CST-1 Crossover upgrade, does anybody have experience to share?

Caliaudioguy · « **on:** 8 May 2020, 05:11 am »

Hello,

I just got my CST-1's from Danny, (Thank you sir) along with the upgrade caps.

I was hoping some of you more experienced folks could share some advice and pictures of your upgraded crossovers.

I've been an live sound audio engineer for years, mixing bands, corporate events and beyond for a while, but this is my first foray into working inside the speaker. Signal flow from the microphone through the console, over to the amps and the speakers I get, but INSIDE is a whole new thing, please go easy on me, most of you I imagine are masters at this and find this really easy and straight forward.

I looked through the crossover assembly 101, most of those seem to be new builds. Before I tear into my working crossover I welcome your advice and help.

Where I'm a little confused (insert jokes here) I'm not sure if I'm supposed to desolder and just replace caps on the existing board or if I'm supposed to start from scratch and remove the parts I need from the existing crossover and transfer to a new build.

Thanks in advance for passing on your experience to "the new guy"

Danny Richie · « **Reply #1 on:** 8 May 2020, 12:58 pm »

Unscrew the board and pull it out to the lower woofer hole. There is just enough room to unsolder the two lead wires from the tube connectors. You can then remove it.

Then pop off the old caps and replace them with the Sonicaps.

Then reconnect the input wires and reinstall the crossover.

AverageNiceGuy · « **Reply #2 on:** 8 May 2020, 05:28 pm »

Thanks both for the question and answer.
I will be practicing that soon.
CST-1's received, been listening for 4+ hours, very impressed, ...not yet received No-Rez / Caps. I will enjoy hearing the difference.

Groovin · « **Reply #3 on:** 8 May 2020, 08:07 pm »

I am going to do the upgrades this weekend i still have not decided on a amp i realized my onkyo only has a 4ohm and 6ohm settings is it bad to use the 6ohm setting ?

srb · « **Reply #4 on:** 8 May 2020, 08:45 pm »

Amps equipped with a speaker output impedance switch do so to reduce the power supply rail voltage or limit current draw in some way when connecting low impedance loads.

I generally run amps like this with the switch in the 6/8 Ω position so as not to limit current, then keep an eye (and hand) on it to see if it runs hot. It it goes into a thermal protection mode, then the switch would need to be set to the 4Ω or low impedance setting to limit current.

Groovin · « **Reply #5 on:** 8 May 2020, 09:20 pm »

Quote from: srb on 8 May 2020, 08:45 pm

Amps equipped with a speaker output impedance switch do so to reduce the power supply rail voltage or limit current draw in some way when connecting low impedance loads.

I generally run amps like this with the switch in the 6/8 Ω position so as not to limit current, then keep an eye (and hand) on it to see if it runs hot. It it goes into a thermal protection mode, then the switch would need to be set to the 4Ω or low impedance setting to limit current.

so much to learn thanks for your answer

Caliaudioguy · « **Reply #6 on:** 8 May 2020, 09:44 pm »

I figure I'll share my progress

Removing the caps

More later

AverageNiceGuy · « **Reply #7 on:** 8 May 2020, 10:31 pm »

Thank you

Caliaudioguy · « **Reply #8 on:** 8 May 2020, 10:36 pm »

Hopefully this is correct. Had a little trouble with one of the caps (10 on the woofer side) almost like there was too much flux? or I over heated it, not sure. Going to slap a meter on it and sort it out.

Also, didn't have a glue that seemed appropriate so I ran a bit of RTV underneath the caps to keep them in place. Was that a good or bad idea? Your comments welcome.

lincolnmat · « **Reply #9 on:** 8 May 2020, 10:43 pm »

Removed my non-crossover question and put it as a separate topic.

Matt

lincolnmat · « **Reply #10 on:** 8 May 2020, 10:47 pm »

Quote from: Caliaudioguy on 8 May 2020, 10:36 pm

Hopefully this is correct. Had a little trouble with one of the caps (10 on the woofer side) almost like there was too much flux? or I over heated it, not sure. Going to slap a meter on it and sort it out.

Also, didn't have a glue that seemed appropriate so I ran a bit of RTV underneath the caps to keep them in place. Was that a good or bad idea? Your comments welcome.

If you are looking for confirmation that you put the right capacitors in the right places, my reading of the crossover diagram agrees with what you did.

Matt

Tyson · « **Reply #11 on:** 8 May 2020, 10:49 pm »

The two tiny yellow caps in the middle of the board - are those bypass caps?

lincolnmat · « **Reply #12 on:** 8 May 2020, 10:56 pm »

Quote from: Tyson on 8 May 2020, 10:49 pm

The two tiny yellow caps in the middle of the board - are those bypass caps?

Yes, the diagram shows them as .1 bypass caps. Danny mentioned them in last week's video - and the fact that they weren't Sonicaps.

Matt

timind · « **Reply #13 on:** 8 May 2020, 11:04 pm »

Quote from: lincolnmat on 8 May 2020, 10:47 pm

If you are looking for confirmation that you put the right capacitors in the right places, my reading of the crossover diagram agrees with what you did.

Matt

And, the cap values are printed on the board under the glue.

Groovin · « **Reply #14 on:** 8 May 2020, 11:33 pm »

Quote from: lincolnmat on 8 May 2020, 10:47 pm

If you are looking for confirmation that you put the right capacitors in the right places, my reading of the crossover diagram agrees with what you did.

Matt

thank you this will make it way easier for me feel free to show your progress and with the placement of the norez i tried to find pictures or videos

lincolnmat · « **Reply #15 on:** 9 May 2020, 12:17 am »

I just noticed your first picture more closely. My crossover did not have a 9uF capacitor, it had 2 10uF units along with the 20uF. It will be interesting to see if the other speaker has the same difference. Maybe just the one crossover was built incorrectly.

Matt

Darphyve · « **Reply #16 on:** 9 May 2020, 08:33 pm »

Hello everyone.
I too just got my CST-1s in. I've made all the recommended upgrades accept for the crossovers. I have about 25 hours on them now and they're sounding great! I'm very interested in everyones opinion on just how much of an improvement the crossover upgrades make.

Caliaudioguy · « **Reply #17 on:** 10 May 2020, 06:07 pm »

Well, I have some sad news. After "finishing" my first crossover, I affixed it back into the cabinet, re attached the drivers and reinstalled them. I got the it into the living room and nothing.

I must have mis soldered or cold soldered something, but it's definitely not passing audio. Tube connectors back to the amp test out continuity, so it's not that, the problem is inside.

As much as it is embarrassing to admit my failure, I figured I'd share my experience so if anyone else has had or will have something similar they won't feel alone.

I'm comfortable behind a 100K+ mixing console, but not a soldering iron.

Now to take it apart again and see what I did. I hope I just didn't do something irreparable. I'm afraid I may have done something to short the circuit board? Or perhaps during reinstallation I managed to pull something loose? I don't know yet.

I am impressed with you guys that do this all the time and even more impressed with you guys that get it right the first time!

corndog71 · « **Reply #18 on:** 10 May 2020, 06:41 pm »

The key to soldering is to get the wire and the pad hot enough to melt the solder. Don’t add solder by pushing it onto the iron tip. Add it to the hot wire. It shouldn’t take but a few seconds to get the wire hot enough.

Doublej · « **Reply #19 on:** 10 May 2020, 07:37 pm »

Danny has an excellent youtube video on soldering