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Maher

Klipsch Reference Premiere RP-450C Frequency & Crossover

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RP-450C has followings:

 

Crossover frequency: 500Hz/1500Hz

Frequency Response:58-25kHz;

 

Does it mean:

 

1. Tweeter's Frequency range  (1500Hz ~ 25kHz)

2. Inner 2 woofers' frequency range (500Hz ~ 1500Hz)

3. Outer 2 woofers' frequency range (58Hz ~ 500Hz)

 

As illustrated in the attached photo.

 

And do Voice/dialogue frequencies handled by inner woofers only ?


 

Klipsch-Reference-Premiere-RP-450C.jpg

Edited by Maher
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You interpreted the attached photo correctly, but crossovers are not "brick walls" -- the transition between speakers is gradual, with some overlap.

 

Several voice fundamental frequencies are below 500Hz, so the inner woofers probably need help from the outer woofers in reproducing voice.  The human voice range is from below 100 Hz all the way up to 16,000 Hz, for overtones and the articulation of fricative consonants, etc. 

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Thank you for the explanation

 

Since inner woofers and outer offers are same size while handling different frequency ranges with overlap; do this setup gives better sound producing overal comparing to if same size single woofer handled wider rang 58Hz-1500Hz ?

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4 hours ago, Maher said:

Thank you for the explanation

 

Since inner woofers and outer offers are same size while handling different frequency ranges with overlap; do this setup gives better sound producing overal comparing to if same size single woofer handled wider rang 58Hz-1500Hz ?

Possibly.  "Division of labor."  Also, the inner woofers may do a better job with middle frequencies because these middle frequencies don't have to ride back and forth on a cone pumping out bass frequencies as low as 58 Hz.  This should give you more clarity and lower Frequency Modulation Distortion (so called "Doppler distortion").  If you follow THX's advice and crossover to a subwoofer at about 80 Hz (or above, if something like Audyssey tells you to), that should help, too.  IMO, the inner woofers shouldn't be called "woofers" at all; 500 Hz is midrange.  "Tuning A" is below that, at 440 Hz, and it doesn't sound like bass to me.  The inner "woofers" are really midrange speakers.  The Klipschorn crosses over to its midrange driver at 450 Hz, and several others crossover to midrange at 500.

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I really appreciated your way of explanation :)

 

So setting this center speaker RP-450CA as Small will give better sound clarity. What is the crossover for small speaker setting ?

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17 minutes ago, Maher said:

I really appreciated your way of explanation :)

 

So setting this center speaker RP-450CA as Small will give better sound clarity. What is the crossover for small speaker setting ?

The exact crossover point depends, in part, on how the speaker behaves in your room, in its position, rather than how it behaves in a lab's anechoic chamber.  If it's good down to 80 Hz, then 80 Hz is a good crossover point.  If the speaker is near a wall, it will probably produce more bass.  You should definitely set all speakers to "Small" and use a subwoofer.

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My understanding of these "tapered array" center speakers is this.  All (4) woofers are playing at the lowest frequencies then it is passed to just (2) woofers and then on to the horn/tweeter.  That is the way the RC-64 is designed.

 

Image result for tapered array RC-64

 

 The RP-450C may be different.

 

Bill

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My understanding of these "tapered array" center speakers is this.  All (4) woofers are playing at the lowest frequencies then it is passed to just (2) woofers and then on to the horn/tweeter.  That is the way the RC-64 is designed.  The RP-450C may be different.








 








Bill




So even though speakers are large, will they sound better if set to small?


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1 hour ago, BlessedPrince said:


So even though speakers are large, will they sound better if set to small?


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  • Maher, according to Klipsch's own picture  -- the one you included in your first post -- the 2 middle "woofers" in the RP-450C, specifically, do not play at the lowest frequencies.   Only the outermost two do.  The middle ones start to roll off below 500 Hz.  EDIT: Apparently, some other Klipsch speakers, like the RC64s Willland was talking about do feed the deepest bass through all 4 woofers, but not the RP-450C -- unless the advertising copy is wrong.   
  • Providing you have a subwoofer, in a Home Theater application, almost all main speakers (Left front, Center, Right front, surrounds) can sound better if set to "SMALL."  The reasons: 1) Lower Frequency Modulation Distortion 2) Less distortion due to the main speakers being unable to cleanly handle very low frequencies 3) By cutting off the deepest bass going to your main speakers, your AVR will have more headroom. 4)Your subwoofer can handle bass better than your mains, in the vast majority of cases, and it has its own amplifier.

 

What kind of AVR or pre-pro/power amps do you have? 

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  • Maher, according to Klipsch's own picture  -- the one you included in your first post -- the 2 middle "woofers" do not play at the lowest frequencies.   Only the outermost two do.  The middle ones start to roll off below 500 Hz. 





  • In a Home Theater application, almost all main speakers can sound better if set to "SMALL."  The reasons: 1) Lower Frequency Modulation Distortion 2) Less distortion due to the main speakers being unable to cleanly handle very low frequencies 3) By cutting off the deepest bass going to your main speakers, your AVR will have more headroom. 4)Your subwoofer can handle bass better than your mains, in the vast majority of cases, and it has its own amplifier.





What kind of AVR or pre-pro/power amps do you have? 




I have Yamaha RX A1050 AVR and adcom power amp powering mains and surrounds. Klipsch 280 system.


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5 hours ago, Maher said:

I have Pioneer Elite SC-LX901

Maher:  There's bad news and good news. 

 

First, the bad news.  Nowadays, true power ratings of AVRs can usually be found only in reviews based on bench tests.  Seek out those reviews, if you're curious. The real power of the amplifiers in the Pioneer Elite SC-LX901 may be quite a bit lower than the advertising may seem to imply.  I couldn't find any specs for power when all 11 channels are driven at once, 20 to 20,000 Hz, at  8 Ohms, at low distortion, such as .05%.  This is the standard used with separate power amps, and is far less misleading than current advertising practice for AVRs,  Specifying power for just 2 channels (or even 1 channel -- I couldn't believe they did that) is rather silly, unless you are going to be running 2 channel music-- or even mono -- not movies.   So is publishing specs at 1KHz.  Somewhere I read that Pioneer claims that it can provide power across all channels with no loss of power.  If so, why are their power ratings so different for 1 and 2 channels, with no 5, 7, or 11 channel power ratings given (the .2 doesn't count because subwoofers have their own amplifiers built in)..  A good explanation of new (and misleading) industry practices for AVRs is given here:  http://www.audioholics.com/audio-amplifier/power-manipulation-in-av-receivers

 

Don't get me wrong -- none of this means the SC-LX901 isn't a fine AVR -- it probably is, it is just not as powerful as one may infer from the advertising.  It is certainly versatile, and has some features I wish I had on my pre/pro.

 

Now the good news.  Your Klipsch speakers are very efficient, so about 100 watts per channel, all channels operating, is probably just fine.  You can be more certain that your Pioneer is not running out of power by setting all main speakers to SMALL, because this channels the deep bass, which is often of high intensity, to the subwoofer, and doesn't strain the amplifiers in the Pioneer as much.

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my understanding is just simply divide total power 880W into 11 channels which gives 80W per channel. which is the maximum capability if all 11 channels are powering.

 

in my current setup (5.1) I'm using only 5 channels which might gives more than 80W per channel. may be between 80W~140W (Average 110W)

 

in near future I will configure it to 5.1.4 (9 channels) which gives around 97W per channel.

 

AM I right ?

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I doubt it---I would expect power numbers to be much lower that you expect.

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14 hours ago, Maher said:

my understanding is just simply divide total power 880W into 11 channels which gives 80W per channel. which is the maximum capability if all 11 channels are powering.

 

in my current setup (5.1) I'm using only 5 channels which might gives more than 80W per channel. may be between 80W~140W (Average 110W)

 

in near future I will configure it to 5.1.4 (9 channels) which gives around 97W per channel.

 

AM I right ?

 

At the top of their SC-LX901 page, they say 140 watts per channel, 2 channels operating, 8 Ohms, 20 to 20K, 0.08% THD, FTC.  That would imply that the figure for 11 channels operating would have a lower power output per channel.  For 5.1 (don't count the .1), a rule of the thumb used to be 80% of the w.p.c. given for 2 channels operating, so that would be 112 W per channel, in the case of the Pioneer, when limiting yourself to 5.1.  I don't know how legit that rule of the thumb is.   I also don't know how to evaluate your technique of dividing the total continuous power output by the number of channels, but the figure for the total to be divided up would not be 880 watts, for the reasons given later in this post.   The power supply will do what it does, so a bench test by an unaffiliated tech might be the best way to find out.  The magazines and online reviewers may have done such a bench test.  I'd start with Home Theater magazine.  If you have a local dealer with a repair department, they might be able to run a test to measure total power per channel, with 11 channels operating, 8 Ohms, 20 to 20K, .08% THD.    

 

If you click on "specifications" on their website, they say 850W total power into 8 Ohms for 11 channels, at 1K at 1% distortion.  IMO, to spec at at 1K and/or 1% distortion is very nearly meaningless, but that doesn't stop the advertising departments.  About all that can be said about that is it's better than at > 1% distortion!  1% distortion is the kind of spec that might have been seen in the 1950s or 1960s and not with good amplifiers -- and at 1K, 1% would be very clearly audible.  Also, even worse, 1K is relatively easy to produce at high power levels with low distortion.  In the '60s, at the old McIntosh Clinic, almost any amp, from almost any manufacturer, measured at about 0.1% throughout the midrange at full rated power, but bumped up to higher levels at the ends of the frequency spectrum because lower and higher frequencies are harder to produce at high levels.  That's why meaningful specs are listed at 20 to 20K Hz, into 8 Ohms, all channels operating at once, and at distortion levels much lower than 1%

 

If you set your Klipsches for SMALL, and use a crossover point that reflects the performance of your speakers, in your room, in their location, you probably won't have a problem, especially if you don't play movies at reference level, i.e., occasional peaks through the main speakers of 105 dB, and 115 dB through the subwoofer (which we don't count regarding the Pioneer).

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I Agree, even I don't know how to calculate the power per channel if more than 2 channels are running such as 5 channels setup. I assumed the dividend of total power into running number of channels. regarding the specs of SC-LX901; you'er right It's total power is 850W. in some websites it's specified 880W such is in the following Japanese website (http://jp.pioneer-audiovisual.com/components/avamp/sc-lx901/spec/)

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I did some quick research and found out it is better to keep all speakers to small for better performance and sound within there spectrum. Also give yourself a little more headroom when setting the crossover point (ex. My RP 280 dip to 33hz on paper but I was reading they kinda roll off around 50. So I'd set the crossover at 60-80hz. Let the sub do the heavy work and your speakers do there job even better. ) I used to have them set to large too. But as I read; when you have them set to large they bypass the bass management and even then they can't produce all the sound your forcing them too. Also if you want more power just buy a power amp. I purchased one to take the stress of my receiver and it also gave me a better(warmer) sound while sending more power to mains for music. Just my opinion.


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