Next Upgrade!!! SVS Ultra in the House!! (1 Viewer)

[Steven Simon]

Ok guys,

I am officially in Upgradidis mode!!! I need some serious help!!! Next on the agenda is an SVS PC Ultra..... I had a 25-31PC , and now am using both in the larger theater.....


This combo produces bone crushing, low detailed bass.....While the single 25-31 threw of good bass, I'm now getting engulfed with LFE... My theater seats are now shaking during the low frequency clips... The sonic energy these cylinders throw off is mindblowing!!!


Kudos to the guys over at SVS.... They make one hell of a product, at a reasonable price point....

 

[steve nn]

>>Kudos to the guys over at SVS.... They make one hell of a product, at a reasonable price point....

 

[Steven Simon]

Steve,

I'm still playing around with the placements... I may just go solo with the Ultra if that is the case.....

 

[steve nn]

My theater seats are now shaking during the low frequency clips... The sonic energy these cylinders throw off is mindblowing!!!
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It's amazing what the PC-Ultra can dish out and still have left in the tank. (Not to take away from the 25-31PC+, incredible unit) Their just differently tuned subs working against each other (basically) to a degree placed in the same room. After trying the Ultra on it's own, I think you will be even more impressed with the sonic energy. Glad your open to trying it out.

Your theater is beautiful

 

[frank manrique]

quote:

"Their just differently tuned subs working against each other (basically) to a degree placed in the same room."

Steve,

Why is it so?

By now you're quite aware of what am trying to accomplish with the B4+s and 16-46s, so would greatly like to get your input as to why it isn't a good idea to "mix" different tunnings in the same acoustical environment...

-THTS

"...hi, my name is Frank...and am an SVS bassaholic..."

 

[Edward J M]

I suspect Steve had some phase problems that could probably be solved with some judicious tweaking of the continuously variable phase control on the PC-Ultra.

On the passive 25-31CS+, he only has the option of 0/180 by reversing the leads (unless he uses the Marchand SVS-01 Bass Box).

There really is no reason why Steven can't get the 25-31PC and the PC-Ultra to work well together, provided he has the capability to conduct FR sweeps in the room and assess the effects of tweaking the CV phase control on the PC-Ultra.

While two subs with the same tuning point and FR curve would be optimum, I still think he can obtain good results here with some time/effort spent on placement and phase.

Regards,

Ed

 

[Ned]

Or just put them together

All this upgrade talk is urging me to make a decision about what to add/replace with my 20-39CSi

Would a CS Ultra get enough juice from 350 watts? (2nd channel of Samson S700)

 

[steve nn]

Hi Guys and Thank you for your help Ed. I decided to work today so am rather late returning back. I did see Franks question at 1:00 A.M. before leaving, but to short on time.

Frank you definitely are a special case and not your typical user. I have never thought your bass endeavor consisted of getting the most spl in any certain frequency range. I applaud your goal and have faith in your path. With as many subs as you plan on running things will work out.

It has always been my experience working with what I have to work with as to not get the full benefit out of a lower tuned sub with a higher tuned. When I did mix the 25-31CS+ with the PC-Ultra I thought it was great but it did negate 6 dbs of my 12 db gain at 19 Hz. It started around 22 Hz and under. Playing with phase, distance and location had no positive affect. All FR sweeps done at present and in the past have always yielded cancellation. In the Freq range of 23 Hz and above it's never a problem. Maybe a db+- here or there but nothing noticeable. I have came to this same conclusion with running a AV-15 with the 25-31CS+ also. In running dual 25-31CS+'s with the PC-Ultra still the same.

In Steven's case. He will realise some headroom but (some) of the lower spl gain do to the lower tuned/EQ PC-Ultra will be canceled out from the higher tuned PC imo. Still a great setup though and still a gain over the PC. I elected to run my PC-Ultra on its own to realize the (most) spl gain in the lower freq. I thought possibly he might want to give it a try on account of him being so enthusiastic and rightfully so about the subsonic level.



now shaking during the low frequency clips... The sonic energy these cylinders throw off is mindblowing!!!

 

[frank manrique]

Thank you indeed, Ed and Steve...for the explanations given.

The more info I manage to collect about this complex aspect of audio reproduction, the better armed I'll be to face the many challenges that lay in wait for me...

-THTS

"...hi, my name is Frank...and am an SVS bassaholic..."

 

[Steven Simon]

Guys,

I reconfigured today using just the one Ultra, and I was surprised... The 2nd smaller 25-31Pc must have been really canceling out the Ultra, because the solo config is night and day better.. Matter a fact, it's perfect bass levels.... I have no need to run both.... I works out because where the Ultra is now behind the curtain, I only have room for one SVS sub... The second would have to go in front of the screen, not to my liking....

Anyways, I'm one happy camper at this point......

 

[steve nn]

Anyways, I'm one happy camper at this point......
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Thats great Steven and glad you were open to trying it out.

 

[dave alan]

The phase shift below tuning differs to a great degree between the 2 differently tuned subs.

If the Ultra has a subsonic filter, it will differ even more.

The CV control on the Ultra's amp is probably too narrow a bandwidth to have any effect below tuning (which would normally be fine in integrating only the Ultra).

Both Mark Seaton, when describing setting up a 2-way sub system, using 2 differently tuned subs, and the Velo rep, who briefly discussed the integration of the 12" and 18" drivers of the 1812 Velo flagship, mentioned the equipment and patience required to accomplish such a task.

Very cool find, Steve, and thanks for posting the info.

Dave

 

[Edward J M]

Awesome point, Dave. This is seems supported by the difficulty Steve encountered, starting at around 23 Hz. Leaving the 25-31CS+ in the 25 Hz tune probably will be the worst case, but even tuning the 25-31CS+ to 20 Hz will not result in the same phase shift as a 20-39 PC-Ultra, particularly with the infrasonic high pass filter enabled. Another very solid reason why doubling up subs is best done with the same model/size enclosure. Very astute observation - great post.

 

[ErichH]

Congrats Steven.
Around 16 months ago I owned my first Ultra and powered with a Crown K1. Amazing to say the least. It would do those little fast things in a soundtrack that no other sub would do. Can you say TV12?
After being without for a few months (not by choice), I'm back in the mix with a new SVU. This time around with the plate amp. I'd be very interested in your results with the PEQ. I have one available in my receiver, so the second via the Ultra will be a nice addition.

Good Luck & Have a Nice LF

E

 

[ErichH]

Steven

Any results to report with the PEQ? The bandwidth formula seems right, but I haven't had time to play with it.

E