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RP-140SA Crossover Setting


Ian

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I have three pairs of RP-140SA speakers in my 7.1.2 set up and I am having trouble with the crossover setting for the RP-140SA.  According to the spec sheet, the frequency response for the speaker, "conforms to Dolby Atmos Specification."  Apparently this is some secret thing because I can't find it anywhere, at least for home theaters.  My pre/pro does the auto-eq routine but like most, it varies and sometimes the RP-140SA crossovers are calculated at 40Hz (yeah right!) and sometimes they are 120Hz + or - 40Hz.

 

I don't know why it's some secretive thing, but it would be nice to know what the bottom range is so I don't over-drive them.  Does anyone know what the low end of the frequency response is?  I'm sorry to sound like this, but I just find it frustrating that this basic number isn't published on Klipsch's or Dolby's site.

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Since no one has replied, I dug out my (old and cheap) RTA and did some very unscientific tests. Ideally this would be done in an anechoic chamber or at least outdoors to remove the room's influence. After shutting off all of my other amps and setting the Atmos channels to full range, I ran pink noise and sweeps at -20, -10, and 0 with a close mic. It looks like the frequency response (+ or - 3dB) is roughly 58-63Hz. I'm going to set my crossovers to 80Hz to be safe, but at least I have a better idea now.

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12 minutes ago, Ian said:

Since no one has replied

Sorry Ian, I was going to reply but I was a bit baffled also by the lack of defining crossover specs on the Klipsch website.  Not sure what "conforms to Dolby Atmos specifications" means.

 

15 minutes ago, Ian said:

It looks like the frequency response (+ or - 3dB) is roughly 58-63Hz. I'm going to set my crossovers to 80Hz to be safe, but at least I have a better idea now.

Glad you were able to better decide what crossover point to use in your setup.

 

Bill

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17 hours ago, willland said:

Sorry Ian, I was going to reply but I was a bit baffled also by the lack of defining crossover specs on the Klipsch website.  Not sure what "conforms to Dolby Atmos specifications" means.

 

Glad you were able to better decide what crossover point to use in your setup.

 

Bill

It is a bit of a mystery, but I certainly don't fault Klipsch.  I'm sure they're just going by the terms of their agreement with Dolby.  It's a bit frustrating when you're trying to set up your home theater and don't want to put too much strain on your speakers, however.  I am impressed that the little 4" drivers in such small enclosures go down as low as they do, however, and they really make excellent surrounds.  

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27 minutes ago, derrickdj1 said:

I have my Atmos speakers XO at 80 Hz and no problems.  

 

I ran auto EQ in Dec. and forgot to change the speakers to small and fired one of the Atmos speaker.  

 

Definitely don't try to squeeze more out of the small speakers if there is a sub in the system.

Is that how that works?  I don't have Atmos so I don't know how AutoEQ deals with it.  I would figure that "auto" means "auto" and the setting would be changed for you.

 

Even so, even if the AVR sets the XO too low, doesn't the Atmos module have a passive XO that should have protected it?

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Auto-EQ is often pretty lousy with crossover points (and distances) and depending on your receiver or pre/pro it will set things too "large" or too low (in Hz).  That's really what got me started with this conversation.  While I think the standard / THX setting of small / 80Hz is appropriate in most cases, I was worried that these little speakers might need to be set higher, like around 100Hz to avoid damage.  I have 200W RMS running to these speakers which are rated for 50W RMS / 200W peak, so I definitely wanted to be sure I had things set right.  While I can't say for sure that they really go down to around 60Hz, I think/hope 80Hz or "Small" should be safe.  Of course clipping with too little power vs. too much is what typically destroys speakers.

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Hmm, just found this:

 

http://www.soundandvision.com/content/klipsch-reference-premiere-rp-140sa-atmos-elevation-module-review-test-bench

 

Test Bench

Elevation Module Sensitivity: 86 dB from 500 Hz to 2 kHz

 

The RP-140SA’s driver-axis response measures +3.34/–2.72 dB from 200 Hz to 10 kHz. The –3dB point is at 121 Hz, and the –6dB point is at 98 Hz. 

 

Perhaps a 120Hz crossover is more appropriate...

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It's not published because it's literally a Dolby spec that only OEM manufacturers have access to.  Response varies based on research of what is needed to pull off the psychoacoustic effect at Dolby, and isn't really your typical flat speaker with -3 db cutoff points.  Don't quote me on this but I think I read somewhere that they really only need to have a decent response down to 140-150 hz.  

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In the Sound and vision review on page 2

 

 "Because the height channels have a 180-hertz lowfrequency cutoff when Atmos-enabled speakers or modules are selected during setup, limited bass from the 4-inch woofers wasn’t an issue."

 
Be careful when using these as full range speakers.
 
I am planning on updating my AVR to an Atmos model and using four RP140SA running 5.2.4
 
What concerns me is I want these for movie watching only. For Bluray concerts I currently use Multichannel stero mode, I am trying to verify that in Multichannel Stereo mode with no Atmos signal present if these speakers will remain silent. It appears reading the Denon X____ manuals this may be an option if it has different memory setting for different modes.
 
 I am concerned about damaging one at my concert SPL levels.
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All, thanks for the additional details and I'm not sure how I missed that in the manual.  I suppose I'll set mine to 150Hz to err on the safe side, but it seems that they are certainly capable of going lower than that from my rather crude tests.

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Ian,

I would have replied much sooner had I seen this post. The 150Hz suggestion in the manual was a conservative number for those volume junkies. I personally use 80Hz on mine, but do not take my settings as "recommended by Klipsch". The speaker was designed with Atmos first and foremost the target, but the speaker is pretty versatile. 

When a speaker is set to "Dolby Enabled" in the AVR, it does NOT set a high pass filter, or engage some hidden filter for those channels. Atmos channels are all full range, it is up to the end user to set bass management properly. 

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21 hours ago, Jay L said:

Ian,

I would have replied much sooner had I seen this post. The 150Hz suggestion in the manual was a conservative number for those volume junkies. I personally use 80Hz on mine, but do not take my settings as "recommended by Klipsch". The speaker was designed with Atmos first and foremost the target, but the speaker is pretty versatile. 

When a speaker is set to "Dolby Enabled" in the AVR, it does NOT set a high pass filter, or engage some hidden filter for those channels. Atmos channels are all full range, it is up to the end user to set bass management properly. 

Jay, thanks for the reply and the excellent work on this speaker.  I had heard you were using these for surrounds and was inspired to give them a try.  I've got them for side and rear surrounds and front Atmos modules and couldn't be more pleased with them.

 

I appreciate your reply and keep up the excellent work!

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  • 2 years later...
  • 2 months later...
On 2/7/2017 at 6:23 PM, Ian said:

All, thanks for the additional details and I'm not sure how I missed that in the manual.  I suppose I'll set mine to 150Hz to err on the safe side, but it seems that they are certainly capable of going lower than that from my rather crude tests.

Hello Ian,

Sorry for the late reaction but I just bought a set of the 140sa and I wonder what is the best crossover?

150Hz or lower/higher?

Because what Gusphan said(80HZ) is a little strange because the the manual says 150 min. crossover.

 

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