Is anyone using these drivers? I have 4 loaded into 176l 30hz tuned reflex cabs.
The measured response is poor with a huge peak at 65hz and low output below 45hz but I believe the dsp in the plate amps I am using is the issue, once I get a proper amp I’ll measure them again.
Product Specifications:
The measured response is poor with a huge peak at 65hz and low output below 45hz but I believe the dsp in the plate amps I am using is the issue, once I get a proper amp I’ll measure them again.
Product Specifications:
- Nominal Diameter: 18"
- Power Handling (RMS): 1800 Watts
- Power Handling (max): 3000 Watts
- Impedance: 8 ohms
- Frequency Response: 30Hz to 1,000 KHz
- Sensitivity: 97.5 dB 2.83V/1m
- Xmax : 13.5mm
- Voice Coil Diameter: 4.5"
- FS: 41 HZ
- Re: 5.5 ohm
- Qms: 9.7
- Qes: 0.41
- Qts: 0.37
- Mms: 247.4G
- BL: 29.3T-M
- Sd: 1216 cm2
- Vas: 124.4 L
- Weight : 42.2 Lbs(19.14Kgms)
- Shipping Dimensions : 20.5" x 20.5" x 17.5"(533.4mm x 533.4mm x 457.2mm)
(4) drivers in one 176 L cab or each are in 176 L?
Regardless, basic max flat alignment:
T/S max flat alignment:
Vented net volume (Vb) (L) = 20*Vas*Qts'^3.3
(Ft^3 = (Vb)/~28.31685)
Vented box tuning (Fb) (Hz) = 0.42*Fs*Qts'^-0.96
F3 (Hz) = Fs*0.28*Qts'^-1.4
(Qts'): (Qts) + any added series resistance (Rs):
https://web.archive.org/web/20220707003028/http://www.mh-audio.nl/Calculators/newqts.html
So what do you wind up with in comparing sims?
Regardless, basic max flat alignment:
T/S max flat alignment:
Vented net volume (Vb) (L) = 20*Vas*Qts'^3.3
(Ft^3 = (Vb)/~28.31685)
Vented box tuning (Fb) (Hz) = 0.42*Fs*Qts'^-0.96
F3 (Hz) = Fs*0.28*Qts'^-1.4
(Qts'): (Qts) + any added series resistance (Rs):
https://web.archive.org/web/20220707003028/http://www.mh-audio.nl/Calculators/newqts.html
So what do you wind up with in comparing sims?
Yes 1 driver per 176l cab.
Attached is the sim in Basta and a rew measurement. The dip at 150hz I believe is from a boundary.
Attached is the sim in Basta and a rew measurement. The dip at 150hz I believe is from a boundary.
Mark,
As far as I can tell, no one other than you has inquired about or used the Lase LF18-3600 and posted about it on DIY Audio.
Your measured response has a 24dB roll-off below 60Hz, looks like it could be a bass boost and HP filter made for a small "full range" speaker like this 12" Mackie:
Since you believe the DSP in the plate amp is the issue, measuring it would be a good idea.
The driver's suspension may need to be broken in, pushing by hand well past Xmax may improve the driver's response.
If the amp is not the problem, could be the Fb is in the 55 Hz range instead of the 30Hz you planned.
Easy to check the box tuning by eye using REW's sine wave tones, the excursion will be least at Fb, and rise at lower and higher frequencies, assuming you use an amp with flat response 😉
Art
As far as I can tell, no one other than you has inquired about or used the Lase LF18-3600 and posted about it on DIY Audio.
Your measured response has a 24dB roll-off below 60Hz, looks like it could be a bass boost and HP filter made for a small "full range" speaker like this 12" Mackie:
Since you believe the DSP in the plate amp is the issue, measuring it would be a good idea.
The driver's suspension may need to be broken in, pushing by hand well past Xmax may improve the driver's response.
If the amp is not the problem, could be the Fb is in the 55 Hz range instead of the 30Hz you planned.
Easy to check the box tuning by eye using REW's sine wave tones, the excursion will be least at Fb, and rise at lower and higher frequencies, assuming you use an amp with flat response 😉
Art
@weltersys
I didn’t think about a sine sweep that’s a great idea!
How would I go about measuring the amp?
The plate amp is inside the port path but from what I understand is that a smaller port area lowers tuning so I assume that would be the affect if any? I do plan on picking up a dats eventually as measuring the impedance as well as the driver. I’ve been beating on them a few times now so I would think they’re broken in by now.
The plate amp also comes in a full range version so maybe the tuning could be not right. I’ve been trying to get the dsp software from lase for almost a year with no luck, I keep getting the run around and I’ve giving up.https://lase.us/shop/ols/products/lase-spm-1000s-sub-woofer-power-amplifier-1000-watts-module
I didn’t think about a sine sweep that’s a great idea!
How would I go about measuring the amp?
The plate amp is inside the port path but from what I understand is that a smaller port area lowers tuning so I assume that would be the affect if any? I do plan on picking up a dats eventually as measuring the impedance as well as the driver. I’ve been beating on them a few times now so I would think they’re broken in by now.
The plate amp also comes in a full range version so maybe the tuning could be not right. I’ve been trying to get the dsp software from lase for almost a year with no luck, I keep getting the run around and I’ve giving up.https://lase.us/shop/ols/products/lase-spm-1000s-sub-woofer-power-amplifier-1000-watts-module
This thread explains how:
https://www.diyaudio.com/community/threads/how-to-distortion-measurements-with-rew.338511/
You don't need to measure above a few volts for amp frequency response measurements.
What have you set the plate amp's high pass filter to?
A smaller port cross section with the same length lowers Fb, whatever the Fb was 😉
@weltersys
The only settings I can adjust are three different eq curves which only seem to make the bump bigger or smaller, the delay and low pass. I cannot adjust anything else from the controls.
The only settings I can adjust are three different eq curves which only seem to make the bump bigger or smaller, the delay and low pass. I cannot adjust anything else from the controls.