is 150 watts enough for a shiva 12? (1 Viewer)

[Philip_G]

I'm looking for an inexpensive monoblock amp to power my first DIY project before I build it, and it's between a titanic 10 and a shiva 12 for the driver, would 150 watts at 4 ohms be enough to power it in a large ported enclosure? the supply of cheap soundstream monoblocks on ebay seems to have dried up?

 

[Greg Monfort]

Depends on how loud you want it at the listening position. I'm betting you will be disappointed unless you normally listen to movies at ~the same volume as regular TV.
GM
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Loud is beautiful, if it's clean

 

[Scott Pultz]

I am powering 4 12-inch drivers (two per side... see www.wisdomaudio.com for more information) with 150 watts per sub using a Citation 7.1 amp. They can play much louder than I would ever want them too in a very large room... so you should be okay!

 

[Greg Monfort]

>>I am powering 4 12-inch drivers (two per side... see http://www.wisdomaudio.com Four drivers increases efficiency 6dB (4x power), plus you have 300W on tap for an additional 3dB (2x power). Assuming ~the same driver efficiencies (your site wouldn't load for me

), drive your subs with only 37.5W total (18.75W each), then let us know if you have enough power for HT at a typical listening distance.

GM
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Loud is beautiful, if it's clean

 

[Chris Sherman]

I'm using a 150w plate amp with my Dayton 12" DVC , which is nearly identical to the shiva driver , and I am more than happy with the levels I'm getting. I think you'll be fine with 150 watts. With the amp gain at the halfway point I measured peaks of 108-110db during the depth charge scene in U-571 at my listening position, plenty loud enough for me.

 

[Philip_G]

Hrm..
sounds like it might be OK, I'm a little antzy about feeding a 300 watt sub half of what it's rated. Keep in mind I like BASS and lots of it

 

[Philip_G]

I was going to pick up a 150 watt adire, but for the 20$ difference I just broke down and bought the 270

I want some bass that'll make the whole neighborhood go "DAMN what was that?" hahaha
thanks for all the great advice!

 

[Jack Gilvey]

...I'm a little antzy about feeding a 300 watt sub half of what it's rated.

A 300 watt amp will give you 3 more db, if that makes a difference in your installation.

 

[Josh O]

quote:
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...I'm a little antzy about feeding a 300 watt sub half of what it's rated.
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Straight from the Shiva Applications Notes:
"At first glance, Shiva would seem to indicate a need for a 600W amplifier, since that’s the power rating of
the driver. However, this is not the case. Very good results can be achieved with Shiva running from as
little as 40W per channel. Even smaller amplifiers (10WPC) can result in a musically satisfying
experience. It really depends upon your tastes and the capabilities of the loudspeakers paired with Shiva.
The 600W rating of Shiva is just that: a maximum power rating. This is the peak amount of power that can
be dissipated in Shiva over the long term. Realize that this level of power would yield an in-room output in
the 120 dB SPL range; this level is well beyond the typical continuous home listening environment.
However, assuming a source peak-to-average ratio of 25 dB (such as is typical for modern music, FM
broadcasts, and most soundtracks), listening at normal levels (80 dB SPL) would require peaks of 95 dB
SPL. This peak level requires 17.5 dBW, or 56.2W of amplifier power. As such, most home receivers
capable of 100W per channel performance will be quite suitable for use with Shiva.
We do realize that such listening levels (80 dB SPL nominal) are not for everyone. Some individuals will
listen to Shiva at higher levels. The 600W rating is intended to allow for those who enjoy musical peaks up
to and beyond 120 dB SPL in-room."
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The Compulsion

 

[Philip_G]

Ahh I missed that on their website. For the difference in cost and the +3 Db I'm glad I went with the adire 250.

 

[Greg Monfort]

This is the HT forum, where 115dB peaks/listening position in the 20-80Hz BW is the goal, not the exception.

You don't do this with 10W/40W, etc., even if you sit within 1m of it, unless it's extremely efficient, like Tom's twelve Shivas. ~20W! will do it in his room/listening position.
WRT to the Shiva apps notes, there's a typo, as 80 + 25 = 105dB, not 95, though the power requirement is correct.
That said, using > the driver's rated half power usually is a waste of Watts, as it heats the VC up so much that thermal compression negates most, if not all, the potenial 3dB gain.
Anyway, what's the point of HT if you listen to a movie at ~ the same volume you would a sitcom?

GM
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Loud is beautiful, if it's clean