28-80Hz Issue

[Qwiz]

Interior Length: ~2,5m

Interior Height: ~1,2m

Interior Depth: ~1,7m

 

Scenario1: Listening position: Driver/Passenger seat, sitting normal; Subwoofer alone playing:

15-27Hz: good

28-55Hz: undefined/muddy/muffled/doubled/overwhelming

55-80Hz: dipped/canceled/almost non-existent

 

Scenario2: Listening position: Driver/Passenger seat, laying flat; Subwoofer alone playing:

15-80Hz: good

 

Tried without any success:

-changing subwoofer position

-soundproofing everything but the ceiling

 

Conclusions:

-it's not a crossover issue

-it's an acoustic issue

 

How would you approach this issue?

 

 

 

[Joe X]

You need to specify what's your vehicle, what is the sub model the box specs and some pictures if possible.

 

Looks like a box issue,  installing a DSP could help flatten your response but not the other issues, in some situations inverting the phase of the signal to the subs can help some cancellation issues, other times box location / sub, port firing direction etc can help.

 

try what is suggested and if you still not get results then  provide the details I asked about above.

[Qwiz]

The vehicle is a Kia Rio UB III 2016, European Edition, 3 Doors.

 

Worth mentioning, once door panels&co. are taken out, that the inside-design looks very strange, such that there is like a tunnel space on both left and right sides, when looking from the trunk, between the trunk and the space where the back-door "is", you could put your hand from the trunk and come to the side all the way to where the back door is.

 

- would not be a box issue, the same subwoofer in the same box sounds good in another car/in another enclosed space

- a Home-Subwoofer instead, by keeping it connected to its home amplifier sounds similar

- inverting the phase + time alignment + position settings + etc: slight differences, but with the same overwhelming feeling

 

If when changing the listening position (like when I lay flat), the bass evens out and seems normal, wouldn't that suggest an acoustic issue?

[Qwiz]

I will measure a 20Hz-200Hz sweep in REW.

[Qwiz]

Turns out it's the acoustis. I have been in two Kias. Mine and another one. Both horrible.

 

The person in charge of the interior acoustic properties is nonexistent to this vehicle producer.

[Joe X]

Your box probably is hitting the car resonant frequency and may be oversized to show muddiness and showing a sharp drop at higher bass.

 

It is interesting that you provide no box specs, you see it doesn't matter much that the enclosure sound normal in another car.

 

Also don't see what is your system, models for the speakers, amps etc.

 

You provide no pictures to document your tests, etc.

 

Even if you have an acoustics problem, there should be a way to work around the issues even if that means try different components, etc.