SPL?

[dano382]

Looking to see how much output people are getting from their setups. Post some spl numbers or graphs showing levels.


Thomas maybe a sticky of graphs IB'ers have posted.

[ThomasW]

Since every IB is a unique installation, comparisons between them really make no sense (apples vs oranges comparisons).

Encouraging high SPL contests (db drag racing) is potentially dangerous to the subwoofers, and the hearing of the listeners, so it's not something I'll be doing.

If someone is having a problem with their EQ settings, or understanding what or how to EQ their sub, that's something altogether different.

I'm currently working on a definitive online guide for subwoofers (all types of subs not just IB's). When its a little further along I'll post some links.

[kkd]

I agree, I've been hearing an invisible low frequency hum when I'm in a quiet room after testing my IB at 12-16Hz@high SPLs. I would recommend wearing ear plugs though it won't prevent the skeletal vibrations from hurting your eardrum.

[shomrighausen]

You can run some simulations with any specific drivers to get an 'anechoic' response. Just enter the number of drivers, and roughly the size behind your baffle/manifold. This will not take room gain into account (which makes a big difference, but is variable with each room/situation.)

You'll soon see that low end SPL is directly related to excursion/displacement of your drivers. More displacement = more SPL (max). The lower you go, the greater the excursion requirements for a given SPL.

That said, as you go lower, the room gain goes up, so it generally helps you out where you need it most. With most drivers being used in IB, 2-4 drivers will give you amazing results from 16Hz up with a couple of hundred watts in an 'average' sized room (not talking 10,000 cu. ft. here). By amazing, I mean, more than you need for 'reference' levels for HT.

Simulated response for a pair of AE Speakers IB15 (sort of an 'average' woofer for IB use). It has 15.5mm Xmax. It will hit that Xmax at 20Hz with 200 watts total to the pair (while playing about 109dB at one meter without figuring in room gain). The same pair will reach the Xmax at 10Hz with only 63 watts (while playing at 97dB at one meter without figuring in room gain). Xmax will remain constant, but lower = less power to reach Xmax.

The room gain is the wild card... it can be simulated - but you would be difficult to 'guess' what it would be for you.

Remember that the ability to play 130dB at 5Hz is sort of silly (or 130dB at ANY frequency). The advantage of being ABLE to play these levels is that you can play LOWER levels with MUCH less excursion, which equates to LOWER distortion.

[dano382]

Isn't it hard to even hear 16hz let alone 10hz? Maybe feel at max excursion but hear? I really wasn't wanting anyone to start a IB DB contest. Just trying to see what levels people are seeing with their installs..

Dano

[shomrighausen]

With four of x drivers, in an 'average' room, using xxx watts per driver, with any amount of room gain, it should be possible to reach xxxdB from xxHz up... is that the sort of information that you're looking for?