Lo Rider 18 TH/FLH

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If you're using it for pro sound don't horn load 18's. You'll shred the cone before you hear distortion. PV specifically warns about this. You'll usually get better performance out of 15's anyway - they're usually a better match to a horn. If you'e using a low power tube amp, well you probably couldn't hurt it.
 
Yah watch that voice coil size to cone size. Many use the same motor on 15s and 18s so the 15s would always be a better choice for horn. All, and I mean ALL, curved cone 15 inch woofers flip phase about 200Hz. I look for the phase flip and usually put the crossover there. Low rider is quality product from a build point of view and has easily replaced voice coil cone assembly which is a real big plus. Check the xmax and make sure it is less than anticipated for the horn you have in mind.
 
OK, 40-120 Hz sounds very reasonable. 120 Hz is about as high as you want to cross any 18", horn loaded or not imho.

Keep the compression ratio around 2:1 for an 18" tapped, rear or front loaded horn, a tapped horn might actually allow a little bit more. A lower compression ratio is easier on the cone at high power inputs.

Do you have any size constraints? Give the bandwidth, an increase in size means more output. Minimal size would be somewhere near 8-10 ft^3, to get a decent output beyond a reflex.

Best regards Johan
 
Here are the measured TSP's

Code:
--- mechanical ---
Fs          37.454E+00 Hz       Free air resonance
Qms          8.614E+00          Q mechanical
Vas        237.769E-03 m^3      Suspension compliance
Cms        110.594E-06 m/N      1/(suspension stiffness)
Mms        163.269E-03 kg       Moving mass
Rms          4.460E+00 kg/s     Mechanical resistance
Xmax **      0.000E+00 m        Maximum acoustic linear motion
Xmech**      0.000E+00 m        Mechanical displacement
Dia        396.900E-03 m        Piston diameter
Sd         123.723E-03 m^2      Piston area
Vd   **      0.000E+00 m^3      Displacement volume
--- electrical ---
Qes        555.789E-03          Q electrical
Re           5.873E+00 ohms     Voice coil DC resistance
Le           1.958E-03 Henries  Inductance @1 kHz
Z           17.668E+00 ohms     Impedance @1 kHz
BL          20.150E+00 Tm       Motor force - Newtons/Amp
Pe   **      0.000E+00 W        Max Electrical Power
--- electro-mechanical ---
Qts        522.103E-03          Q total
no           2.167E+00 %        1/2-space ref efficiency @ 1m/1W
1-W SPL     95.358E+00 dB       sensitivity at 1m on-axis 
2.83V SPL   96.700E+00 dB       sensitivity at 1m on-axis
 
Wow, those are quite a bit different from the spec sheet! :confused:

Suddenly small enclosures are pretty much out of the window.If you don't mind 20 cu.ft. enclosures, I would personally prefer a PWH for this type of speaker if maximum output is the desire, otherwise just a large reflex. If you want portabilty other drivers are more likely suited.

Best regards Johan
 
Code:
--- mechanical ---
Fs          37.454E+00 Hz       Free air resonance
Qms          8.614E+00          Q mechanical
Vas        237.769E-03 m^3      Suspension compliance
Cms        110.594E-06 m/N      1/(suspension stiffness)
Mms        163.269E-03 kg       Moving mass
Rms          4.460E+00 kg/s     Mechanical resistance
Xmax **      0.000E+00 m        Maximum acoustic linear motion
Xmech**      0.000E+00 m        Mechanical displacement
Dia        396.900E-03 m        Piston diameter
Sd         123.723E-03 m^2      Piston area
Vd   **      0.000E+00 m^3      Displacement volume
--- electrical ---
Qes        555.789E-03          Q electrical
Re           5.873E+00 ohms     Voice coil DC resistance
Le           1.958E-03 Henries  Inductance @1 kHz
Z           17.668E+00 ohms     Impedance @1 kHz
BL          20.150E+00 Tm       Motor force - Newtons/Amp
Pe   **      0.000E+00 W        Max Electrical Power
--- electro-mechanical ---
Qts        522.103E-03          Q total
no           2.167E+00 %        1/2-space ref efficiency @ 1m/1W
1-W SPL     95.358E+00 dB       sensitivity at 1m on-axis 
2.83V SPL   96.700E+00 dB       sensitivity at 1m on-axis

That total Q is to high for any use really except as HUGE box- wait someone already said that. Look for a softer suspension and lower Q...under .383 for any application. Also the high efficiency means probably a low Xmax. Short voice coil makes high efficiency and low Xmax. Fs is pretty high also. Here is a 15 that looks pretty good and not to expensive:

Parts-Express.com:Dayton DVC385-88 15" DVC Series Subwoofer | subwoofer dvc385-88 15" subwoofer dvc dual voice coil dayton subwoofer dayton dvc dayton 15" woofer subwoofer dayton dvc coils COIL bandpass auto 8 ohm 15" woofer 15" subwoofer special-2-
 
The best tapped horn I came up with is (only) 101 dB/2,83 V/m in a 17 cu. ft. enclosure (38"x 23.5" x 31.5") with an f3-ish of 40 Hz. The problem with high Qts drivers in tapped horns is they require a low compression ratio (lower then the cone strength would dictate) to get a smooth response AFAIK.

Is it high SPL (PA) or low/medium SPL (home/HT) you're after?

Best regards Johan
 
Code:
--- mechanical ---
Fs          37.454E+00 Hz       Free air resonance
Qms          8.614E+00          Q mechanical
Vas        237.769E-03 m^3      Suspension compliance
Cms        110.594E-06 m/N      1/(suspension stiffness)
Mms        163.269E-03 kg       Moving mass
Rms          4.460E+00 kg/s     Mechanical resistance
Xmax **      0.000E+00 m        Maximum acoustic linear motion
Xmech**      0.000E+00 m        Mechanical displacement
Dia        396.900E-03 m        Piston diameter
Sd         123.723E-03 m^2      Piston area
Vd   **      0.000E+00 m^3      Displacement volume
--- electrical ---
Qes        555.789E-03          Q electrical
Re           5.873E+00 ohms     Voice coil DC resistance
Le           1.958E-03 Henries  Inductance @1 kHz
Z           17.668E+00 ohms     Impedance @1 kHz
BL          20.150E+00 Tm       Motor force - Newtons/Amp
Pe   **      0.000E+00 W        Max Electrical Power
--- electro-mechanical ---
Qts        522.103E-03          Q total
no           2.167E+00 %        1/2-space ref efficiency @ 1m/1W
1-W SPL     95.358E+00 dB       sensitivity at 1m on-axis 
2.83V SPL   96.700E+00 dB       sensitivity at 1m on-axis

Strange. A couple of years ago I measured the Low Rider 18 and found the TS very similar to the published spec. They were not exactly spot on but close. The QTS was no where near that high and around .36 if I remember correctly. I wish I still had the results but it was a long time ago. Maybe they have a problem with consistency. In a good old ported box the driver performs really well and is a tough driver to beat for the money.
 
Strange...In a good old ported box the driver performs really well and is a tough driver to beat for the money...

Hi,
Agree. FYI: The posted T/S data looks plausible but the nearly 10 Hz fs difference and the Qts increase of > 50% is more than expected. See the consequences when designing a T-TQWT with the two different sets of T/S data:

b
 

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Hi,
Agree. FYI: The posted T/S data looks plausible but the nearly 10 Hz fs difference and the Qts increase of > 50% is more than expected. See the consequences when designing a T-TQWT with the two different sets of T/S data:

b

Also I remember the Fs on a brand new woofer was at 30Hz. I beleived published is 27Hz so this was also close considering it was pretty much right out of the box.

I've used many of these woofers in installs but only measured a couple. I never noticed any changes in performance between installs but I also didn't take measurements so the results would be very subjective.
 
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