Thanks 5th Elements, very usefull answers for my better understanding 🙂
speaking Home spl and drivers choice for the mids till 2 khz and woofs till 200/500 hz , Is Le at 1 K hz data sheet spec is still a good factor to choose the said "fastness" of the the driver i.e. more exactly his behavior to react to suden dynamic demands and controll to stop it (dynamic peak in ms time windows as drums for illustration) ?
Or same conclusion about what you say about BL ? Bigger Le number at 1Khz on the datasheet then just bring more Tesla- Force factor specs that are so good with PA driver? - makes me thinks about Earl G. choice with his 15" B&C driver in his bigger model btw.
Edit : when I read 0.4 Le/1K hz on the Faital 12PR300 : I find it attractive, more than the 15PR unit on the paper...but people seem to like more the 15" unit till 500/600 hz and the snap behavior perhaps because the greater Sd !
Or don't care just choose a good designed amplifier ? Your answer about amplifier made great sense to me.. it's really a combo you can NOT split in real life but we split it in discussions for convenience when designing a speaker. While off topic I ill be curious to know what amp you daily use or what an enthusiast should choose if picking PA drivers for his speakers please ?
speaking Home spl and drivers choice for the mids till 2 khz and woofs till 200/500 hz , Is Le at 1 K hz data sheet spec is still a good factor to choose the said "fastness" of the the driver i.e. more exactly his behavior to react to suden dynamic demands and controll to stop it (dynamic peak in ms time windows as drums for illustration) ?
Or same conclusion about what you say about BL ? Bigger Le number at 1Khz on the datasheet then just bring more Tesla- Force factor specs that are so good with PA driver? - makes me thinks about Earl G. choice with his 15" B&C driver in his bigger model btw.
Edit : when I read 0.4 Le/1K hz on the Faital 12PR300 : I find it attractive, more than the 15PR unit on the paper...but people seem to like more the 15" unit till 500/600 hz and the snap behavior perhaps because the greater Sd !
Or don't care just choose a good designed amplifier ? Your answer about amplifier made great sense to me.. it's really a combo you can NOT split in real life but we split it in discussions for convenience when designing a speaker. While off topic I ill be curious to know what amp you daily use or what an enthusiast should choose if picking PA drivers for his speakers please ?
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Never heard one so please bear that in mind, it might sound great, but purely on paper...
(1) 3 Inch voice coil in a heavy coned 15 inch driver is bad. Both from a physical / mechanical stance ie small 75mm centre tube for the voice coil to be attached to the cone, and limited power handling compared to a 4 inch VC.
(2) Mms is to high.
(3) Bl is too low.
(4) Qts is to high ( I look for low and ultra low Qts more like the attached)
(5) Beween 100Hz and 800Hz its low sensitivity of 93dB is a problem.
You've conveniently edited my replies to suit your agenda. None of what I said was in contradiction.
Do people not understand what on the whole means on this website.
Keep in mind that this is not a PA driver but intended for studio monitor use. Power handling is not a problem due to the voice-coil arrangement. I guess the voice-coil surface is at least the same as that of a 4" voice-coil. But I do usually also prefer 4" coils for 12" and 15" woofers. The newer Version of that driver has higher Vas, lower Qts and lower fs.
Regards
Charles
Edit: I was a litle slow with typing, I refer to the second last post, made by Hydrogen Alex.
Regards
Charles
Edit: I was a litle slow with typing, I refer to the second last post, made by Hydrogen Alex.
I did indeed leave that out on purpose, but I'm really not sure if I had a specific agenda (specially not a dark and nefarious one 😉 ). I just found it a very interesting combination of statements and from where I stand it's still contradictory though, even with the on the whole statement. Because in the end the only thing that counts, like you said yourself, it's about the complete design and the factual performance, and not just one single attribute of it.
I think everybody can agree to that 😎
This is not how it works. You can see how 'fast' a driver is capable of moving by looking at its frequency response. If the driver isn't capable of reproducing a signal of a certain speed (ie of a certain frequency, higher frequencies have faster transitioning waveforms) it rolls off or has no output.
With regards to stopping that is done by the amplifier. The recorded signal has an attack, the peak of the impulse and then the decay. The amplifier controls all aspects of the cone. It starts and stops it. Only around resonance (the tuning frequency of a box etc) is the drivers motion controlled by the amplifier and the mechanical compliance of the system. Almost all of the range of the system is covered by drivers used away from resonance, except for the bass. Bass is inherently slow anyway. Dynamics are not felt through deep bass although a lot of energy can be felt with deep bass, it's not the chest thumping, hard hitting sounds that come from the bass driver.
It's all a balancing act between driver parameters to get where you want to go. If you want a high sensitivity driver then you need a lot of driving force within the motor coupled to a cone of suitable mass. It's a means to an end.
I actually use a multichannel class D amplifier built around the TPA3251. Under measurements they basically produce nothing but noise at very low power levels. I need 6 channels of amplification for my main speakers and these perform very well for my needs. It's just a plus that they have low power consumption and fit into a small space!
You attached a PD.158 Sim. Did you (or anyone else) find any 3rd party measurements of this woofer? It coincidentally sparked my interest a few days ago for usage in a reflex enhanced front loaded horn. It won’t go very deep, but can reach deeper than other woofers with lower fs in the same enclosure (I’ve simulated to many to count by now). And the low-ish Le means it will go fairly high as well. With a bit of EQ it might go from 40 to 600Hz in that horn.
I'm planning a build a pair of W/M/T/M/W and the W's are 8 inch sealed.
Thinking about getting a pair of LAB 12's, one for the bottom of each speaker in a sealed box, to be equalized to go as low as possible for medium listening volume. I can cross to the 8's at 100-150HZ.
Any thoughts? Better choices? I guess I'm a little stuck on the idea that "Pro" woofer might not be the best idea, but the Box modelling for LAB 12 looks very attractive. when I take into account the price, there appears to be nothing offered as a new purchase that comes close. LAB 12 Price $150ca
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It's maybe not a trend but it seems like "hifi" drivers take a premium for these kind of measures. I would also rethink if it's necessary with distortion figures as of recent developments in drivers, sort of diminishing returns. Also the ability to measure for the average customer have not made it better...
Very interesting, thx.
Solved the center to center problem with using an 18" higher in freq, rather elegantly.
Would love to hear it.
double spider is an advantage in the PA cone drivers ? Some PA brands uses it more... B&C for illustration !
For high power application yes. The "lower" power drivers usually don't have double spiders.
Somehow I missed this one. Not as much xmax and a bit higher inductance than the 18N862, but sims very similar in extension and sensitivity for half the price.
I was all set to go the semi-practical route, yet now I find myself contemplating a pair of 390L monoliths with 10in mids and 1in cd.