Restoration Project Klipsch KG 3.5 (KM 4) worth to do ?

[MicroMara]

The X-Over´s are reassembled now

 

 

 

 

My plan is , once they are fully reassembled during next week,  to listen to them for a couple of weeks before I change the caps

[Deang]

That soldering looks much better than I expected to see. Many years ago I did it for someone, I believe it was 12 awg though, and the foil lifted on me. It was an awful experience. That ended up being a one and done, and I won't do it for people no matter how much they cried.

[MicroMara]

What you can do today, never leave it until tomorrow .....old german saying , so I continued today to finish the first part on my KM 4 restoration project

 

Damping 10 insulation cutted in scale 1 : 1 to the original damping , for sides and rear panel and inner head surface of the cabinet

 

 

 

Inner cabinet from Top > Bottom

 

 

 

Inner cabinet from Bottom > Top

 

[MicroMara]

Next step was to reassemble the front bass port and the terminal with the x-over

 

 

connected the tweeter as well as the woofer

 

 

 

 

[MicroMara]

Positioning and connection with the cayin mono tubes

 

 

 

It´s a complete new start with the KG 3.5 , like unboxed and brand new , sounds totally different in view to my first audible impressions , much better of course ! Needs a couple of hours operation . Will tell you more about the audible changes a.s.a.p. 

[MicroMara]

My Lifetime experience dealing with audio says , if you´ve got something new whatever it is , after 5 to 6 hours from first time operation the gear must show it´s performance , if not put it back in the box and return it to your soleagent . I´can tell you now, after restoration from the KG 3.5 with origin x-over , its worth to restore them . For their size and concept, they´re amazing speakers ,can compete in a much higher price ranges . Brilliant what Klipsch had developed more than 20 years ago ! The only thing that I will do in the near future is a refresh from the caps .

[MicroMara]

@Deang  Hi Dean , merry christmas to you and your familiy . Would be nice , if you´re online within the next few days to have a look at the 4 uF & 8 uF origin caps on x-over board , they look a little bit puffed up , or do these caps always look like this ? What do you recommend when I´m going to replace them ? Please scroll up , there you can see them better.  Thanx

 

 

[henry4841]

I believe Dean will agree, the deep orange caps look like that new, epoxy coated. They will crack if ever swelling occurs which should never happen unless something goes terribly wrong upstream with the amplifier. Dean may say replace them with authorized Klipsch replacements but appearance wise they look fine. 

[oldred]

A job well done.

 

Enjoy them,

 

George

[CCG]

On 10/7/2022 at 3:35 PM, MicroMara said:

Today I took care of the internal parts of the KG 3.5. The single wire terminals are rebuilt, the new pole binding posts are in place.

 

 

Here you can see the old solid brass binding posts, after all these were far better quality than the ones on my RF7 MK II

 

 

 

 

Howdy and newbie here. Nice posting and restoration. Definitely a must on the banana female plugs. My sewelle connectors  feels loose and flimsy  with the original ones and I dont feel comfortable using it. I wanna replace it with the ones you have. How does it feel on the fittings and mating both plugs?

[CCG]

I have a question with the KG-3.5 porting position. What is the concept or design why they put it in the front and not the back side?

I didn't have much experience with front fire porting. How do you get the best out of this design in positioning and possible type of music to listen to?

Thanks, CCG

[Peter P.]

With front porting, positioning from the wall behind the speakers is not important, bass-wise so you have more flexibility in placement.

With rear porting, often the manufacturer will recommend a minimum distance between the rear port and the wall.

For instance, the manual for the Heresy IV recommends 12" minimum between the rear port and the wall.

I'm sure placing the port too close to a wall disturbs air flow out of the port.

[CCG]

Thank you...

[MicroMara]

6 hours ago, CCG said:

 

Howdy and newbie here. Nice posting and restoration. Definitely a must on the banana female plugs. My sewelle connectors  feels loose and flimsy  with the original ones and I dont feel comfortable using it. I wanna replace it with the ones you have. How does it feel on the fittings and mating both plugs?

the plug connections sit bomb-proof if you take good bananaplugs for the binding-posts.  If you like to diy own spaker cable have a look in here, lot´s of infoas about cables, plus, bananaplugs ....

 

 

 

[MicroMara]

7 hours ago, CCG said:

I have a question with the KG-3.5 porting position. What is the concept or design why they put it in the front and not the back side?

I didn't have much experience with front fire porting. How do you get the best out of this design in positioning and possible type of music to listen to?

Thanks, CCG

The installation of a Speaker with bass reflex port to the front also follows certain physical laws. In addition, one must understand / know what interaction chassis housing and reflex port enter.The bass reflex port allows, with the same cabinet size, an extension of the frequency range downward. This is due to the fact that the bass reflex box makes use of the sound radiated backwards by the bass driver. Physically, this is based on the following principle:

 

The air behind the bass driver exerts a spring force on its diaphragm (you can literally feel this spring effect when you press on a driver with your fingers). If, on the other hand, the diaphragm itself emits impulses at the rear, the elasticity of the air volume causes the excitation of the enclosed air and the air at the exit of the bass reflex tube to take place via a spring effect - generated by the air itself. Ultimately, therefore, air and driver form a springy and thus oscillating system (resonant circuit).

A spring (think of the suspension of a car) usually transmits impulses in a softened manner and also with a more or less time delay. However, at a certain impulse sequence, it can also have an impulse amplifying effect (resonance frequency: the spring gets a further "push" at exactly the right point, when it wanted to swing back anyway.

 

Back to the loudspeaker:

Here, too, the sound impulses that the diaphragm radiates to the rear are now passed on to the outside through the bass reflex port with a time delay due to the spring principle of the enclosed air. This results in phase shifts between 0 and 180 degrees. (At 180 degrees: diaphragm moves inward, at the same time air is pushed out of the bass reflex tube in the opposite direction). Exactly in the middle of these extremes lies the mentioned resonance frequency, it takes place at 90 degrees phase shift (tuning frequency). Exactly at this point, the rear sound supports the front sound to the maximum: Higher frequency ranges are namely more or less "sprung away", although the phase shift would be lower here. Lower frequencies cause the phase shift to increase to 180 degrees, which, due to the sound signals working against each other (= destructive interference), also leads to weaker amplitudes.

 

What are the practical advantages or disadvantages of bass reflex speakers? First of all, bass reflex systems are said to have a generally poorer impulse behavior compared to closed loudspeakers. In addition: Despite the actually better low bass capability, they tend to drop quickly in level in the range of the lower cutoff frequency.

 

However, the bass drivers experience a not insignificant workload reduction due to the described mode of action. As a result, fewer diaphragm strokes are necessary, which in turn leads to less sound distortion due to distortion, intermodulation and Doppler effect.

 

As a rule, the greater the listening distance to the bass reflex speaker, the cleaner the acoustic perception of the low-frequency spectrum. If you place the speakers near a wall and corners, this will increase the bass volume by about 3 to 6 dB. However, this can also lead to an unbalanced sound image.

 

[CCG]

5 hours ago, MicroMara said:

the plug connections sit bomb-proof if you take good bananaplugs for the binding-posts.  If you like to diy own spaker cable have a look in here, lot´s of infoas about cables, plus, bananaplugs ....

 

 

 

Those are amazing work on the connectors.  would lover to update my playback system along the way. Thank you for posting.

[CCG]

5 hours ago, MicroMara said:

The installation of a Speaker with bass reflex port to the front also follows certain physical laws. In addition, one must understand / know what interaction chassis housing and reflex port enter.The bass reflex port allows, with the same cabinet size, an extension of the frequency range downward. This is due to the fact that the bass reflex box makes use of the sound radiated backwards by the bass driver. Physically, this is based on the following principle:

 

The air behind the bass driver exerts a spring force on its diaphragm (you can literally feel this spring effect when you press on a driver with your fingers). If, on the other hand, the diaphragm itself emits impulses at the rear, the elasticity of the air volume causes the excitation of the enclosed air and the air at the exit of the bass reflex tube to take place via a spring effect - generated by the air itself. Ultimately, therefore, air and driver form a springy and thus oscillating system (resonant circuit).

A spring (think of the suspension of a car) usually transmits impulses in a softened manner and also with a more or less time delay. However, at a certain impulse sequence, it can also have an impulse amplifying effect (resonance frequency: the spring gets a further "push" at exactly the right point, when it wanted to swing back anyway.

 

Back to the loudspeaker:

Here, too, the sound impulses that the diaphragm radiates to the rear are now passed on to the outside through the bass reflex port with a time delay due to the spring principle of the enclosed air. This results in phase shifts between 0 and 180 degrees. (At 180 degrees: diaphragm moves inward, at the same time air is pushed out of the bass reflex tube in the opposite direction). Exactly in the middle of these extremes lies the mentioned resonance frequency, it takes place at 90 degrees phase shift (tuning frequency). Exactly at this point, the rear sound supports the front sound to the maximum: Higher frequency ranges are namely more or less "sprung away", although the phase shift would be lower here. Lower frequencies cause the phase shift to increase to 180 degrees, which, due to the sound signals working against each other (= destructive interference), also leads to weaker amplitudes.

 

What are the practical advantages or disadvantages of bass reflex speakers? First of all, bass reflex systems are said to have a generally poorer impulse behavior compared to closed loudspeakers. In addition: Despite the actually better low bass capability, they tend to drop quickly in level in the range of the lower cutoff frequency.

 

However, the bass drivers experience a not insignificant workload reduction due to the described mode of action. As a result, fewer diaphragm strokes are necessary, which in turn leads to less sound distortion due to distortion, intermodulation and Doppler effect.

 

As a rule, the greater the listening distance to the bass reflex speaker, the cleaner the acoustic perception of the low-frequency spectrum. If you place the speakers near a wall and corners, this will increase the bass volume by about 3 to 6 dB. However, this can also lead to an unbalanced sound image.

 

Very well explanation. As I measured the box volume size is approximately  41.68 liters
3.5 inch front port.  I notice on the playback this produces a "very good" bass dynamics pleasantly on medium power lets say around 10 watts of tube power. I'm trying to break in my newer and see if this is truly if this cabinet will be a perfect match including the size of my living room which is 600 sq ft. 

The other thing that confuses me  on these klipsch speaker cabinet is the ohm reading. It says 8-ohms and the readings I'm getting is 3.9 ohms. O'm kind of a bit alarmed because I intend to use this in hi fidelity purpose listening to tube amps with only an 8-ohms speaker output. I'm nit sure if this is compatible enough not to hurt my output transformer.

Are you using your KG-3.5 speakers in audio or video setup? What if your comment in your new speakers?

Thank you. CCG

Thank you.. 

of KG-3.5

[MicroMara]

I use them as two channel audio only.

 

I use them from time to time as I got my RF7 EvoTec also, at 8 Ohm amp outputs a well. Sometimes via streaming, sometimes SACD, sometimes vinyl. The KG 3.5  has a sensivity of 94 dB at a FQ of 36 Hz to 20 KHz. I do not have to cranck it before it opens completely and everything is " there " . So from 65 dB sound pressure it fills the large room with a very open clearly structured stage. At higher levels, from 80 dB is here really the "hell" going on, impressive !

 

The KG 3.5  is very homogeneously tuned, the horn plays silky and crystal clear. They draw high resolution but just never "annoying.  Weasel-quick is the emotional musical flow , with wonderfully localized voices. Piano passages make me think ..they are so so beautiful,fascinating !

 

Wind instruments...I hear the "blowing" of the mouthpieces, classical instruments are authentic in reproduction, really graceful to me. Everything comes very very smoothly as well as with a good portion of "emotion",amazing !

 

There is no "hole" in the FQ of 36 Hz > 20 KHz. Treble, brilliance, presence, midrange, midbass, upper bass,lower bass ..everything fits, meshes, sophisticated !

 

Subbass punch ?  They have, the pitches are just right..stunning !

 

They are "all-round" flawlessly play through any genre. THe KG 3.5 wants you to listen to him ! They manage to take you on their musical journey. You don't get tired of them either...new tune = new attention to their performance...unusual !

 

Well..okay they get playback equipment in the 10 K€ league each , not depending as I run them with Hybrid Mode ( Tubepre with SS powerstage or Transistor Pre with Tubemonos , or Tubepre with Tubemonos, or as Transitor Pre > SS powerstage ) That probably plays an important role behind the scenes, but it challange them and just gets everything out of them.The harmony between electronics and KG  3.5  fits apparently in these combinations from the beginning, endlessly harmony !

 

[CCG]

On 1/3/2023 at 8:14 AM, MicroMara said:

I use them as two channel audio only.

 

I use them from time to time as I got my RF7 EvoTec also, at 8 Ohm amp outputs a well. Sometimes via streaming, sometimes SACD, sometimes vinyl. The KG 3.5  has a sensivity of 94 dB at a FQ of 36 Hz to 20 KHz. I do not have to cranck it before it opens completely and everything is " there " . So from 65 dB sound pressure it fills the large room with a very open clearly structured stage. At higher levels, from 80 dB is here really the "hell" going on, impressive !

 

The KG 3.5  is very homogeneously tuned, the horn plays silky and crystal clear. They draw high resolution but just never "annoying.  Weasel-quick is the emotional musical flow , with wonderfully localized voices. Piano passages make me think ..they are so so beautiful,fascinating !

 

Wind instruments...I hear the "blowing" of the mouthpieces, classical instruments are authentic in reproduction, really graceful to me. Everything comes very very smoothly as well as with a good portion of "emotion",amazing !

 

There is no "hole" in the FQ of 36 Hz > 20 KHz. Treble, brilliance, presence, midrange, midbass, upper bass,lower bass ..everything fits, meshes, sophisticated !

 

Subbass punch ?  They have, the pitches are just right..stunning !

 

They are "all-round" flawlessly play through any genre. THe KG 3.5 wants you to listen to him ! They manage to take you on their musical journey. You don't get tired of them either...new tune = new attention to their performance...unusual !

 

Well..okay they get playback equipment in the 10 K€ league each , not depending as I run them with Hybrid Mode ( Tubepre with SS powerstage or Transistor Pre with Tubemonos , or Tubepre with Tubemonos, or as Transitor Pre > SS powerstage ) That probably plays an important role behind the scenes, but it challange them and just gets everything out of them.The harmony between electronics and KG  3.5  fits apparently in these combinations from the beginning, endlessly harmony !

 

Thanks for sharing your thoughts and will use that as a basis on my venture with the cab. I was testing  it last weekend and made a video with the new amp since its still on break-in. I will use this video as a basis after I do a slight mod in the tweeter section this coming weekend and see if there is a change for the better.

Edited January 4, 2023 by CCG

[MicroMara]

21 minutes ago, CCG said:

Thanks for sharing your thoughts and will use that as a basis on my venture with the cab. I was testing  it last weekend and made a video with the new amp since its still on break-in. I will use this video as a basis after I do a slight mod in the tweeter section this coming weekend and see if there is a change for the better.

That sounds great to me , I listened to your video via headphone ! You´ve changed the caps allready as far as I understood , kindly let me know which manufacturer you´ve choosen . You ´ve changed the caps in the low and high pass together ? Changing the diafragms as well to titanium ? Great Gear btw .