Shiva levels in my small room (1 Viewer)

[James Slade]

I built an Adire alignment ported Shiva for fun a few weeks ago. My real sub project is a ported tempest 220L, but it is not done yet so I have playing around with this Shiva.

My room is 1518 cubic feet in volume. DxWxH is 11.5X16.x5.8

Anyway I went to calibrate the sound system today using my Denon AVR3300 internal test tones (I know I sohuld be using a disk, but that is a lot more work). Anyway I set the volume on the sub to half way before calibration. I had to turn down the sub channel 3/4 of the way on the Denon to get down to 75db. Is this normal, seems like I have tonnes of power to spare?

By the way I don't plan on living here for much longer so no the big Tempest won't be in this room.

 

[Jack Gilvey]

The level readout on the receiver, or the position of the volume control on the sub amp have nothing to do with the actual wattage being delivered to the sub.

 

[James Slade]

Jack,

Thanks for the valuable information you provided.

 

[Jack Gilvey]

The actual voltage delivered from the sub-out and the sensitivity of the amp's input are what counts. I have my sub-out at -10db, and my actual amp volume knob at slightly less than 1/4, and I can still clip the amp (~280 watts).

So, the positions of the controls don't indicate "power to spare".

 

[jeff lam]

Jack,

Is that the plate amp? How can you tell it's clipping without a clip indicator LED?

 

[Jack Gilvey]

I hear it.

 

[Rudy H]

James, barring some nasty standing waves, you should be able to crack at least 115db @ 20hz.
I do with my 15inch Dayton DVC in a 5.3cf sealed box with the PE 300-794 plate amp (just finished modding it too )
I gotta re-run bass sweeps to make sure the SPL reading were accurate now that the XO is different.
But yeah, you should be able to go VERY loud in that small room. My rooms ~2500cf.
Jack, I never knew you were one to drive your sub to clipping :b

 

[Jack Gilvey]

Hey, I can clip with the best of 'em when I get goin'. You should hear what I do to a Marshall stack...

 

[Rudy H]

Oh really......well.... ever get that MaxSPL measurement of your DVC yet?

 

[Jack Gilvey]

For the PR/DVC, probably in excess of 115db on peaks at my listening position, that's when I can hear some clipping from up close to the driver. Tough to really test and get useful results. Unibox predicts a peak of almost 120db anechoic at tuning with all the PR displacement I've allowed, and more up over 60Hz, but I don't have enough power for that.

 

[Rudy H]

Jack, hehe, power is nice to have
I'm thinking...a pair of plate amps would be sweet...180watts RMS per coil, plus the added damping factor. But you could also get a *real* amp for the $250 a pair of 300-794's would cost.
Anyhoo, that's some nice SPL. I gotta re-run my SPL measurements now having re-modded my amp. Check PE later today for my page on the mod

 

[jeff lam]

Rudy,

Nice to see you finally stop by the HTF, I'm sure you can offer a lot of useful info to many of us here(that is when you're not at the PE board). BTW, are you ever on AR.com's boards anymore? I don't think I have seen you post much there lately. Although I haven't really been hanging around there much either lately.

 

[Rudy H]

Thanks Jeff
I rarely go there anymore...the DIY forum is very slow, and I'm not one to go start looking about the Speaker forum where people recommend Klipsch or Velo's over the Adire Dharman for pure HT use.
/end rant

 

[jeff lam]

Rudy,

I hear ya! So you going to stick around for a while or are you just checking it out over here?

 

[Rudy H]

I think I'm gonna stick around.
I know a few people here already, so it should feel like home
Rudy