From KEF Reference Model One to KEF Reference Model 103/4: upgrade or downgrade?

[JayPare]

I currently have a set of KEF Reference Model One and I love them. However, I came accross a pair of Reference Model 103/4 on a local listing website that need internal speaker refoam. The price is accordingly (cheap) so I was wondering if it could be a nice upgrade if I buy then refoam them?

 

[wmgwizard]

https://us.kef.com/explore-kef/kef-museum/1990s/reference-series-models-one-two-three-four

https://us.kef.com/explore-kef/kef-museum/1990s/reference-series-model-1034-1992-95

Looking at the specs it appears the 103/4 has two low frequency drivers while the Reference One has only one. The 103/4 also appears to be more efficient and has a slightly more extension at the lower end of the frequency spectrum. Strangely it seems as though KEF underrates their low frequency capabilities as many reviews claim they have much better bass than the specs might suggest.

I have heard the 103/4 and thought they sounded quite nice but I'm not so sure the potential "improvement" is worth the cost to upgrade, only you can decide that.

 

[JayPare]

The 103/4 also appears to be more efficient and has a slightly more extension at the lower end of the frequency spectrum.

Sorry if it's a noob question, but how can you know the efficiency with the specs? I know KEF are known to be not really efficient, but I'm not sure how to check this?

 

[wmgwizard]

The specs list the "Sensitivity" measurement usually displayed as DB @ 1 watt@ 1 meter. This means they set up a calibrated microphone 1 meter from the speaker and send 1 watt of "pink" noise to the speaker and measure it's Sound Pressure Level(SPL).

Reference One 89db
103/4 91db

Higher is better.

The scale is not logrithmic, a 3db increase would sound twice as loud when fed the same signal at the same power level.

A more sensitive/efficient speaker will play louder and/or require less amplifier power to fill the room with sound.

 

[JayPare]

The specs list the "Sensitivity" measurement usually displayed as DB @ 1 watt@ 1 meter. This means they set up a calibrated microphone 1 meter from the speaker and send 1 watt of "pink" noise to the speaker and measure it's Sound Pressure Level(SPL).

Reference One 89db
103/4 91db

Higher is better.

The scale is not logrithmic, a 3db increase would sound twice as loud when fed the same signal at the same power level.

A more sensitive/efficient speaker will play louder and/or require less amplifier power to fill the room with sound.

Thanks for the explanation!

 

[sqlsavior]

Higher is not 'better'. Higher is louder.

Specifications won't and don't describe the sound quality.

An increase of 10 dB is perceived as 'twice as loud'. 3 dB is perceived as 'noticeably louder'. A 3 dB increase requires twice the power.

 

[JayPare]

Higher is not 'better'. Higher is louder.

Specifications won't and don't describe the sound quality.

An increase of 10 dB is perceived as 'twice as loud'. 3 dB is perceived as 'noticeably louder'. A 3 dB increase requires twice the power.

I think @wmgwizard should have add quotes around better, but I got that it does not always mean better.

Also, I thought 6 dB was twice as lound? 3dB seems to be 1.5 times as loud, isn't it?

Source: http://www.sengpielaudio.com/calculator-db.htm

Edit: Are we talking in voltage dB or in power dB when measuring sound loudness? From the source, power is "Sound intensity, sound energy density, sound energy, acoustic power". Therefore if we are talking power dB wmgwizard is right, ~3dB is twice as loud.

 

[sqlsavior]

We are talking power, so click the 'energy size' option, put in 3 dB and click calculate. You will get 1.995262314968879, which reflects rounding error in the program, but should be 2, for the factor. Twice the power is needed for an increase in volume that most people will notice.

With the 'energy size' selected, enter 10 dB and calculate. You will get 10 for the factor. Ten times the power is perceived as 'twice as loud', by most people.