Component Power Questions

  • 6
    Participant count
  • Participants list

ThxOne
Premium Member

The Boss
I see a lot of component sets and they say stuff like for example "150w rms". How does this happen without blowing the tweeter? If you look at individual components, the tweeter almost always handles less power than the mid/woofer. Ok, so what is making the tweeter not blow? Is it just the crossover frequency not allowing bass to get to the tweeter that allows it to handle more power or does the crossover absorb or divert power away from the tweeter or both or is there some other magic at work?

 
They do blow, just not for everyone. Picking up what I'm laying down?

Anyway, it really comes down to time versus power and the averages you're running over the long term. As in, what is the average amount of power you are giving to the driver, say, for the period of 30 seconds versus a full song versus a full day. These are tiny bursts of power, rarely do pure tones go to a tweeter. But they add up over time and hamper the driver's ability to shed the thermal energy. This leads to thermal compression and everything that follows, including death. So you can send some pretty significant spikes of power (hundreds of watts for milliseconds) to a HF driver and it will survive. But this assumes everything is clean about it; the signal, the power. The shorter the time period, the more power you can dump into a tweeter coil. The longer the time period... you get it. The rest of the picture, of course, involves the more obvious things like clipping and the fact that the tweeter is only seeing a certain percentage of the full musical spectrum. Elliot Sound is a great site for information, I posted a related article below. Hope it helps.

http://sound.whsites.net/tweeters.htm

 
Last edited by a moderator:
Best to buy good drivers and not worry so much about it. I like Transducer Lab tweeters unless I'm running ribbons. The carbon fiber and the ceramic are my favorites.

1.jpg

2.jpg

3.jpg

 
Another old school trick that you still see now and then is the current limiting bulb in the tweeter circuit. It diverts power away from the tweeter coil above a certain threshold.

image.jpeg

image.jpeg

 
I follow what you are saying... maybe my speakers are just that beastly. I run them on average 3 to 4 hours a day at 3/4+ volume which is pretty darn loud. They say 80w rms... I think my ears give out before the speakers would.

 
Those are some very nice looking drivers. 
Yeah, these Transducer Lab tweeters are about as good as it gets for the price. The link below shows one of the cleanest spectral decay and plots I've seen for a dynamic driver. I think the only step up would be the more expensive beryllium or diamond domes from SBA, Scanspeak, and Accuton at much higher price points.  

http://www.robsandiy.com/tweeter/TD_N26C-A 

 
Yeah, these Transducer Lab tweeters are about as good as it gets for the price. The link below shows one of the cleanest spectral decay and plots I've seen for a dynamic driver. I think the only step up would be the more expensive beryllium or diamond domes from SBA, Scanspeak, and Accuton at much higher price points.  

http://www.robsandiy.com/tweeter/TD_N26C-A 
Nice. It would be a sin to cover them up if being used in the home.

 
Tweeter power handling is based on frequency and the crossover. if you play a low enough frequency it will blow really quickly. In music most of the power is taken out in higher frequencies so they will not see a lot of power naturally, so as long as you use a crossover that fits well with your driver you will be fine.

 
Tweeter power handling is based on frequency and the crossover. if you play a low enough frequency it will blow really quickly. In music most of the power is taken out in higher frequencies so they will not see a lot of power naturally, so as long as you use a crossover that fits well with your driver you will be fine.
This is false.

Simply sending low frequency content to a tweeter will not cause it to die, even with a decent amount of power. I'm not saying it will sound good, the THD would be quite high if the driver is not designed for low frequency use.

Yes, low frequency content can and will destroy a tweeter, especially if it's not built for it. But it's not the same thing as saying if you cross high enough you will not blow your tweeter, which is basically what you've indicated. I have video proof of a Vifa tweeter being subject to a true unfiltered 50Hz sine wave, stroking it for all it's worth. The driver suffered no damage and is still in use today.

You can very easily destroy a tweeter that has been appropriately protected from low frequencies in a mechanical and thermal sense. Even if you've crossed at something as high as 5kHz at 24 dB, if you send enough content and power to the tweeter above 5k, it will still die from a thermal perspective. There's not escaping the driver's inherent ability to dissipate heat, doesn't matter how that heat is generated.  

 
This is false.

Simply sending low frequency content to a tweeter will not cause it to die, even with a decent amount of power. I'm not saying it will sound good, the THD would be quite high if the driver is not designed for low frequency use.

Yes, low frequency content can and will destroy a tweeter, especially if it's not built for it. But it's not the same thing as saying if you cross high enough you will not blow your tweeter, which is basically what you've indicated. I have video proof of a Vifa tweeter being subject to a true unfiltered 50Hz sine wave, stroking it for all it's worth. The driver suffered no damage and is still in use today.

You can very easily destroy a tweeter that has been appropriately protected from low frequencies in a mechanical and thermal sense. Even if you've crossed at something as high as 5kHz at 24 dB, if you send enough content and power to the tweeter above 5k, it will still die from a thermal perspective. There's not escaping the driver's inherent ability to dissipate heat, doesn't matter how that heat is generated.  
I must be missing something, the tweeter doesn't "bottom out" or strike the case it's in?

 
I must be missing something, the tweeter doesn't "bottom out" or strike the case it's in?
You can't bottom out a tweeter voice coil because of how thick the magnet is below the top plate. I put a picture below to help with this.

Most tweeters have a voice coil that is the same height or slightly less than the height of the top plate. The top plate and the coil are not very tall, only a few millimeters. The voice coil former is usually much taller by comparison and on top of that is where the dome and surround junction occurs. The allowable stroke would be limited by the former height and surround width so if there's any amount of width, you can actually produce a pretty impressive physical stroke. The stroke is not always clean but if it is, you can choose between playing low frequencies (800Hz to 1500Hz) at low power levels, or playing normal frequencies (2kHz and above) with higher output and better dynamics. There are a few tweeters that can actually do both with very impressive freedom from thermal compression or IM distortion being generated from the dome moving back and forth. The ones pictured above and below are in that category. It's all in the motor and suspension, just like any other driver.

image.png

 
Last edited by a moderator:
This is false.

Simply sending low frequency content to a tweeter will not cause it to die, even with a decent amount of power.

Yes, low frequency content can and will destroy a tweeter, especially if it's not built for it.
So which is it??

I was speaking in the realm of playing music, where as most of the power is in the lower frequencies. So proper crossover will provide protection from over driving the tweeter.

 
So which is it??

I was speaking in the realm of playing music, where as most of the power is in the lower frequencies. So proper crossover will provide protection from over driving the tweeter.
I was making distinctions for others that may be reading this thread, that you clearly did not pick up on.

I'll make it simpler for you. Even with the proper crossover you can overdrive the tweeter and kill it. Keeping out low frequencies does not guarantee you will not blow your tweeter.

 
Activity
No one is currently typing a reply...
Old Thread: Please note, there have been no replies in this thread for over 3 years!
Content in this thread may no longer be relevant.
Perhaps it would be better to start a new thread instead.

Similar threads

I’ve tried it in 3 different vehicles and multiple locations. Rear deck is best for me. Unless it’s a midbass I don’t want anything in the rear...
10
530
Crutchfield can tell you what speaker will fit your car. for subs, Image Dynamics and Adire are still around. my last sub i bought was from...
3
650
I’m sure they will be a good budget setup. I think they will lack some midbass but door treatment is super important so definitely be sure to do...
1
708
Sound deadening and door preparations are key to getting the best results towards more SQ oriented within the vehicle, as well as speaker locations
2
869

About this thread

ThxOne

Premium Member
The Boss
Thread starter
ThxOne
Joined
Location
The United States of America
Start date
Participants
Who Replied
Replies
22
Views
2,223
Last reply date
Last reply from
ThxOne
Screenshot 2024-03-07 184329.png

Doxquzme

    Mar 27, 2024
  • 0
  • 0
IMG_3075.jpeg

Daniel Lee

    Mar 27, 2024
  • 0
  • 0

Latest topics

Top