SVS 16-46 PCI in 30 foot room.

**Chrisbee** · **07-20-06, 07:57 AM**

Nobody would ever believe it when I said how powerful my 16-46 PCI was.
So I just ran REW through it straight off the soundcard.
No speakers or EQ. Shack old analogue meter correction file loaded.
Despite the massive natural house curve it never sounded bottom heavy and is very easy to calibrate by ear or meter.
We even run it a few extra dB hot on films!

**Vader** · **07-20-06, 09:49 AM**

Chris, what are the dimensions of your room?

**Chrisbee** · **07-20-06, 10:13 AM**

Quote:

Vader wrote:

Chris, what are the dimensions of your room?

Hi Vader

I use an attic space shaped like a boy scout ridge tent:

Roughly 30 feet long x 17 feet wide x 7 feet high. 6' wide flat ceiling. 18" kneewalls.

Open via an open stairwell to a very similar floorspace: A conventional room on the floor below.

The sub sits about 8-9 feet from the corner. It is pulled out into the room with the back top edge 18" from the 45 degree sloping ceiling and overlooking the open stairwell in the floor.

Measured from 8 feet away at listening chair. I listen across one half of the room due to the stairwell and a central obstructing chimney.

My 4x15" IB in the end wall shows no sign at all of this massive SVS house curve.

**brucek** · **07-20-06, 10:23 AM**

Quote:

old analogue meter correction file loaded

You're using a very old meter calibration file that was created before we split into offering three files for the three meters..

Download the latest ones HERE

brucek

**Chrisbee** · **07-20-06, 10:49 AM**

Thanks brucek

Here's a retake of the SVS using the new file.

Do you recognise the correction curve as the correct one now? Looks exactly the same to me.

**brucek** · **07-20-06, 10:58 AM**

Quote:

Do you recognise the correction curve as the correct one now?

It's incorrect...........

Here's what the new one looks like - quite smooth.... I just downloaded it to be sure.

graphcal.jpg

brucek

**Chrisbee** · **07-20-06, 11:40 AM**

Thanks brucek

I cleared the old file from REW and downloaded the old-style analogue meter file from the downloads page exactly as you suggested just now and opened it with REW.
My RS meter is probably around 15 years old. Is this still the wrong file?

**brucek** · **07-20-06, 11:54 AM**

Quote:

My RS meter is probably around 15 years old. Is this still the wrong file?

So is mine. The oldrsanalog.cal file on the site is the correct one for your meter and should produce a picture like the one I posted above....

**Chrisbee** · **07-20-06, 12:27 PM**

I think you call this "best of three" (attempts). 1/3 octave smoothing applied.

**brucek** · **07-20-06, 12:34 PM**

And you're telling us this isn't bass heavy?

Is it because your entire house is shaking at 15Hz?

**Chrisbee** · **07-20-06, 01:09 PM**

No it sounds fine. On films it makes our eyes rattle and the floor melts under our chairs.

It's not just the house vibrating either. My wife's seed trays rattle out ín the conservatory.

I like to believe that the response nicely matches the Fletcher-Munsen curves with added compensation for aging.

**Sonnie** · **07-21-06, 01:36 AM**

As ThomasW says... we can't tell the difference between 10hz and 15hz (did I get that right?)... looks like you don't even need an IB.

That is amazing response!

**Chrisbee** · **07-21-06, 02:49 PM**

Quote:

Sonnie wrote:

As ThomasW says... we can't tell the difference between 10hz and 15hz (did I get that right?)... looks like you don't even need an IB.

That is amazing response!

Hi Sonnie

Do not confuse a steeply rising response curve from a reflex enclosure with what an IB can do in terms of incredible clarity and a real sense of brute power unleashed. My IB plays tunes on organ pipes that the big SVS can only pretend to know. It's never enough just to play low frequencies at high levels unless it is done without unwanted distortion components muddying the effect.

Since the infrasonics are inaudible you can only feel them. The human physiology is poorly adapted to judging the frequency of infrasonics. Provided it makes the room rattle you have nothing to really lock onto. In my experience a 15Hz sinewave is no different from 12 or 10Hz Hz test tone unless your windows, doors, walls or floor begin to resonate in sympathy with the acoustic energy generated by the sub. I can sense nothing at these frequencies myself. There is not the same feeling of pressure in the head that I usually get up around 18-20Hz. At 15Hz and downwards the windows and doors start to shake violently and that is the only warning that something is happening.

Here the SVS presently seems to have the edge in getting our boarded floor vibrating so hard it feels competely soft. I'm hopefully working towards this same effect with my IB using Thomas' and other Cult member's help and recommendations. It can only be a matter of degree since the IB keeps on going where the SVS falls off a cliff at around 15Hz.

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