Chorus I's, how much power?

[USNRET]

As you see it's all over the board. With my Quartet, Forte and Chorus systems I found that while 100 watts was fine, appropriate amps around 250 wpc woke them up. OTOH, moving to LaScalas, Belles, KHorns I preferred lessor wattage.

Yep, my opinion.
 

Edited April 1, 2015 by USNRET

[oldtimer]

Overall power may miss the point.  What you want is a quality amp that can handle the impedance dips in the speaker you are driving.  Any amp that doubles in power as impedance halves is quality in my book and will do the job very nicely.  Lesser amps that do not do this may still work just fine but will probably need to have more raw power numbers.

[jjptkd]

With my old Carver TFM-45 (375 wpc) I was surprised to find that about 90% of my listening only registered about 4 watts on the meters. The Chorus do not need massive power but they can take it. I'm just pointing out that if you want to really drive them to their max output without distortion I've found that it takes about 300 watts.

[Fjd]

Pulled from the web:

 

"Decibels, dB, are a measure of loudness. Unlike other measurements, decibels are logarithmic in scale not linear.

 

Speed is linear, 40km/h is twice as fast 20km/h. Time is linear, 60 seconds is twice as long as 30 seconds.

Decibels arent, 80dB isnt twice as loud as 40dB. 80dB is twice as loud as 77dB !

 

This is how "decibels" interprets into "loudness":

 

+1db is 1.25x louder

+3db is 2x louder

+ 20db is 100x louder !"

 

This is how I've always understood it. If the above is true than 4.77db would be about 2.5 times louder as I stated above.

 

 

You piqued my curiosity. I’m curious if you were able to validate the source or corroborate the information in any manner where all three measurements relate to "sensed" loudness?  The quote you have referred to doesn’t have any citation or author and the cross-reference to information in Wikipedia has been corrected in Wikipedia and no longer appears to support the original quote that all three measurements are related to 'sensed' loudness.  Here are the links I found with the information you have.

 

http://www.decibelcar.com/forum/5-spl-questions/4584-twice-as-loud--lets-talk-dbs.html

https://www.facebook.com/teamwattsup

 

http://en.wikipedia.org/wiki/Decibel

 

 

I believe that the quote you have is trying to outline "power" or sound intensity level, which does not equal "loudness" or psycho acoustic sound level.  Essentially, there are three different "measurements" in relation to sound; (1) power (sound intensity level - calculated), (2) Amplitude (sound pressure level - measured), and (3) Loudness (psycho acoustic - sensed).  The three measurements outlined in that quote are not all related to the psycho acoustic or sensed loudness.

 

If all three were measures of psycho acoustic 'sensed' loudness, think about it this way. If you consider the typical frequency response of +/- 3dB (Khorn, Belle & La Scala +/- 4dB in literature but often more in measurements) would result in an overall swing of a 6 dB swing meaning that music could have swings of 4 times (3 dB double loudness; therefore, 6 dB would be quadruple loudness) increase in the loudness or 4 times decrease in loudness that would not be attributed to the dynamics in the music itself. 

 

Note that the term “perceived” sound volume and the term “loudness” are both subjective terms trying to describe the strength of the ear's perception of a sound.   Essentially, loudness is only a subjective feeling that is commonly confused with objective SPL measurements in decibels.

 

When you consider the works of psycho-acoustic researchers such as Stanley Smith Stevens and Richard M. Warren; a more accurate rule of thumb would be that a doubling of the sensed volume (loudness) is equivalent to a level change approximately between 6 dB and 10 dB.

 

Think of it this way in that you have three different situations. There are two objective measurements, power and amplitude; and one subjective measurement, loudness.

 

 

 

 

 

Here is a nice sound level comparison chart showing the various ratios the respective ratios of subjective volume (loudness), objective sound pressure (voltage), and sound intensity (acoustic power).

 

 

 

 

From the chart above:

 

Power (sound intensity level - calculated):

Sound power ratio 2 (two times the intensity) changes the sound power level by 3.01 dB

 

Amplitude (sound pressure level - measured):

Sound pressure ratio 2 (two times the pressure) changes the sound pressure level by 6.02 dB

 

Loudness (psycho acoustic - sensed):

Loudness ratio 2 (two times (twice) the loudness) changes the sound loudness level by 10 dB

 

 

From the chart above:

20 dB gain change should give about the ratio of 4 (four times) for sensed volume and loudness

20 dB gain change gives the ratio of 10 for measured voltage and sound pressure

20 dB gain change gives the ratio of 100 for calculated sound power and acoustic intensity

 

 

Some additional resources:

 

http://trace.wisc.edu/docs/2004-About-dB/

 

http://www.campanellaacoustics.com/faq.html#basic_loudness

 

http://scitation.aip.org/content/asa/journal/jasa/48/6B/10.1121/1.1912298

Edited April 1, 2015 by Fjd

[Mystik Cabs]

Thanks for the replies, I am not really concerned with more volume but more "oomph". So far I have tried a 27 WPC Fisher X-1010C, a Denon 80 WPC, a Marantz 2216 @ 16 WPC and a Pioneer SX-850. The Pioneer is the clear winner here, just wondering if I'd be better of with even more power for quality of sound.

[oldtimer]

More quality power is always a good thing.

[Kent T]

50 quality, low damped SS watts is all you need. A McIntosh MA 5100 or MC 2505 is all you need unless your aim is hearing impairment. 

[OO1]

The Chorus models can sound very good up to reasonable volumes with a very small amplifier. However, if you are looking to fully drive them to their max potential or output you really need about 300 watts per channel. 200 watts gets you about 80-90% of the way there but they will bottom out at the upper end of the volume knob. I've driven my Chorus II's with a Sunfire 600x2 and they seemed to love the extra juice but really a 300x2 will do the job just fine.

I am confused -    CHORUS 1 is rated at 100 watts - you are suggesting 3x or 6x the rating - how can the speaker hold up with 3x or 6x the rating - aren't you going to blow components

 

http://www.klipsch.com/chorus-floorstanding-speaker/details

Edited April 27, 2015 by Randyh

[John Chi-town]

As Old Timer mentioned, reserve capacity power is what you are looking for.  An amp with caps the size of beer cans, something with more than 60,000 UF of filter capacitence.  This is what provides the "OMPH" or "Headroom" you need.  My amp is rated at 250 continuous but has been bench tested at well over 300 prior to cliping.  2 Channel forte II setup.  This type of arrangement INMHO provides for difficult passages and or loads. Use an amp capable of literally driving as close to a 0 ohm load as possible.

Edited April 27, 2015 by John Chi-town

[John Chi-town]

 

The Chorus models can sound very good up to reasonable volumes with a very small amplifier. However, if you are looking to fully drive them to their max potential or output you really need about 300 watts per channel. 200 watts gets you about 80-90% of the way there but they will bottom out at the upper end of the volume knob. I've driven my Chorus II's with a Sunfire 600x2 and they seemed to love the extra juice but really a 300x2 will do the job just fine.

I am confused -    CHORUS 1 is rated at 100 watts - you are suggesting 3x or 6x the rating - how can the speaker hold up with 3x or 6x the rating - aren't you going to blow components

 

http://www.klipsch.com/chorus-floorstanding-speaker/details

 

That is what your volume control is for.  Sorry did not mean to come off sarcastic.  Your speakers are rated at 100 continuous, 1000 watts peak.

 

Best regards,

John

Edited April 27, 2015 by John Chi-town

[jjptkd]

I have hosted many parties where the stereo is turned up near max for literally hours on end and the only thing I've ever had give out on any Chorus is a tweeter diaphragm. I cannot say the same thing for the Forte or the KLF-30 as those woofers will go south in a hurry if you're not careful.

[derrickdj1]

This is how I understand the things with watts and power handling:

 

The speaker is roughly 100 db sensitivity

1 watt @ 1 meter =100 db

10 watt @ 1 meter=110 db

100 watt @ 1 meter=120 db

 

Large caps will allow a speaker to perform transient swing well.   Anything over 200 watts that can double down at 4 ohms should be way more than enough.  Most of us will not be in this hobby long if we are listening at 120 db on a regular basis.  I use an 80 watt amp on my Forte's and do not want to hear anything any louder, lol.

[John Chi-town]

Derrick & jjptkd

 

 

I agree I never play at ear bleeding levels.  The point I was trying to make was that an increase in performance will be heard and felt accross the entire volume spectrum.

 

Best regards,

John

Edited April 27, 2015 by John Chi-town

[djk]

Any good amp from about 45W~60W and up should be fine.

 

I ran a pair on bridged Adcom GFA-555 (900W) and they sounded a bit 'scared', but it didn't hurt them.

[garyrc]

You willl most likely loose 10 db at the MLP on average.

 

Yes, that's what PWK said about Khorns, if the Main Listening Position is about 16 feet from the front of the speaker.

[garyrc]

Pulled from the web:

 

+3db is 2x louder

 

+ 3 dB is 2 times the power in watts, not 2 times louder.   "Loudness" is a psychophysical judgment call, but in experiments, it took + 10 dB for most people to say that the stimulus was 2 times louder.  Sound Pressure Level (SPL) is measured in dBs, as read on a SPL meter..  "Volume" originally referred to how far you had to rotate a control to fill halls of different volumes with sound of the same SPL.