Klipsch Forte acceptance

[SET12]

So, this is correct? I am not sure of German C core wiring.

First off given a choice between the Duelund Copper VSF and The Mundorf Silver and Oils I would increase the Inductors to 10 ga or AWG and go all Mundorf "M" caps. I found in DaveC's RF25's the Tonality was a very good combination and the Mundorf "M" really did a great job with North Creek.

If you wanted to you always could later invest into the Copper VSF or the Copper Cast version.

With the C-Cores I would specify 1db steps instead of the 1.5db steps. This allows the use of the C-Cores with many other Klipsch.

The 40 ohm resistor is a Duelund 39 ohm. This is pretty much a must have as it really was significant in sweetening up the treble they are that significant vs other resistors.

Schematic for the C-Core it is in German. I don't use an L-Pad as he does. The C-Core works just like any other Auto-Transformer I get back to you more on the hook up but basically mine are 1db down for each step from the top #15 is in and #0 is ground #9 is 9db down for the Forte. If you get the standard winding it would be #6 for the 9db down.




SET12

 

[SET12]

I really doubt there's much of a market for $2000 dollar crossovers.

Check these B&W 801 and 802 network replacements out that North Creek sells for $2000 and he sells a lot of them the chessy stock networks are on the left in the right picture with the North Creek replacement.

Read about what it does and I can certainly a test it certainly could as I hear essentially much of the same in my networks.

http://www.northcreekmusic.com/801web.html

 

[sony6060]

First off given a choice between the Duelund Copper VSF and The Mundorf Silver and Oils I would increase the Inductors to 10 ga or AWG and go all Mundorf "M" caps. I found in DaveC's RF25's the Tonality was a very good combination and the Mundorf "M" really did a great job with North Creek.

If you wanted to you always could later invest into the Copper VSF or the Copper Cast version.

With the C-Cores I would specify 1db steps instead of the 1.5db steps. This allows the use of the C-Cores with many other Klipsch.

The 40 ohm resistor is a Duelund 39 ohm. This is pretty much a must have as it really was significant in sweetening up the treble they are that significant vs other resistors.

Schematic for the C-Core it is in German. I don't use an L-Pad as he does. The C-Core works just like any other Auto-Transformer I get back to you more on the hook up but basically mine are 1db down for each step from the top #15 is in and #0 is ground #9 is 9db down for the Forte. If you get the standard winding it would be #6 for the 9db down.


View attachment 413966

SET12

Thanks for sharing your work & expense upon getting the Forte to that level. I am on my way. Will get back once the mods are in-place. Could be a month.

Also, no doubt the Forte are in an acceptable size enclosure. I do not own a castle.

 

[sony6060]

Thanks for sharing your work & expense upon getting the Forte to that level. I am on my way. Will get back once the mods are in-place. Could be a month.

Also, no doubt the Forte are in an acceptable size enclosure. I do not own a castle.

BTW- Google search stated Mondorf M cap is MKP or about $4 each. Seeing inductors are going to cost $800, $4 caps seem a little under rated & could pull down the 'troops' so to speak?

EDIT- Oh I get it 'M' is just a nickname you gave all Mondorf caps. All 'M' caps are not equal. I ordered the Silver/Oil. I just could not order Solen, Use these in PS in past and still do not get best results. I ordered Obligatto 47uF poly.

 

[shacky]

I have Forte's and love them. Mine needed lots of work. SET, Bob Crites, and others helped guide me. Bob's cap kit and Ti diaphragms were added.

I particularly like them with my Eico HF-81 but they sound great with my Sui receivers as well.

I love AR speakers. Big Polks, KHL, Dynaco A25. The wife whose ears are better than mine says the Fortes sound rich and sophisticated.

My Forte's aren't going anywhere soon.

 

[sony6060]

I have Forte's and love them. Mine needed lots of work. SET, Bob Crites, and others helped guide me. Bob's cap kit and Ti diaphragms were added.

I particularly like them with my Eico HF-81 but they sound great with my Sui receivers as well.

I love AR speakers. Big Polks, KHL, Dynaco A25. The wife whose ears are better than mine says the Fortes sound rich and sophisticated.

My Forte's aren't going anywhere soon.

Amen.

 

[shacky]

My supposedly original Fortes had the following:

resistors in line with the mids

Wound not re-soldered wires on crossovers

Lesson - when you listen to speakers that are supposedly original they may not be! I almost sold mine before opening and seeing this.

 

[shacky]

And now my crossovers look like this:

 

[sony6060]

One more question

Is it better to install the crossovers outside the cabinet on the back? I could install a factory appearing cover if outside.

 

[shacky]

Is it better to install the crossovers outside the cabinet on the back? I could install a factory appearing cover if outside.

My thought is it doesn't matter unless you may want to make changes down the road or have Bi-Amp options where outside better. Plus if you use nice wood and are tidy it just looks good outside :yes:

 

[sony6060]

And now my crossovers look like this:

No solder on crossover connections. Hummmm

 

[SET12]

My supposedly original Fortes had the following:

resistors in line with the mids

Lesson - when you listen to speakers that are supposedly original they may not be! I almost sold mine before opening and seeing this.

Very good catch shacky.

The resistor in line changes the crossover specs for the mid completely.

It causes the crossover frequency to be lowered which would put a lot of low frequency stress on the mid.

SET12

It does this because the resistor plus the mid resistance is in series with each other.

In the Forte the mid is lowered to -9db or about a voltage ratio reduction of 2.83 to 1. The actual impedance the mid coupling cap see's is the mid drivers impedance plus whatever the series resistors value is times the voltage ratio of the auto-transformer squared.

I measured around 11 ohms of DCR of course their is some inductance with this that adds a few more ohms.

So if you square the 2.83 turns ratio you get 8.0 that times the 11 ohms is 88 ohms your amplifier see's.

Now if you add say a 6 ohm resistor in series that 88 ohms now becomes 136 ohms.

So in order to add resistance to the mid one has to change the coupling cap value.

A better way would be to change the tap and recalculate the necessary cap for the stock network.

Only an ALK network allows one to change taps because he uses what is called a swamping resistor in parallel with the whole Auto-transformer winding. This swamps the reflected impedance value from any tap. ALK usually uses 9-10 ohm resistor to do this with a large coupling cap sometimes as large as 40uf instead of the 1uf that is used on the Forte.

I recently heard that PWK did this because the higher resistance lowers distortion. Though ALK doesn't like this practice at all he would prefer a constant load for an amplifier.

 

[shacky]

No solder on crossover connections. Hummmm

Yeah one of these days I'll go back in and solder them. Crimped but not soldered.

 

[shacky]

Easier to see in this picture - I took Bob's advice and strapped all grounds together on the strip with thick copper wire. I think Bob's got something here :yes:

 

[SET12]

I owned Pro Ac 2.5 Response- no contest compared to Forte. Perhaps my ears, my equipment matches better- it is what it is per my ears. I build SET amps for fun. Iron is expensive, but......

So just build new crossovers & skip the Crites 6kHz add on. I'll pay the costs, but those German iron transformers. How does one buy them? Not listed in eBay USA. EDIT- Never mind, I just sign in & bought them. Thanks for heads up. In fact, parts kind of look like girls to me. Those are nice puppies.

I believe the last Stereophile show I attend yrs ago may of had the 2.5's setup in a room with Cary Audio and Dennis Had was having a very difficult time getting to play to his taste. I think I would rather have the 2.0's

Yes the German C-Cores are very nice indeed.

 

[SET12]

Thanks for sharing your work & expense upon getting the Forte to that level. I am on my way. Will get back once the mods are in-place. Could be a month.

Also, no doubt the Forte are in an acceptable size enclosure. I do not own a castle.

BTW- Google search stated Mondorf M cap is MKP or about $4 each. Seeing inductors are going to cost $800, $4 caps seem a little under rated & could pull down the 'troops' so to speak?

EDIT- Oh I get it 'M' is just a nickname you gave all Mondorf caps. All 'M' caps are not equal. I ordered the Silver/Oil. I just could not order Solen, Use these in PS in past and still do not get best results. I ordered Obligatto 47uF poly.

Yes the enclosure does is quite acceptable. As I pointed out my stage width can get up to 30ft on my 18 foot wall that I have mine. YMMV depending on associate equipment.

The "M" caps are also known as the Supremes. They are around $20 each. Total $120

But Silver\Oil Total about $350

If your going with 8AWG I see about $700 not including shipping. Is this what your thinking about doing?

Are getting the .16mH special wound for you?

Sounds as though your going all out...

I'm guessing its all in the implementation of a power supply as to whether they work for someone and not.

Obbligato those are very nice.

I'm actually using AEON's in my SET amplifiers augmented with 1800uf's of Electrolytic in each Monoblock of course this typically does not work well "meaning pretty ugly" using traditionally designed power supply schemes which I don't use.

 

[Rex Everything]

I just sold me Chorus II's with Crites upgraded cross overs in favor of a pair of Forte's with the ALK network and Crites Ti tweeters. Just need to get a set of Ti mids for them and they'll be done.

Very happy with these speakers.

 

[SET12]

Is it better to install the crossovers outside the cabinet on the back? I could install a factory appearing cover if outside.

I don't think you could get away with mounting networks on the back of the Forte, they would have to close of proximity to the driver magnetic's.

They would have to go inside or outside away from the cabinet.

I use a plate with 3 pairs of binding posts to connect woofer, mid, tweeter. Yes its a lot of work but I believe there are dividends to be had as all caps are microphonic, Even inductors can be influenced, though with North Creeks vacuum varnish impregnation they are pretty immune to resonance.

This works OK I believe because of the depth of the cabinets.

My layout is designed to be able to change parts in a few minutes I used Velcro along with automotive stereo terminal blocks. The box has my Autotransformer in it.

 

[SET12]

I just sold me Chorus II's with Crites upgraded cross overs in favor of a pair of Forte's with the ALK network and Crites Ti tweeters. Just need to get a set of Ti mids for them and they'll be done.

Very happy with these speakers.

It doesn't surprise me, I had a friend with Chorus's but I had a hard time with them for some reason. The network is quite a bit different then a Forte.

So whats your take on the ALK Forte networks vs stock?

I'm tempted to get a pair with his parts for a side by side comparison of my extreme networks, I would like to here a Crites network as well.

SET12

 

[Rex Everything]

It doesn't surprise me, I had a friend with Chorus's but I had a hard time with them for some reason. The network is quite a bit different then a Forte.

So whats your take on the ALK Forte networks vs stock?

I'm tempted to get a pair with his parts for a side by side comparison of my extreme networks, I would like to here a Crites network as well.

SET12

I did like my Chorus II's a lot and it's been a bit of an adjustment to get used to these.

I'd say the ALK network brings a "smoothness" I've not found in other Klipsch speakers. Never any fatigue. In fact, I find that when the cd or song ends that I had the volume up far more than I'd ever imagined. These speakers do not have the "forwardness" I was used to but are over all "smoother" and more pleasing to listen to than my Chorus II's or even the Forte with stock network or Crites network.

I really like the ALK network in this speaker. I think if Al had a network for the Chorus II's that I'd probably still own them.