My Nad 2200 burns all my tweeters.

[Hemiguy]

Hey Guys;
I'm new at this, so forgive my ignorance.
I have an intresting story. You see, in 1984, I was playing music in a band and stopped playing and decided to sell my gear and purchase Hi Fi stereo and listen rather than play. So I tried to get the best for my ears. I purchased an amp Nad 2200 and all the other components, and a set of Kef 104/2. Boy I love the sound.
A short while I had my system, I started to have trouble when I open the throtle higher. My amp fell into "soft clipping" and switch back to normal after a second or two. It was getting very anoying and I wasn't too happy about it, so I went to the area where I purchased it to let them look at it.
They checked it and told me that there wasn't anything wrong. So I brought it back home. Same thing happened. I brought it back and this time they told me to purchase another amp and run each speaker with it's own amp. So I purchased another Nad 2200. The sound was pretty awsome, but same thing, after it warms up, and I open the throtle for more power, both amps, falls into "soft clipping" at the same time and resets themselves at the same time.
So, I called my sales person and told him this. He told me to not drive it too loud. Anyway, I used them like this for about a month and then my speakers started to sound awfull. I brought them to my sales person and they looked at them and told me that the tweeters were burned. They installed two new ones. They sounded great; (for a short while). They both burned again. Now I have two amps that always falls into soft clipping and two speakers that sound like a tin can. Again I brought my speakers to my sales person, and they suggested me to use another set and plug them in parralelle with the amps. So I purchased another set of Kef 104/2 and hooked them like he told me. "Guess what?"
You guys probably know this, but my amps stills fall into "soft clipping" and believe me, this time I burnt three nice t-33's. It is starting to cost me a lot.

Now I have four great speakers, two nice amps, but can't listen to it and I don't have any sources to get anymore tweeters for repairing my speakers. I sure would love if someone could guide me through the process in repairing this mess, as I called dozens of repair persons all over the nation and I even studied electronics to try to figure out what was happening and I went to various internet sites to get information with absolutly no valuble help. It seems hopeless.
This problem has been stretched for the last 23 years and I never had the pleasure to listen to a decent stereo. I believe that my amps are 8 ohms and my kef's are 4.
I don't want to get rid of it, because if I ever get it to run right, it would be like a high performance hotrod. Cheers my friends.

[djk]

I sold both NAD and KEF in the mid 80s.

The 2200 is way too much power for the 104/2, and the 104/2 tweeter is a bit fragile anyway.

Dump the pair of NAD and get a single McIntosh MC2200. It can drive 2 ohms (which is what both pair of your KEF end up being), sounds better, and won't blow anything up. You should be able to turn up an MC2200 at an estate sale in Florida for a reasonable amount.

[sreten]

Hmmm.........

circa 1KW per channel and 2 pairs of 92dB/W speakers.

You wouldn't be hard of hearing by any chance would you ?

One 2200 and one pair of Kef 104/2 would suit most people just fine.

You seem to be one of those people who like it too loud. You turn
it up, your ears get used to it, so you turn it some more, your ears
get used to it, so you turn it up some more, something has to give.
(In the long run it will be your hearing if you have a very loud system.)

Find a high quality listening room, low ambient noise, very good room
acoustics. As long as the room is not too large one 2200 and one pair
of 104/2 should be fine. Get used to realistic listening levels.

/sreten.

[Original Burnedfingers]

How about a small light bulb in series with the tweeter to limit the power?

[ocool_15]

For troubleshooting I would play a test tone through the system and measure the voltage being applied. I suggest 50-60Hz. P=(V^2)/R will give you the output power. For listening to music about 20dB of headroom is what has been suggested.

Myself excluding the subwoofer I use only up to about 5w and thats with an 82db sensitivity.

[clem_o]

A pair of KEF 104/2 can go pretty loud - more than what most will ever want to sustain. Do you have an extremely large room?

I find it hard to believe that the tweeters would blow (agreed, KEF tweeters are fragile) without the bass drivers bottoming out first (or the crossover capacitors giving up the ghost).

Cheers!

[clem_o]

Originally posted by burnedfingers
How about a small light bulb in series with the tweeter to limit the power?

I'd bet that the T33 is good enough so that using such an approach would seriously drop its performance. The additional resistance of the bulb would also throw the crossover frequency off...

Cheers

[Gold_xyz]

For to save the tweeters connecting a light bulb in series.
(after crossover) try a car bulb of 12V 5W or 10W.
a light bulb works as a PTC Resistor

[Hemiguy]

Hey, thanks all you guys for your help.
I really don't want to get rid of my 2200's, I think that it is not normal to purchase something and doesn't work as it suppose to.
Saywe have a car and the electronic injection was wrong with it, do we need to change the car?
I am not hard of hearing, this system was like this when I purchased it 23 years ago, 23 years ago I was 23 years younger and heard the same thing.
There must be something wrong as my speaker tweeters burns. I think that I don't listen to my systen too loud, I have friends that drives their JVC much much higher than mine and been doing this in parties for years with no problems, and they paid about 25 times less money for it.
When I blow up my tweeters, the amp is at (3), and I never drove my amps over (4), you are right guys, in saying that music needs to be heard in an acoustical manner, but, when I want to hear the snapping punch of a snare drum hitting, I really need to feel it and while the bass drums are pounding, at the same time a small litte bell is ringing, I want to hear it also crisp and clear.

Here is what I tried in the two decades I went through.
I tried to hook my speakers in duel parrarlelle, no, difference, can't drive more than (3), then I hooked duel speaker in series to each amp, again, no difference, can't drive more than(3) and I blew two more tweeters.
Hey, (ocool_15), you seem to have a way to make a test. I would really appreciated if you can guide me with details. Please, I am no proffessional in electronics, just a bit handy.
Cheers my friends.

[jacco vermeulen]

104s deserve better than crabby NAD2200s.

But i actually only came overhere to see beautifull HEMIspherical pics.
NAD is like a Ford, get a Mopar