Klipsch RF-7III, the journey begins.

[Dave C]

I recapped the second speaker tonight and got about 20 min of time to listen. My first impression is that the clarity is better, that's saying a lot because they sounded good before I started. Sound is smoother and more detailed. The inductors for the woofers are on their way, I'm hoping for the same level of improvement with that upgrade.

 

[Dave C]

It's my understanding that Klipsch will not release x-over schematics for their current speakers. I noticed seeing several requests on the Klipsch forum and they don't bother to even reply.

Years ago I upgraded the caps in my RF-7 1's along with my RC-7 using Auricaps and Solon's along with the Dean G mod. Still enjoying them today. For the RC-7 I had to seperate the x-over into 2 seperate boards because the new caps were too large.

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Klipsch will not give out information on current speaker crossovers, I get that. However some of us were born with a soldering iron in our hands. I spent more time last night listening and feel the "new sound" is better than stock. I'm not sure that I will replace the high pass resistors and inductors,,,,possibly.

 

[SomeGeoffGuy]

Klipsch will not give out information on current speaker crossovers, I get that. However some of us were born with a soldering iron in our hands. I spent more time last night listening and feel the "new sound" is better than stock. I'm not sure that I will replace the high pass resistors and inductors,,,,possibly.

OK - you have convinced me to try this! I saw in another thread where you can buy an original Klipsch crossover service part from a vendor for like $100 (each) including the wiring. I think I am going to buy a pair and try this so I can always go back to stock (that will calm the wife when I start tearing them apart...).

-Geoff

 

[Dave C]

The new inductors for the woofers unexpectedly came in on Friday, I decided to dig in. I had come to the conclusion that the small diameter wire on the stock inductor wasn't going to do since it was directly in the signal path so I ordered a Solen litz 14 gauge inductor. I could have gone 12 gauge but calculated and read articles that indicated the 14 gauge was as good a choice. I built this low pass or woofer cross on a small piece of wood and mounted it to the inside bottom of the cabinet right behind the hookup terminal. (see attached pictures.) I removed the lower woofer rear port and snipped all the woofer wires off the stock cross over and correctly connected them together and re assembled. I always do i speaker at a time to document the difference in sound and to be sure I didn't screw anything up. From the first 30 seconds of play had no idea that the low pass cross would make this big of a difference! This was a huge improvement in sound. The second speaker went under the knife right away. I paired the 14 ga Solen with a 33uf Auricap, this is the PERFECT combination. The bass was deaper and more controlled and the lower midrange is concert hall perfect. I'll post some better shots of how I back engineered the secret schematics.

 

[Dave C]

OK - you have convinced me to try this! I saw in another thread where you can buy an original Klipsch crossover service part from a vendor for like $100 (each) including the wiring. I think I am going to buy a pair and try this so I can always go back to stock (that will calm the wife when I start tearing them apart...).

-Geoff

Ha! you won't be sorry Geoff! These images may help.

 

[Dave C]

I may have to re evaluate the input resistor on the high pass. Some of my music buds were over last night and feel the highs are a bit loud.

 

[SomeGeoffGuy]

I may have to re evaluate the input resistor on the high pass. Some of my music buds were over last night and feel the highs are a bit loud.

Lord, I just looked up how much those capacitors cost. I could literally spend as much on the crossover as I did the speakers. That is crazy. No wonder Magico speakers cost so much with their high end Mundorf Caps!

-Geoff

 

[Dave C]

Lord, I just looked up how much those capacitors cost. I could literally spend as much on the crossover as I did the speakers. That is crazy. No wonder Magico speakers cost so much with their high end Mundorf Caps!

-Geoff

The Auricap XO combination (6caps) came to about $200.00 the two Solen inductors came to about $100.00. Not bad for the payback I got.

 

[Dave C]

For whatever reason these caps made the top end louder as I stated in an earlier post. I had a set of Bob Crites audiotransformers (#3636) from another project. I hooked them into the horn feed using the -1db connections, perfect. Looking further the input on the stock crossover enters through a 3 ohm resistor, I want that out of there as well as long as I have the audiotransformers in the circuit already. I'm also looking into the second choke that feed the 12 ohm resistor. I may disconnect that and see what result I get. Fun stuff!

 

[Dave C]

Saturday night's thrash session. Crossover removed from the cabinet and laying on the floor with jumpers. Bob Crites audiotransformer hooked to the input. 3 ohm resistor jumped. I feel I'm hearing better depth with the resistor out of the circuit. Low pass is no longer on this board.

 

[Dave C]

After an extended listening session last evening I've elected to completely rebuild the high pass and eliminate all parts of the stock crossovers. If you look at the picture of the crossover laying on the carpet in a previous post you'll see a white jumper wire across a 3 ohm resistor. I make changes 1 speaker at a time, this added a lot of space or depth to the music. I then did the same to the other speaker and was amazed at the difference. The remaining resistor is a 12 ohm and I'm not going to be able to jump that and get the same output from the circuit. I ordered Path 12 ohm resistors for this location and will eliminate the 3 ohm completely. Solen Litz inductors are also coming. I've done some research on inductors, ribbon vs wire and have decided that Litz is the way I want to go. I'll make a new mounting board for this stuff and locate it behind the speaker terminals.

 

[SomeGeoffGuy]

That is why I wanted to start with a second factory part or just from scratch. You are getting deep in the crossover rabbit hole!

-Geoff

 

[Dave C]

It’s a nice rabbit hole and boy it’s made a difference! Looking forward to the rest of the project.

 

[Dave C]

I hate waiting for parts, but when you buy this boutique stuff that’s life. Reports will hopefully continue soon.

 

[Audible Nectar]

Crossovers really elevate the speaker if the work's done right.

Lord, I just looked up how much those capacitors cost. I could literally spend as much on the crossover as I did the speakers. That is crazy. No wonder Magico speakers cost so much with their high end Mundorf Caps!

-Geoff

I bought three pairs of 60's/70s era Cornwalls in the early/mid-2000s for about $2500. I spent $2700 on the new B2 crossovers for these three sets of speakers, including Multicap RTX caps (2 and 3uf) which cost about $100 each.

I also went through some serious "capification" in "tefloning" my gears, including my NOSValves custom preamp now loaded with Cardas Golden Ratio caps (NOS) - basically an early predecessor to the V-Cap in the market. I paid $165 for a pair of these, cut to 40% of price (they sold for about $175 each) which is a deal compared to the V-Cap versions which sell for $700 each......for a 2.2uf!!!!!! The Cardas were such a deal I bought a set for my builder (who has the same preamp I do as he designed/built it).

All this is to say that "caps are not just caps" on horns and one reason there's been such a warwhoop over on that "other forum". Manufacturers had "bean counters" so they used what was cost effective and made a certain sense, nut when we rebuild we can do better. Klipsch has really good designs but they also have shareholders and accountants.

 

[Dave C]

Parts arrived for the hi cross and I soldered one crossover together. I bought Solen Litz inductors, Path resistors and the Auricap XO caps. If you read the earlier posts you'll see I had installed the Auricaps a couple weeks ago and reported on that. Once again the mods provided me with what I was looking for. The speaker is very smooth, not sure if that came from the inductors or the Path resistors, I've read up on both and feel the resistors are probably the bigger gain. I omitted the 3 ohm resistor from the factory circuit and installed a Crites 3636 audiotransformer and have it wired to the -1db setting. This mod is to the right channel speaker only so I could do an A - B comparison. I played around with different taps on the audiotransformer but settled on -1db. I need to get the circuit mounted to a board and then get started on the other speaker. When standing 1 meter in front of each speaker it's very easy to hear the difference. Sitting back on the couch the modified speaker definitely has smoothness and transparency that the other doesn't. I have to add, these are fantastic speakers to start with.

 

[Dave C]

Today I drew up the mount for my crossover parts and laser cut the mounting boards. I'm not able to fit the Crites audiotransformer into the cabinet so will mount them outboard. The weight of the new inductors and considerations on the hole size on the back of the speaker just aren't a good fit. I'm anxious to get his done, the right speaker crossover is still laying on the floor next to the cabinet. The sound is so good from that speaker that the room balance is off. Hopefully by Sunday evening it will be complete.

 

[Dave C]

Second speaker is finished, I've included pictures of how the high cross is installed in the cabinet. Low cross is screwed directly to the inside bottom of the speaker cabinet. The Sound improvement from this upgrade was huge! The transparency and depth is bowling alley deep.
The Crites audiotransformer is installed outside the cabinet. I removed the tie strap and wired it in instead. Anyone that has a glaring horn could probably benefit by doing this on any speaker. Order a set of 3636 units from Crites Sound. As stated I eliminated the 3 ohm resistor from the stock schematic and used the transformer instead, It simply offers better control. I'll 3D print a box for it in the future and attach it to the cabinet back using the existing screws from the terminal plate.

 

[Deang]

An autotransformer is an impedance multiplier. As impedance goes up, voltage is reduced. So, how do you think that might affect the transfer function and the parts values in the network?

 

[Dave C]

An autotransformer is an impedance multiplier. As impedance goes up, voltage is reduced. So, how do you think that might affect the transfer function and the parts values in the network?

Hi Deang, You've done way more crossover work than I have and am sure you can explain better than I can. This is what I know and what I hear and is what I can offer. Before starting the project I could put an ohm meter across the terminals and it measured 3.8 ohms. When I did the cap change it measured 3.8 ohms. I then did the low cross upgrade and had 3.8 ohms. The final build on the high cross with audiotransformer came out at 3.8 ohms. What is happening to the load as the speakers work I have no idea. I can tell you though that I'm very pleased with the results. I'm running the -1db tap on the audiotransformers so the reduction isn't much. If you care to share your knowledge I'd sure like to learn how to correctly calculate this.