Low frequency range of the trilam tweeter?
soiset
Posts: 724
I'm sure this is probably proprietary, but does anyone know the low freq capacity of the trilam (e.g. sl600) tweeters?
Post edited by soiset on
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Im not familiar with that tweet, what models is it use in? and what is the crossover frequency?If you know this it will give some indication of its low freq extension.Most designers will try to cross the tweet over as low as they can as this will improve the systems off axis response.The general rule is to place the xover about one octave above the tweeters natural resonant frequency.However the crossover point could be lowered somewhat if a steep 4th order slopes are used.Testing
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They were used throughout the LS series. They are a 1" dome (laminated silk or some other fabric). As far as the xover point, the ad brochures make a point that it is high, "significantly outside of the "critical midrange" because the xover introduces "phase shifts and frequency errors." The ad does not say where, but it includes a log graph that indicates that it is above 4 kHz.
I would hope that a nice 1" tweet would extend at least below 2.5. -
Typically 1" domes have a resonant frequency in the 1-1.5k range assuming it doesn't have a rear chamber.So it should be usable down to 2.5k as long as atleast a 12db per octave hi pass filter is used.
I would hope that a nice 1" tweet would extend at least below 2.5.Testing
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I suppose that if the xover point is set lower than the response of the tweeter, there would be an easily measurable dip (by pink noise analyzer) from the xover point to the the tweeter's actual range, no?
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hey, look - I'm not the first to ask:
http://www.polkaudio.com/forums/archive/index.php/t-24437.html -
You must set the crossover point at approx 1 octave above the tweeters resonance.If you tried to do what you suggest the tweeter will fail because it will not have adequate protection from low frequency signals.It will be destroyed from overexcursion.I suppose that if the xover point is set lower than the response of the tweeter, there would be an easily measurable dip (by pink noise analyzer) from the xover point to the the tweeter's actual range, no?Testing
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You must set the crossover point at approx 1 octave above the tweeers resonance.If you tried to do what you suggest the tweeter will fail because it will not have adequate protection from low frequency signals.It will be destroyed from overexcursion.
I suppose that would be one way to measure it. -
Yeah you could measure excursion ability and lifespan:D I suspect the first would be too long resulting in the second being very short.I suppose that would be one way to measure it.Testing
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Well, I use 24db slope active xovers (none of those errors in the "critical midrange"), so I should be able to set it pretty low. I'll try 2.5 and see if it blows up. Fortunately, I have plenty of them.
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With the 4th order slope you should be fine even at 2k.You might want to add a large capacitor (>20uf)in series with the tweeter to protect it from any potential DC from the amp.Testing
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With the 4th order slope you should be fine even at 2k.You might want to add a large capacitor (>20uf)in series with the tweeter to protect it from any potential DC from the amp.
I have done that already. I read about that after running my 2 channel system without caps for a while. I was fortunate not to have damaged my PSB's tweets.
