine. Then I can compare your levels with mine, although your amp has some more power than mine... But at least I know I will never play at reference levels (I actually don't know if I can reach them with my amp, because -25 dB on the display is about half of the amp power, and that is usually the limit for playing without distorsion). I never play louder than -35 dB on the display (for an average recording level, if that can be said...), maybe I'll try... but that means I have to invite my neighbours, or I'll get the police knocking on my door

About the recording levels, you are of course right, and I would guess that THX certified should have a kind of standard, but I don't have any official info about it...

Off topic: I went for another listening session this weekend, I'll write my impressions soon, but I don't know if I should continue the thread I started with the first session, or continue that one... I promise it is interesting!!

 

[RobDickinson]

But at home, isnt more complicated than that?

Amp power/current deliver, speaker efficiency etc all need to be factored in. I assume with the use of a SPL meter you'd get it close to accurate (at least across part of the spectrum).

He only wanted a feel. a decent, loud cinema will give him a feel.

Personaly conemas are often too loud for me, loud at the start is ok , oy adjust, but some are loud near the end when they need not be - but were all individuals, one reason I like home cinema is to be able to control all the variables to tastes I prefer.