you crazy
Watching a podcast on YT, one of the manufactures suggested two subs is a must anything more then 4 subs degrades the sound field.
Which is a relief, for a moment i had the bright idea of getting a sub for each ch. 7.11.4. Seven 10in floor subs and 4 (i kid you not) 8in mini subs to be mounted high on the walls. For non existent IMAX THX full range movie soundtracks.
If we are in a field of normal and normal sized rooms.
1-4 (regular sub’s) is enough. Most cases being 1 sub, some go for 2 if possible and result are good but kinda after that you need to step to 4 subs and for optimal placement, choices are limited.
Have seen only 3 sub system, but that probably was a temporary solution before upgrading.
Not sure how imax enhanced works, guess thats why some run floorstanders for the bed channels. the question is how are you going to get full range for the height channels short of mounting subs in-ceiling or thx certified speakers which are pricey and a chore to mount.
Subwoofer sound cannot (should not be) be localized, if you have 4 covering the room (same locations) with optimal placement.
So the ultra low and low FR sound’s cover the entire room already. Why would you what more? No point. So no need to add more “subs” to height channels.
You can mount sub’s to roof or wall’s as well but same principal remains.
You already have all the sound needed.
If you want full range height channel’s you need full range speakers.
Have been pretty satisfied with ± 1.5 dB (60 Hz - 20 kHz) FR on height channels. Very little bass usually is present with effects or it is more directed to low level speakers.
Phil jones of sound united mentioned on a podcast the studio will release over 100 titles with IMAX THX surround if it detects the viewer has the proper equipment in their home theater. IMAX THX commerical theaters utilize full range speakers. So the idea is when you play a imax thx movie with a imax enhanced AVR the reciever will send signal to all channels at full range. Which kinda answered my own question and brings up a new one.
To play a imax thx enchanced movie title you would have to run something like 4 klipsch THX certified speakers heights and 4-6 floorstanders for the bed channels. What happens to the sub channels, they turn off during THX playback ?
On quick look up. The THX format is another surround format, like Atmos or Auro3D. Think it also did something with the image so it’s sound and image format.
So THX is another way to deploy and experience the surround sound. Auro also turns or can make low level surround sound -> upper level sounds and if speakers can play “full range” if you have full range.
The term “full range” is kinda miss leading. They still limit low FR ranges.
LFE channel still is a LFE channel -> subwoofer. Low and ultra low bass notes.
So you just play full range audio to low and upper level speakers.
As example: If you look THX speakers like Klipsch LCR Speaker, 2-way Speaker, Frequency Response 80Hz-20kHz. So you won’t be playing “full range”.
Or Klipsch LCR In-Ceiling, 2-way in-ceiling speaker, Frequency Response 45Hz-20kHz.
Still not “full range” as to say. They do not play LFE or “low” low bass. Still, plenty of bass.
Thing to notice. Room damping or sound absorption comes even more important role when having full range speakers blasting on upper level, normal rooms usually do not have furniture or floor rug’s on sealing and upper walls. 
Thats what is frying my noodle if true that the studio will release blurays with theatre THX then one would need all speakers to be full range. So lets say my setup is klipsch rp450c center RP floorstanders and RB-81 heights. THX is detected by the AVR, receiver sends full range to all channels. The speakers gets the signal and will reproduce the signal within its range. Phil talked about how in a thx theater LFE is coming out of all the channels. Not sure how the codec will work.
If THX IMAX does not have a dedicated “LFE channel”, everything is 7.0 or 12.0, it has to have some other way to cut FR range to sub’s if speakers cannot produce low FR’s. It’s just not called/named LFE but “just directing low” FR to sub. Same end result.
In the other hand. If you would have all around speakers that can produce 20hz-20khz. Then no sub’s would be needed. Full blasting all around. That indeed does sounds fun.
I would still bet money.
There are not very many Full range 20hz -> 20khz speakers surround setups, in home or theater environment. Many i mean many of them, cut FR and send them to x.1 or x.4 subs etc subs. Cause it’s damm much cheapers!
Have to rewatch the podcast to refresh how it suppose to work
The last IMAX theater ive been in had from what i saw 2 gargantuan speaker arrays hanging from the ceiling like an arena at the rear of the theater. I mean were talkin the size of a 4runner lol.
One other is the actual sound track of the movie and what happens on it. Even if it’s IMAX THX.
You probably wont see or hear a tank exploding on top of building, makes more sense to blow the tank on the ground so “ground level surround” will produce the explosion.
upper level is more of the echoes and wind noise etc. Jet engine or flying maybe… but if you have small speakers -> then low FR would go to sub. Would still sound nice. Oh a jet flying from upper back left to upper front right and afterburners blasting from sub’s.
Even if you had full range upper speakers. The movie might not have anything that would need -50hz blast range sound coming from it.
There is always “marketing involved” with surround format’s and gear related to them.
So bit of salt and clear view is good.
Okey got a better understanding of IMAX enhanced. So there is no .1 in a IMAX DTSX theater the signal is full range. for home theater the format is DTSX imax enhanced, when the imax enhanced reciever detects imax DTSX, a sub menu is unlocked and the speaker config is 70hz high pass and 70hz low pass with a 12db slope and on/off function for the sub to protect from burnt speakers. But if you have speakers that can get lower than 70hz you can adjust accordinly, pretty neat. Only caveat there no imax enhanced titles yet. (Chuckle) . Youre correct on the mix, example the atmos mix for HT is not the same as the commercial mix that everyone complains about, which i agree.
If they do start releasing titles in IMAX DTSX would be awesome if the mix is full fat commercial surround.
Sorry OP for going into the weeds.
1 Like
Upper right hand.
