I suspect this topic is covered dozens of times, but I couldn't find the answer I'm looking for.
So I have a speaker design that, in any case, woofers will be crossed to a horn around 800 Hz. This is constant. I'm either gonna use a single Faital 12RS430 in a 70L ported box and have decent F3 and 800 Hz covered, or I will use a woofer like Fostex FW 305 in a sealed box and use a second woofer starting from 100 Hz to the low end.
My question is about the quality of this 100-800 Hz. Which one might sound better? More resolution. The goal is not higher SPL, just more mid/low-mid clarity. Using a low Mms midwoofer vs. a heavier woofer (although Faital's Bl/√RE is higher...). If you have any woofer suggestions that can beat the FW305 in an even smaller box, please don't hesitate.
Thanks for the answers in advance!
So I have a speaker design that, in any case, woofers will be crossed to a horn around 800 Hz. This is constant. I'm either gonna use a single Faital 12RS430 in a 70L ported box and have decent F3 and 800 Hz covered, or I will use a woofer like Fostex FW 305 in a sealed box and use a second woofer starting from 100 Hz to the low end.
My question is about the quality of this 100-800 Hz. Which one might sound better? More resolution. The goal is not higher SPL, just more mid/low-mid clarity. Using a low Mms midwoofer vs. a heavier woofer (although Faital's Bl/√RE is higher...). If you have any woofer suggestions that can beat the FW305 in an even smaller box, please don't hesitate.
Thanks for the answers in advance!
I like option #2.
Excursion increases quickly with decreasing frequency.
If you can avoid the longer excursion of the sub 100Hz frequencies in the mid-woofer you will reduce the Intermodulation side bands in the below 800Hz midrange frequencies. IMD is the worst distortion, you can hear it and it sounds bad.
Excursion increases quickly with decreasing frequency.
If you can avoid the longer excursion of the sub 100Hz frequencies in the mid-woofer you will reduce the Intermodulation side bands in the below 800Hz midrange frequencies. IMD is the worst distortion, you can hear it and it sounds bad.
Thanks @DualTriode
But will there be audible SQ difference with these 2 speakers, when listening music around 80 dB? (< 90 dB at speaker)
I know technically it looks better, but will it differ subjectively?
But will there be audible SQ difference with these 2 speakers, when listening music around 80 dB? (< 90 dB at speaker)
I know technically it looks better, but will it differ subjectively?
Either way, for the purposes of clarity and detail…..you’re compromised by your choice of crossover point……most fundamentals and 1st harmonics in music are in the 500- 1000hz range. By placing the crossover there, you’ve now introduced phase interference…….something I’ve never really understood people doing after spending tons of $$$ on drivers with low distortion
Midrange is midrange where hifi is concerned…..3 octaves maximum coverage from a single driver based on complex music. 500hz to 3khz is a MUCH better solution when the goal is clarity and detail. A quality 6-6.5” pro midrange driver can do this easily.
Midrange is midrange where hifi is concerned…..3 octaves maximum coverage from a single driver based on complex music. 500hz to 3khz is a MUCH better solution when the goal is clarity and detail. A quality 6-6.5” pro midrange driver can do this easily.
I admit it’s better to lower the xover point, but I can’t do that with the current horn. So is it better to have it after 1kHz? Where we are more sensitive 🤔
(2-3kHz, even more so…)
Your speakers your ears, you tell us.
As you turn up the SPL Force Factor modulation becomes a bigger player. IMD increases and becomes more irritating, much more so than Harmonic Distortion.
I would really build both speakers if I had time. I'll think about it. @mayhem13 's comment is also valuable. But I think I can't do anything about it unless I go extreme. Can't lower the xover point with the horn I chose. I wouldn't want any woofer to play higher either, even if I do 3-way (sealed mid that I wrote above), the 1-2 kHz region is also important. 800 Hz looks like a good compromise. (maybe not! 😀)
You want to cross where the woofer and your waveguides disperion matches..
More important then the exact xo frequency.
Also 1khz is not the worst place nessecearily, your ears have problems with localization in that range.
Sealed is easier to implement.
Better for integration with a sub.
What you loose is efficiency. midrange leakage through port and possible chuffing etc. Are things thats avoided.
Trade offs either way
More important then the exact xo frequency.
Also 1khz is not the worst place nessecearily, your ears have problems with localization in that range.
Sealed is easier to implement.
Better for integration with a sub.
What you loose is efficiency. midrange leakage through port and possible chuffing etc. Are things thats avoided.
Trade offs either way
That’s good to hear!
I still think sealed bass/mid envelope might be easier to manage in an untreated room. But I don’t know if it’s worth the extra effort (and more volume…)
What is the best 12 inch woofer to use below 100 Hz, in a sealed box. Even hitting 40 Hz is enough. Just trying to see what might be the minimum volume and box size for subwoofer + midwoofer + horn setup. I guess it’s around 100 L.
Everything is a compromise of course…..but there’s some silliness in what defines a compromise as well as some well grounded strategies….
Some things to remember…..there is no perfect speaker nor are there any reference recordings……subjectivity is a biological boundary worthy of respect.
Measurements will give you some insights…..but how a driver behaves with complex music is impossible to map. This is where voicing and practical experience come in to play along with some basic acoustic principles.
Source content/recordings inconsistency brought rise to the ubiquitous bookshelf two way where if properly done, EVERY recording sounds good……..but because of the inherent compromise of the crossover point, very few recordings sound exceptional.
If you want to take the path to foundational perfection……a single driver without distortion or phase overlap from 500hz to 3k is a great place to start.
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Use sealed for the mid-woofer, then you can increase the enclosure volume to hit a Qtc below 0.5, giving more control...a critical thing considering the frequencies we are sensitive to..
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A pair of sealed 12" at 4 meters can do ~80dB at 30Hz with only 1.7mm excursion with no room gain.
Porting could cut that low excursion level in half.
The Faital 12RS430 is rated for 13.57mm Xmax, should have very little IMD or AMD at such low excursion, I'd expect they would be clean to near 10mm, ~107dB at 1m.
I'm all for three-way if the SPL demands it for clarity, but at 80dB it's not required, two-way should work fine.
Art
Thanks for all the answers!
Now I feel like with my relatively low SPL use case, 2-way is OK, and Faital is a good woofer. The only thing is to decide if I want the sealed sound or ported sound (12RS430 in 70 - 75 L @34 Hz is QB3 alignment, but I don't know if it affects the envelope at all. It should be -18 dB / octave instead of -24 dB...)
Shouldn't I opt for 0.7? (Sorry if it's a really noob question, I don't know much about the effects of box volume on the driver in sealed boxes.)
Thanks for the great information above.
Now I feel like with my relatively low SPL use case, 2-way is OK, and Faital is a good woofer. The only thing is to decide if I want the sealed sound or ported sound (12RS430 in 70 - 75 L @34 Hz is QB3 alignment, but I don't know if it affects the envelope at all. It should be -18 dB / octave instead of -24 dB...)
By modeling your Fatal twelve incher, it is firmly in the ported camp....if in a sealed enclosure, I get an enclosure of a at 130 liters worth for a "high control" value of 0.50, but the lower end rolls off badly at -3.01 DB at only 66.75 hertz...the bottom end sorely lacking.
But, if you port it with a tuned frequency of 33.6 hertz, your enclosure is at a common 125 liters, and a deep bottom end of -3.06 decibels at 31.53 hertz....this configuration is much much better.
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But, if you port it with a tuned frequency of 33.6 hertz, your enclosure is at a common 125 liters, and a deep bottom end of -3.06 decibels at 31.53 hertz....this configuration is much much better.
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I would put the mid in a sealed enclosure. It's easier to work with, and I'm lazy. The problem I see is getting the two, a mid woofer and a sub woofer, to cooperate. One solution is to have two identical woofers cover the bass with one rolling off the highs at 50-100hz where the sealed mid woofer rolls off, and the pair then cross over to the tweeter. This doubles the output in the lowest octave, which can reduce the low frequency roll-off, and with EQ you can add bass boost with less distortion. The next problem is the phase of the two woofers with the low crossover and a vented sub woofer all interfering. I've tried this with two woofers in the same box and it works very well. I've not tried it with a sealed woofer and a vented woofer, I thought that would get too crazy. It might work with DSP.
If one is sealed, I would go sealed mid + sealed bass. The whole point is having the fast envelope of sealed bass/mid. I don't want to mix a ported in this solution.
I still don't get the concept of what 2.5-way would do when I use the same woofer in the same liters, one is playing all the way to 800, the other one is crossed at 80 Hz. Wouldn't the lower one only play 60 Hz (roll off) - 80 Hz? Where would it take the F3 in this case?
WinISD models 72 L @ 34 Hz for ported, what is the reason for 125 L?
When using WinISD for ported, it gives a plain flat response before falling off on the bottom...now if you don't like just how low it gets, you can "tweak" the tuning by decreasing the frequency (fb) slowly & increasing the enclosure volume to match. This has the "cost" of a "dipping down" response somewhere around 80 hertz....the rub is, how much of a dip in decibels will you sacrifice to reach these lowest of frequencies? ...I find some 0.5 to 0.8 loss in decibels an acceptable trade-off.
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If you put two 8 ohm woofers together in parallel then you get 6db more output from the impedance (3db) and cone area (3db). What I'm proposing is to add one woofer for the bass only below the roll-off frequency. Both woofers have the same roll-off but the 'sub' woofer doubles the lowest frequencies. These low frequencies are maybe 3db down, but add the 'subs' 3db down response to the 3db down of the 'mid' woofer and the two sum to make a system response that is flat and extended lower, maybe 10hz lower F3?. You will have to try several different inductors to get it right, or use a sub output of a home theater receiver or DSP, but I think it has promise to extend the F3 and get more bass.
The second 'sub' woofer is more of a helper woofer. You also get the addition of cone area for the lowest bass. If you add any boost the IM distortion will be less since the low bass is now handled by two woofers one of which doesn't extend to the midrange.
@Arthur Jackson I see! I’m not sure if it lowers the F3 by 20 dB or not, but I do have 3 channel Hypex so I’m sure I will find perfect balance between them.
Now it comes down to find the right woofer to use sealed… I don’t hava any idea 😅
Now it comes down to find the right woofer to use sealed… I don’t hava any idea 😅
Keep in mind that X-Max is defined at the point where THD is 10% or greater.
80 dBs is an artificial limit. Why are you going to stop at 8 when it will turn up to 11?