OP
Tarun Nigam
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- Feb 14, 2023
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- #21
Hi folks, more inputs please.
You did not respond to my earlier questions.What are your crossover frequencies?
How did you calculate the box volume, port width and length?
Did you add internal bracing and insulation?
Ohms
Again, easy. When listening to music, that consists of many 'frequencies' simultaneously. Each musical tone would bring with it a series of overtones. E/g that's the reason fo having a (western) tonal system, the just intonation and so forth. The overtones are 2, 3, 4 ... times the base tone.Thanks for appreciating FineMen, Can you please elaborate more on how bass will reduce to 20W, I cannot see this from the graphs anywhere. The woofer are 40W RMS.
Not necessary, me thinks. It doesn't take a new design, but it takes some care in using the speaker. Most of all speakers around are designed with a power spec that is way too high for the bass range, if the latter was pushed alone with the watts specified. And now think of how often a speaker' woofer is blown off. You better come to understand the wider context, the simulation tricked you.Hi folks, more inputs please.
I think x-over is irrelevant here anyway.You did not respond to my earlier questions.
This information will help us help you...
Ohms
Simply put, no. It would only throw away efficiency. You would better destroy that precious amp power in an electrical resistor in front of that woofer.Making the box smaller will help limit excursion to some degree, ..
As said above, the "overexcursion" is a common feature of nearly all loudspeaker around.The Dayton DC series are 'classic' woofers which aren't very sophisticated ...
I agree, but the subject (I think?) was over-excursion.Simply put, no. It would only throw away efficiency. You would better destroy that precious amp power in an electrical resistor in front of that woofer.
You can make anything you want from my input. Once it is understood that music has overtones, the case is closed. Maybe this helps further:I agree, but the subject (I think?) was over-excursion.
I believe you. In any event, the OP is the one to convinceYou can make anything you want from my input. Once it is understood that music has overtones, the case is closed. Maybe this helps further:
Let's think of a speaker that is excursion restricted to what the amp delivers, e/g an amp of 100Watts and a speaker/enclosure combination that restricts the woofers excursion so that it would remain "linear" -- whatever that means anyway, with that 100Watts.
Now the system is fed with a real musical signal originating in a bass guitar, base tone 60Hz (most demanding for common ported boxes) plus overtones 120Hz and 180Hz an 240Hz and so on. Let's assume the series of base and overtones has a quite realistic distribution of levels as such: 60Hz : +/-0dB, 120Hz: +3dB, 180Hz: +/-0dB, 240: -6dB
The overtones consume more than three times (!!) the base tone's portion of the amplifier power, that is the +3dB at 120Hz (+3dB: double) plus an additional 0dB (equal to base tone) at 180Hz and so forth.
In order to keep the amp in non-clipping mode, within its specs, the base tone (60Hz) would consume 25Watts, and the overtones (120Hz, 180Hz, ...) 75Watts. With that 25Watts for the base tone one would only use 1/4 of power, while it was designed to be limited at 100Watts, so half of the available excursion is wasted (a 1/4 power == -6dB == half excursion).
Please replicate the calculations by your own. That is why "overexcursion" is actually needed, except one has less briliant people at the power control.
You can make anything you want from my input. Once it is understood that music has overtones, the case is closed. Maybe this helps further:
Let's think of a speaker that is excursion restricted to what the amp delivers, e/g an amp of 100Watts and a speaker/enclosure combination that restricts the woofers excursion so that it would remain "linear" -- whatever that means anyway, with that 100Watts.
Now the system is fed with a real musical signal originating in a bass guitar, base tone 60Hz (most demanding for common ported boxes) plus overtones 120Hz and 180Hz an 240Hz and so on. Let's assume the series of base and overtones has a quite realistic distribution of levels as such: 60Hz : +/-0dB, 120Hz: +3dB, 180Hz: +/-0dB, 240: -6dB
The overtones consume more than three times (!!) the base tone's portion of the amplifier power, that is the +3dB at 120Hz (+3dB: double) plus an additional 0dB (equal to base tone) at 180Hz and so forth.
In order to keep the amp in non-clipping mode, within its specs, the base tone (60Hz) would consume 25Watts, and the overtones (120Hz, 180Hz, ...) 75Watts. With that 25Watts for the base tone one would only use 1/4 of power, while it was designed to be limited at 100Watts, so half of the available excursion is wasted (a 1/4 power == -6dB == half excursion).
Please replicate the calculations by your own. That is why "overexcursion" is actually desired, except one has less briliant people at the power controls.
Before the expected doubt comes up: positively and specifically the overtones' spectrum looks like that. ( I have a bass guitar (a) and evaluated bass heavy synthetic music also (b). Side note: that is why a smaller portion of harmonic distortion (HD2, HD3 ...) is nearly always masked by the music. But not the intermodulation distortion. )
This is why I'd play around with a low shelf filter and/or a limiter rather than just kill off low frequencies altogether with a HPF. If you get a subwoofer, then using a HPF is a better idea.
Assuming by "from" you mean "high passed" in regards to the L&R speakers, then that's correct!But if I need a subwoofer, then I can also keep the sub frequency from the stereo speakers.