Ditton 44 tweeter caps replacement..HELP !!!

[andyrlb]

Hi Guys , so after a very kind member donated his spare caps I have now removed the old black ones and replaced them with the donor ones and my tweeters are still not working ( I know they work when wired direct ). The same member also sent me a bunch of smaller blue alcap ones so I'm thinking I must use this too but I don't know which ones I replace those with on the crossover??

[spendorman]

Never, connect a tweeter directly to an amplifier output without a suitable filter, easy way to end up with a blown tweeter.

In most cases if the volume is kept lowish, a suitable single 2 uF capacitor can be used in series with the tweeter to check it.

[spendorman]

I suggest measuring the tweeters with a multimeter set on the the Ohms range. Your tweeters might measure around 4 to 6 Ohms.

[ScottL]

You replace like-for-like, so whatever value the original caps were (this should be marked on them), replace with the new ones of the same value (which should also be marked on them).

As a general rule, if the XO uses electrolytic caps, do not substitute polyester (MKT) polypropylene (MKP), film & foil or oil-types for them, unless you can measure the system response & are happy redesigning the filter. The ESR of the original electroyltics will almost certainly have been accounted for in the crossover, so any changes there will alter the behaviour away from what they were designed to have. That said, if the original electrolytics have dried out, they will already have drifted somewhat from that. Nevertheless, no point in making multiple changes to the speaker's voicing at the same time.

[andyrlb]

Understood, thanks

[karma67]

were they working before you bought them?
have you done anything to cable connectors at the back of the speaker?
i ask because when i changed the terminals i didnt check to see if they were properly insulated from the plate they screw against,they weren't and it caused the speaker to stop working,when tested separately the drivers worked,might be worth a check.

[DarrenHW]

Hi Andy,
The Blue capacitors are for the mid range (red caps). You have 1 x 6uF and 3 x 10uF for each speaker, the 10uF caps need to be soldered together to make a total of 30uF. The red capacitors should have the values labeled, if not check out one of Ken's diagrams from the link I posted in your other thread.

[andyrlb]

Hi , the tweeters were not working on both when I got the speakers home, all other drivers are OK , when I test the speakers directly ( with a dab stereo on very low volume) they work but when I test them with my cheap multimeter there's nothing !! ( other drivers show ok on multimeter)
Also the larger new donated caps show nothing on multimeter when all the other caps do show a reading

[andyrlb]

Hi Jamie , only the tweeters not working .

[Reffc]

Hi

If you send me your tweeters and are happy to cover return P&P, I will run a full frequency test on them at varying voltages which will show up any issues very clearly on the corresponding impedance curve. If you include the caps that you say don't show any reading, I can test those too for you. No charge, happy to help.

As Scott says, only replace like for like when it comes to speakers using electrolytics, although you can sometimes get away with using MKT/P caps in the situation where the original was a low loss capacitor at higher frequencies (but it will still slightly alter the voicing and often, the phase response accuracy providing the originals were designed to be phase aligned properly in the first place!).

[andyrlb]

Hi Reffc
Thanks for the very kind offer , unfortunately it turns out that when I wired the tweeters directly I wasn't actually hearing the tweeters!! Instead I was hearing the tweeter signal pass through the midrange !!
So the tweeters are no good , trouble is the cabs and other drivers are lovely so I guess I'll have to buy some tweeters.

[karma67]

bummer!
has darren got any left i wonder?
they do come up on ebay,about £80 gets a good pair or go the seas replacement option ;)

[andyrlb]

My ocd won't allow me to replace with none originals ��
Knowing me they will now sit in the garage for 10 years !!
I'll focus on the 66's now I think .

[karma67]

much better idea! :)

[andyrlb]

Hi Jamie , are you saying its a better idea to focus on the 66's mate ? I was going to list/sell them this week !!

[karma67]

just kidding mate,i went from 44's to 66's and love them,even though they are playing havoc with the room their in.
i'll be doing a small recap on them next week,just the bass caps to start and see how their perform.

[walpurgis]

Hi Jamie , are you saying its a better idea to focus on the 66's mate ? I was going to list/sell them this week !!

The Ditton 66 is the better speaker.

[andyrlb]

No worries mate , I couldn't and wouldn't have those monsters in the lounge .
I'll be selling them

[karma67]

yeah but by the time you factor in the stands needed for the 44's the 66's arnt a great deal bigger :)

[andyrlb]

Yeah but they're just ugly as !! Plus the spot is reserved for the Yamaha ns-1000m's

[andyrlb]

Ok , so I'm about to list the 66's