Jump to content

KG4 with 1 wpc amp


Boriso

Recommended Posts

Hello

 

I know that these are very efficient speakers, but how low can one get with the power with them? Do people have experience driving KG4 speakers with very low power amplifiers? I am considering buying a 1 wpc amp, and trying to understand the implications.

 

Thank you

Link to comment
Share on other sites

The real experts will chime in here, but from what I see...

 

The KG4s apparently have a 94dB sensitivity, which is good but not really great. They are bass reflex, so they're not going to be all that sensitive. So driving with a 1W amp isn't going to give you that much sound especially in something other than a small room.

 

It really all depends on how loud you like to listen to music. Punching the info into an amp power calculator, at a reasonable listening distance (9 feet) one watt will give you about 78.5dB of SPL, which isn't exactly room shaking. 

Link to comment
Share on other sites

3 hours ago, Boriso said:

Hello

 

I know that these are very efficient speakers, but how low can one get with the power with them? Do people have experience driving KG4 speakers with very low power amplifiers? I am considering buying a 1 wpc amp, and trying to understand the implications.

 

Thank you

 

Welcome to the forum!

 

How big is the room (in cubic feet)?

How far do you sit from the speakers?

Do you use bass boost?

What kind(s) of music?

Do you like your music loud, medium, or soft?   

Do you crossover to a powered subwoofer?

 

The 94 dB sensitivity @ 2.83v @ 1m  indicates that the Sound Pressure Level ("loudness" or "volume") will be 94 dB when you are sitting very close (1 meter, or 3.28 feet, away) at 1 watt at 8 Ohms when there is 4 dB total room and boundary gain.  For the SPL in an anechoic chamber, subtract 4 dB. 

 

The SPL in a 3,000 cu.ft. room of average liveness at "normal" distance (whatever that is -- 13 feet?), at 1 watt will give you approximately 86 to 88 dB (medium to just barely loud) from each speaker.   I would think that would be  enough if you like your music at a medium level, sit fairly close, and don't play music with very high dynamic range.

 

My guess is that the full dynamic range of a symphony orchestra is beyond the capabilities of the KG4, and a 1 watt amp unless you have a very good, powered, subwoofer to add to the mix.  For every 3 dB increase in SPL, you need to double the wattage.  A loud passage might average about 95 dB, with instantaneous peaks (measured in milliseconds) of 105 dB through the main speakers and, rarely, up to 115 dB through the subwoofer.  THX suggests that you can do with 5 to 8 dB less in a home size listening room, because of early reflections (early compared to those of a big hall or commercial theater).  Don B. Keele Jr. (former chief engineer at Klipsch and frequent engineering writer -- see his website) characterized an average level of 115 dB as "too damn loud" (Dope from Hope, January 1977).  I may detect a whiff of Paul W. Klipsch's wording in that language.  PWK did say, if I remember the quote correctly, "To get the blood stirring effect of a full symphony orchestra, you need very brief peaks of 115 dB at your ears."   PWK recorded, and probably measured, full orchestras from time to time.  I believe I measured peaks generated by an orchestra I played in at 110 dB, C, "fast" from the 10th row, during the climax of "The Great Gate of Kiev."  I have an analog needle meter, so the real figure is probably much higher for very brief peaks, due to meter ballistics.  With "Fanfare for the Common Man" my Klipschorns get up to that level easily, and pressing my hand over the microphone makes no difference in those passages -- the sound goes right through, unthwarted.  Of course, in classical or modern orchestral music there is a lot of variability, and while OSHA says 115 dB is permissible for 15 minutes, musical peaks of this magnitude are truly instantaneous, with valleys between them of 15 or more dB less intensity.  Other kinds of music, with sustained sound of this level -- Rock, Metal, some electronic, etc. -- can harm your hearing if played back at this SPL. 

  • Thanks 1
Link to comment
Share on other sites

2 hours ago, fmalloy said:

.... Punching the info into an amp power calculator, at a reasonable listening distance (9 feet) one watt will give you about 78.5dB of SPL, which isn't exactly room shaking. 

@fmalloy

Although outdoors, one loses about 6 dB for every doubling of distance, indoors it is usually more like 3 dB, due to room reflections.  This may partly account for the difference in our SPL estimations.  Some calculators use the 6 dB figure, then make up for it later by adding back in the effect of the room, which is like using the 3 dB figure.

 

There is also some disagreement in the audio world as to what is "loud."  Loudness is a perceptual phenomenon, not a physical one, although the perceptual is related to the physical.  The amount of distortion makes a difference.  Frequency response makes a difference.  That being said, some of the charts online have a quaint idea of what is loud.  There is no way that 60 dB is "moderately loud" unless something pretty bizarre is affecting perception.  In my experience, Klipsch's chart is pretty good, i.e., with good, low distortion, equipment, or with live, unamplified music, "loud" can be expected to occur starting at about 90 dB at one's ears.   With an old fashioned, highly distorted, hashy transistor radio, 70 or 80 dB can seem mighty loud.  Some of them had more than 30% THD and IM distortion.  "Good" speakers at 105 dB can have 1.75%, 3%, 7%, or even almost 10% IM distortion.  

 

  • Like 1
  • Thanks 1
Link to comment
Share on other sites

1 hour ago, garyrc said:

@fmalloy

There is no way that 60 dB is "moderately loud" unless something pretty bizarre is affecting perception. 

Or unless the SPL meter is my grandma, where anything I play at any volume is "blaring"...well, unless it's Perry Como or Bing Crosby. :)

 

Seriously though, I always learn a lot from your posts - thank you for that!

 

I think with these speakers and a 1W amp, it's just not going to cut it for the OP, unless he/she/they listen to Muzak at elevator levels.

  • Like 1
Link to comment
Share on other sites

Thank you so much! I've learned a lot here already.

 

My reason for going this low is really economical. The speakers are relatively sensitive, and I do not listen at high volumes (low to moderate at best), and so I do not need high power. However, I just can't find low power high quality amps in my price range (<$1.5K). The one I found is this, and it's 1W.

 

Are there other low wattage amps anyone can recommend? My intuition is that I can do with as little as 5-10 wpc.

Link to comment
Share on other sites

If you're going to spend that kind of coin I'd suggest a vintage SS integrated amp that's been completely gone through.  Something from Marantz, one of the monster Pioneers, etc.

Otherwise on the used market you should find some nice tube amps in that price range with outputs of 10-20 watts/channel.

Link to comment
Share on other sites

10 watts would probably be enough (an extra 10 dB, compared to 1 watt) as would 20 watts (a total of an extra 13 dB), or 100 watts (a total of an extra 20 dB). 

 

The KG4s might need new capacitors. 

 

Go to the tube section of the forum,Talkin' Tubes, and see what they say about good amps.

 

As to vintage solid state, beware amps that used a great deal of feedback to achieve a minuscule level of THD and IM, but gave rise to a "new" kind of distortion Transient Intermodulation Distortion, or TIM.  I don't know exactly when they stopped doing this, but someone else probably does.

  • Thanks 1
Link to comment
Share on other sites

16 hours ago, Boriso said:

Do people have experience driving KG4 speakers with very low power amplifiers?

 

 

Yes!!!  And, depending on your listening requirements, it can be more than enough power.  In addition, you need not spend anything even close to your maximum budget to achieve excellent performance.

 

Definitely consider posting this question in the Talkin' Tubes section of the forum along with answers to the questions that Gary asked you above.  I'll try to check in this afternoon to provide some perspectives for you to consider.

 

Where are you located?

 

 

Maynard

  • Thanks 1
Link to comment
Share on other sites

I'm a huge Elekit fan - build yourself a TU-8200 for half the price, investing about $80 into tools and to replace the 12AU7 preamp tubes.

If you've never soldered before get a couple practice kits - I got some off Amazon even though I've done lots of point to point soldering in the past I didn't have much circuit board soldering experience.  I run mine in Triode mode, powering Heresy IIIs with 4.0 W/channel; but I have run my KG1s off it in UltraLinear Mode at 8.0 W/channel and it would drive you from the room.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...