JTR Captivator 2400 vs RS1 group delay related question

[geek101]

my room is 5000 cubic ft, with 24ft the longest side. I am supposed to get room gain starting from 23.4Hz but I am not certain in reality how much I could get.
I am attempting to build something that can get me 105db at 10hz and play reference past 20hz.

Without room gain two JTR RS1s do not hit 105db at 10hz. Mostly around 97db for two JTR RS1.
For JTR Cap 2400 single sub gets me to 101db at 10hz and two would mean more than 105db for 10hz.

My fundamental concern is group delay JTR RS1 has world class group delay across the frequency range. If my room was smaller I would be happy with them. But I wonder the higher group delay for JTR Cap 2400 can a make bass experience (must be perceptible) worse for certain applications?. For music etc?.

Group delay for JTR Cap RS1 from audioholics:

Group delay for JTR CAP 2400 from data-bass:

Any one with experience with both these subs in a sealed room of large size please let me know what you think about these two.

 

[Ktacos]

No doubt these subs could vibrate your space to pieces. Ever been to a show with subs? Ever go "man the group delay is poor on those subs"? I'd wager no.

Your room is gonna make group delay differences inaudible. Focusing on a non-issue imo.

 

[geek101]

No doubt these subs could vibrate your space to pieces. Ever been to a show with subs? Ever go "man the group delay is poor on those subs"? I'd wager no.

Your room is gonna make group delay differences inaudible. Focusing on a non-issue imo.

Thank you for the comments.
Many people prefer sealed because of port chuffing at the limit etc. I certainly like the output headroom in the cap 2400 , but if I don’t need it because of room gain then I don’t have to go for it.

 

[Ktacos]

Thank you for the comments.
Many people prefer sealed because of port chuffing at the limit etc. I certainly like the output headroom in the cap 2400 , but if I don’t need it because of room gain then I don’t have to go for it.

If the ports are done well there shouldn't be much in the way of detrimental port chuffing. I can imagine JTR knows how to port a speaker well.

 

[Golfx]

I didn’t think room gain was probable above 3000 cubic feet. For your size room ported subs at least two would be advisable. 105 at 10hz???? Better get Harbottle or Funk 24s.

 

[geek101]

I didn’t think room gain was probable above 3000 cubic feet. For your size room ported subs at least two would be advisable. 105 at 10hz???? Better get Harbottle or Funk 24s.

Please help me understand why rooms larger than 3000 cubic feet won’t get room gains. I am still learning about these things.

 

[Golfx]

Please help me understand why rooms larger than 3000 cubic feet won’t get room gains. I am still learning about these things.

Hard subject—not sure i can “explaina’ what i have read/known for a while. I just accepted it as a fact from reading experts. To the trained engineer it may seem simple but below posts my help. Basically in larger rooms the bass has fewer compressed reflections—those are my words.

What is Subwoofer Room Gain? | SVS Sound Experts Blog

Harnessing subwoofer bass in a room to make it a friend, not an enemy.

www.svsound.com

Analytical Analysis - Room Gain

So-so? We see the flattening out of the SPL down to 5 Hz, with a perfect match to the theorectical response, taking into account the two rooms total volume, and they must be quite air-tight to have this response. It is not possible to show all kinds of leakage and absorption effects, as all...

www.audiosciencereview.com

The 3000 anecdote was from an old data bass article and resulting forum no longer available.

 

[mcdn]

Hard subject—not sure i can “explaina’ what i have read/known for a while. I just accepted it as a fact from reading experts. To the trained engineer it may seem simple but below posts my help. Basically in larger rooms the bass has fewer compressed reflections—those are my words.

That SVS article is just wrong, room gain is not related to room size for any reasonable room up to dedicated home theatre size. Someone from marketing must have got confused by what someone from engineering said. This is made clear by Rene in the second link, with his explanation of room gain as the "0Hz mode" of the room. Wavelengths are infinitely long at 0Hz so room size doesn't come into it.

Think about a perfectly sealed subwoofer in a perfectly sealed room, and it's obvious it will modulate the room pressure just fine at 5Hz, albeit not by a huge amount, whereas a ported subwoofer will just move air from inside it to the room and vice versa with almost no pressure change.

What does matter is how sealed the room is at those frequencies, which will be a matter of its construction. A room can be well ventilated but still effectively sealed at 10Hz.