Setting crossover w SVS/Def Tech 450s

[sweeppicker]

I'm thinking of getting the SVS PB12-plus/2 to go with my SM 450s. Biggest concern is I'm trying to ride these monitors to 105 db for theatrical levels. Theyre going in a post production studio. As much as I love Def Tech I take their freq resp claims with a grain of salt. Anybody think these speakers will start to sound compressed at those levels ? I'm not sure where best to set the crossover ? Seamless blending and linear response is a priority. Would I be better off with the powermonitor 900s ? I m not a fan of self powered speakers esp with built in subs but I have been told these bookshelfs sound pretty damn good. Bascially we need a sytem that wont strain and will sound clean. Thanks

 

[rschleicher]

Yeah, Definitive's stated frequency response numbers are more of a "usable" response range, rather than -3 dB points. My old BP10's have a stated lower end of 20 Hz., but measurements I've seen reflect a -3 dB point of more like 27 Hz. (still pretty low for a floorstander with 6.5" mid-bass drivers).

You are probably not going too far astray if you just use 80 Hz. for the receiver's crossover setting, especially with a nice sub. Even if the fronts can go somewhat lower, your surrounds may have less bass extension, and most receivers don't let you set a different crossover for different speaker positions. (Or maybe also try 60 Hz. to see if you like that better.)

 

[AVRat]

What is the low-pass crossover frequency to 10in. woofer in the 450s and what are the dimensions of your space?

 

[sweeppicker]

Hi AVRat,
The 450s have a passive 10" radiator, a 6.5" midrange and dome tweeter. I havent been able to find any info on the cross over point for the midrange driver. I'm moving into a new studio which should be around 20" x 15". Maybe bigger. Room will be acoustically treated.

 

[jaxvon]

You're planning on using these as studio monitors? If so, I recommend that you look into the B&W's offerings. While I'm not a fan of their speakers for pleasure purposes, they are used in many highly regarded studios for their neutrality.

Edit: I think that you'd do best to look into the 700 or 800 series.

 

[AVRat]

This info from Chet @ DefTech:

Thanks for your recent email to Definitive Technology. The crossover frequencies used in the StudioMonitor would be 60hz, and 3,000hz.

(The 10" side-firing passive radiator takes over around 60hz, and the 6.5" bass/midrange driver naturally rolls off around 60hz.)

I didn’t expect these numbers, but I shouldn’t be surprised since I prefer to limit the 6.5” driver to 60Hz also (no matter how many there are). Speaking with Chet a while back, he told me the powered units were X-over at 120Hz, which is where I was going to suggest your X-over point. So, as you can see, even at 60Hz you are somewhat negating the 10in. driver of the 450. At this point I’m not sure what to tell you since most bass managements’ lower X-over point is 40Hz. I would prefer to use the CLR 2000/2002 with sub(s), if it were me.

BTW, you will have no problem achieving that sound level in that space with any of the gear you are planning to use. Even my ProCenter C-2 does it cleanly, and my space is the same size.

I think I missed what exactly you are setting up. Is it a 2/5/7.1/2 system?