I wonder who makes Tobian speakers' 15" high efficiency woofers..
https://tobian-soundsystems.com/new_website/product-page-15-signature-horn-speaker/
https://tobian-soundsystems.com/new_website/product-page-15-signature-horn-speaker/
Looks a little like the surround of a Celestion woofer. Since he uses Celestion for horn drivers he might use the same brand for woofers.
Regards
Charles
Regards
Charles
That are indeed Celestion woofers, likely the FTR15-3070C or a custom version.
Sometime, it is 'constant directivity', also loudspeaker-related.
That's right but increases with the excursion.
Intermodulation in a speaker is directly dependent on the excursion. Ofc there are other components like the Bl and suspension progression but if you're using a larger excursion, the rougher it will sound for higher frequencies. A larger X-max can help but doesn't automatically do. To select a mid-woofer by the maximum excursion isn't the best criteria and you have to keep in mind every speaker brand calculates it differently, some adding 1/4 or even 1/3 on top of the mathematical excursion
(VC winding height - pole plate height) / 2
which means a woofer with (according to the specs) 6mm Xmax could indeed have less linear excursion than a different one which does not add a factor and only states 4,5 or 5mm.
Yes, the quoted 99dB sensitivity is the same as well, likely with some customization.
But I do like the price of that 15" compared to others mentioned. Anyone tried it? These Tonian speakers are reported to sound wonderful..
Also the "5 inch" Celestion compression driver used by Tobian must be Axi2050, whose price I don't like so much, and apparently the SQ is not exactly at the top:
https://josephcrowe.com/blogs/news/celestion-axi2050
Do you have other constraints, like maximum enclosure volume? Closed/Bassreflex? And what -3dB frequency for the low end?
I am looking for maybe something similar, and was checking some 15inch drivers to see what would be a reasonable f3 for a 70L BR. The B&C 15NBX100 seems to do quite a good job with 70L/45Hz, see below.
According to Humble Homemade Hifi, mentioned in the PDF of the Calpamos speaker, a woofer/midwoofer for hifi use and played at low volume the following is important:
He also uses the acceleration factor BL/mms, to show that the speaker he choses (Faital Pro 15PR400) has the highest factor of the three considered Faital Pro speakers even though it has the lowest BL value.
HHH Calpamos speaker:
B&C 15NBX100:
Faital Pro 15PR400:
I do not have experience with these woofers, but trying to find some guidelines as well for selecting a proper 15" woofer for a 2-way.
I am looking for maybe something similar, and was checking some 15inch drivers to see what would be a reasonable f3 for a 70L BR. The B&C 15NBX100 seems to do quite a good job with 70L/45Hz, see below.
According to Humble Homemade Hifi, mentioned in the PDF of the Calpamos speaker, a woofer/midwoofer for hifi use and played at low volume the following is important:
- Low mechanical losses
- Low moving mass
- Low resonance frequency
He also uses the acceleration factor BL/mms, to show that the speaker he choses (Faital Pro 15PR400) has the highest factor of the three considered Faital Pro speakers even though it has the lowest BL value.
HHH Calpamos speaker:
B&C 15NBX100:
- Mms: 151g
- BL: 25
- Fs: 36Hz
- BL/Mms: 0.166
Faital Pro 15PR400:
- Mms: 85.2
- BL: 16.7
- Fs: 35Hz
- BL/Mms: 0.196
I do not have experience with these woofers, but trying to find some guidelines as well for selecting a proper 15" woofer for a 2-way.
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In my case, I would like to make a BR enclosure of 70L or less and the Faital Pro 15PR400 would not be that great:
The B&C 15NBX100 has some other advantages: it can play louder due to its Xmax and power limits.
The B&C 15NBX100 has some other advantages: it can play louder due to its Xmax and power limits.
I modeled the B&C 15nbx100 and like it. I want to see if earl Geddes will respond to a question about the spike at 1600hz. I'm going active so I don't think it would be an issue.
In 4 cubic feet, it does 121db at 35hz with a 35hz tuning. It may or may not be used with subs. The 10mm xmax is important as is the strong Bl product.
I'm also wanting the 4-ohm version.
In 4 cubic feet, it does 121db at 35hz with a 35hz tuning. It may or may not be used with subs. The 10mm xmax is important as is the strong Bl product.
I'm also wanting the 4-ohm version.
Using that is simply old fashioned and worthless way of evaluating drivers. Bl/mms without RE is worthless.
Make 2 identical drivers in a sim program like Winisd etc.
Change one to Re=2 ohm, and one to RE=14 ohm. And see the resulting BL. Might give a clue as to the worth of using BL/mms when comparing drivers.
And in that context, how is low MMS beneficial?
Inductance on the other hand "kills acceleration" in some ways.
None of these parameters tells one anything about inherent flaws in the drivers. Or shows the effect of power compression, BL(x), LE(x) etc.
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Even with completely linear woofer excursion, IM will occur from frequency modulation of an HF tone by a LF tone. Paul Klipsch wrote a paper on it back in the day to justify his use of horn loaded woofers
I didn't want to offend you, glad I did not say I came up with it myself! 😀
Whether this 'factor' is useless or not, if all your drivers you are comparing have an Re of 5.1Ohm, it does not matter if you include it in your equation (which is the case for the 3 Faital Pro speakers which were considered (and even for the B&C as well)) or not. Maybe it was left out for this reason, But I agree, if this term should be in the equation, it must be there.
And in this context he probably aims for a low Mms because this attributes to a higher acceleration factor.
I understand your inductance and kills acceleration bit, and indeed got me thinking about the value of this accelerating factor.
Power compression, BL(x), Le(x) data is often not available?
So if you are restricted to only the datasheet a manufacturer is providing (for example B&C / Faital Pro). what should you consider for your design? Let's say a bassreflex design up to ~750Hz:
- Frequency response simulation of speaker + enclosure (determine f3)
- Required sound pressure (Limited by Xmax and power, estimation of some power compression included)
- Frequency response curve of datasheet for abnormalities?
- Impedance curve for rising Impedance at higher frequencies if you want to filter passively?
- Demodulation rings?
Again, I am not telling the OP to look to this and that, but I am looking for some guidelines myself as well and thought to have found some nice info from the HHH webpage.
Posts like "Faital Pro 15PR400 or PR450 are MUCH better choices." do not really help if it is not included why ...
Intermodulation occurs if the Bl isn't linear. Klippel shows that can occur before the Xmax/excursion is reached. That should not happen but it does because of the motor linearity and symmetry is not granted. There are many drivers which can do great excursions but do not have a symmetrical motor/Bl. And that means a high excursion does not grant low IMD.
E:
E2: That can occur if there's a DC offset, the magnet field is asymmetrical, eddy current, inductance rise, non-linear / asymmetrical suspension, asymmetrical air load (ie horn with too small back chamber or asy compression chamber)
Of course.
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Hijack aside, I guess B&C and JBL are decent depending on the crossover to the CD (that's a compression driver).
If only the JBL 2216nd would just come back in stock. The 2216 models really well in 5 cubes if it had to run without a sub.
If only the JBL 2216nd would just come back in stock. The 2216 models really well in 5 cubes if it had to run without a sub.
The B&C 15TBX100 actually models better on the low end if the weight isn't an issue. It's essentially the same driver cone with a different magnet although the motor strength looks the same. OFC (that means of course), it's also 50 bucks cheaper than the 15NBX100. Since parts express sells the TBX and not the NBX, it ships for free while US Speaker wants 160 to ship the pair of 15NBX100 to me which makes the TBX about $250 cheaper.
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