My new precious is a 25th Anniversary - part 2

[RichardFX]

At long last I got around to changing the weedy headlight bulbs for some a little bit brighter. Compared with the Niseko’s NC1 lights or my Mazda3’s these 25AE NC3.75 headlights are almost useless especially on the dip beam.

Main beam on both sides is a five minute job for each bulb, access is tight for big hands but perfectly manageable from inside the engine bay.

The owner’s manual shows where to squeeze the Dip beam plug to release the connection.

I studied the problem of the dip beams for a couple of days and did some research.
Initially I thought access on the driver’s side can be helped by bending back the wheel arch liner until I realised dropping the fat loom under the slam panel above the light cluster made it quite easy, well, almost easy, and I did not need to move the washer bottle.

But on the passenger side, branches of the loom are well in the way from the wheel arch and the only solution is to move the fuse box back an inch, again helped by releasing the fat loom running from across under the slam panel.

Then left hand only access through here.

I needed to assemble a fork-tool to push the spring clip because my fingertips were not strong enough at the awkward angle.

Now all they needed to do was hold it in place while the right hand pushed from beside the fat loom going back from the fuse box, suddenly it’s easy, almost no effort .

[RichardFX]

A couple of days ago I added some “edge seals” for the bonnet along the wings. Similar ones seemed to keep the Niseko a lot cleaner under the bonnet, so it is worth trying here.
However these are poorer quality than those seven years ago, and I expect these might peel off in hot sun. Never mind, it was very cheap.

[Scarletpimpernel]

Just being curious, what dipped bulbs did you use?
I put these in and seem better.

[RichardFX]

@Scarletpimpernel

Just being curious, what dipped bulbs did you use?

HB3/9005 high beam and H7 Low beam

Nothing extreme, I don’t like a blue light, but the dull yellow on the originals was no good either, positively scary coming back down the M1 in the damp of rush hour from Weedon last year.

I took it round the block last night after the change and the improvement was very noticeable for such a small nominal increase in output.

These oriental cheapos from Az each claim 2500 lumen and 3800K. The halogen bulb part of the lamps looks identical across both HB3 and H7, just differing on the relevant mounting to exactly match the originals.

Supposedly they have more output and are “whiter” than the values as found on websites like Osram, but they are never going to upset an MOT examiner.

And changing all four bulbs for the same manufacturer means they are all the same colour, and also have the best uniform effect.

Osram pdf specifications for info.

Osram HB3/9005 Original Euro-spec 1700lm

Osram H7 Original Euro-spec 1500lm

[Scarletpimpernel]

Thanks for that.

[RichardFX]

I finally found time to update the Alpine’s firmware, having taken note from successes gained by others in previous adventures recorded on the Forum.

It was on the factory original 1.1 version

The first small, old USB2 1GB Stick I tried formatted OK and passed H2TestW with no errors, but turned out to be so old it was too slow for the Alpine! A much faster USB3 32GB chip worked a treat and loaded version 1.3.

This allowed me to see the parametric equaliser, and the bass end looked like the Alps! No wonder it sounded awful. I forgot to take a pic because I saw the magic word “Flat” …

I set it Flat and instantly the sound was so much cleaner and better balanced. Result!

I might not need to change the drive units after all, only add a bit of dampening .

I’ll sleep well tonight.

[RichardFX]

This morning I listened to the Ray of Light CD from Madonna, with its superb audio quality especially in the smooth low bass.

The Alpine is doing OK, not yet hifi, but a lot closer. Still some speaker/cabinet/door resonances that might need damping down.

Next job, possibly this afternoon, I’ll make some acoustic measurements using the Aux socket and my rudimentary test gear and try to find out what the Alpine speakers are actually giving me.

Then the PE might allow me to set the system audio response truly flat without having to take off the door cards.

I’ll do it both lid-up and lid-hid, since the PE offers a couple of settings options to be stored.

[RichardFX]

I enjoyed a couple of hours with tone source and noise meter this afternoon measuring the “Entertainment system”, one door a t a time. It brought back happy memories of speaker design in 1970s/1980s.

I concentrated on the driver’s door. Passenger door sounds much the same, so I didn’t do any detail testing on it.

I found the main resonance in the system is the outer skin of the car doors, the old cushion test dropped the 50Hz (approx +/-2Hz) audio inside the car by a few dB, curing the peak. But I cannot expect any glamorous assistant to agree to run alongside the car holding a cushion against it.

The PE setting I ended up with saved in a preset is with all the other pre-programmed enhancements and options turned off. This Parametric Equaliser is quite a nice beast and it allows one to shift centre frequency of each band, adjust gain between +7dB and -7dB, and its Q (sharpness of the peak/dip). The graph looks coarser than the actual effect.

Tweeters are both about twice as loud as the main drive units, and there is too much overlap at cross-over, so the PE result might look a bit odd but reflects this.

Next task will be to take off the door cards, add sufficient Silent Coat inside the outer skins to minimise the resonance, and try to cure a buzz that happens sometimes with the window open.

While it’s off I also hope to measure the free air resonance (Fs) of the drive units if I can extract them without damage. This is because speaker output at 41Hz (Bass guitar E string), while audible, is about a tenth of that at 50Hz, and the 30Hz needed for the B of a 5 string bass is there, but very faint at about a hundredth.

New drive units with lower Fs might be useful in the absence of a Sub-woofer. With Sub cross-over filter turned off the amplifier sends the speaker the whole spectrum.

The tone source + signal level meter I used are a small portable pair in the first decent prototype I built back then, mostly for audio equipment testing. It’s still reliable and accurate! The short production run had a lighter, prettier box with proper legend etc.

The noise level meter I used is a cheap modern thingy but it’s accurate enough on relative levels for ad hoc testing like this.

[benfieldl]

A brilliant write-up of your audio improvements, thank you. It’s food for thought for the rest of our community who have that stock Mazda/Alpine unit.

[RichardFX]

Much cursing two days ago when I dropped a small trim tool into the impenetrable depths of the front of the engine bay. I finally thought it through last night, and today dug out the old bore-cam and laptop.

The tool was not visible from the top with normal eyes and torch or with bore-cam so I took out the air-box for better access and found the tool, not in the cooling fan as I feared, but all the way down in the front under tray.

The hole it went though is only about an inch square!

Bore-cam lead fits easily,.

And after a bit of wiggling around it gave me this indistinct but reassuring picture of the offending item all the way down on the under-tray.

I’ll take the under-tray off later when I’ve finished varnishing the oak shelves I machined yesterday

[RichardFX]

I mentioned shelves, but things have been so busy the last couple of weeks I’ve not done anything to the 25AE except re-secure the front number plate.
I’m still not happy with how the plinth fits to the nose cone, some surgery is needed to prevent it rocking.

In the meantime, these are the shelves

[RichardFX]

Applied Dinitrol inside the front chassis rails and down-links to sills.

Passenger side shown, the plastic arch liner clips provide excellent access holes, spray in the direction of the arrows. Something inside the rail prevents access past behind the springs, but spray from each side and the long-wand reaches far enough for full coverage.

I took off the lower front liner, but this is not necessary because there is no access big enough to aim the wand, and the clip holes are ample. So I didn’t bother dropping the driver’s side or taking the wheel off, much quicker that way while still on the axle stands, and no pics because I was in a hurry to be done before a visitor arrived.

And I retrieved the trim tool.

[RichardFX]

After seeing the discussion on theft prevention I thought I’d give (what we’ve called The Flexy) the cheapest mentioned seat-belt-steering-wheel-lock a try.
And obviously I compared it with my old trusty Stoplock Pro both fitted in the 25AE just now. This Stoplock is almost exactly eight years old now.

Now it will take a thief twice as long to nick the car, maybe twenty seconds instead of ten.

I think the biggest off-put for us about the Flexy cable one is that the key is so big, it feels twice the size of the Stoplock key, and it does not look as secure.

I’ve been trying to find a video I saw a couple of months ago on this topic where the “thief” had what looked like a big secateurs, maybe a branch lopper with ratchet handles, and it went through one of those cable locks (on a motorbike) in a couple of seconds.

I think the Stoplock is more visible from outside the car, and obviously the secateurs would fail on it.

But a battery-powered angle grinder would sort the Stoplock in a few seconds, and only take a little bit longer on the wriggly cable.

My decision, gut feeling mostly, is keep the Stoplock in the 25AE.

I’ll let SWMBO have the Flexy (if she wants it) in the Mazda3 because it is marginally easier to fit, although slightly less easy to remove.

And what thief is going to worry about a seatbelt?

[RichardFX]

A busy day today investigating doors and speakers, and finding someone has “been there before”.

Most important thing first, I tightened this screw two and a half turns, its friend at the other end of the passenger door handle only needed half a turn to reach 7.5 N.m, and now the door handle doesn’t flop about or let water into the car.

Taking out the inner trim and ‘door unit’ revealed missing hex head self-tappers and already broken trim clips.

I need some of these, ten of each should cover future breakages and losses.

And the tweeter plug is so mangled it was much quicker to unscrew the unit from the trim panel than work out how to unplug it.

I measured the Free-Air self resonance frequency Fs of the bass unit; it is 80Hz. Therefore it is incapable of any useful bass regardless of what cleverly designed enclosure it might live in. The door resonance of 50Hz is actually helpful!

I’m now thinking about the Sub that was mentioned a couple of days ago, cheaper and much quicker than tracking down some decent speakers with Fs of say 40Hz. Crossing over at about 85Hz (an Alpine preset) would allow for quite nice fine tuning if I can believe the In Phase data sheet.

I also finally got around to popping bits of silent-coat on the outside of a door with a sheet of newspaper to protect the paint with lots of mini magnets to hold it all on place. The doors-skin sounded better, but resonance was still close to 50Hz. Thus no point in trying to lower resonance this way, especially since access inside is limited by crash-bar, stiffeners, window-mech etc. I forgot to take any pointless pics here!

However two slices of silent-coat cut into suitable smaller bits to fit inside the outer skin of the passenger door have damped down its “tinginess” to more of a dull clunk when I tap it. Alas no pic here.

[RichardFX]

I did the same exercise on the driver’s door today. Only two clips broken previously (not me, no white shards on the floor) and the tweeter was undamaged, but still tricky to extract the plug.

On both tweeters I added a ring of thin weather strip (6mm wide 3mm thick) because one rattled, and I noticed the gap is 2mm.
Luckily I had some of this stuff, and it’s a perfect fit.
The raised lip on the panel is about 2-3mm inside the outer ring of the tweeter, almost like it was designed to have a cushion.

I repeated adding some mass to places on the door card to help remove resonances, same as before, this time remembering to take a pic.

And some more inside the outer skin of the door, awkward taking pics which might make any sense.
Rear opening, looking towards the catch end.

Same spot but looking forwards

Furthest forward opening looking up

It might look a bit messy, but random and overlapping can actually be quite good acoustically for minimising standing waves. But I don’t think I’ve put enough in here, mainly because of limited access and sore fingers.

It certainly sounds significantly cleaner, less ting, tizz and whoosh and now no buzzes either, but no real change in the missing low bass.

I tweaked the equaliser to put dips at 80Hz and 50Hz, and it is almost good enough, but still not quite. The sub will definitely be useful, but ONLY IF it performs as claimed.

[RichardFX]

The InPhase USW300 arrived this morning and before ripping the car apart I tested it with a 10Amp bench supply set at 14V and the tone source and noise meter.

Alas, the USW300 is disappointing.

With LPF set Minimum and Bass boost on Maximum there is a peak in output level around 100Hz,
then when reducing frequency the level drops a few dB then peaks again at 60Hz,
but it is almost 20dB down by 40Hz (where I really want to hear that bass E string).

Looking at current consumption vs output levels.

“Off” has a dark current of about 1mA
“On” with no sound about 0.4A (This is meant to be an efficient Class D amplifier. Really?)

At a comfortable indoor listening level chosen to be without distortion at any frequencies (ie peak current less than the hard limit in my power supply) and meter at 1metre away these readings are an ad-hoc measurement just now. (In brackets are the No Boost readings)
100Hz 0.9A 66dB (58dB)
90Hz 1.0A 63dB (55dB)
80Hz 1.0A 63dB (55dB)
70Hz 0.8A 65dB (57dB)
60Hz 0.9A 68dB (50dB)
50Hz 2.9A 50dB (40dB)
40Hz 3.9A 46dB (32dB)
35Hz 3.7A 46dB (31dB)
30Hz 3.5A 38dB (<30dB)
28Hz 3.2A 30dB (my meter cuts off at 30dB)

This is not what I would call a Sub woofer, more of a simple woofer.

The first ever decent bass unit I built (actually for a guitar) was measured flat from 25Hz to somewhere around 1KHz and produced useful (painfully loud) clean output up to 10KHz. It was an 18" Goodmans Audiom 91 in the hifi cabinet. Once we had it on a Rag float playing Motown for our go-go dancers, and with a 50W (true RMS) amplifier it was clear and undistorted a quarter of a mile away at the other end of the Rag procession. Alas, it was also quite a bit bigger and heavier than this In Phase.

[RichardFX]

I’m in two minds about sending back the USW300, it will add another 20Hz-30Hz of smoother range below 60Hz, almost a whole octave!

But is the connectivity there on the Alpine?

Accordingly, I had a look at the back of the Alpine to see what is actually there, and confirmed it is the 600 version, not the 620.

I found the extra connector for the reversing camera, taped to the loom, now I need to find a suitable plug for it. But I’ve yet to identify the sub leads. All the plug contacts seem to be populated, so there might be a possibility the RCA plugs are tucked away out of sight. I’ll have a closer look for these tomorrow.

I had a bit of fun taking it all apart, and having learnt on the Niseko I began by taking out the hand-brake sleeve; using a trim-removal-tool where the white catches are for quickest exit.,

and the window switch, trim-tool-lever from near the gearstick, and the metal spring tangs allow easy removal, a pain otherwise. Unplugging is then easy.

Console lifts out easy after undoing the three screws and also unplugging the USB+Aux.

Side cheeks slide forward after undoing each one’s retaining screw.

I put together a slim bendy 1/4" hex drive and a small 10mm nut driver to reach the notorious 10mm locking screw. The old drill chuck worked well as a handle gripping the hex inner.

More tomorrow when/if I’ve found what all the wires are. The Alpine is optimistic in its menus, but they could be pie in the sky.

If I do fit the Sub, it will be on the bulkhead at floor level behind the driver’s seat, no room anywhere else and it allows short wiring along the console. I’ll have the most benefit, and a hint of gentle massage. But it’s nowhere near powerful enough to do much more…

[NickM0864]

I installed an Audison sub in the footwell of the passenger seat. It’s easily removed with an XT quick connector on the speaker wires, but it works a treat at filling out the last couple of octaves with music. The box was a pain in the ■■■■ to make, but fits in so tightly it doesn’t move at all.

[RichardFX]

@NickM0864

Audison sub in the footwell

I do like that floor mounting for your sub. Alas, that option had already been vetoed by a higher power.

I’ve been playing with the back of the Alpine today, identifying wiring etc and planning where I might make the required connections.

I think I’ve found the 5-pin connector for the Reversing camera, (only four pins used)

The Remote Turn-on (pin 10) in the main socket should be a Blue/White but here it is a Blue/Red, I’ve not yet found out where it goes to, if anywhere; hopefully it’s waiting for a connection to wake the sub.
And the AUX PRE-OUT socket is empty and waiting for a pair of RCA leads to run off to the sub.

An oddity I found in the “Mazda AVN2 Harness” loom is this dongle box with seven wires going into it, Violet (RRsp+), Blue/Red (Remote power), White (RFsp+), White/Black (RFsp-) and three blacks, two of which are slightly thicker than the other wires. I’ve not yet unbundled all the tidy, neat (!) loom wrapping for a closer look.

What is the dongle for?

[RichardFX]

I’ve tracked down lots of options for the Alpine Pre-out to RCA leads, but the 5pin Reverse to RCA camera adaptor is difficult, all I can find are six pin, unless I go to Aliexpress, which I really don’t want to do.

Hmm, there is a video input on the Pre-out connector. I wonder if Reverse can be configured to switch that on to the screen?

Edit. According to the manual, yes, so the 5-pin lead is not needed. Cross fingers.