1986 Toyota MR2 - get kicked into the weeds.

[bstardchild]

Oct 20, 2024 20:46:23 GMT Sweetpea said:

That said any car is the worst place to try and listen to music and expect it to sound great.

James

Pretty much that - It's not easy to make tunes in a car sound great -Loud is easy

but clarity and the right level of Treble, Mid range and bass is very hard to achieve in a car

My 90's Vauxhall has Kenwood speakers, Pioneer head unit and a nice compact sub in the boot - I can listen to my favorite album (ABC Lexicon of Love is anyone is interested) in the car and then come home and stick it on the home system (nothing flash just NAB CD player and NAB amp with wharfdale diamond speakers) and go wow where did all that detail come from!!!

[Sweetpea]

Right, now you know where we are starting let’s do something about it…


Clearly what we need is some bass. I’ve looked at adding the passive crossover and the speakers in the bottom of the doors a few times. The problem is it requires moving a couple of electronic modules to another position in the doors, Then I’d need to modify the metal work to allow the speaker’s spider to sit back. And I’d need to make a ‘something’ that fills the gap between the door frame (which isn’t flat) and the speaker. Apart from wanting to mount it like that if you have a gap round the side of the speaker frame the pressure waves in front of the speaker gets sucked through the hole to fill the opposite pressure area behind it. In other words you lose the bass and that’s what we need.

That’s hard so let’s do something else.

The idea of adding speakers in the doors was never to get decent bass. It was just to extend it down bit so it could meet a sub woofer that I was going to put behind the drivers seat.
You probably didn’t notice but the equaliser that I have has a sub woofer crossover and output built in. So let’s forget the doors and just chuck the sub in.



Is this big enough?





Remember I said that the Pioneer amp drove a sub? Well I still have the speaker too. That’s it. It’s about 9 inches across. When I was a young person that was behind the rear seats in a saloon car. It drove through the seats and used the boot as the cabinet.
The seats took all but the lowest frequencies out so you didn’t really hear it but, my God, it made its presence felt. Literally. Not the sort of bass that blows the glass out. Just a really nice, smooth, well balanced sound that goes low enough to feel it.

To put that behind the drivers seat of an MR2 is utterly stupid. It barely fits for a start. But worse is that it’s never going to have any space in the cabinet. It’s not really going to have a cabinet - just a bit of board. In the MR2 any cabinet would be so small that when the speaker moves it’s just going create pressure changes behind it that try to stop it moving. It won’t even be able to breath let alone resonate in a sympathetic way.

Ridiculous. You’d have to be as dumb as a goat to think this’ll ever work. Oh well. I’ve got it. It’s from the correct period, It’s going in.





That’s a bit of MDF I had kicking around. In fact it’s part of the speaker enclosure that this very speaker lived in when it was last in use.

The amp that used to drive it in the old days is currently running the speakers in the dash. I need an amp… I’m afraid we are now going completely modern.





This tiny little thing sitting on the carpet is a Vibe 400.1. It was pretty cheap. It’s tiny. It bangs out 170W RMS into 4 ohms. I think that huge Pioneer managed about 70W in bridged mode.

So I chucked it all together just to see how bad it sounded.





Well it sounds sh….

Sh….

Shockingly good actually.
I refitted the seat and spent some considerable time fiddling with the controls while listening to a wide variety of music. Yeah, I was enjoying myself and that tells you more or less all you need to know.
It’s really quite nice.

Just need to do a proper installation now.

James

[mk2cossie]

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

[skinnylew]

That vibe box is an amp?!?!? Man the game has changed sooooooo much since I last did this kind of thing, 15years ago. Ah yes that's because it's 15 years ago. Oh, never mind my stuff must be prehistoric dinosaur these days 😂😂

[jimi]

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

[Sweetpea]

Oct 21, 2024 21:14:16 GMT mk2cossie said:

Those Vibe powerbox amps are very good!
So good, I actually have 3 of them

I've read a lot of good reviews about them and, so far, it's performing. Not even getting warm. And they are apparently British. Top hole, what what! Pip pip old fruit, don't cha know!
Silly name though. Not like the old brands that I grew up with.

Oct 21, 2024 21:21:59 GMT skinnylew said:

That vibe box is an amp?!?!? Man the game has changed sooooooo much since I last did this kind of thing, 15years ago. Ah yes that's because it's 15 years ago. Oh, never mind my stuff must be prehistoric dinosaur these days 😂😂

Class D. You missed class D. It is now a thing and amps can be smaller. If anybody wants to know how class D differs from the old school stuff I can write a short 400 page explainer.
Essentially, for a given power, they are very small, very efficient, and don't get particularly hot. They've taken over where those things are important, car audio being a prime example. I don't know anybody in the Public Address / Events world anymore but I'll bet class D has taken over there too. High end hifi will still be old school linear though. If it isn't I'm giving up and becoming a monk.

Oct 21, 2024 22:34:51 GMT jimi said:

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

Hurrah! For once my car helps me out!
You'll see in the next post but it's literally a board. Much simpler than your build. I figured that if I made an enclosed cabinet the volume would be so small as to be pointless. So I went minimalist and figured that having the board rattle around might actually make it work like a sounding board. Literally no science was done. Entirely 'suck it and see'.
I did ponder running a couple of 32mm drain pipes from the void to under the drivers seat to allow it to breathe. I figured the sound would get lost in the carpet and seat base like a transmission line speaker. Ideas with no basis in fact. In the event it sounded ok and I didn't bother with the pipework.

The bottom line is that the volume of the cabin of the MR2 would make an excellent bass cabinet. I'm sitting inside the speaker...

James

[blackpopracing]

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.........

[spacekadett]

The audio stuff is interesting because it’s something I never really bothered with back in the day; I’d never had a subwoofer in a car until I got my old Freelander with the Harmon Kardon setup 😂.
However I have been playing with the setup in the Sierra, which has my old Kenwood head unit with similar age Alpine components up front and JBL co-axials in the back and china’s finest under seat sub currently living in the boot. For what it is it sounds pretty good but I think I’ll change things around in the future, if only to get back some of the bass currently lost under the racket from the Ashley exhaust 😂

[The Cat Herder]

Oct 24, 2024 12:03:12 GMT blackpopracing said:

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… 

[Sweetpea]

Oct 24, 2024 12:03:12 GMT blackpopracing said:

Have you considered cutting a hole in the roof and putting a box on top?

Well, no... But also yes.
It had crossed my mind that if I vented it into the B pillar then that (sort of) has a path to the boot over the rear arch.
But it'd mean cutting out a piece of the B pillar strengthening and I don't think the speaker would see the boot as a resonant cavity because there is too much of a distance round the engine bay that's made of wobbly steal.
If you want a great sounding hifi don't start with an early MR2.
If you want a great sounding hifi start with a house.

Oct 24, 2024 12:58:34 GMT spacekadett said:

if only to get back some of the bass currently lost under the racket from the Ashley exhaust 😂

It has occurred to me that I'm going to have to rebalance it once the car is moving because all the base will disappear.
If I die in a car crash with my head between my legs you'll know I was trying to adjust the bass. No honestly, I was, really.

Oct 25, 2024 1:31:50 GMT The Cat Herder said:

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… 

I had to look. I think I'd fit in there. Oh dear.
I did see this and had a giggle...





He's got a bit to go yet, poor lamb. This thread is older than his car by a fair few years!
Amateur!

Anyway, some interesting stuff over there. I may go quiet while I read it all.

James

[Sweetpea]

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

[blackpopracing]

Nice, I'm quite fond of a couple of bits of Katy Perry too.

Might have to pick your brains a bit on stereos then. My head unit has a sub output, can I just wire it to a sub or does it need one of those Vibe things?

[mk2cossie]

Oct 30, 2024 13:01:30 GMT blackpopracing said:

Nice, I'm quite fond of a couple of bits of Katy Perry too.

Might have to pick your brains a bit on stereos then. My head unit has a sub output, can I just wire it to a sub or does in need one of those Vibe things?

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

[blackpopracing]

Thanks Mr Cossie, Sorry to hijack your thread James, but any advice/recommendations on subs?

[Sweetpea]

Oct 30, 2024 18:53:12 GMT blackpopracing said:

Thanks Mr Cossie, Sorry to hijack your thread James, but any advice/recommendations on subs?

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

[mk2cossie]

Oct 30, 2024 18:53:12 GMT blackpopracing said:

Thanks Mr Cossie, Sorry to hijack your thread James, but any advice/recommendations on subs?

As we've had the blessing of sweetpea, I'll carry on

Both my latest sub box builds have been 6.5 inch subwoofers. Each in a box about 9litres in size.
Both have more than enough oomph for me, and aren't even turned up a great deal on the amplifier gains.

1 sub is a Ground Zero Iridium, and the latest is a Skar audio dual voice coil.
Do you have any spare equipment or will you need to buy anything for the pop?

[blackpopracing]

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.

[Sweetpea]

Hey Mark (and everybody else that’s reading)

As Mr Cossie said you’ll need an amp to drive the speaker. The sub output on your radio will be like any other low level output except it’ll have all the mid and high frequencies filtered off. There’ll be controls (probably in the menu) that set the level and crossover frequency. You’ll only get sound below that frequency. Well, it’s not a brick wall cut off, it sets what frequency the sound rolls in.

You can buy built sub woofers in boxes. The idea is that you wire them up and chuck them in the boot. If you need to put stuff in the boot you leave them at home. Some are just a speaker in a box so you’ll need an external amp. Some have the amp built in. I’ve not heard any of them so I can’t comment.

To get decent bass you need to move lots of air. The easiest way to do that is to have a big speaker in a big box with a fairly powerful amp to drive it. You can do clever things with smaller boxes and drivers by having resonant cabinets and ports to extend the frequency range down. That involves sums and I don’t like sums. You are also rather restricted by what you can physically do in a car.
You said you could use the boot space as a cabinet. That’s what I’d do given the choice.

I dug up a photo you your interior.





I’d remove the trim vertical panel and put the driver into the (presumably) metal panel behind it. Then, if possible, cut the hardboard out of the trim panel where the speaker is, leaving the soft trim in tact. Then refit the trim and you can’t see the speaker. You can have as big a speaker as you like ‘cos nobody will ever see it. The soft trim would take some of the high frequencies off but it’s a sub so there aren’t any high frequencies. Years ago that Pioneer speaker of mine was playing through he entire rear seat cushion and sounded lovely.

In an ideal world the speaker should be mounted in something acoustically dead and heavy. An MDF board 15 or 18mm thick is perfect. You want the speaker cone to move without it moving the thing it’s screwed to in the opposite direction. If you are thinking ‘it’s metal and heavy and welded to the car, it won’t move’ stop thinking like that. We are talking about it moving at 50 or 100 Hz and it definitely will.
Hit the thing you are mounting the speaker into with your hand. If it ‘rings’ like a piece of metal then you may have a problem. Ideally it should be a low dull thud. You could use a load of heavy sound deadening on the back of the panel if a lump of MDF is out of the question.

None of this is going to make you car quicker down the quarter mile by the way.

How big are your main speakers? And do they have a separate tweeter or are they a single cone?

James

PS, If you decide this is all too much of a pain in the bum, that’s fine. I’m very happy to chew the cud even if you don’t do it.

[blackpopracing]

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.

[mk2cossie]

Nov 2, 2024 20:43:46 GMT blackpopracing said:

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.

You may find that just an amplifier for the speakers gives the setup you have a nice and suitable lift

Otherwise, do you have access to a 3D printer? If so, check out hexibase on YouTube. As he has some very good and impressive sub box builds, and with 2inch "subwoofers" as well
Take up little room, need less driving, and very impressive results as well