How low to go, ht sub

[Tordenguden]

Originally Posted by bjorno

Hi Tordenguden,

Only looking for a place to land these suggestions:

b

PS: They too would add an 'image', like subs that don't exist - like they should.

Not sure I understand your question.
I only have simple measurement of my own XXLS subs. The SB subs, I have only briefly heard at a friend. But I have alot of experience listening to very different speakersystems - both cheap and very expensive, and found the SB brand as great quality in both build and sound. But remember, this is my personal view

[mikeford]

Bass is like up, no natural higher limit, only those you decide on. Bass is also fun, why put a limit on how much you can have? Thats what spouses and neighbors are for.

Systems with substantial output between 15 and 30hz usually have a visceral sense of space and three dimensionality missing in systems without much output in that range.

All of the full range speakers I've played with sound better high passed, removing the last octave or so that the speaker has to work hard to output. For the high pass to work the subwoofer needs to match the character of the mains, and do a better job of recreating the frequency range.

Its very very easy to turn down a big sub slightly if the level is too high, and impossible to get more out of a sub if its too small.

[freax]

Originally Posted by chris661

How did you arrive at that conclusion?

I've got a 15" ported down throwing subwoofer back at home in the shed on a cement slab and I need to move my lounge chair farther away than 2 metres inorder to hear 20Hz, at a shorter distance from the subwoofer I cannot hear it and all I hear is 50Hz and above.

I can feel 50Hz and below though at any distance, it makes the drywall flex by 2 mm at any distance from the sub.

The distance from the subwoofer at least in my case plays a large part in wether or not I can hear below 50Hz, maybe your ears are better than mine.

To me too low of a frequency is when I start to feel it, I don't like feeling my bass I want to hear it, it causes too much pain in my ear canal and head when I can feel it.

If I want to feel sub frequencies all I gotta do is get up and move around, the local highway and the trucks going along it at 20km/h above the speed limit is enough to make everything shake, constantly.

That and all of the idiot drivers with illegal exhaust systems on their cars.

So I guess I'm a bit weird in that I don't design my subs to shake the floor, I design them to move air, my choice of music probably plays a big part in this aswell. Industrial.

Another reason why I got rid of my 22" customs, bass gives me a headache now if I can feel it.

Another reason yet again is that if you can feel it then so can your neighbours, if you go and stand outside you will be able to hear 20Hz and below for quite some distance, these days instead of arguing with pissed off neighbours I just put a steep curve at 30Hz and drop everything below that frequency.

Maybe I'm just getting old.

[mikeford]

Any chance you are using tones instead of noise?

What you describe seems much like standing waves related to the room with hot spots and nulls.

[chris661]

Originally Posted by freax

I've got a 15" ported down throwing subwoofer back at home in the shed on a cement slab and I need to move my lounge chair farther away than 2 metres inorder to hear 20Hz, at a shorter distance from the subwoofer I cannot hear it and all I hear is 50Hz and above.

I'd suspect the room is at play here: if, at close proximity, low frequencies were cut off, headphones wouldn't produce the low end they can.
If you put your head next to the sub and play 20Hz, can you hear it?

Chris

[Moonfly]

Originally Posted by freax

I've got a 15" ported down throwing subwoofer back at home in the shed on a cement slab and I need to move my lounge chair farther away than 2 metres inorder to hear 20Hz, at a shorter distance from the subwoofer I cannot hear it and all I hear is 50Hz and above.

I can feel 50Hz and below though at any distance, it makes the drywall flex by 2 mm at any distance from the sub.

The distance from the subwoofer at least in my case plays a large part in wether or not I can hear below 50Hz, maybe your ears are better than mine.

To me too low of a frequency is when I start to feel it, I don't like feeling my bass I want to hear it, it causes too much pain in my ear canal and head when I can feel it.

If I want to feel sub frequencies all I gotta do is get up and move around, the local highway and the trucks going along it at 20km/h above the speed limit is enough to make everything shake, constantly.

That and all of the idiot drivers with illegal exhaust systems on their cars.

So I guess I'm a bit weird in that I don't design my subs to shake the floor, I design them to move air, my choice of music probably plays a big part in this aswell. Industrial.

Another reason why I got rid of my 22" customs, bass gives me a headache now if I can feel it.

Another reason yet again is that if you can feel it then so can your neighbours, if you go and stand outside you will be able to hear 20Hz and below for quite some distance, these days instead of arguing with pissed off neighbours I just put a steep curve at 30Hz and drop everything below that frequency.

Maybe I'm just getting old.

Chances are that boundary gain is boosting low frequencies when your further from the sub and closer to boundaries, but thats a guess. The subs tune point will also be a factor. The idea low frequencies cant be heard at certain distances or in rooms that are too small is a misconception often spoken of. Try a decent pair of headphones and a 20hz sine wave, if its loud enough it will become quite audible, and thats at a listening distance of only a few centimetres.

I always strive for 10hz performance from sealed systems. Sealed systems dont over bloat these low frequencies, and flat extension to 10hz will give a more balanced sound. Sealed systems also integrate into a system better, but they wont match a ported system for efficiency and outright output without adding more drivers and power at considerable expense.

[djn]

Originally Posted by Moonfly

Chances are that boundary gain is boosting low frequencies when your further from the sub and closer to boundaries, but thats a guess. The subs tune point will also be a factor. The idea low frequencies cant be heard at certain distances or in rooms that are too small is a misconception often spoken of. Try a decent pair of headphones and a 20hz sine wave, if its loud enough it will become quite audible, and thats at a listening distance of only a few centimetres.

I always strive for 10hz performance from sealed systems. Sealed systems dont over bloat these low frequencies, and flat extension to 10hz will give a more balanced sound. Sealed systems also integrate into a system better, but they wont match a ported system for efficiency and outright output without adding more drivers and power at considerable expense.

How big is your box that you can get sealed down to 10hz? are you EQing? I don't do the HT thing and don't listen to much organ music, but I like a strong signal down to 30hz as it gives the low and mid bass better presences.

[Moonfly]

Originally Posted by djn

How big is your box that you can get sealed down to 10hz? are you EQing? I don't do the HT thing and don't listen to much organ music, but I like a strong signal down to 30hz as it gives the low and mid bass better presences.

Eq is a given if you want a flat response to a target frequency. Its actually not that hard to go deep, the hard bit is doing it cleanly at good output levels. My minimum has been a pair of 15's in about 100 litres each, upto a pair of 18's using 250 litres each. Getting good quality mid bass presence is a matter of properly designing your sub to deliver the detail and punch you want in that system. This is also something that is more easily controlled in a sealed system.

[djn]

Thanks Moon. I agree about sealed boxes. I just finished my speakers tonight and they have two 4" ports 10" long each but I can use plumbers plugs to block them if I want. I'll get them set up and test both sealed and vented and go with what sounds best.

[mikeford]

I used to know guys that built system around the EV30, and with a freezer sized sealed box it wasn't flat to 20 hz, but sure kicked at 30 to 60hz.

What people need to keep in mind with boost is that if you need 8 db of boost to be flat at 15 hz, at best you have 8 db less overall max level flat if you don't run into excursion limits even sooner.