Upgrading my floor standers

[madman29]

Hi everybody,
Few days back I found this Onkyo Tweeters from Metro Galli. The back printing says:
REXY-ONKYO
TW-12S
8 OHMS NOM.20W
MAX. 50W
F. RANGE 5K~16KHZ
JAPAN
(looks like piezo but weight is much more than a piezo)
It is a mid tweeter sort of thing as far as I could understand. But I thought I would replace my Philips dome tweeter (used as super tweeters) with those. Bad idea I know! But if I can belive my ears they sound better than those domes. (says a ton about the philips tweeter)
As a matter of fact I was using the bolton 8PT22 tweeter as the mid tweeter and the philips as a super tweeter.
Now the plan is I will put those Onkyos as mid tweeters in place of the Bolton as soon as I find a real super tweeter to go with those.
My original diy thread could be foun here:
http://www.hifivision.com/diy/4338-my-diy-efforts.html
Am attaching some pics of the modification.

 

[kapvin]

Hi everybody,
Few days back I found this Onkyo Tweeters from Metro Galli. The back printing says:
REXY-ONKYO
TW-12S
8 OHMS NOM.20W
MAX. 50W
F. RANGE 5K~16KHZ
JAPAN
(looks like piezo but weight is much more than a piezo)
It is a mid tweeter sort of thing as far as I could understand. But I thought I would replace my Philips dome tweeter (used as super tweeters) with those. Bad idea I know! But if I can belive my ears they sound better than those domes. (says a ton about the philips tweeter)
As a matter of fact I was using the bolton 8PT22 tweeter as the mid tweeter and the philips as a super tweeter.
Now the plan is I will put those Onkyos as mid tweeters in place of the Bolton as soon as I find a real super tweeter to go with those.
My original diy thread could be foun here:
http://www.hifivision.com/diy/4338-my-diy-efforts.html
Am attaching some pics of the modification.

8PT22, oh such nostalgia!! I did not know that Bolton still makes them!! I used them in my first DIY in 1988!! in fact I did not know they were still in operation. Senior. Mr. Monga was the driving force behind the co, and I felt there was a void after he passed away.

My experience with the 8PT22s was that they had a huge tendency to burn out esp. if you crossed them over at the "stock bolton" crossover frequency of 4khz.. I found 6khz and a 6db/octave slope worked better for them, but they were high directional after 8khz.

your "onkyo tweeters are horn loaded. won't you have a significant efficiency mismatch?

what crossover frequencies are you using currently?

 

[madman29]

Hi Kapvin,
Yes The Onkyo does have a higher efficiency, hence the look out for a new super tweeter which will have horn loading. As for the crossover friquency I cannot tell you much as I myself dont understand these circuits much. But I am posting my circuit diagram for you.
As for the super tweeter I have found something in Kolkata. It is a 1" Titanium super tweeter with horn loading. I am posting a pic of the unit. The specs are : 1 1/4" High temp voice coil, 275w rms/550w peak, 8ohms, ferro fluid enhanced voice coil, Sensitivity 108db/w/m, Freq response; 2k-23khz.
Do you think I need to change any component in th crossover if I use this unit as a super tweeter?
I will use the Onkyos as mid tweeter then.