Tweeters making noise at high volumes during bass heavy music

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bobdehunt

Audioholic Intern
Ratings
1 1
#1
I have an old pair of Jenson speakers that I'm pretty sure were custom made by somebody. It's a three-way system. The x-over for the tweeter and mid it at 1500 hz and itit's relatively steep. I have the Dayton audio apa-150 amplifier. The problem only started after I changed amplfifiers and tweeters, but I don't believe that I've listened to these speakers quite as loud before replacing the tweeters and the amplifier due to the distortion my old amplifier brought at higher volumes. The x-overs look well built and are fairly large and complicated. Does anybody have any ideas as to what could cause this? Could it be the amplifier, or should I try to reproduce the old crossovers and get some better tweeters?
 
TLS Guy

TLS Guy

Audioholic Slumlord
Ratings
7,281 17 25
#2
I have an old pair of Jenson speakers that I'm pretty sure were custom made by somebody. It's a three-way system. The x-over for the tweeter and mid it at 1500 hz and itit's relatively steep. I have the Dayton audio apa-150 amplifier. The problem only started after I changed amplfifiers and tweeters, but I don't believe that I've listened to these speakers quite as loud before replacing the tweeters and the amplifier due to the distortion my old amplifier brought at higher volumes. The x-overs look well built and are fairly large and complicated. Does anybody have any ideas as to what could cause this? Could it be the amplifier, or should I try to reproduce the old crossovers and get some better tweeters?
Sounds like you changed the crossovers and tweeters. A very bad move. If you have the parts put them back. There are not many tweeters that can be crossed at 1.5KHz. Clearly you are driving the tweeters too low, and you will blow them. Since you don't state what you have then I have no idea how low your tweeters will go and what sort of slope they need.

To put it bluntly you have made an absolute hash of things and bad results would be guaranteed.
 
B

bobdehunt

Audioholic Intern
Ratings
1 1
#3
Sounds like you changed the crossovers and tweeters. A very bad move. If you have the parts put them back. There are not many tweeters that can be crossed at 1.5KHz. Clearly you are driving the tweeters too low, and you will blow them. Since you don't state what you have then I have no idea how low your tweeters will go and what sort of slope they need.

To put it bluntly you have made an absolute hash of things and bad results would be guaranteed.
I haven't changed the crossovers. The crossovers are the originals, but i believe there may be a problem with them because when the bass is low and loud, the tweeters make noise with it. The highs aren't distorted when this happens
 
TLS Guy

TLS Guy

Audioholic Slumlord
Ratings
7,281 17 25
#4
I haven't changed the crossovers. The crossovers are the originals, but i believe there may be a problem with them because when the bass is low and loud, the tweeters make noise with it. The highs aren't distorted when this happens
So you need the old tweeters. I suspect you are trying to drive a tweeter with too high a Q below free air resonance. What were the old tweeters and what are the new?
 
B

bobdehunt

Audioholic Intern
Ratings
1 1
#5
I don't know what the old tweeters were, but the new ones are dayton audio DSN25F-4. The low end stops at 2500 hz, but in my system they sounded just fine and way better than the old tweeters untill I crank the volume. I was looking for something really efficient. Should i look for different tweeters? Thanks.
 
TLS Guy

TLS Guy

Audioholic Slumlord
Ratings
7,281 17 25
#6
I don't know what the old tweeters were, but the new ones are dayton audio DSN25F-4. The low end stops at 2500 hz, but in my system they sounded just fine and way better than the old tweeters untill I crank the volume. I was looking for something really efficient. Should i look for different tweeters? Thanks.
The problem is that you think this is a simple problem it is not.

I have no idea of the construction of this speaker system and especially no idea of the crossover circuit or slopes.
Can you copy the crossover circuit and provide pictures?

The tweeter you sight is a cheap low powered tweeter. Its free air resonance Fs is right at your crossover point of 1500 Hz. The tweeter is very high Qts 1.42. So the way you are using it it is going to be set into violent resonance and destroy itself if you keep doing what you are doing. So this tweeter actually needs a pretty steep roll off at 3000 KHz and not 1500 Hz.

Since I have no details of your system I can not begin to recommend a tweeter for you, except to say that it needs an Fs below 700 Hz and the crossover needs to have pretty steep slopes, preferably fourth order, for a 1500 Hz crossover. If the slopes are not steep, then you are looking for a tweeter with Qts below 0.3 as well with high power handling. With the crossover where it is there is a lot of energy the tweeter has to cope with.

Under any circumstances you are looking at a far more expensive unit than the Daytons you have bought. If you need low Fs and low Q you are looking at an unusual and expensive item.
 
Last edited:
B

bobdehunt

Audioholic Intern
Ratings
1 1
#7
The problem is that you think this is a simple problem it is not.

I have no idea of the construction of this speaker system and especially no idea of the crossover circuit or slopes.
Can you copy the crossover circuit and provide pictures?

The tweeter you sight is a cheap low powered tweeter. If free air resonance Fs is right at your crossover point of 1500 Hz. The tweeter is very high Qts 1.42. So the way you are using it it is going to be set into violent resonance and destroy itself if you keep doing what you are doing. So this tweeter actually needs a pretty steep roll off at 3000 KHz and not 1500 Hz.

Since I have no details of your system I can not begin to recommend a tweeter for you, except to say that it needs an Fs below 700 Hz and the crossover needs to have pretty steep slopes, preferably fourth order, for a 1500 Hz crossover. If the slopes are not steep, then you are looking for a tweeter with Qts below 0.3 as well with high power handling. With the crossover where it is there is a lot of energy the tweeter has to cope with.

Under any circumstances you are looking at a far more expensive unit than the Daytons you have bought. If you need low Fs and low Q you are looking at an unusual and expensive item.
Thank you, this is very helpfull. I will take photos of the crossovers.
 

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