Klipsch Forte

[Magnaryder 757]

Before JH passed he mentioned in his review of the Forte it had the flatest frequency response of any speaker he'd measured. I'm currently building new crossovers for my Fortes using Al Klappenberger's research and design. The Forte has a HUGE peak in the lower band, Al's crossover design works wonders on the Forte. I modded mine replacing the parts with Obbligatto film caps and Mills resistors. Quite a difference getting rid of the electrolytics.

 

ray

[RichP714 3,163]

Before JH passed he mentioned in his review of the Forte it had the flatest frequency response of any speaker he'd measured. I'm currently building new crossovers for my Fortes using Al Klappenberger's research and design. The Forte has a HUGE peak in the lower band, Al's crossover design works wonders on the Forte. I modded mine replacing the parts with Obbligatto film caps and Mills resistors. Quite a difference getting rid of the electrolytics.

 

ray

 

AK knows his stuff; when it came time to refurb my Cornwall II's I considered redoing the crossover; I ended up going active, bypassing passive crossovers entirely; the Cornwall II is already a very dynamic, revealing sound, but active amping was a great improvement 

[Magnaryder 757]

Before JH passed he mentioned in his review of the Forte it had the flatest frequency response of any speaker he'd measured. I'm currently building new crossovers for my Fortes using Al Klappenberger's research and design. The Forte has a HUGE peak in the lower band, Al's crossover design works wonders on the Forte. I modded mine replacing the parts with Obbligatto film caps and Mills resistors. Quite a difference getting rid of the electrolytics.

 

ray

 

AK knows his stuff; when it came time to refurb my Cornwall II's I considered redoing the crossover; I ended up going active, bypassing passive crossovers entirely; the Cornwall II is already a very dynamic, revealing sound, but active amping was a great improvement

 

 

 

Rich, How do you like the Cornwalls? There seems to be alot of modding going on over on the Klipsch Forum. I've been looking for a set of Belles. They're quite hard to find.

ray

[SteveK 89]

Before JH passed he mentioned in his review of the Forte it had the flatest frequency response of any speaker he'd measured. I'm currently building new crossovers for my Fortes using Al Klappenberger's research and design. The Forte has a HUGE peak in the lower band, Al's crossover design works wonders on the Forte. I modded mine replacing the parts with Obbligatto film caps and Mills resistors. Quite a difference getting rid of the electrolytics.

ray

 

Ray, 

Aren't these claims in conflict? On the one hand, "flatest frequency response of any speaker he'd measured" vs a huge peak in the lower band.

 

Did you hear a HUGE peak in the lower band with your stock crossovers?

Steve

[RichP714 3,163]

Rich, How do you like the Cornwalls? There seems to be alot of modding going on over on the Klipsch Forum. I've been looking for a set of Belles. They're quite hard to find.

ray

 

I've owned two pair in a D'apollito configuration (poor man's Duntech Soverigns) for almost three decades; fantastic dynamics, very revealing sound (they are here vs you are there)

 

Upgrading to Crites tweeters was very nice; time alignment probably made the biggest soundstage change 

[Daddyjt 9,645]

Rich,

 

Have you posted system pics anywhere on the site?

 

Would love to see photos of the "tower of power":-)

 

From one Carver/Klipsch fan to another....!!

 

Mark

[RichP714 3,163]

Rich,

Have you posted system pics anywhere on the site?

Would love to see photos of the "tower of power":-)

From one Carver/Klipsch fan to another....!!

Mark

 

It's not current, but http://thecarversite.com/yetanotherforum/default.aspx?g=posts&m=1824#post1824 

[PDR 1,194]

Ah yes.......I remember those posts, was a long time ago.

 

Rich, you should have that stack as your avatar again.......that was very cool. 

[Gene C 1,748]

 

Rich, you should have that stack as your avatar again.......that was very cool. 

 

+1  That avatar meant business.

 

[Magnaryder 757]

 

Before JH passed he mentioned in his review of the Forte it had the flatest frequency response of any speaker he'd measured. I'm currently building new crossovers for my Fortes using Al Klappenberger's research and design. The Forte has a HUGE peak in the lower band, Al Klappenberger's crossover design works wonders on the Forte.He did note the drivers are quite good by themselves. I modded mine replacing the parts with Obbligatto film caps and Mills resistors. Quite a difference getting rid of the electrolytics. 

ray

 

Ray, 

Aren't these claims in conflict? On the one hand, "flatest frequency response of any speaker he'd measured" vs a huge peak in the lower band.

 

Did you hear a HUGE peak in the lower band with your stock crossovers?

Steve

Imagine what the rest must look like:-)

 

 

I'll try to find the link over at Klipsch.

 

 

That was referring to an impedance spike, which probably corresponds to a amplitude drop in that area of the frequency range(guessing here). I was repeating what JH found, AK verified during his measurements and I hear(nothing jumps out at me, it seems the frequency response is 'smooth' for lack of a better term). No I didn't hear the peak, but how much more detail would there be if it was corrected?

 

 

I bought my Fortes from VHoP in October of 2012. I knew after 5 minutes of listening I had to take them home. This may not make much sense but, they sound like what I want to hear. Lately I've noticed alot of speakers sound 'shrill' to me. The HF is just plain annoying. I can't listen to that very long. I would have thought the Fortes would have sounded like that given they're horn loaded but they don't. The sound is just plain nice. After I got then home the more I listened the more I liked them. Because I got them so reasonably I figured I could spend some dosh and change the 20yr old caps. I stumbled across the Klipsch Community and found the Al's Forte crossover work and went from there. Updating the stock crossover is less expensive than doing his complete mod, but it does give a glimpse of what will happen using good parts. 

 

 

Running the Fortes with Lightstar makes the impedance peak less of an issue but having a network where the impedance issues are addressed  would have its advantages. It would make them easier to run with a SET or a low powered PP amplifier.   

 

 

ray

[Magnaryder 757]

Rich, How do you like the Cornwalls? There seems to be alot of modding going on over on the Klipsch Forum. I've been looking for a set of Belles. They're quite hard to find.

ray

 

I've owned two pair in a D'apollito configuration (poor man's Duntech Soverigns) for almost three decades; fantastic dynamics, very revealing sound (they are here vs you are there)

 

Upgrading to Crites tweeters was very nice; time alignment probably made the biggest soundstage change 

How did you time-align them? Crossover mod?

[SteveK 89]

 

Before JH passed he mentioned in his review of the Forte it had the flatest frequency response of any speaker he'd measured. I'm currently building new crossovers for my Fortes using Al Klappenberger's research and design. The Forte has a HUGE peak in the lower band, Al Klappenberger's crossover design works wonders on the Forte.He did note the drivers are quite good by themselves. I modded mine replacing the parts with Obbligatto film caps and Mills resistors. Quite a difference getting rid of the electrolytics. 

ray

 

Ray, 

Aren't these claims in conflict? On the one hand, "flatest frequency response of any speaker he'd measured" vs a huge peak in the lower band.

 

Did you hear a HUGE peak in the lower band with your stock crossovers?

Steve

That was referring to an impedance spike, which probably corresponds to a amplitude drop in that area of the frequency range(guessing here). I was repeating what JH found, AK verified during his measurements and I hear(nothing jumps out at me, it seems the frequency response is 'smooth' for lack of a better term). No I didn't hear the peak, but how much more detail would there be if it was corrected.

ray

 

I'm wondering what a huge impedance spike sounds like. It is at 2150hz right around where we hear best. Maybe it has an effect on sound stage width or depth etc.

 

Although the components are different values AK designed a similar crossover for the Forte IIs. Nothing jumps out at me either.

Steve

 

 

 

 

[RichP714 3,163]

Rich, How do you like the Cornwalls? There seems to be alot of modding going on over on the Klipsch Forum. I've been looking for a set of Belles. They're quite hard to find.

ray

 

I've owned two pair in a D'apollito configuration (poor man's Duntech Soverigns) for almost three decades; fantastic dynamics, very revealing sound (they are here vs you are there)

 

Upgrading to Crites tweeters was very nice; time alignment probably made the biggest soundstage change 

How did you time-align them? Crossover mod?

 

I'm using Rane crossovers (I think most active crossovers have some type of time delay provisions) 

[RichP714 3,163]

.....I'm wondering what a huge impedance spike sounds like......

 

Much depends on the crossover design (series or Parallel(most are parallel), the frequency involved, and the amplifier output impedance

 

All drivers have a resonance peak; the only one that is typically in it's passband is the woofer; the mid and tweeter resonance are usually way below their crossover points

 

4-way systems, popular for a time, almost universally operate one midrange in its resonance region; effects vary from 'more clarity' to 'more strident' depending on the amplifier design (if the amp sags a bit, the resonance will compensate somewhat, if the amp is more linear it will sound harsh)

 

Parallel crossovers aim to provide constant voltage across the audible range, and will do so as long as the resonance peak isn't in the passband of the driver 

 

Most solid state amplifiers aim to be an ideal voltage source; most tube amplifiers have a higher output impedance, and start to behave a bit like a transconductance amplifier (ideal current source)

 

With regard to loudspeaker impedance, the higher output impedance amplifier will be more sensitive to impedance fluctuations (the resonance peak of the woofer tends to make the bass bloomy, the rising voice coil inductive impedance of the mids and highs tend to make the sound 'sweeter' and more liquid)

 

The empirical result of transconductance is a frequency response that somewhat follows the impedance curve (higher impedance equals more current flow) so if your amp has a high output impedance, then it's output will be more effected by load impedance swings than an amplifier that aims to be an ideal voltage source