Is 250watts enough for CS-Ultra? (1 Viewer)

[mctague]

I'm hoping the SVS guys chime in here, since virtually no one has their Ultra's setup yet:
I plan to use a spare channel from an outlaw 750 (165@8ohms/250@4ohms) to power ONE (no room for two, yet) CS. Will a CS-Ultra have sufficient performance on 250 watts, or should I downgrade to a non-Ultra. In other words: is the Ultra harder to drive than a normal CS, or do you promote more power because she'll take it? I could get a second sub a few years from now for a dedicated HT room.
I'm not the ultimate bass-hound, so I won't be pouting over a few lost dBs....

 

[Tom Vodhanel]

>>>I plan to use a spare channel from an outlaw 750 (165@8ohms/250@4ohms) to power ONE (no room for two, yet) CS. Will a CS-Ultra have sufficient performance on 250 watts, or should I downgrade to a non-Ultra. In other words: is the Ultra harder to drive than a normal CS, or do you promote more power because she'll take it? I could get a second sub a few years from now for a dedicated HT room.
I'm not the ultimate bass-hound, so I won't be pouting over a few lost dBs....

 

[mctague]

Good answer on the power front!
I'm probably one of the few enthusists who still happily runs a 5.0 system....so I've got NO sub right now....pricey full range mains rated @ 35hz at -3, so I haven't been doing totally w/o.
I'll need to double check dimensions, but it has 9' ceilings and the short wall is probably over 18' since I just measured 14' for some potential in-wall cabling. So its slightly bigger than my old apartment. Like I said though, NO room for dual subs here....

 

[mctague]

24 x 19 x 11....so its barely over 5000 cu ft.

 

[Tom Vodhanel]

Ok, 5000 cu-ft.
I've pushed a couple CS_U woofs far beyond driven, And here's what I know...
BTW---(for me)the term *ground plane* implies a subwoofer place on the ground...at least 60-70ft from the nearest reflective boundary...with the measuring mic 2 meters away. This is synonymous with free-air or anechoic using a 1 meter measuring distance.
We have a series of response tests on the CS_U on the website. I swept the CS_U from 95-110dBs using a groundplane method. You can see from the chart...
http://www.svsubwoofers.com/images/r...tsmisc/no1.JPG
Even with 110dB sweeps, the single CS_U stayed pretty linear.This was using one side of a S1000...about 550w max. From what I've seen using lesser amps...there's no way we were pushing more than 500w into the woof. So if we got a linear 110 sweep with 500w, then 250w would = a linear 107dB sweep...125 would equal a linear 104dB sweep and even 60w would equal a linear 101dB sweep.
Remember, this is measured at 2 meters---groundplane. If you put this in a good corner of a 5000 cu-ft room..I'd guess you couls expect about 9dB increase in output from the boundary reinforcement+room gain effects.
So that's a solid 115dBs down to the 18-20hz range.
Not bad,
TV

 

[John Cain]

McTague???
I am thinking about doing the exact same thing with an Outlaw Amp.
Did you ever use your extra channel for the CS-Ultra, and how well does it work for you??
Thanks,
-- John
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[Doug_B]

Do understand the potential tradeoffs of using a multichannel amp to drive most of your 5 channels as well as a sub channel. I can't speak to the 750 in particular, but I would bet you'd be driving your amp harder (with bassy HT material) using 3 channels for the front 3 speakers and 1 channel for the CS_U versus the 3 front + 2 surround speakers. In the former case, if you add a rear center as well, then it strains the amp even more. Guess it doesn't hurt to try if you have the spare channel available, just keep an eye and ear on the results.
Doug
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"Today is a good day to die." ...Old Lodge Skins

 

[Randy G]

Or go with a Sherbourn 5/1500A type amp. Monoblock-style construction with separate transformers. 200watts into 8 ohms, and over 300 into 4.

 

[John Cain]

Good point Doug.
Here is my situation.
I need an amplifier to power my four rear speakers.
Two side-surrounds and two rear-surrounds are all I need to power.
I'm thinking that if I get a 5 channel amp, I can use the extra channel for my Subwoofer.
I saw this older thread and was wondering if this fellow had done this. I am also wondering how this would work if four of the speakers were nominally 8 Ohms and the SVS was 4 Ohms.
-- John
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