CSi A6 Lack Of Treble/Crossover Help

Markardi

Hi

I have a CSi A6 center speaker and just last week noticed there was no treble coming out.
Swapped it for a RTi A3 and it sounded fine so not the receiver. The CSi A6 tweeter was then swapped in the RTi A3 and sounded fine so not the tweeter either.

Looking at the crossover board behind the binding posts, 05371-E, nothing looks blown.
Using a multi-meter, I measured the resistance across the two white resistors and they seem fine, within tolerance. I was also able to check the capacitance of the 12uF capacitor at 13.3uF. Nothing from the other three, but as all four of these are in the circuit, I can't accurately measure them. I would have to take them off and measure which I don't want to do if I don't have to.

Any suggestions as to what I should test, or what cap I should focus on to solve the issue?
Could it be something other than the crossover board that I haven't looked at yet?

Thanks,
Mark

F1nut

Check that the binding post jumpers are in place and the posts are tight.

Markardi

Thanks for the tip, didn't think to check the binding post jumpers.
Unfortunately, that wasn't the culprit. I did clean them and re-secure them though just in case.

One thing I noticed while the binding post jumpers were disconnected; if I tested continuity between the lower posts, I got a 1 (beep). Where as, if I tested continuity between the upper posts, I got a 0 (nothing). Could that be a clue?

I found a link to the crossover schematic and it looks like the 12uF and the 0.47uF caps are part of the upper circuit. Does this schematic look correct?
http://techtalk.parts-express.com/filedata/fetch?id=1191581

Are there other speakers that use the 05371-E crossover board? Maybe I can reference that if I have it.
(RTi A9, RTi A3, and FXi A4)

F1nut

The crossover is unique to that speaker as most are. Pull the crossover and look for a fried resistor.

Markardi

As I've got the crossover board out right now, it seems like a good time to change the resistors to Mills MRA line. (Which is now Vishay correct?)

Question about the 3.3 ohm resistor as Mills only offers a 3 or a 3.5.
Will one of those be fine or should I parallel a 10 + 5 for 3.33..?

pitdogg2

factory 3.3 is +/- 10% most likely. Vishay/Mills are 1% ... you'll be fine with either.

Markardi

So my tweeter is working again! Thanks for your help.
I also upgraded it while I had it open.

To my original issue, I think it might have just been a cold solder joint?
With all the original parts off, I tested them and they all work. The caps and resistors were all within their 10% spec too.

That being said, I still switched the components to Mills resistors (2 and 3.5 ohm) and Solen caps. The PPE line for the 0.47, 8.2, and 12uF while the 82uF is a PB model. The PPE line didn't offer something as high as 82 and I would have need to go triple parallel to get the addition right.

I know Solen isn't what a lot of people recommend on this forum, but for the price, sheer size of these things, and my first time trying, I'm happy how it turned out.

As for perceivable sound difference, that's hard to say right now.

Here's a photo of how I tested it before finishing it up and stuffing it back inside.

tonyb

Cool, give it some time to break in, the sound will change a bit after. Good to see you got it working again.

pitdogg2

Congrats on the work. 400v dc are huge. It has been awhile since I have searched for caps. Was there nothing else out there in 200v that would have been much smaller I'd think.

Viking64

pitdogg2 wrote: »

It has been awhile since I have searched for caps.

Markardi

pitdogg2 wrote: »

Congrats on the work. 400v dc are huge. It has been awhile since I have searched for caps. Was there nothing else out there in 200v that would have been much smaller I'd think.

Thanks!

From what I've read through these forums, to get a reputable brand that offers good performance, this and bigger seemed to how things are.

You can get smaller caps, but then they're non-polar electrolytic and the consensus seemed to be to avoid those. I actually did buy some Solen non-polar electrolytic in case the others were too big. The price difference was huge at $3.64 vs $32.46 for the 82uF. Note that $32.46 was a bargain compared to Mundorf caps at $500.
I'm also in Canada so I didn't have the luxury of a place like Parts Express.

The whole upgrade was about $60 for the resistors and caps.

pitdogg2

Film caps come in 200v -250v I was not referring to anything electrolytic. Yes I understand and I have ordered many caps from https://www.partsconnexion.com/ in the past and yes at a certain point with large caps it is very limited as to values and voltage if we do not have the room tie them together that is always a concern as well.

not all Mundorf are that expensive
http://www.soniccraft.com/product_info.php/mundorf-mcap-82uf-250vdc-p-3556

https://www.partsconnexion.com/MUNDORF-75181.html


I have never ordered any film caps from parts express. I have always used Parts connexion or Sonic Craft. The shipping to the USA is not prohibitive for me at all I'm not aware if the opposite is true for you up north.

once again great job on that XO.

Markardi

Didn't even know to check out Parts Connection! Must have glazed over it in my searches. I ended up buying my parts from Solen Canada.
That's a handy place to keep in mind.
They even have the 3.3 ohm resistor I should have bought instead of the 3.5.


And fair point, that Mundorf cap is $55 here. The size is 47mm diameter x 61mm long vs the 54mm diameter x 65 long of the Solen.

There's a lot to read!

gp4jesus

Later consider similar upgrades w/similar brand & model components for your RTi A3s. Enjoy!