Underseat Sub

[JB007]

I have replaced my 182’s head unit, changed the front speakers to a JL Audio 6.5 inch component set powered by a 4-channel Phoenix Gold amp in the boot.

Initially I was going to replace the rear speakers but was disappointed by the bass from the front and also think the mids/highs are loud enough.

Now I’m thinking to install a sub but don’t want to lose any boot space, so an underseat sub is probably best.

I see lots of discussion on here about pre-made underseat sub/amp enclosures, but I already have aspare 300 watts RMS bridged from the amp.

The shape of the space under the seat looks tricky to work with; I think fibreglass would work well but I’ve never used it.

Does anyone know of a custom underseat sub enclosure for 8 or 10 inch subs, or have any advice for making one?

 

[Louis]

Swe1200

 

[hipwell]

Hertz do a nice small 8" enclosed sub which might fit.

 

[JB007]

Thanks guys.
I’ve seen that alpine unit get a lot of mention on here but it has an integrated amp - I would rather spend same money on a better sub.
My guesstimation gives a possible enclosure size of 8-10 litres under passenger seat and there are subs that will work with this.
I am interested in how to procure/fabricate the enclosure given the odd shaped recess in floorwell.

 

[SWL16]

Swe1200

This.

 

[Gus]

Swe1200.

Sounds like it would be possible to make an underseat sub yourself . Take the seat out and get some measurements.

An other idea is doing the same as a Nissan gtr and having the sub in the backseat.

 

[JB007]

I stand corrected: the SWE-1200 has a separate 75w rms amp, and I managed to find just the sub on eBay for £40.
It has a dual voice coil, so I wired it in series to a single 75w channel on my amp.
It fits perfectly under the seat and packs a nice punch - just what was needed - and was MUCH easier and cheaper than messing around making a custom enclosure.
Thanks for the advice everyone!

 

[DomP182]

I stand corrected: the SWE-1200 has a separate 75w rms amp, and I managed to find just the sub on eBay for £40.
It has a dual voice coil, so I wired it in series to a single 75w channel on my amp.
It fits perfectly under the seat and packs a nice punch - just what was needed - and was MUCH easier and cheaper than messing around making a custom enclosure.
Thanks for the advice everyone!

Would this work on a standard 172 head unit? I just want to add some bass so I can leave the bass down on the door speakers. Not looking for a mega sound system just a tweak

 

[JB007]

Would this work on a standard 172 head unit? I just want to add some bass so I can leave the bass down on the door speakers. Not looking for a mega sound system just a tweak

I do not have the factory SWE1200 wiring harness, but looking at the manual diagram, the speaker input are RCA terminals. In theory you could lose the 172’s rear speakers, run + and - wires from a rear speaker to the SWE1200, but you would need to fit RCA terminals to the ends or cut the RCA from Alpine leads and use a connector.
Personally, I think the sub is too loud for the standard 172 stereo and would be out of balance. Perhaps try it first but i think you would be better getting an Alpine head unit, and upgrading the front speakers to a decent 5.25in component set.

 

[JB007]

As an anecdote, after only changing the head unit, I could not hear people properly when making Bluetooth calls with the standard speakers. After upgrading the front speakers I can have clear conversations. The standard speakers are poor quality.

 

[DomP182]

As an anecdote, after only changing the head unit, I could not hear people properly when making Bluetooth calls with the standard speakers. After upgrading the front speakers I can have clear conversations. The standard speakers are poor quality.

I'll be honest mate, my audio knowledge goes as far as pluging a replacement speaker in. I'd like to keep the original head unit ideally as I like standard looks but not the sound, my 182 sounded so much better that my 172 does but I think the rear speakers my be shot(replaced the fronts for SXE-1325S)

What is the deal with component speakers then?

 

[JB007]

I agree the factory head unit looks cleaner but the sound is poor and there are no features like Bluetooth. I think the benefit of a decent single-din headunit outweighs the non-factory look, but that’s me.
You replaced the fronts in your 172 with coaxials (tweeter integrated into woofer)? There are factory tweeters on the dash, which if you haven’t disconnected, will also be putting out high notes, so the sound may be imbalanced.
Whilst it’s best to replace the front with components (separate woofer and tweeter), this is a bit fiddly, so perhaps stick with what you have. I’m not sure if you can disconnect the factory dash tweeters through the grilles on top of dash - I changed mine with the dash out. Not too difficult to try this to see if it helps balance the sound.
FYI, if you do decide to get an swe1200, the best place to run the power lead to the battery is through the same rubber grommet going through the bulkhead that the bonnet opening cable passes through.