I’d submit that this is even better and readily available…take a look at the LeAn older B&C 15" as they were available until about the mid-2000s.
Rare in the US and certainly in Canada, so check your PM
https://www.parts-express.com/Faita...Professional-Woofer-8-Ohm-294-1271?quantity=1
Those freq resp graphs are not that special.An older B&C 15" as they were available until about the mid-2000s.
Rare in the US and certainly in Canada, so check your PM
B&C (as well as other brands) still makes wonderful speakers, so I don't get why to hunt for those "rare" mythical speakers.
Except for the phase......lol
I thought FIR had higher resolution filters vs IIR?
It's rather the opposite, especially for lower frequencies.
IIR is just limited by the sampling frequency, FIR is limited by the amount of taps.
Which works against you for lower frequencies (aka, you need a lot more taps for lower frequencies).
The main benefit and advantage with FIR filters is not really being used for traditional biquard filter and EQ blocks.
Except for the fact that FIR filters have linear phase (meaning phase is not being "changed"), as I said before.
But also like convolution filters (as mentioned before) or things like moving-average filters and other fancy things.
(basically any fancy form you can think of)
*This is in a nutshell, there are things like single and double precision for IIR filters.
But that only has to do with how many significant digits are being used (by the DSP chip or software)
Not as a fundamental rule per se.
Also, those errors are in the realm of rounding errors of the filter curve.
It's extremely debatable how audible it is when the Fs and/or Q of a certain filter is off by like 2-3% (at most)
This difference will be an order of magnitude bigger with insufficient amount of taps.
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Yep, pure smoothing can be done with anything. In fact, minimum phase IIR smoothing is the correct way to smooth drivers.
But as Dave Gunness says in this video, thinking smoothing is the main function of DSP/FIR is off the mark..
Sure, FIR is a very powerful tool that needs to be used correctly, but that's no reason to shy from it, or withhold recommending it.
Funny. The only exception IS one of the two main reasons to use FIR !
The next vid in the Gunness series shows such use.
The other main reason to use FIR is complementary linear phase crossovers. (which are extremely valuable even if FIR is used for nothing else)
Put linear phase xovers together with; drivers individually corrected by minimum phase EQs and with what Gunness calls Temporal EQ (impulse convolution).
And then....... we've moved out of the stone age when it comes to tuning speakers....
Theres no reason to not use FIR for the whole process, if thats within your DSP capabilities I guess I could say.
I agree with that, other than for the system high-pass (sub high-pass), which i still think is best implemented as true IIR. (subject to further change of mind).
I'm ok with embedding all needed min phase EQs in the FIR file using 16k taps per channel @ 48 kHz, but even that tap count shows a little slippage vs true IIR at sub frequencies.
Hi Paul, yes I am. Absolutely love it.
It has a 16k FIR taps per channel software design limitation. Not sure why, because my setup....15 channels of 16k is using only 39% of processing capability.
I guess QSC doesn't envision DIY nuts using the Cores for speaker building haha
No we haven't since a big portion of people as well as companies still don't understand a thing about drivers/speaker/context properties and magically think some math or the push of one button, will solve everything for them, lol
The tool is only as good as the knowledge, skills and experience of the user.
I don't know why you show me those videos, but I guess it could be helpful for some here.
Btw, there are also quite some errors/misconceptions in that video, so be aware.
I don't think there's any need to downplay FIR filters. They make things possible/available that couldn't be done before.
Increase the tab count if needed, personally I never needed to use more than 65536 tabs. But I do use IIR too and even some passive components. Whatever gets the job done.
One can learn how to use these tools (any kind of EQ, FIR or IIR) properly. Instead of blaming the tool for any misuse, educate the (potential) user!
There's also a valid place for first order crossovers. If you're not a fan, then don't use them. But why downplay the use of them? Or even the preference for them?
They have their place and can be useful, I do appreciate what Dunlavy did with them to name a sample. In another thread there was an example of an expanding array with lots of first order crossovers and one second order on the tweeter. What's wrong with it if it gets a specific job done?
I could perfectly understand (and agree with) what @AllenB said, but there is a place for these tools.
Thanks Mark. Since I own several QSC PLD amps, I get marketing e-mail from QSC. Their Q-Sys marketing seems to be for conferencing and Malls. The pro use PLD amps are no longer made. I've been trying to wrap my head around their sense of direction while wanting to use the Q-Sys system for my own 'DIY nut' use.
I need 14 channels - 7 ch bi-amp. I would like to try something more than the built-in IIR DSP in the PLD's.
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This post has some examples:
https://www.audiosciencereview.com/...-suppression-inspiration-from-technics.13202/
The Technics SB-C700 "padded partition" in front of the flared port seems effective, suppressing 20-30dB of 400-600Hz output compared to other designs.
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I guess its the flair that reduces noise? and the smaller CSA serves as a High pass filter?....Wow its not even that complicated.
If it works well....one could possible get away with a larger than usual BR port that doesn't bleed midrange excessively, and maintains the efficiency of an undamped enclosure, tune that bad boy to 20-25hz....what we talkin? 500cm2? 1000cm2? lol
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if anyone understood the physics of acoustics enough to easily explain how port CSA effects the amount of midrange and treble that comes through, I'd appreciate it. I don't think I ever fully understood why folding helps in this area as well...I just accept that it is lol
Something to do with how higher frequencies travel, and diffraction....path to the Port and CSA of the port.... but I'm not sure how to look at CSA's function in this.
I would theorize that some how treble has to take a longer path length to get to where its going, if where its going is out of the way and the way its pointed is not directly at, where its going....Does that make sense>?lol Like its high directivity lowers energy by increasing path length...
Lets say that purple is treble and green is mid bass.....The lower directivity of the mid bass sends more energy at angles that can take shorter paths out of the port.... Then I guess that a smaller CSA would serve as more Surface to reflect energy back into the enclosure.
The question is, how restricted is too restricted.....Lets say with the 500cm2 BR Port....if we placed a flared restriction into the line, how low is too low.....How effective is the flair for reducing noise....exponential flair? The ol 15-20m/s or less, that won't exact work.....I would design the port at desired final CSA, then incorporate the flared restriction from there, but velocity in the restriction is going to peak, then what? I mean velocity would fall off again but.....no noise whatso ever from the flair? I mean does fairing 100% reduce noise?
Something to do with how higher frequencies travel, and diffraction....path to the Port and CSA of the port.... but I'm not sure how to look at CSA's function in this.
I would theorize that some how treble has to take a longer path length to get to where its going, if where its going is out of the way and the way its pointed is not directly at, where its going....Does that make sense>?lol Like its high directivity lowers energy by increasing path length...
Lets say that purple is treble and green is mid bass.....The lower directivity of the mid bass sends more energy at angles that can take shorter paths out of the port.... Then I guess that a smaller CSA would serve as more Surface to reflect energy back into the enclosure.
The question is, how restricted is too restricted.....Lets say with the 500cm2 BR Port....if we placed a flared restriction into the line, how low is too low.....How effective is the flair for reducing noise....exponential flair? The ol 15-20m/s or less, that won't exact work.....I would design the port at desired final CSA, then incorporate the flared restriction from there, but velocity in the restriction is going to peak, then what? I mean velocity would fall off again but.....no noise whatso ever from the flair? I mean does fairing 100% reduce noise?
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