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Introduction
This page details the issues I've faced (or am facing) with this
installation and the steps I'm taking (if any) to try and solve them.
Issues:
Background whine
Once I completed assembly, I noticed that there was background
alternator whine, albeit at a low level - but just high enough to be
annoying. I eventually got enough enough with it to tear down the front of
the dash and and ground the RCAs to the deck (a typical fix for this kind of
problem). Once I put everything back together, I noticed that the
negative leads for the front and rear speakers were not fastened properly to
the speaker terminals - likely the real cause of the noise. I fastened
them down properly. The system now has absolutely no audible
background noise, even at high volume levels.
Auto Time Alignment not functioning
properly
Possible phasing problem between front and rear speakers
Imaging is a bit off ("hole in the center" type of sound at times)
I'm getting some really strange results with the deck's auto time
alignment feature.
When I ran the auto-EQ and time alignment
feature, it returned the following adjustments for the speakers (right-side
driver listening position):
| Speaker |
Adjustment |
Delta1 |
Delta2 |
| Left Front |
163.75 cm |
36.25 cm |
n/a |
| Right Front |
127.50 cm |
n/a |
n/a |
| Left Rear |
371.25 cm |
243.75 cm |
n/a |
| Right Rear |
298.75 cm |
171.25 cm |
72.50 cm |
| Subwoofer |
400.00 cm |
272.50 cm |
n/a |
However, using my own measurements (physical
distance as well as phasing), I ended up with the following:
| Speaker |
Adjustment |
Delta1 |
Delta2 |
| Left Front |
145.00 cm |
40.00 cm |
n/a |
| Right Front |
105.00 cm |
n/a |
n/a |
| Left Rear |
135.00 cm |
30.00 cm |
n/a |
| Right Rear |
83.75 cm |
-21.25 cm |
51.25 cm |
| Subwoofer |
155.00 cm |
50.00 cm |
n/a |
I'm not sure what's causing the problem, but
it might be a phasing issue, as I'm noticing what might be phasing problems
between the front and rear speakers, and a "hole in the center" type of
sound at times.
Buzzing / Rattling
from front doors and rear hatch
As expected, the front door panels buzz at lower frequencies. The
fasteners for these panels are for for just keeping them on the doors,
rather than making an airtight rattle-free connection between the panels and
the doors. I'm presently contemplating a number of different ways of
tackling this, including making sub-enclosures for the speakers to isolate
them from the doors.
Subwoofer enclosure vibrates too much for my
liking
Yes, amazingly enough, even with all of the bracing that I put into the
enclosure, the damned thing still vibrates. The only thing I haven't done so
far is bolt the enclosure down to the floor, which I plan to do shortly. If
that doesn't work, I'm going to add an extra layer of 3/4 ply to the baffle.
Subwoofers
08-NOV-2008: The picture below indicates the current status of the
enclosure - carpeted and braced, and holding an Elemental Designs 13Kv-2-D4.
The enclosure is about 3.2 cu.ft. and I tuned it to 22 Hz with a 3" flared
vent. The combination of the woofer's measured specifications, the alignment
and the Tucson's transfer function should result in a sub that has a flat
response from 60Hz down to below 20 Hz. Above 60 Hz, the response will
slope gently downwards to 100 Hz (-9dB). This is a temporary
arrangement - the 13Kv.2-D4 and vent will be replaced with two 12" drivers
(I still have to decide on the replacements).
08-FEB-2009: I've cleaned up the
subwoofer installation a bit, though I'm still using the same Elemental
Designs subwoofer. I'm hearing some noises from within the enclosure, which
may be because it isn't bolted down to the spare tire well yet. I still
haven't decided on what replacement subwoofers to use, though I'm leaning
towards the Infinity 122.7W or perhaps the Infinity Perfect series.
03-MAY-2009: I finally purchased the Infinity
122.7Ws. The first picture shows them installed in the original
enclosure. The second picture below shows the enclosure being rebuilt with a
few extra layers of fiberglass on the baffle, and the second picture shows
the Infinity 122.7Ws installed in the re-carpeted enclosure. I had to
remove the previous carpeting in order to apply the fiberglass to the
baffle. I opted for black carpeting this time, for greater visual
effect. I also used some flash-band at the bottom of the enclosure to reduce
rattles. The results have improved the response of the subwoofer, but it's
still not as great as some of my better builds. It will do for now
however.
[head unit]
[main speakers]
[amplifiers]
[subwoofers]
Brian Steele
brian@spiceisle.com
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