Autotuba measurements, plus shiva

[mike.e]

If the AT rolls off at 2nd order below 80hz id be glad,since in the car this will yield an approximately flat response - otherwise youd be complaining about how bloated and slow it sounds

I expected more change with distance from corner- but remember that you have to consider how acoustically close things are - considering 40hz waves that are 8m long youd have to near 2m from the corner to affect things down here
where as 80hz waves much easier to affect things with a 1m distance from the boundary.

[simon5]

Shiva EBS measurements :
This is not a max SPL chart and this is in the center of a small room, not in the corner.
I don't know if she used the RatShack SPL correction chart on these numbers, I'll ask her.

16 107,5
18 107
20 107,5
22 108,5
25 109
28 111
31,5 113
36 114,5
40 114,5
45 114
50 114,5
56 113,5
63 111,5
71 112,5
80 113,5
89 111,5
100 110
125 109

[simon5]

I know it's not a really fair comparison, but it would be fun if you can include my measurements in your graph. Drop the curve to match the sealed Shiva with a reference point at 70 Hz or so maybe?

[simon5]

I asked her, and the values are already corrected.

[kornmong]

simon5

Could you show you box on this post and tell me the specs of that box, eg how many litres, box dimension, port tuning watt driving the woofer and what shivs model.

because those numbers are unbeleivable 16HZ at 107db that better then any subwoofer on the planet and its not even corner loaded

your box must be HUGE or somthing

juding from your success if i bought a tempest 15" could i beat those numbers (DB)

[GM]

Greets!

It appears you've led a rather sheltered life WRT infrasonic BW output capability from a single driver. 107 dB/16 Hz is rather ho-hum by today's high Xmax/power handling, low Fs driver standards.

GM

[johninCR]

Especially in room and a small room at that.

[kornmong]

It must be me because i have a bigger xmax than a shiva and I dont get 16hz at 100Db! even corner loaded

[GM]

I'm not touching this one with a ten foot pole..........

[rcw]

Some years ago an Australian hi-fi magazine did some tests on typical Australian houses for room gain. They concluded that for all the typical room gain you get you may as well set your sound system up in the middle of a field.
Typical Australian houses are brick veneer, plasterboard wall and ceiling, picture windowed creations, that are open plan and leaky. The fact is you are flat out setting up a decent standing wave in them let alone pressurising them.
In short if you live in a typical Australian house your subwoofer has to be flat down to its lower cut off. and if that is 20Hz.it needs to play at least at 103dbm. otherwise you can't hear it.