Have you ever attempted to compensate for your speakers' lack of treble by adjusting the treble output on your outboard gear? And were you concerned about potential damage, especially to the tweeters? On this episode of Ask The Expert, we take a look at whether this is a viable solution to a common problem, and whether there's really cause for concern.
Don't forget that Ask The Expert is only made possible because of your questions, so keep sending them in via the "Send us your questions" form at the bottom of this page and we'll do our absolute best to try to answer them on an episode in the near future!
For this episode, we have a very interesting case study from an owner of a set of Dynaudio Audience 9's, Audience 10's and Audience Centre speakers. The gentleman in question has had his Dynaudio speakers for more than 20 years and has noticed that he's gradually losing treble in his speakers.
In his pre-amplifier there's the option to increase or decrease the bass and treble. The question is then: will increasing the treble on the pre-amplifier help to compensate for the missing treble from the speakers themselves? And if so, how much should this treble be increased? Can it it be damaging?
First and foremost, it really depends on how loudly you're playing, because such a treble setting on your pre-amp is basically an increase in level at a certain frequency, or above a certain frequency. If you're not playing loudly, then it's not an issue. You're unlikely to cause any damage.
If, however, you sometimes play your speakers very loudly, then increasing the treble will increase the amount high-frequency energy going to the speakers, which could indeed present a risk of damaging the tweeters, if you were to really overdo it. Having said that, turning up your pre-amp's treble control will obviously mostly increase the signal in the highest frequencies, which is less dangerous for your tweeters than you might think. In fact, it is among the lower frequencies that the most energy resides, meaning that excessive mid-to-low-frequency input actually presents greater risk than high-frequency energy – even to your your tweeters.
What this means is that increasing the treble on your pre-amp is relatively low-risk, making this a fairly viable option for regaining some of the lost treble in your loudspeakers. One thing to consider is that the increase in treble that you're applying from the amplifier might not be at the same frequencies as where your speakers' tweeters are actually lacking, so it's up for discussion how effective this solution. Indeed, the absolute ideal solution would be, quite simply, to replace the tweeters entirely, thus ensuring the best possible sound for years and years to come.
On a similar topic, people are often worried about burning out tweeters when playing loudly, and especially with increased treble from their other gear. But does this sort of scenario actually give cause for concern? Well, yes and no. First of all, what typically burns out tweeters is, in fact, not too much treble but – as we explained earlier – excessive mid-to-low-frequency input. We'll elaborate on why that is the case now.
When you drive your speakers too hard, the amplifier clips, because it is unable to put out the energy required by your speaker's the woofers. At some point, your amplifier simply reaches a point where it can’t play any louder, and therefore it will being to clip.
By "clipping" we mean that, instead of producing a nice, clean sine wave, the top of the waves become "clipped." Those harsh edges of the clipped signal occur at very high frequencies, meaning that you've now taken what was bass energy and directed it towards the tweeters in the form of clipped sound waves. It's this clipped energy in the low frequencies that ends up in the tweeter, and which can often damage the tweeters. Excessive energy in the high frequencies themselves is rarely to blame, contrary to this seeming more logical.
So again, there's little risk of damaging the tweeters simply by increasing pre-amp treble, but fully replacing the tweeters is the better and more viable long-term solution.