I've been on a roll with Alpine budget builds of late and so felt I would post my most recent, which has also be a great success.
After having a terrific result with my previous SWR-1522D budget build
(and smaller SWR-1243
), I couldn't resist jumping on the earlier version of this great sub when one came up for sale used for a steal.
They model very similarly in a 97 liter box, slightly different port lengths, both tuned about 20hz
Single 4Ohm Coil
Re – 3.6
Le – 4.05mH @ 1Khz
Fs – 23Hz
Vas – 115l
Qms – 10.38
Qes – 0.48
Qts – 0.46
Xmax – 16.25mm (Linear)
Xmech – 68mm p-p
Hag/Hvc – 15/47.5mm
Sd – 754.77 cm2
Basket displacement – 8.86 lt
This sub came to me as a terminal patient. The roll surround was partially unglued and made some terrible noises as a result. Perfect for a budget build then!
I used some off cuts, cut to size, to carefully lift the cone once I had her all cleaned up...
Then I used this glue recommended for repairing rubber roll surrounds
And following the instructions laid up some glue to both mating surfaces, frame and under roll surround lip
The result came up great I think, it was really pleasing to get this done successfully
I was intrigued to see the magnetic structure of this driver so I unbooted her
For context - AA battery
The enclosure cut sheet in centimeters is as follows
Some obligatory build pics, I really like using this 30mm ply
Rounded end of the inside edges of slot port
SWR-1540 vs SWR-1522D - Looking beyond the cosmetic I can see a lot of similarities here, magnet, voice coil size, frame size. The 1540 weighs a little more ...
Installed in her new home
Measurement (this is how I did it
Near field (20hz LR HPF & 80hz LPF)
At MLP (no filters)
How does she sound? Amazing.
Having the two 15's in my system has given it a BIG lift in impact. My system, I feel, also got a big lift from some eq after REW room measurements
so that has helped too. The 15's just sound big and I couldn't be happier.
Hope this is helpful to other budget builders out there.