THX cinema with pro cinema audio gear

[Andysu]

direct frequency response monitored on THX 3417 amp return .
strange it has high level of infersonic with no doubt low pass filter in the B-chain , but where in my B-chain ?

1 i would have check Denon 8500h SW connected directly to the computer REW

2 i would have to check Denon 8500h SW connected to Sony SDDS D3000 to computer REW

3 i would have to check Denon 8500h SW connected to Sony SDDS D3000 connected to Behringer FBQ2496 to computer REW

4 i would have to check Denon 8500h SW connected to Sony SDDS D3000 connected to Behringer FBQ2496 connected to DCX2496 connected to computer REW

5 i would have to check Denon 8500h SW connected to Sony SDDS D3000 connected to Behringer FBQ2496 connected to Behringer DCX2496 connected (back to THX 3417 )

6 i would have to check computer REW connected to Behringer NX3000 connected safely to THX 3417 (otherwise the amp would destroy the computer) and the test the REW

7 i would have test each part of the gear used in the B-chain one at a time . i would have to run so many tests to see which part of the B-chain gear has a low frequency filter roll off , not a big deal only hours/days of testing .

8 i would have to test Behringer RX1202FX to see if in any way it has filter frequency low pass filter ?
otherwise i see no issue with the REW frequency sweep directly to amplifier measured with THX 3417 . if i can see it then it must be real ?

 

[Andysu]

the untouchables 1987 , DVD release 2007 , brought 2014 and watched once or few times not played since 2014 8 years .
not worth buying uhd that has about same colour and framing of the scope .

another reason why i won't spend out for uhd is some are priced at silly prices £40 to £50 what ? maybe if it was in plastic bargain bin for £1.50 i may consider it ?

there is faint dialogue leakage in left channel sort of piggybacked into left maybe due to first transfer and would the bluray and uhd have same technical issue ? it is like so -dB faint down below the centre channel and most home theatrs wouldn't know what to look for ? wouldn't notice it ?

ennio morricone music/score opening/end credits play in L R only with low level of "baby boom" LFE.1 .

mono surrounds originals are on this transfer which is better than some re-mixed if even done correctly using actual stem track and careful mixing . so the dolby labs atmos and where it was remixed at for atmos for shake of rubbish overhead surrounds isn't for me as some lots of outdated movies using dolby labs atmos cash cow to milking every movie with poor mixing has certainly put me right off uhd 4k discs .

i may not watch the movie now for another 8 years and the DVD will still acceptable enough .

split lens diopter used in many of brian de palma movies and other movies as well .

THX/TAP newsletter

https://www.in70mm.com/news/2015/letters/pdf/the_untouchables.pdf

 

[GXAlan]

'star wars' with proper surround channel configuration , try doing format 04 in your home theatres . the echo sound "i think we took a wrong turn" sounds proper with left-half right-half surrounds , where AVR's will only play fake Dolby surround upmixer with fake stereo surrounds with extra crosstalk in those surrounds and digital dps upmixer processor distortion noise as well

Can you clarify what you mean? Is this the old THX “Adaptive Decorrelation” that the THX AVRs used to have?

 

[Andysu]

Can you clarify what you mean? Is this the old THX “Adaptive Decorrelation” that the THX AVRs used to have?

cinemas and THX do not use Adaptive Decorrelation circuity . would if i guess two speakers for surrounds . i have no use for it since all of my surrounds are set the same as cinema and do , diffused and localizable . the THX "AD" always sounded like a handsaw effect on right surround when testing with pink noise . the surround signal never plays the same twice always different sort of like a pseudo stereo effect due to the delay effect in right surround .

i read in , maplin electronics magazine , still have it there was few theories on what might have been used for THX "AD" . the actual i guess is top secret ? lol

 

[Andysu]

found the pdf article that appeared in maplin 1994, dolby surround and THX part 3 scroll down the page

https://worldradiohistory.com/UK/Mapelin/Maplin-Electronics-1994-09.pdf

 

[Andysu]

Bear with flower

 

[Sal1950]

Bear with flower

Oh boy, he's a furry guy, a major shedder I'd guess.
Did you ask the big guy how he feels about wearing flowers.
He may not be too pleased about being dressed like a girl.

 

[Mart68]

I imagine that he's comfortable with his sexuality.

 

[Andysu]

when i brought Bear (rambo) i didn't think i was buying my own amok alpha male attack cat , to attack Magic when he feels like it . Magic uses the "slap defence" it often works .

 

[Andysu]

Bear (rambo) laying on JBL 8330 mkII THX

 

[Andysu]

2nd great day the DVD has been in the player since yesterday .

split lens diopter positioned horizontally it's tricky to do handheld with the two images being focused with foreground and background otherwise without the split lens only one image can be in focus . best results is the camera must be tripod mounted so the subject matter is both in focus . taken with a Canon 750D DLSR .

Bear keeps jumping up onto the JBL 8330 mkII THX, the weather is warm today and Magic and he has had extra water added to their wet food .

 

[Sal1950]

2nd great day the DVD has been in the player since yesterday .

DVD? How 1987

 

[Andysu]

negotiations failed with my cats demands for more feeding and instead they fed on my JBL G12 .

 

[Sal1950]

my cats demands for more feeding and instead they fed on my JBL G12 .

Cabinet doors tied shut I get but why the duct-tape on the drawer handle? LOL

 

[Andysu]

Cabinet doors tied shut I get but why the duct-tape on the drawer handle? LOL

these cats are smarter than you , myself and every one else . do not underestimate them .
anakin , i was right . the jedi cats are taken over .

 

[Andysu]

254 speakers actually 508 coaxial speakers for a proper surround surrounded sound of side to side back ceiling and floor using diy approach to reduce the cost of a single crazy speaker cost tens of thousands and doesn't evenly surround . with all the diy surrounded surround speakers covered with fabric so they are invisible . it's just an idea ? oh the speaker size also matters and the stud framing attached to the walls ceiling with a new wooden floor as don't want to chop up the floor . speakers so loud they won't actually be played loud with given how many amplifiers used to drive so many in series then another amplifier and so on . the baffle for the speakers attached to the wall have be firm so it doesn't wobble or rattle when speakers are sounding with test tones sine wave spot frequencies , pink noise frequency sweep graph . so the surrounded sound speakers are reduced with resonance frequency .

point is speakers used for surround channels just simply have gaps in the sound field . if you stand up and walk around the room you can hear how flawed that cheap and extremely expensive speaker is when used for the surround channels be it side back , overhead or matrix below surround .

shallow profile speakers would be best and so many used the surrounded sound system would have decent low end down below past 20Hz but it's making sure it doesn't rattle as the rattling isn't part of the soundtrack unless rattle sound effects are added to a soundtrack mix to give the impression the bird of prey in "star trek IV" is rattling and about to come apart during the time warp travel .

should it be sealed or ported can be ported and ports can be sealed to change the low end frequency roll-off .

designing the EQ , active or dsp crossover (or would it be done using passive crossovers) amplifiers speaker (cheap amazon brand non of that snake oil stuff) and that would be it for the surrounded sound speaker system . diy but still not cheap but cheaper than most speakers made of the same common MDF .

the surrounded sound system should be customize to use with all past/present surround formats

1. Dolby pro-logic decoder 4.2.4 would be main system decoder so the surrounded sound speakers sees the same original used for "star wars"

2. Dolby PLIIx AVR added to main AVR to expand only the stereo surround and back surround channel with additional few more Dolby PLIIx for overhead and below surround . PLIIx offers 5 steerable outputs . arr , yes a matrix switching box to switch the zones for certain surround formats .

3. Dolby Atmos with the cluster surrounded sound system speakers on the ceiling and depending on the mixed encode/decode sound for heights 1 2 and 3 each overhead channel could be made into not 2 speakers or 3 speakers like an LCR on the ceiling but can be made into 5 speakers so sound can pan speaker to speaker depending on the mix if the source mix is done well in stereo and using additional signals mixed into that stereo signal there is no reason why it can't have the sound image panning into each speaker so it reduces the centre-phantom and new sound will be heard speaker to speaker .

the rest i make up as it's all diy trail and error but still it would sound thee best least it would if i actually had something like this up and running in my room ?

in cinema the seating is so far away or to the sidewalls the speakers so high above for the regular surround speakers and back row of an auditorium the surround speakers will be less higher up so that you can just about touch them . but still holes in the surround sound speakers there are gaps in the sound field .

so got surround in your home theatre ? i doubt it very much but maybe you like to go diy route or get ebay cheaper speaker parts and build one , may have to get a divorce first ?

 

[Doodski]

when i brought Bear (rambo) i didn't think i was buying my own amok alpha male attack cat , to attack Magic when he feels like it . Magic uses the "slap defence" it often works .

Hehehe. The movie soundtrack in the background was very fitting of 2 cats going at it.

 

[Sal1950]

254 speakers actually 508 coaxial speakers for a proper surround surrounded sound of side to side back ceiling and floor using diy approach to reduce the cost of a single crazy speaker cost tens of thousands and doesn't evenly surround . with all the diy surrounded surround speakers covered with fabric so they are invisible .so got surround in your home theatre ? i doubt it very much but maybe you like to go diy route or get ebay cheaper speaker parts and build one , may have to get a divorce first ?

I think you need to leave the catnip alone for a while.
It's going to your head.

 

[Andysu]

I think you need to leave the catnip alone for a while.
It's going to your head.

yeah , i like catnip but it is great .

 

[Andysu]

indiana jones and the last crusade has low frequency below 20Hz ! laserdisc still rules .

dvd same scene region 2 pal plus 4% speed up which shifts frequency upwards a few cycles . low frequnecy is of left and right . centre shows a different frequency range .

centre channel shows the amount used in the mix and a mix can go in any low frequency direction . no LFE.1 during the scene chapter 33 , 1hr 42min 52sec surrounds still give sense but not low depth abyssal low end during the scene more of the backing choir voices echoing on left-half right-half split surrounds .