CT Sounds Meso 12 D2 Port Area?

[JoshuaKNelson]

I am trying to design and build a slot vent enclosure for the CT Sounds Meso 12D2. The manufacturer calls for a 1.5 cubic foot enclosure with a port area of 40 square inches. That is like 26.66 square inches per cubic foot which seem extremely large. I haven't seen many that go above 12 to 16 squa.re inches per cube. Would I be OK to go with 16 square inches or am I wrong? I need to tune it to 32Hz and with that large of port area the length of the port won't fit into the enclosure. Any insight into this is welcome. Thank you.

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[CarAudio.com - Hal AI Bots]

I am trying to design and build a slot vent enclosure for the CT Sounds Meso 12D2. The manufacturer calls for a 1.5 cubic foot enclosure with a port area of 40 square inches. That is like 26.66 square inches per cubic foot which seem extremely large. I haven't seen many that go above 12 to 16 squa.re inches per cube. Would I be OK to go with 16 square inches or am I wrong? I need to tune it to 32Hz and with that large of port area the length of the port won't fit into the enclosure. Any insight into this is welcome. Thank you.

When building a slot vent enclosure for your CT Sounds Meso 12D2, it's critical to adhere to the manufacturer's specifications as closely as possible, particularly when it comes to enclosure volume and port area, as these designs are typically optimized for performance. The specified 1.5 cubic foot enclosure with a port area of 40 square inches is indeed on the higher side, but there are reasons manufacturers might suggest these dimensions.

### Understanding Port Area vs. Enclosure Volume:
1. Port Area Calculation: The recommended 40 square inches for a 1.5 cubic foot enclosure breaks down to about 26.66 square inches per cubic foot, which is indeed higher than typical values (12-16 square inches per cube). However, larger port areas can reduce port noise and allow the sub to move more freely, which may be necessary to prevent distortion at higher volumes.

2. Tuning Frequency: To tune your enclosure to 32Hz, the length and area of the port must work together efficiently. A larger port area allows for a shorter port length, while a smaller port area would require a longer port to maintain the same tuning frequency.

### Recommendations:
- Port Area: If you are considering reducing the port area to 16 square inches, you absolutely can do this, but it will require you to either extend the length of the port significantly or adjust your tuning frequency if this compromises other aspects of the system.

- Port Length Calculation: If you reduce the port area to 16 square inches, you'll need to use a port length calculator or formulas to find out how long the port needs to be to achieve your desired tuning frequency of 32Hz. Remember, the larger the port area, the shorter the port; conversely, if you reduce the area, you need to increase the length, potentially leading to space issues within the enclosure.

- Alternative Designs: If space is an issue with maintaining the required port length, consider designing a dual-port configuration or experimenting with different port shapes that allow you to fit within the enclosure while still achieving your desired tuning.

### Conclusion:
While you can reduce the port area, it is essential to calculate the new port length accurately to achieve the tuning frequency and performance you seek. It would be advisable to prototype the enclosure if you have the resources, evaluating performance based on the actual output during testing.

Feel free to reach out with more specifics, or if others have experiences or insights to share regarding slot vent enclosures and tuning, please chime in!

 

[JoshuaKNelson]

Awesome. Thanks for the detailed response. I love this forum. You are very helpful. Have a good day.

 

[deez283 10+ year member]

Do you know how to use wisisd? You can check port velocity and other useful stuff as well.

With that said 14' of port area per cubic foot always seems to be what I go with.

 

[Doxquzme Premium Member]

If you have room for the box, this is the optimal enclosure for that driver.

Box External Dimensions Width x Height x Depth	24.00" x 14.00" x 16.22"
Material Thickness	0.75"
Net Internal Volume	1.75 ft3
Tuning Frequency	31 Hz
Port Area	23.62 inch2
Port Inlet Width x Height	1.89" x 12.50"
Port Length	31.86"

Decreasing the port opening is a recipe for noise (wind/farting). I would not reduce the area suggested by much as I have provided above.

As noted on the CT Sounds website, that is a "boomer" response enclosure, not my cup of tea.

Keep in mind that going with a box over the 1-1.2 cu ft recommendation also decreases the power capacity you can feed the sub because it changes the efficiency and the reactive resistance the amplifier will experience.

For all-around performance that sounds fantastic, go with the following setup:

Box External Dimensions	External box using .75" material - LxWxH should equal 4720 cu inches of total outside using only one baffle, 2nd baffle recommended, just decrease the internal length of the port (as it is added back on the baffle addition) by however many baffles you add, provided the port is exiting the same baffle, which is optimal.
Material Thickness	0.75"
Net Internal Volume	Internal (net) 1.25 ft3 External (gross, single baffle) 2.73 cu ft
Tuning Frequency	29 Hz (roughly 3.75db below the resonant frequency of that driver)
Port Area	16.87 sq inches
Port Inlet Width x Height	= to 16.87 sq inches
Port Length	38.20"

This design accounts for all the variables, including efficiency, output, and reactive resistance (impedance rise), flattens the response a bit, and lowers the tuning frequency to provide a boost from 29 Hz.

 

[Doxquzme Premium Member]

Do you know how to use wisisd? You can check port velocity and other useful stuff as well.

With that said 14' of port area per cubic foot always seems to be what I go with.

Fyi, the free software noted is called WinISD.