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[FIXED] Cornwall 1 bad crossover help


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7 minutes ago, Crankysoldermeister said:

I don’t know if they are B or B2. Both use 2uF for the tweeter. B uses 4uF, B2 uses 3uF for the primary. I have some 2uF Sonicaps, which I consider to be a bit bright, but they would be free. 

 

 

In his last post above gsgleason mentioned that he needs 4mF beside the 2mF value. That is more than accidentally nice of you👍

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@Travis In Austin There shouldn't be a thread by any seller.  I got them through FB marketplace.  I'm pretty sure the seller doesn't participate in these forums.  I did post on whether or not I should consider them given their bad condition.  I ended up getting them for $450 for the pair knowing the tweeters needed to be replaced and that replacement diaphragms aren't too expensive.

 

The only thing I intend is to (hopefully) get them into working order, and based on that, decide on if I want to invest the time and money into making them look nice.

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1 minute ago, gsgleason said:

@Travis In Austin There shouldn't be a thread by any seller.  I got them through FB marketplace.  I'm pretty sure the seller doesn't participate in these forums.  I did post on whether or not I should consider them given their bad condition.  I ended up getting them for $450 for the pair knowing the tweeters needed to be replaced and that replacement diaphragms aren't too expensive.

 

The only thing I intend is to (hopefully) get them into working order, and based on that, decide on if I want to invest the time and money into making them look nice.

Got it, I'm slow on the uptake as many will confirm. So two threads, one when you were considering, and now this thread to finally see how they sound after the new diaphragms are in place, which has been delayed by the crossover network/capacitor issue. 

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3 minutes ago, gsgleason said:

@Crankysoldermeister That is beyond kind of you.  Since these are 42 year old speakers, my plan in troubleshooting the crossovers is to just replace all 4 capacitors since it needs to be done anyway to get them sounding the same.

What general area are you located in?

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Good Lord, 7 pages on capacitors and all the guy wants to do is fix a crossover where it works first. Start talking capacitors on this forum and members start reaching for their knives. He seems to have covered the simple steps first and replacing the caps may be the next step to solve problem. I would just throw some Dayton caps in the bad crossover first and see if that fixes the problem. Then proceed fine tuning the crossovers using other caps or kit from JEM. 

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1 hour ago, henry4841 said:

Good Lord, 7 pages on capacitors and all the guy wants to do is fix a crossover where it works first. Start talking capacitors on this forum and members start reaching for their knives. He seems to have covered the simple steps first and replacing the caps may be the next step to solve problem. I would just throw some Dayton caps in the bad crossover first and see if that fixes the problem. Then proceed fine tuning the crossovers using other caps or kit from JEM. 

At least a loving and tolerant thread where it shows that all have made good intentions for the new year🤓

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I'd rather have a lively discussion than have the thread be ignored.

 

Anyway, here's the current status:

 

I'm confident the connections are all sound.  I've removed, checked, and re-connected everything on the terminal block and re-flowed all solder joints except the two wires that go underneath the paper wrapped 2.5 mH inductor, but according to the schematic that is only for the woofer, so I'm not worried about it.

 

I couldn't find the Dayton 4uF PMPCs in stock (only the DMPC), nor the polyester Kemet version, so I ordered some Jantzen crosscaps in 3.9 and 2.2 uf to replace all 4 caps in both crossovers.  I ordered from partsconnexion.com.

 

Once that's done I'll let you know the outcome.

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Hello everyone.  I have an update.

 

I received the cross caps today and just did updated the problematic crossover.

 

The issue is fixed.

 

I'm going to do the other tomorrow and then do some listening.

 

I don't know if it's my imagination, but the speaker with the updated network seems less bassy, but looking at the schematic that shouldn't be possible.  It could absolutely just be the room and whatnot. 

 

It's a bit brighter than the one with the original but still working network.

 

The 2.2 measures right at 2.2 on my multimeter, and the 3.9 measures at 4.

 

Thanks for your help.  I'll report back later.

PXL_20220116_051432001.jpg

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9 hours ago, gsgleason said:

Hello everyone.  I have an update.

 

I received the cross caps today and just did updated the problematic crossover.

 

The issue is fixed.

 

I'm going to do the other tomorrow and then do some listening.

 

I don't know if it's my imagination, but the speaker with the updated network seems less bassy, but looking at the schematic that shouldn't be possible.  It could absolutely just be the room and whatnot. 

 

It's a bit brighter than the one with the original but still working network.

 

The 2.2 measures right at 2.2 on my multimeter, and the 3.9 measures at 4.

 

Thanks for your help.  I'll report back later.

PXL_20220116_051432001.jpg

First of all, it is very good that you have found the error and that you have first of all chosen inexpensive capacitors.
What does less bassy mean? Too thin or more balanced? Is it nicely balanced on the other speaker with the original parts or is the bass there too thick?

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@KT88Initially I tested with the new caps on the problematic crossover along with the stock crossover on the other speaker. 

 

Comparatively it was more bright with a lot more mids, but I think it's not a fair comparison with the old caps.

 

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9 minutes ago, gsgleason said:

@KT88Initially I tested with the new caps on the problematic crossover along with the stock crossover on the other speaker. 

 

Comparatively it was more bright with a lot more mids, but I think it's not a fair comparison with the old caps.

 

So you like the sound better with the old crossover that still works in the other speaker?

(no matter if it is a fair comparison). You say that the renewed crossover delivers too much midband and high freq. or in other words that bass now is leaner or thinner?

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Thanks for all the help, everyone.  I never expected so much attention given to a new member such as myself.

 

Just did the other crossover and got it installed.  The other pair of caps measured exactly the same at 2.2 and 4.0, so that's awesome.

 

Instead of soldering the cap leads directly to the wires like I usually see, I copied an idea I found when looking at tons of pictures of DIY crossover upgrades and mounted some 12 AWG bare copper to the board and soldered the wires low and the caps high.  This way if I want to replace the caps at some point it's a lot easier. 

 

They sound good now.

 

I have them connected to my Yamaha AS701 amp along with my old speakers, some cherry RF-5s.

 

I've been doing some listening and some A-B testing (literally switching between A and B speakers on the amp).

 

There is just so much more sound with the cornwalls.  The treble is smoother and less in your face compared to the RF5, and having an actual midrange 'squawker' really adds so much to the mix.  Female vocals are less brash with the cornwalls, which I noticed listening to Norah Jones and Taylor swift.

 

Now that I know the caps were the issue, I can either just enjoy these as they are, or look into higher end caps and try to figure out what the sonic differences actually would be.

 

Now I kind of want to play with the caps in my RF5s.  I am sure @Crankysoldermeister would love to talk about that.

 

PXL_20220117_184753978.jpg

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They are undoubtedly a little brighter than they were, which will make it seem like there is less bass. You can fix this by moving them closer to the wall or corner. While a bit brighter, it should also sound smoother and more open.

 

You should explore moving to the Type B2 in the future.  

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1 hour ago, gsgleason said:

 

 I copied an idea I found when looking at tons of pictures of DIY crossover upgrades and mounted some 12 AWG bare copper to the board and soldered the wires low and the caps high.

 

 it's the 1st time , I see this method used on the klipsch Forum  ,

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58 minutes ago, RandyH said:

 it's the 1st time , I see this method used on the klipsch Forum  ,

This looks very practical and smart. But still I would solder the caps on the copper piece directly to the wires so that they touch, you can just as easily swap the caps. Otherwise you have double contact resistances.

A brief thought regarding your sound impression, we have talked more than enough about it here in the threat, the quieter bass (or louder midrange/tweeter) can be the result of the low ESR of the polypropylene caps. First of all your speakers work and that's the most important thing.
By the way, you can connect a polyester Kemet 3.3 uF and a 0.67 uF in parallel to reach 4 uF. The resulting ESR is comparable to a single 4 uF cap. Although you have a parallel connection which reduces the ESR, the smaller capacitance has a higher ESR to compensate.

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  • gsgleason changed the title to [FIXED] Cornwall 1 bad crossover help

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