RCF NX Subs

F

Fernando Lopez

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Jan 14, 2011
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www.runaway69.com
Does anyone know the difference between the RCF NXS21-A and the NXS25-A

I saw in the specs that the NXS25 is a double 15, goes up to 136dbs and down to 40Hz, while the NXS21 is a 21 inch, goes up to 135dbs and down to 30Hz.

Both enclosures are the same size and the stores that sell them recommend one of each per side with 2 NXL23-A on top for an audience of about 500

This is one example:
http://www.musicstore.com/es_ES/ESP/_SET_-RCF-NX-L-23-Groundstacksystem-/art-PAH217

If anyone can enlighten me on the differences and why to purchase one of each I would appreciate it.

Also has anyone used them?, are they really as loud as 2 4Pro subs (8001 or 8003)?


Thanks,
 
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Re: RCF NX Subs

Fernando Lopez said:
Does anyone know the difference between the RCF NXS21-A and the NXS25-A

I saw in the specs that the NXS25 is a double 15, goes up to 136dbs and down to 40Hz, while the NXS21 is a 21 inch, goes up to 135dbs and dows to 30Hz.

Both enclosures are the same size and the stores that sell them recommend one of each per side with 2 NXL23-A on top for an audience of about 500

This is one example:
http://www.musicstore.com/es_ES/ESP/_SET_-RCF-NX-L-23-Groundstacksystem-/art-PAH217

If anyone can enlighten me on the differences and why to purchase one of each I would appreciate it.

Also has anyone used them?, are they really as loud as 2 4Pro subs (8001 or 8003)?


Thanks,
Click to expand...

Hi Fernando,

I have not used or heard the NX series subs yet. With that said, my assumption is that RCF is playing off the strengths of each sub-design to improve the efficiency of the overall system (and provide more versatility). The double 15" subs probably provide more punch and definition than the 21" subs. Whereas the 21" subs probably provide more extension. Using the two together when properly implemented would give you the best of both worlds.

Conversely, if the genre you were reinforcing would be more adequately represented using one sub more heavily over the other, that would be possible too. As a speaker company, this has the added benefit of selling more boxes too!

If you're seriously considering this system (which I would think is very good based on one of my Customer's experiences with the NX series monitors), I would highly recommend giving it a real listen! Then you can fill us in on what you think of the difference between the subs and how they work together in the larger system.

Jeff
 
Re: RCF NX Subs

Jeffrey Knorr said:
Hi Fernando,

I have not used or heard the NX series subs yet. With that said, my assumption is that RCF is playing off the strengths of each sub-design to improve the efficiency of the overall system (and provide more versatility). The double 15" subs probably provide more punch and definition than the 21" subs. Whereas the 21" subs probably provide more extension. Using the two together when properly implemented would give you the best of both worlds.

Conversely, if the genre you were reinforcing would be more adequately represented using one sub more heavily over the other, that would be possible too. As a speaker company, this has the added benefit of selling more boxes too!

If you're seriously considering this system (which I would think is very good based on one of my Customer's experiences with the NX series monitors), I would highly recommend giving it a real listen! Then you can fill us in on what you think of the difference between the subs and how they work together in the larger system.

Jeff
Click to expand...


Thanks Jeff,

Another question which you might help me answer, do both of the subs have the same phase?

Would it matter if I place them vertically (as pictured by RCF) or couple them in the middle even if I have 2 of each model (2 S25s and 2 S21s)?

Thanks!!
 
Re: RCF NX Subs

Fernando Lopez said:
Thanks Jeff,

Another question which you might help me answer, do both of the subs have the same phase?

Would it matter if I place them vertically (as pictured by RCF) or couple them in the middle even if I have 2 of each model (2 S25s and 2 S21s)?

Thanks!!
Click to expand...

I almost guarantee that the phase responses are different, though they could be similar. Similar enough is not something that can be answered without measurements.

Unfortunately, advice on deploying subs is also very difficult over the Internet, especially as a general setup, and not something specific to one room.

If I were buying subs, I would find the one sub that fit most of my uses and buy that one. I don't like having lots of different boxes because when it comes time to combine everything for a larger show, it's really difficult if the stuff doesn't all match! It's also less flexible in many other ways, such as if we're talking about subs, you can't build sub arrays (easily?) with two different subs, or really even use them together without an extremely careful deployment.

Subs are always tricky.
 
Re: RCF NX Subs

Silas Pradetto said:
I almost guarantee that the phase responses are different, though they could be similar.
Click to expand...

Given that both subwoofers are front loaded ported cabinets of similar design, and probably identical electrical low pass, they are actually fairly likely to have similar phase response. They will differ in the low end where the 21" supposedly has greater extension, but should line up for the majority of their range.
 
Re: RCF NX Subs

Marjan Milosevic said:
If you look at the spec sheets of both nx25 and nx21 you will realize that they are more of a bandpass boxes then simple reflex ones.

http://www.rcf.it/professional-speaker-systems/nx-series
Click to expand...

I can't find anything on the double 15 sheet that says anything about how it's loaded, nor can I tell from the pictures. The response looks extremely narrowband, so it might imply a bandpass configuration, or they're just processing it strangely.

The 21 specifically says it's front loaded, and I can't find any evidence to suggest otherwise.
 
Re: RCF NX Subs

Narrow band? It operates from 40Hz to 120kHz!

I ASSumed that they were both front loaded, the group delay of the box will be dominated by the low pass filter, if they are of similar slope then the boxes will likely be compatible. Of course, the only way to know for sure is to measure, and once you can measure you can line up even subs of differing designs with a few tricks.

Of course, if you're at the level where you're capable of measuring and aligning diverse subwoofers, you can also demand that you not have to waste your time aligning diverse subwoofers!
 
Re: RCF NX Subs

Bennett Prescott said:
Narrow band? It operates from 40Hz to 120kHz!
Click to expand...

Haha. Yeah, RCF's spec sheets are a good laugh. But in reality, it's 10dB down by less than half an octave on either side of 70Hz...it's more of an Everest than the Great Plains...

Of course, if you're at the level where you're capable of measuring and aligning diverse subwoofers, you can also demand that you not have to waste your time aligning diverse subwoofers!
Click to expand...
Does that level also demand a Hawaiian shirt? :twisted:
 
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