Manufacturer datasheets yeah, or preferably measured impedance by yourself or some other independent party. Here is example of 15fh520 impedance measurement I took when I bought them. Can't remember if this is free air or in box, probably some sort of free air. The blips are some form of resonance and I think the surround resonance is the lowest one, here around 550Hz. They are hardly visible in the manufacturer datasheet though. To my knowledge every driver has them, the edge resonance for example and eventual cone breakup, but is better or worse and higher or lower in frequency depending on cone diameter, shape, material, and all sorts of other things I'am not able to imagine with current knowledge. Perhaps ear can tell the difference, even if EQ was used to make two driver response the same. It would only make sense to choose better behaving one but getting the data to compare with might mean buying them all.
Anyway, these are my first measurements and might contain error but anyway you now know what the blips look like. Note also how the free air resonance is around 48Hz instead of 36Hz in datasheet.
Anyway, these are my first measurements and might contain error but anyway you now know what the blips look like. Note also how the free air resonance is around 48Hz instead of 36Hz in datasheet.
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Hah, yeah, the more I've thought about it only important thing for bass performance is to have enough big drivers and thats it. It is about the easiest thing to do for any speaker system due to long wavelengths, just throw more drivers and power until happy, not much trade-offs other than increased cost and complexity but both of those trade-offs are outside audio quality so not a problem really if one seeking audio quality, what ever that is. Lacking bass robs of audio quality that is for sure 🙂
It is very important always remember to think about trade-offs. In this case, when trying to reach low frequency extension with multiway speaker bass woofer and not thinking about what happens to the mid range performance is bad. On the other hand if you just think about the mid range performance and let the bass extension be what it happens to end up you can easily fix it just by adding more bass speakers to the system. And yes there is the trade-off here as well, already mentioned cost and complexity. This is the reason people want their main speakers play all the lows instead. This is ok, it just means there might be some compromise on the mid frequencies or SPL capability or something, which should also be ok since reducing cost and complexity was considered higher priority than audio quality 😉 If one takes choices on the speaker design so that the trade-off fall outside audio quality to cost and complexity, or size, or looks for example, it is exactly the right way to do if you are looking for audio quality. No compromises on audio quality, what ever that is.
Most of the time it is matter of finding a balanced system, not too much SPL capability, not too much bandwidth, not too much anything but just about the right amount for the application so that the trade-offs are not starting to rob performance somewhere else. Power in DIY is exactly here, you can sacrifice things you don't need in order to gain advantage on aspects you need. For example the looks can be sacrificed to lower cost, or better audio performance. What ever. Have fun!
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Yes your right, again lol.
The very limit for my lows would be 500hz, somewhere between 300 and 500.
Then right, fight the good balance between lower extention and mid quality.
Anyway I would avoird evrything with mms > 120g
QTS not between 0.3 0.35
It is also good to look at well known 15" that do what I want to do : JBL 2226H, TAD.
2226H
Bl Factor: 19.2 N/A (H)
Effective Moving Mass: 0.098 kg
QTS 0.33
fs 40hz
From Faital the closest would be 15FH500 or 15FH530 I guess...
found this too
https://www.beyma.com/en/products/c/low-mid-frequency/115WRS408/altavoz-15wrs400-8-oh/
The very limit for my lows would be 500hz, somewhere between 300 and 500.
Then right, fight the good balance between lower extention and mid quality.
Anyway I would avoird evrything with mms > 120g
QTS not between 0.3 0.35
It is also good to look at well known 15" that do what I want to do : JBL 2226H, TAD.
2226H
Bl Factor: 19.2 N/A (H)
Effective Moving Mass: 0.098 kg
QTS 0.33
fs 40hz
From Faital the closest would be 15FH500 or 15FH530 I guess...
found this too
https://www.beyma.com/en/products/c/low-mid-frequency/115WRS408/altavoz-15wrs400-8-oh/
Each time I wonder about that, many people seems to think whatever the quality of the 15", the midrange above the punch zone of 100/200 hz is never as good than a lower sized midrange for home listening. Something like 150 to 300 hz cut off according the filter slope with a 15 THEN a 12 or a 10 from there may sounds better. Some people testimonied for illustration than the midrange of the 12pr320 is much better than the 15pr400 at hearing both the Faital 15 W3c from Troels G and the 12W3C...
Thougths ?
However some people wants also really a max 700 hz cut off before a mid treble horn.... so...2 octaves for a mid driver, not sure it is a good idea either...a little short width for a pass band with passive filter.
Thougths ?
However some people wants also really a max 700 hz cut off before a mid treble horn.... so...2 octaves for a mid driver, not sure it is a good idea either...a little short width for a pass band with passive filter.
I would reason it is the enclosure that makes bad sound, there is no reason 15" wasn't good below all the resonances, like any other driver. It is all relative to size and wavelenght and most of the time one would want to crossover to smaller driver before beaming/resonances no matter the size.
I dont have too much experience on this, comparing drivers, but it is easy to mess up with the cabinet. Anyone tested both 15" and 6" driver on same 100+ litre cabinet? 🙂
I dont have too much experience on this, comparing drivers, but it is easy to mess up with the cabinet. Anyone tested both 15" and 6" driver on same 100+ litre cabinet? 🙂
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It is hard to make the human voice no too fat and not too ligtht, voices fundation are very near from this punch zone.. I surmise it is also power response related... But I dunno, you certainly must have to build tons of loudspeakers and setup tons of filter to know...experience matters so I just can wonder. It is a little like thickness of guitar strings...hard to makes good, this high bass low mid aera is very critical from the few I experienced withh the loudspeakers I have or had...
This is way it is good to be able to have a flexible set up between 300 and 500hz which is not possible for example if your horn only allows 500hz...
It is true that resonances have to be taken care of...
And yes we could wonder if it is better to have 12+sub or 15 no sub...
It is true that resonances have to be taken care of...
And yes we could wonder if it is better to have 12+sub or 15 no sub...
I had a look at the AES power ratings, and they specified pink noise, 2nd order and with some kind of shaping to get 6dB peak to rms. Therefore a max dB line on a frequency plot seems very ambitious to me. When a pure tone (say 200Hz) could hit the minimum impedance above resonance, and in the absence of lower frequencies there would be minimal convection, the coil would get very hot, very fast.
When they specify a 3.5k-4k upper frequency limit, that also spreads the energy across a wider band, bringing up the average impedance.
The pink noise colour also prioritizes bass energy, while the 2nd order filter prevents overexcursion, so it ensures plenty of convection.
With that in mind, it seems like, the big horn and line array installations would be more aligned with hifi, rather than the smaller rigs that pack a lot of SPL into a mobile package. The big arrays gain efficiency in numbers and would need comparatively little power.
When they specify a 3.5k-4k upper frequency limit, that also spreads the energy across a wider band, bringing up the average impedance.
The pink noise colour also prioritizes bass energy, while the 2nd order filter prevents overexcursion, so it ensures plenty of convection.
With that in mind, it seems like, the big horn and line array installations would be more aligned with hifi, rather than the smaller rigs that pack a lot of SPL into a mobile package. The big arrays gain efficiency in numbers and would need comparatively little power.
Yes why not if I am sure I get the "best" low mid and that it is a 15" and not a 12". Space is not a concern in that room and I want wide baffles so I can either use 12 or 15 low mids. I could wait and see if I need the extra bottom frequencies...
Buy once, cry once. One of the few advantages to being in the EU is that lots of good pro drivers are made there and are relatively cheap. Apart from potentially a larger enclosure and some modest extra cost, I don't see a reason not to use a 15.
if at least they were produced 400 l Vas 15" pro driver in US (or Mexico) yet... it should be a real advantage.... halas !
Ok ok great! Usually or traditionally everything was cheaper elsewhere...
I remember coming back from the us with the suitcase full of fostex drivers 20 years ago...
I guess those faital drivers would suit anyway...
Or look at this looks great
https://www.eighteensound.it/en/products/lf-driver/15-0/8/15W750
This guy here is happy with his new 15fh520
https://www.diyaudio.com/community/threads/15-punch.183436/page-3
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I noticed that parameters here for 15fh520 are different...
https://www.costruireaudio.com/PDF/Faital Pro/LF Drivers/15FH520_datasheet_8.pdf
https://www.costruireaudio.com/PDF/Faital Pro/LF Drivers/15FH520_datasheet_8.pdf
....due to the price and difficulty to source commodities, you can apply -20% on all the cones weigth...
I have some days off at the end of the month...
I wonder if I should get a pair of 15fh520.....
I wonder if I should get a pair of 15fh520.....