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Discussion Starter #1
So 14Hz is minimum for LLT, 8Hz is "Bottom C", and I've heard 5Hz is a lot of DIY'ers dream or goal. At some point, there has to be a cut off... 4Hz is after 8 and may still be felt?, 2Hz, 1Hz... 1Hz, but then it is infinite... 1/4, 1/8...

So if there was no limit... you won the $350 million lotto, you could get as many of your choice of subs as you want, as many amps to run them, your choice in design...IB, TL, LLT, sealed... your own power grid from the city....

What is the lowest you would tune, and why? Keep in mind, if you chose say 100 18" RL-p's, or 1000 Maelstrom-X's, EP2500's or whatever.... even at "low volume" you have enough "mid" and "high" bass, and at high volume, you don't have to worry about excursion at any point.... your so rich and limitless, you can still have as many of whatever other subs in whatever other enclosure you want to take over where you think the low-end setup would need help.


So what is the absoulte lowest valuable frequency, and why?
 

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Well, there's not much point tuning too far below 10hz as there's not much activity down there in recordings. I imagine you'd reach a limit where the ocillations become so slow that they no longer shake things as much as pressurize the room. If I had the money and could design something no holds barred, I'd probably design a system good to a solid 10 hz, with -3 somewhere around 8hz, and employ buttkickers for anything lower. Some movies have bass below 10hz but they are so rare I'm not sure there would ever see any use.
 

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Discussion Starter #3
I have already edited my initial post 4-5 times, and now I see I included sealed in the "tune" list... lol... but you got the idea thxgoon! So I'll put you down for 10Hz, and I considered mentioning 10Hz as well only for the fact I used to love putting my 20-10Hz sweep on repeat at home waiting to see how long it took people at home to notice :D



1: there's not much activity down there in recordings.

2: I imagine you'd reach a limit where the ocillations become so slow that they no longer shake things as much as pressurize the room.

3: If I had the money and could design something no holds barred, I'd probably design a system good to a solid 10 hz, with -3 somewhere around 8hz, and employ buttkickers for anything lower.

4: Some movies have bass below 10hz but they are so rare I'm not sure there would ever see any use.
1: not much, as in there is some...and this system is designed specifically for those that do!

2: there's not much to being pressurized, is there? So i think i agree with you on that point...

3: even if you could use unlimited dedicated to say 14Hz on down, and also unlimited LLT or what have you for 14Hz-80Hz?

4: this setup is still designed specifically for movies, recordings, and anything else that has intentional information as low as possible, as well as sine waves just for fun! I could see myself standing in the mouth of a 10'X10' mouth of the largest horn/TL ever in a 4Hz sine wave... I'd rather death from this than from coitus! :D
 

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Discussion Starter #5 (Edited)
Umm, no it isn't :scratch: There is no limit.
requirement. I am terrible with words. It's been a while since I've checked into LLT, but I believe something like 6" port for a 15" sub, 8" for an 18", minimum tune of 14Hz, over 13 cubes, 80Hz crossover.... IDK...

But Steve, I'd really like your number! What do you think? An unlimited number of Maelstrom-X's in an unlimited LLT... as much airspace, as much port area, whatever tune.... what would you do???

EDIT:

LLT
- Tuning <=15hz
- Cylindrical port diameter >= 6” for 15" drivers and >=8" for 18" drivers
- Port opening clearance equal to at least the port diameter in all directions
- First port resonance >=190hz
- No discrete high pass filter
- FR with a ~4db/octave rolloff between the tuning frequency and the lowest room node
- Minimal resonance enclosure (use of cylindrical concrete forms made of paper – generically referred to
as Sonotube - for the enclosure makes this easy)
 

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I'd settle for a solid 10Hz. It's very seldom any useful information below that anyway.

On an unlimited budget I'd spend a lot on minimizing rattles and buzz from the room, so I could run my subs at the required SPL to be useful at those frequencies. We are terribly insensitive at 10Hz.
 

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Discussion Starter #7
I'd settle for a solid 10Hz. It's very seldom any useful information below that anyway.

On an unlimited budget I'd spend a lot on minimizing rattles and buzz from the room, so I could run my subs at the required SPL to be useful at those frequencies. We are terribly insensitive at 10Hz.
So we have 2 at 10Hz... Steve??
 

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I have to agree as well 10Hz is about as low as you require due to the wavelengths being so long below that I doupt that you could notice it however if the DB is high enough you sure could make the neighbors wonder what is going on.
 

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I win the lotto 350 million:yay:. 180million after taxes:sob: I have a dedicated theater building built with non parrallel walls, ceiling, room treatments, the whole nine yards. 32 RE XXX 18's sealed, dispersed throughout the theater powered with 16 QSC PL380's or PL9.0PFC's. I'd go for 3hz to match the Dolby 3-120hz LFE spec.

Estimated cost of this sub system? Probably $80-$90,000.
 

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Discussion Starter #11
I win the lotto 350 million:yay:. 180million after taxes:sob: I have a dedicated theater building built with non parrallel walls, ceiling, room treatments, the whole nine yards. 32 RE XXX 18's sealed, dispersed throughout the theater powered with 16 QSC PL380's or PL9.0PFC's. I'd go for 3hz to match the Dolby 3-120hz LFE spec.

Estimated cost of this sub system? Probably $80-$90,000.
:D somebody's pickin up what I'm layin down... (no, I didn't win, but this is what I'm getting at)

no time to type now... to be continued!

But... I want FR to get louder as it nears 10Hz (or 3 in his case) so sealed and IB out, ported and PR possible, how about horn or TL???


Bunker-style underground totally reinforced enclosure, sound room in front...

to be continued.....gotta go for now!!
 

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kryponite said:
requirement. I am terrible with words. It's been a while since I've checked into LLT, but I believe something like 6" port for a 15" sub, 8" for an 18", minimum tune of 14Hz, over 13 cubes, 80Hz crossover.... IDK...
I'm sorry, I thought you meant 14hz was as low as it could go. My mistake.
 

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If I may vent for a second, I don't think extended low frequency bandwidth necessarily correlates to an improvement in the perceived quality of a system. There is a point where "deeper extension" is as meaningless to the sound quality as the spectrum content of the lightbulb in your neighbor's garage.

By definition, the goal of a high-fidelity system is to reproduce (not produce) as accurately as possible the content contained in the recording. With that in mind, I think the answer to your question resides in knowing what is contained in your source material....AND knowing what is important to the perception of accuracy.

Btw, with a large budget, I can think of a few "alternate subwoofers" that could yield true DC performance on up to a few Hz...maybe even up to 10Hz with a really big budget, where you could cross into your totally insane direct-radiating system.

For me personally, I could be very satisfied with flat response down to about 22Hz (putting the F3 probably around 18Hz). I've got a few recordings that have significant content down to 14Hz or so, but it's few and far between...and having it there doesn't always improve the perceived quality of the playback. However, not having it there when the source material calls for it is usually a big let down...I've got all sorts of source material that sounds rather bad without solid extension below 30Hz.
 

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Discussion Starter #16
If I may vent for a second, I don't think extended low frequency bandwidth necessarily correlates to an improvement in the perceived quality of a system. There is a point where "deeper extension" is as meaningless to the sound quality as the spectrum content of the lightbulb in your neighbor's garage.

By definition, the goal of a high-fidelity system is to reproduce (not produce) as accurately as possible the content contained in the recording. With that in mind, I think the answer to your question resides in knowing what is contained in your source material....AND knowing what is important to the perception of accuracy.

Btw, with a large budget, I can think of a few "alternate subwoofers" that could yield true DC performance on up to a few Hz...maybe even up to 10Hz with a really big budget, where you could cross into your totally insane direct-radiating system.

For me personally, I could be very satisfied with flat response down to about 22Hz (putting the F3 probably around 18Hz). I've got a few recordings that have significant content down to 14Hz or so, but it's few and far between...and having it there doesn't always improve the perceived quality of the playback. However, not having it there when the source material calls for it is usually a big let down...I've got all sorts of source material that sounds rather bad without solid extension below 30Hz.
Lets set aside SQ for a sec and make this simply a kid's toy :D If I hit the big one, I shall get Kevin Haskins and Dan Whiggins together, maybe an engineer or 2 from Kicker unless someone talked me out of a square... and probably even Scott of... I hate to mention... Ascendant/Fi.... I'd send them each $50,000 just to get them to come to my design party, and drop a million into each of their production efforts into a mammoth sub emplimenting the Parthenon...


so for you it is 22/18Hz?

tell me more about your "up to 10Hz" air displacer... fan sub??
 

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Totally forgot about the TRW-17. Let's go ahead and add 8 of those into my Bill Gates system to handle 3-20hz.
 

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Discussion Starter #19
Totally forgot about the TRW-17. Let's go ahead and add 8 of those into my Bill Gates system to handle 3-20hz.
Im assuming thats a fan sub or some other non traditional transducer?

As for as a normal driver goes, what is the largest Sd a driver could be before 40Hz were an issue with beaming, and other factors as well? ( I was hoping to go up to at least 30Hz with this, or maybe even 40....but 20 will do! Listen to me, like Im really doing this...)
 

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Discussion Starter #20
Since we're talking winning lotteries here, personally I'd go with something like this:

http://www.royaldevice.com/custom.htm

"110 dB/1W/1 meter sensitivity starting from below 10 Hz"

Mike, you are the man. This was what I had in mind, but to a much, much larger scale. I have re-read that site here and there over the years... now that main pic of the horn... that is excactly what I had in mind, except...

A huge underground "bunker" type deal, much much larger, and a horn/TL that implements both the front and rear wave. Basically a rhediculous 1Hz horn with say a 10'X10' woofer with the parthenon design but beefed up to support an Sd of 100 cubic feet, or the largest a woofer could possibly be. The mouth the same size as the sub, so a 1:1 ratio, the same dimensions throughout.

And just 1, not dual.... the rest of the house would be built underground as well in front of the sub and mouth, the sub and mouth being side by side, and a giant listening room.... the rest of the top-of-the-line HT in there.
 
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