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View Full Version : Digital Designs 1510 enclosure questions/math check

JBurn244
12-13-2007, 12:23 AM
Ok well, since I have yet to get a response back on my email from DDs tech department, I seek the wisdom of those who are familiar with DD woofers, and enclosure design for DDs...or even better the 1500 series specifically.

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I am designing an enclosure for 2 1510s, that will be going in my Scion tC. I just got finished with all of the math, and was hoping you could look it over and make sure I calculated things correctly and didn't leave out anything (I'm new at this). I also had a couple questions concerning tuning and box size. Woofers and port will both be facing the rear of the car.

1. I calculated the box size and tuning based on the recommended 16" long port which tunes to 40hz. You'll see below since the standard DD formula came out to 3.5 cubic feet after displacements, I calculated the port size to be 56 square inches for these two 10's. I listen to a lot of rock/metal type music, so it would seem 40hz would be a great tuning for those hard kick drum notes to come through with a lot of clarity and impact. But sometimes I like to listen to rap as well, so I guess I'm concerned as to whether tuning the box at 40 would handle the low frequencies well and loud. Perhaps I'm wanting the best of both worlds here, but will tuning at 40hz perform well on both types of music or should I perhaps tune a bit lower? Like 35hz maybe? How might the construction of the car (hatchback) effect tuning and performance at higher and lower frequencies?

2. As you'll see from my calculations below, I came up with a NET internal volume of 3.5 cubic feet after displacements. Would this be too much for these two 1510s, or should I go down more around 3.0 or 3.25 cubic feet?

Digital Designs 1510 (pair) - S4

External
38 wide
13 high
19.5 deep
38x13x19.5= 9633 (gross external)

Internal
36.5 wide
11.5 high
18 deep
=7555 (4.3 cubic ft, gross internal)

Approximate NET airspace
7555x.82= 6195
/1728= 3.5 cubic feet (NET internal approx)

Port area:

3.5x16= 56 sq in. of port
56/11.5(height of port) = 4.75 inches wide (rounded off)

Sub displacement

.108 cubic ft x 2 = 373.248 (.216 cubic ft)

Port displacement

4.75 + .75 x 11.5 x 16 = 1012/1728 = .585 cubic ft.

Total Displacement

373.248 (subs) + 1012 (port) = 1385.248 / 1728 = .801 cubic ft.

Final NET Internal Volume (subs/port displacement included)

7555 - 1385.248 = 3.570 cubic ft.
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Just needing some double checking on my calculations and efficiency of this enclosure for these woofers. Thanks in advance!

12-13-2007, 08:07 AM
Good calcuations:)

I would definatly go down to 3cu.ft. especially if your wanting a lot of kick, a box that big(3.5cu.ft) will be very efficient and not need a lot of power to get them to reach xmax. It also will be a lot more low bass oriented.

Tune it to 3cu.ft at 40hz, and it'll be perfectly fine for rap and still have GREAT kick...trust me, my 8's have crazy amount of lows down to 31hz while the box is tuned to 40, so don't worry about tuning lower;)

SeanDub
12-13-2007, 01:38 PM
I would go with less volume, probably around 3. DD recommends 1.5 per 1510 and 24 sq in per 1510. Right now you have 3.6 with 56 sq in. I usually go with a little more port than they recommend, and around the box volume. So I would try to get it down to 3 cubes tuned to 36 hz. What is the box you have now tuned to?

JBurn244
12-28-2007, 07:51 PM
Ok this is outdated but to post but figured I would give the results of my little build...

I went with 3 cubes, 52 sq inches of vent, and tuned at 40hz.

These things pound hard! They play low just fine and move a ton of air. Thanks for the replies, guys.