1986 Toyota MR2 - swapping the phase of the sub.

Those Vibe powerbox amps are very good!
So good, I actually have 3 of them
2 of them are that same 400.1 sub amp, and 1 is the 65.4 speaker amp. Both the 400.1 amps are running a 6.5inch sub woofer, and I'm still amazed how much bass they output

Nice solution James 👍 your quite correct in that's there very limited options for sound improvements in the MK1
I've actually seen and heard a similar setup in a MK1 (many years ago at J.A.E.) and it sounded pretty good
We actually compared setups and there was little if anything to choose between them, both sounded great.
I only have one amp that drives the two boxes and a newer Pioneer 50w head unit that drives the dash speaker, the head unit has built in filtering that allows me to choose what frequencies go where.

Also mine are flat topped so I can still store the T-bars behind the seat, a problem you don't have to bother about

My home amp is a class A, great for those cold evenings to warm the room up

Have you considered cutting a hole in the roof and putting a box on top? Nice punchy bass and would look great inside - maybe less so outside though.........

it’s probably best you don’t go look at the project forums at DIY Mobile Audio and see the crazy people installing big systems and cutting holes in cars to let the subwoofer play into the open air, so your whole car becomes the subwoofer cabinet… 

My proof of concept experiments had proved that, amazingly, the concept worked. Who’d have thought that slapping a ridiculous speaker in a tiny bit of wood and lobbing it behind the seat would actually sound ok? Not me. I seem to have proved myself wrong again. Ah well, it’s a happy wrong.

We’d better tidy the mess up.
The little Vibe amp is so small that it can live on the back of the board. Oh, by the way, the speaker is off set to the middle of the car because the floor comes up and that’s the only place it’ll fit.





The black and grey connectors will allow me to disconnect it from the loom and remove it if I need to. I mean, it’s not ‘factory’ so it’ll lose me points at the MR2 car show. At least now I can take it out and hide the cable under the seat.

Here’s the loom.





Somewhere I have a roll of cloth covered insulating tape which’ll allow it to blend in with the carpet better. Shame I have no idea where I put it. It’ll turn up just when I’ve forgotten why I wanted it.

And here is the nearly finished installation ready for further extensive testing and tweaking.





I wish you could hear what it sounds like but you can’t. No microphone in the car will ever sound anything like it does in real life. I have made a small video just to give you a visual idea of what it’s capable of though.

I have to apologise for the sound. Firstly, it was recorded on my little camera and as I just said, no microphone in the car will ever…. Certainly not the mic on my little camera.
Secondly it’s Katy Perry. If that’s not to your taste then sorry, but tough. I’m not a massive fan but there are a couple of bits of Katy Perry that I’m quite fond of.

No. No! That’s not what I meant! God, what are you like?






Clearly this is going to immediately liquidise any poo in the drivers colon leading to an uncontrollable evacuation of the bowels. I may have to wear a nappy when driving the MR2 in future.

Well, actually, no. As much as the video suggests otherwise it’s actually really nice. It just extends the bass down. You feel it a bit if the track has a load of low stuff like ‘Wide Awake’ does, but it’s not kicking me in the bum. It does sound like the bass guitar and kick drum are playing over my right shoulder though. It’d probably be better with the cross over set a little lower but that would create a hole between the sub and the speakers in the dash so there is a bit of a compromise to be had.

I’m an audio engineer, have been for 35 years, so I can be pretty critical. I know what I like and this isn’t far off. But what does that mean? How does it stack up against other car hifi? To put it into perspective I had to pop to Canterbury in the Lexus. I had to drop in on the Arch Bishop, you know how it is… The stereo in the Lexus is pretty decent. Not fantastic but perfectly acceptable. Well I suddenly found it a bit lacking. Not very dynamic. A bit meh. So for a modest investment and some vintage gear that I already had I’ve managed to get something that can hold its own against a major manufacturer’s luxury brand. I’ll take that as a win.

It just needs to not look like a lump of MDF and be a bit more hidden - a bit more subtle. I have some black speaker cloth.






In real life it’s not even that visible. And when the seat is back you don’t see it at all.

Another question that Jimi mentioned on another forum is ‘how much seat travel have I lost?’
I think it’s one or two notches. I’m 6 foot, or I used to be. Apparently somebody has reimagined how long a foot is and I’m now only 5’10” plus and a very important half an inch. I might round that up to 5’11” or go metric?
What was I talking about? Does anybody remember?

Seat travel… I’m 181.61 cm tall and with the seat against the board I can’t press the clutch all the way down. It’s only going to be a problem for a really tall driver.

I was so pleased that I spent another few hours testing and adjusting the sound. Sound takes a lot adjusting apparently. With many different genres of music.

Like some sort of obsessive car owner I also cleaned the interior with my new dash cleaner just in case a passer by showed interest in my audio experiments.





The one on the left is a French product inherited from my late father in law who used to live in Brittany. It perfectly reflects the ‘relaxed’ attitude the people of France seem to have towards their cars.
It has the scent of stale Gauloises cigarettes and after about three days the car looks worse than it did before you started.
It accidentally fell in the bin and was replaced by the bottle on the right which is a better fit to my English personality of compulsive, fastidious, cleaning of a car that should have been turned into bean cans about 25 years ago.





Lovely! I’d be proud to eat beans from there.

James

The "sub out" pre-outs need to go to an amplifier (the Vibe Powerbox 400.1 was 79quid on amazon the other week).
Then the subwoofer is wired up to said amplifier.
If you have an amp laying around, unused, pretty much any can be used for subwoofer use

I'm a big fan of the Powerbox amps, as they are quite literally palm sized and easy to tuck out the way. And give out a lot of oomph for their size and price as well

Sorry!? What do you mean 'sorry'? What are you talking about you crazy fool!?
Sound, recording, broadcasting, music - it's my life. I could talk about it endlessly. I'd literally go nuts without music. Music can make or break my mood, it can energise me or reduce me to tears. It keeps me sane. It's everything. Don't be sorry for talking about it and how to reproduce it.

I'm an incredibly lucky person in that I can make a half decent job of almost anything I turn my hand to. But there is no 'art' in me and, strangely given my love of music, I can't play any instrument. If there was one thing I could change about me that'd be it.

I'm not long back from work, it's been a long day. I'll jump in on the sub thing in a day or two. For the time being - carry on chatting. It's all good.

James

I like HiFi too

I might buy something for the pop, I'd prefer to keep it discrete so small would be good. It would use the boot space as a bass box.

Hi James, the trim is just vinyl with a thin sponge behind it. It's a 2mm steel panel behind that which if I thump it is pretty dead.
I'm running 4 speakers at present, rears are 6inch 3 way in rear side panels and fronts (in roof panel just in front of my head) are 4 inch 3 way.

I wondered if 2 4inch subs would work? Our telly only has a 4 inch sub box and that can kick serious butt.

I don't mind the subs showing as if I could use 2 small ones they could go at the extreme sides of the panel in the photo you posted rather than a big one in the middle.