Hi, as the title suggests, I just want to point out this new interesting 18sound subwoofer:
https://www.eighteensound.it/en/products/lf-driver/18-0/4/18NLS4000
The parameters are interesting, in particular the xmax of 22mm and the xvar of 25. The peak-to-peak excursion is not indicated but seeing the thickness of the suspension I would say that it's very high. It's really atypical for a "pro" subwoofer, it seems more meant for home theater use. Another interesting thing is that, in relation to the size, it doesn't require huge cabinet (qts 0.35), less than 150 liters (B4 130L Fb @30Hz), not bad for 18" bass reflex but of course it can be profitably used in closed boxes with good equalization, the huge excursion makes it possible without issues
https://www.eighteensound.it/en/products/lf-driver/18-0/4/18NLS4000
The parameters are interesting, in particular the xmax of 22mm and the xvar of 25. The peak-to-peak excursion is not indicated but seeing the thickness of the suspension I would say that it's very high. It's really atypical for a "pro" subwoofer, it seems more meant for home theater use. Another interesting thing is that, in relation to the size, it doesn't require huge cabinet (qts 0.35), less than 150 liters (B4 130L Fb @30Hz), not bad for 18" bass reflex but of course it can be profitably used in closed boxes with good equalization, the huge excursion makes it possible without issues
There is a misprint on the spec sheet: Winding depth is not 520.1 mm but 52.01, weird that they didn't noticed/checked before publication..
No it isn't. According to B&C (18sound it's in the same group) Xvar is the value beyond which there is a considerable variation of the T&S parameters.
The only addition is this quote: "high excursion capabilities of the double-action roll surround and suspension system, together with the 52mm deep voice coil, enable the 18NLS4000 to achieve very high levels of linear excursion (up to 60mm)". But that it is not xmech
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Foam surround and 433g membrane ... that's really strange for a pro subwoofer.
But Qms is VERY high for such a design - interesting. Also Xvar is higer as Xmax - seems to be a great motor.
Still 12kg for a neodym design ... why are these drivers so heavy? My old ferrit 18" drivers (Oberton 18XB700) have 12,5kg. These modern ones should be lighter?
Also frequency response seems to be realistic. About 86dBSpl - and it's a 4R driver.
And now - please make a 15" version with 8R from this! Maybe in ferrit to keep the price down - I will not carry my home cinema around ;-)
But Qms is VERY high for such a design - interesting. Also Xvar is higer as Xmax - seems to be a great motor.
Still 12kg for a neodym design ... why are these drivers so heavy? My old ferrit 18" drivers (Oberton 18XB700) have 12,5kg. These modern ones should be lighter?
Also frequency response seems to be realistic. About 86dBSpl - and it's a 4R driver.
And now - please make a 15" version with 8R from this! Maybe in ferrit to keep the price down - I will not carry my home cinema around ;-)
For a B3 requires 107liter tuned at 29Hz. The manufacturer suggests 100 liters with 28hz tuning. With same 28Hz Fb, can use up to 130 liters and get better F3/F6 ( 29 - 25Hz) with a still "smooth" roll off
Probably targeting dedicated infra subs for large scale PA. It can be helpful to split the sub into dedicated arrays for pattern control reasons and to avoid reduction in kick output due to limiting/compression caused by production of 'infra' sound. As an example the VLFC from Meyersound: https://meyersound.com/product/vlfc/
These drivers are heavy as they have a large magnetic gap and maintaining a sufficient magnetic flux in the gap requires a lot of magnet. It would not really be feasible to make a driver like this with ferrite.
These drivers are heavy as they have a large magnetic gap and maintaining a sufficient magnetic flux in the gap requires a lot of magnet. It would not really be feasible to make a driver like this with ferrite.
The 18NLS4000 finally appeared on the TLHP website: https://en.toutlehautparleur.com/18-sound-18nls4000-speaker-4-ohm-18-inch.html
ok, so xmax is 24mm but power handling it is 1200watts only and 91dB sensitivity
FS is 27 so, looks like it is for a HT setup instead of a PA sub
but BL is only 24 for a 799 euros driver ?
on the same site TLHP... 556 Euros B&C 18DS115 have a BL of 34 and 97dB sensitivity
in the other hand 18DS115 have a BL of 34
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FS is 27 so, looks like it is for a HT setup instead of a PA sub
but BL is only 24 for a 799 euros driver ?
on the same site TLHP... 556 Euros B&C 18DS115 have a BL of 34 and 97dB sensitivity
Informations | |
| Nominal impedance | 4 ohm |
| Dimensional category | 18 inch |
| Frequency coverage type | Sub |
| Manufacturer sensitivity | 88 dB |
| Calculated sensitivity | 91.48 dB |
| Nominal power handling | 1200 W |
| Max power handling | 2400 W |
Fundamental parameters | |
| Sd | 1225 cm² |
| Mms | 433 gr |
| Le | 2.6 mH |
| Re | 2.9 ohm |
| BL | 24.2 T.m |
Small signal parameters | |
| Fs | 27 Hz |
| Qes | 0.36 |
| Qms | 13.7 |
| Qts | 0.35 |
| Vas | 168 L |
in the other hand 18DS115 have a BL of 34
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Product Specifications | |
|---|---|
| Nominal Diameter | 18" |
| Bolt Circle Diameter | 17.32 |
| Power Handling (RMS) | 1700 Watts |
| Power Handling (MAX) | 3400 Watts |
| Impedance | 4Ω |
| Frequency Response | 30 to 500Hz |
| Sensitivity | 97dB 2.83V/1m |
| Voice Coil Diameter | 4.5" |
Thiele-Small Parameters | |
|---|---|
| Resonant Frequency (Fs) | 30Hz |
| DC Resistance (Re) | 3.3Ω |
| Voice Coil Inductance (Le) | 2.8mH |
| Mechanical Q (Qms) | 4.75 |
| Electromagnetic Q (Qes) | 0.18 |
| Total Q (Qts) | 0.17 |
| Compliance Equivalent Volume (Vas) | 6.25ft³ |
| Mechanical Compliance of Suspension (Cms) | 0.0809mm/N |
| BL Product (BL) | 34.68T·m |
| Diaphragm Mass Inc. Airload (Mms) | 348g |
| Maximum Linear Excursion (Xmax) | 16.5mm |
| Surface Area of Cone (Sd) | 1241cm² |
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A "one number" sensitivity number for a subwoofer rating is pretty useless, the 18NLS4000 is 75dB at 30 Hz, 85 dB at 100Hz, while the 18DS115 is 72dB at 30 Hz, 92 dB at 100Hz.
The Xvar (70% of Bl) specification is not useless, the 18NLS4000 has 25mm compared to the 18DS115 at 14mm excursion.
The 18NLS4000 is capable of far more output in the excursion limited 30 Hz range, the 18DS115 more output in the thermally limited upper sub range, different horses for kicking different assets
.
The Xvar (70% of Bl) specification is not useless, the 18NLS4000 has 25mm compared to the 18DS115 at 14mm excursion.
The 18NLS4000 is capable of far more output in the excursion limited 30 Hz range, the 18DS115 more output in the thermally limited upper sub range, different horses for kicking different assets
.