Right. So from a RFI/EMI point of view it is not any better than what you get by lowering the gain of the nc400.
Very allergic to humor ?
Smileys ? In the real life, did you smile at your own jokes, or at the contrary, did-you try to stay as serious as possible ?
Of course, it requires a minimum of respect for the intelligence of a contributor, reading a comment like this, to understand it is a joke, and, anyway, i do not see where could be any attack or injury in the mr_push_pull's joke, even if you read-it first degree.
On the contrary, your post can be considered as a personal attack against him.
Please think to all that, mister the , hum, 'moderator'.
We have not build Internet to return in middle aged inquisition, and, running a forum myself, i request from my moderators the most extreme respect of deontology and freedom of expression. In fact, we moderate only in extreme situations (means near never) and everything is smooth and friendly.
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The RFI will be reduced 'before' the first active stage of the amp and its parasitic capacitance. And you can add an additional cap to filter further. Agree ?
It can on a 110dB/1w/1m compression driver and horn, and these are very common devices around here.
I have a JBL 2450SL compression driver with a 16ohms Truextent Be diaphragm.
Despite the 3dB lower sensitiviy compared to the 8ohms version (that choice was made on purpose), I can definitly hear some hiss on a 90x50 CD horn at a 2m distance (with the amplifier alone, no source). It would be even more audible with a norrower directivity horn (60x40 for example) or a beaming horn (tractrix, expo, etc.).
A gain selector would have been a must, but Bruno has already explained how difficult it would have been for it to be non intrusive...
Let get some facts straight:
Horn loaded drivers ( compression drivers included) do not need a high damping factor because of the high acoustic loading on the diaphragm. The damping is for 99.99% controled by this. That is why they work so nice with tube amps.
So a L-pad or a series resistor will not harm the sound quality!
Horn loaded drivers ( compression drivers included) do not need a high damping factor because of the high acoustic loading on the diaphragm. The damping is for 99.99% controled by this. That is why they work so nice with tube amps.
So a L-pad or a series resistor will not harm the sound quality!
Agreed, and an autoformer will even preserve a good damping factor.
That is why I let those R141 alone for now (and also because I am scared to even touch those things with a solering iron...).
Still, I would prefer getting ride of them...
That is why I let those R141 alone for now (and also because I am scared to even touch those things with a solering iron...).
Still, I would prefer getting ride of them...
More than that, it will help.
The good practice with horn driver is: Or to feed them in current, or to compensate them both for selfic and motional impedance.
Once you get a flat impedance curve, you can set a passive attenuator to them. They don't need electrical damping, and your amp will thank-you for the reduced motional signal's attenuation in his feedback loop.
http://www.diyaudio.com/forums/multi-way/140190-jean-michel-lecleach-horns.html#post3246631
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I am aware of the fact that English isn't the native language of either of us, but I do not understand what you are saying here.
So maybe we can conclude it is wise to solve the hiss problem on compression drivers with "something" between the amp and driver instead of f..king around with the Ncore?????
Sorry for my poor English.
When the moving coil moves inside the magnet gap, it create a current /tension (motional). More the QTS of the speaker, more it is. And a high efficiency horn is a high efficiency microphone.
This signal is seen by the amplifier, and will be added in the feedback loop of the amp. Any resistance in serial with the driver will create an attenuator with the very low impedance of the amp, and eliminate this. Low impedance cables helps to dump the bass cone speakers resonances, no need for a horn driver.
Yes 🙂
More than that, as the Ncore is a class D amp, it would be stupid to loose its definition. Limiting its power is like reducing a digital delta sigma DAC to the first bits, in a way. The good way to adapt its power would be to reduce the power supply voltage.
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Maybe we can conclude that each one of us can do whatever we want with our Ncores? This is diyAudio after all, and there are no absolute reasons for one solution over another...
Wasn't familiar with that one - haven't lived in Finland for 15 years. But the cover of the magazine from -89 was a nice nostalgic reminder - I got my Linn Isobariks (still going strong!) from Kruunuradio around that time...
(apologies for the totally OT ramblings of an old expat)
Gain adjustement (either up or down) has always be a documented feature in Hypex amps, nothing wrong with that... (when you know what you are doing)
Everybody can do what he wants, but making decisions on wrong assumptions should be avoided ( and can lead to serious damage). The first wrong one, and will not point a finger😛, is the preservation of the damping factor in use with a horn( aka compression) driver..........
Horns don't make any exception to preserving damping factor - while the difference between horns and "normal" speakers might be that the horns don't benefit as much from a high damping factor, it doesn't change the fact that a series resistor will spoil the damping factor.
But the question is how much influence it has. As I stated before horn speakers are acoustical damped devices, they do not need any electrical dampening by the amplifier. So there is nothing to spoil with a series resistor. It is a utterly wrong assumption that the damping factor of an amp has an influence on sound quality in horn speakers!
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