Estimated SPL?

[ThxOne Premium Member]

3,000w on two Tropo XL 10's in a ported enclosure. 3.1cuft tuned to 32hz. This is in the back cargo area of the Equinox. Subs up, ports to the rear. What is the best guess at SPL and at what frequency?

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[CarAudio.com - Hal AI Bots]

3,000w on two Tropo XL 10's in a ported enclosure. 3.1cuft tuned to 32hz. This is in the back cargo area of the Equinox. Subs up, ports to the rear. What is the best guess at SPL and at what frequency?

To estimate the SPL (Sound Pressure Level) of your system with two Tropo XL 10" subwoofers powered by 3,000 watts in a ported enclosure tuned to 32 Hz, we can consider various factors that influence SPL, including:

1. **Subwoofer Efficiency**: The sensitivity rating (usually measured in dB at 1 watt/1 meter) of the subwoofers. For example, if the sensitivity is around 85 dB, and you are providing them with 3,000 watts of power, you can estimate the SPL.

2. **Power Handling**: The efficiency of converting power to sound will also affect the overall SPL output. Each doubling of power increases the potential SPL by approximately 3 dB.

3. **Enclosure Design**: The ported design helps enhance low-frequency response and can significantly affect the overall SPL.

4. **Listening Environment**: Placement and acoustics of the vehicle's interior will also play a role in the overall SPL.

### Estimation Process:
- Assuming the average sensitivity of a 10" subwoofer is around 85 dB:
- SPL at 1 watt would be 85 dB.
- With 3,000 watts, you can calculate the increase in SPL due to added power:

\[
\text{SPL}_{\text{total}} = 85 \, \text{dB} + (10 \times \log_{10}(3000))
\]

- The increase due to 3,000 watts is roughly:
\[
10 \times \log_{10}(3000) \approx 10 \times 3.477 \approx 34.77 \, \text{dB}
\]

So, the estimated SPL would be:
\[
\text{SPL}_{\text{total}} \approx 85 + 34.77 \approx 119.77 \, \text{dB}
\]

### Frequency Response:
Given the tuning frequency of 32 Hz, the peak SPL will likely be around that frequency. The enclosure's design provides a boost at the tuning frequency, so you can expect the highest SPL at or near 32 Hz.

### Conclusion:
- **Estimated SPL**: Approximately 120 dB
- **Peak Frequency**: Approximately 32 Hz

Real-world performance may vary based on installation specifics, car acoustics, and other variables, but this provides a solid theoretical estimate for your setup.

 

[administrator]

3,000w on two Tropo XL 10's in a ported enclosure. 3.1cuft tuned to 32hz. This is in the back cargo area of the Equinox. Subs up, ports to the rear. What is the best guess at SPL and at what frequency?

Now let’s buzz our community SPLBTQ expert @Mitchell Fosgate III for his advice.

 

[spokey9 5,000+ posts]

3,000w on two Tropo XL 10's in a ported enclosure. 3.1cuft tuned to 32hz. This is in the back cargo area of the Equinox. Subs up, ports to the rear. What is the best guess at SPL and at what frequency?

I had 2 15's on 3k sealed in my Saturn I think I was in the high 130's but I never meter that...my scalp vibrated at full tilt and that all I need to know

 

[ThxOne Premium Member]

I know I metered 145db on two JBL 12's in the back of my Grand Cherokee with an Alpine amp. I am hoping with the XS Power AGM, the D4S JP630 Cap Bank and the JP77 I would get close to or better than that.

 

[shredder1 10+ year member]

I know I metered 145db on two JBL 12's in the back of my Grand Cherokee with an Alpine amp. I am hoping with the XS Power AGM, the D4S JP630 Cap Bank and the JP77 I would get close to or better than that.

I'm unsure when you metered your old setup in the Cherokee but a 145db score with JBL's and an Alpine amp is a good score, practically impossible to get these days if you metered it with an old RTA meter (I cant recall what it was called its been so long). I metered like 151db with 2 15's in 1998 but nowadays it probably would meter 145-6db.
I'd say anything over 142db would be a pretty good score in the Equinox with a modern Spl meter using your gear.

 

[ThxOne Premium Member]

I'm unsure when you metered your old setup in the Cherokee but a 145db score with JBL's and an Alpine amp is a good score, practically impossible to get these days if you metered it with an old RTA meter (I cant recall what it was called its been so long). I metered like 151db with 2 15's in 1998 but nowadays it probably would meter 145-6db.
I'd say anything over 142db would be a pretty good score in the Equinox with a modern Spl meter using your gear.

It was at Columbus Car Audio in Columbus, Ohio. They put the meter in the passenger floorboard.

Edit: sorry, it was 2016

 

[ThxOne Premium Member]

Twas these JBL's in this box that I built.

 

[shredder1 10+ year member]

Twas these JBL's in this box that I built.

Nice enclosure, looks like 75-80in2 of port in 4.5-5ft3 net. Its nice when the enclosure don't limit output let me tell ya'. Nice daily if mid-low 30s are your thing. For numbers its best to tune 6-10hz under cabin frequency and you'll still have a daily. Extreme burp designs for #'s consider wavelengths and I personally stayed away from those one note wonder results as I listen to music.
I designed a few over the years but a single 18 that does 159db at 57hz just ain't goin' in my ride, heck... 152.4db @ 47hz with a single 18 was enough for me. Wipers bouncing, hood flexin' and people grabbin' doorhandles was all fun but a daily tune for YOUR music is all you need. A 32hz tune?.. Sounds like rap music to me and with that tuning big #'s are hard to hit in a suv without cone. 2-10's? I still predict sub-142db even on a legit 3K amp like a crossfire C7 3K wired down.

 

[ThxOne Premium Member]

Nice enclosure, looks like 75-80in2 of port in 4.5-5ft3 net. Its nice when the enclosure don't limit output let me tell ya'. Nice daily if mid-low 30s are your thing. For numbers its best to tune 6-10hz under cabin frequency and you'll still have a daily. Extreme burp designs for #'s consider wavelengths and I personally stayed away from those one note wonder results as I listen to music.
I designed a few over the years but a single 18 that does 159db at 57hz just ain't goin' in my ride, heck... 152.4db @ 47hz with a single 18 was enough for me. Wipers bouncing, hood flexin' and people grabbin' doorhandles was all fun but a daily tune for YOUR music is all you need. A 32hz tune?.. Sounds like rap music to me and with that tuning big #'s are hard to hit in a suv without cone. 2-10's? I still predict sub-142db even on a legit 3K amp like a crossfire C7 3K wired down.

Those cubic feet are very close. It was just over 5ft3. I estimated the tuning to be pretty low but I may have been off. It was powerful from 30-38hz. Pretty useless above that lol.

 

[ThxOne Premium Member]

I want to say it was supposed to have been tuned to like 27hz. That too may be wrong. I have a video that shows the subs @ 30hz and they looked dead still while playing.

 

[shredder1 10+ year member]

Those cubic feet are very close. It was just over 5ft3. I estimated the tuning to be pretty low but I may have been off. It was powerful from 30-38hz. Pretty useless above that lol.

Big enclosures naturally peak hard at tuning but can fall off hard the further you get away from tuning.
Tuned 27hz in that large of airspace would definitely kill the 40-60hz response imo. I try to avoid tuning under 30hz for that reason. Specific subs like the Pride S5-18 are what I would tune 28 ported and I better have 10K to throw at it. JBL 12's not so much... lol

 

[ThxOne Premium Member]

I am hoping more attention to details will have my current subs more playable up to near 60hz (0-80hz crossed over) with the Earthquake shallow 6.5" subs helping out by playing mid-bass in the doors from 80hz and up.

 

[spokey9 5,000+ posts]

I am hoping more attention to details will have my current subs more playable up to near 60hz (0-80hz crossed over) with the Earthquake shallow 6.5" subs helping out by playing mid-bass in the doors from 80hz and up.

FRONT SUB!!!

 

[Old_Slapper]

Now let’s buzz our community SPLBTQ expert @Mitchell Fosgate III for his advice.

I'm actually surprised he didn't respond.

 

[ThxOne Premium Member]

I am really curious what this cabin will do to boost or cut frequencies. OH!! I decided of the 3 DSP's I have, I will use the Audio Control. It has a coaxial digital input and my music player has the coaxial digital output.