Audio upgrade, DIY style, Hertz speakers + amplifier

maxufeiss

Active Member
So i thought upgrading audio on my A2 and to not forget it, i bought front speakers and amp. Set them on my desk to constantly nag about doing it.
Since today i finished overall concept for passenger door (for us who don't drive at wrong side of road), i'll start a thread.

Front door speakers will be Hertz MPK 165.3, powered by four channel amp HCP 4D. Don't know if i'll try to add small sub later.
At the moment i think that rear doors are fine powered from from head unit (will remove original rear amp). Have not decided on speakers etc for rear.
Amp will go under floor.

Go to post #17 for second version. Sealed box idea was dropped.

Overall speaker will go in like that and there will be covering made from original grille to hide some of mess i make.
Probably already removed more plastic than was needed. Not a big problem.
eBkZXzc.jpg

Grille removed:
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Further away:
dmStF1B.jpg

Speaker removed:
a16XQDy.jpg

Door panel off:
m3qXSde.jpg

As you can see, i made closed box for the speaker. To stop leaking so much outside and get better sound inside. Very time consuming and deepened my love for the door strap placement.
It will fit inside there:
DQCrVyD.jpg

Cutoff for door strap:
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Door almost closed:
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Available space:
AqDu6FZ.jpg

Space vs. box:
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Door panel modified. Removing corner thingy did not went so well, so i chewed + grinded other two away. I'll screw door panel with black screws to speaker box where available. Cut away little bit more to gain some valuable space hidden there.
iLc5OoT.jpg
 
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maxufeiss

Active Member
For science i filled it with sand, fitted 3,5l inside. Minus speaker + added perceived space from wool, so not as bad as i feared.
Speaker needed to be lower because of magnet size and door strap being in the way. That's highest i was willing to go, even rotated speaker little bit to give few millimeters more.
Needs some modifications for metal thingy in door, tweeter, crossover etc, but that is for another informative post when done.
 

Jeetesh

Member
I admire the wood work as anything wood related I love. My question is really around why? Wouldn’t it be easier to get the Bose upgrade done instead, doing that for each door adds weight especially in ply wood.

I’ve seen pictures where some have added a sub in the drivers footwell or in the boot and upgraded the door speakers instead of Bose and that’s another easier alternative.

This is just me and only because I’m all for OEM (just my personal preference). Out of curiosity what output do you expect from your mods? Is it going to be like a 1000w sound system?
 
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maxufeiss

Active Member
Mainly because i just wanted to do it. Stock speakers are not so bad either behind aftermarket stereo, but they are far from good. And the leak through doors to outside is massive. After making just one enclosure, i'd be happy to just slap heavy sound deadening behind speaker and install better speaker, but we are missing speaker adapter and this speaker probably would not fit even then to factory location.

Sealed box will eliminate some leaking sound and rattles so decided to go with that. Better low end bass too, might need some help from equalizer and more power to do so, but both are available for use. Might be enough to eliminate need for subwoofer.

It does add weight (when done i'll weight the box), probably add some sound deadening material to door too, but most of the weight will be near hinges, so maybe not so bad. Probably not doing same for rear doors. Thought of trying glass fiber reinforcement for weight reasons, but went ahead with plywood idea.

Car is not very OEM from start, so i don't mind that. I have A8 (Bose standard) that is nice and oem inside except for aux in, not very nice outside. And A2 that is nice outside, not very nice inside :D.

I was once in love with music, and sometimes still want to remind those feelings. But with standard speakers that is impossible, not clear enough etc. Especially in vocal range. Power levels will be as amp provides (Hertz HCP 4D), 85Wx2, 85Wx4 or 85Wx2 + 290W if i add single subwoofer someday. And if rear speakers will be powered by head unit, then that will be another 2x22W or something (Pioneer SPH-DA230DAB).

To better clarify my feelings for music, this is what my computer place looks (old picture):
1lBkd9x.jpg
While i mostly listen at very quiet volume levels, i appreciate the quality they provide with help from decent receiver tuned to my head location. And sometimes there will be moments where that power is needed...
No subwoofer there too, for lower bass there are 2 larger speakers slightly visible under desk...
Of course that gets you spoiled and therefore need for ever better sound to satisfy me.

Bose would not be as powerful and probably lacks behind in quality as well. Price would not be much cheaper also. Lot less work i agree. And wind noise etc will still be there (unlike A8 that is nice and quiet), but seeing that A2 will be the car of choice for me, i'll try to make it better.
 
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Jeetesh

Member
Mainly because i just wanted to do it. Stock speakers are not so bad either behind aftermarket stereo, but they are far from good. And the leak through doors to outside is massive. After making just one enclosure, i'd be happy to just slap heavy sound deadening behind speaker and install better speaker, but we are missing speaker adapter and this speaker probably would not fit even then to factory location.

Sealed box will eliminate some leaking sound and rattles so decided to go with that. Better low end bass too, might need some help from equalizer and more power to do so, but both are available for use. Might be enough to eliminate need for subwoofer.

It does add weight (when done i'll weight the box), probably add some sound deadening material to door too, but most of the weight will be near hinges, so maybe not so bad. Probably not doing same for rear doors. Thought of trying glass fiber reinforcement for weight reasons, but went ahead with plywood idea.

Car is not very OEM from start, so i don't mind that. I have A8 (Bose standard) that is nice and oem inside except for aux in, not very nice outside. And A2 that is nice outside, not very nice inside :D.

I was once in love with music, and sometimes still want to remind those feelings. But with standard speakers that is impossible, not clear enough etc. Especially in vocal range. Power levels will be as amp provides (Hertz HCP 4D), 85Wx2, 85Wx4 or 85Wx2 + 290W if i add single subwoofer someday. And if rear speakers will be powered by head unit, then that will be another 2x22W or something (Pioneer SPH-DA230DAB).

To better clarify my feelings for music, this is what my computer place looks (old picture):
1lBkd9x.jpg

While i mostly listen at very quiet volume levels, i appreciate the quality they provide with help from decent receiver tuned to my head location. And sometimes there will be moments where that power is needed...
No subwoofer there too, for lower bass there are 2 larger speakers slightly visible under desk...
Of course that gets you spoiled and therefore need for ever better sound to satisfy me.

Bose would not be as powerful and probably lacks behind in quality as well. Price would not be much cheaper also. Lot less work i agree. And wind noise etc will still be there (unlike A8 that is nice and quiet), but seeing that A2 will be the car of choice for me, i'll try to make it better.
Fully understand, I agree I really like my music too and good quality at low volume.

I opted for Bose as it was better than the standard 8 speaker setup. I also have a merc E-class with a Burmester system and that car is setup for good quality music, aside from all the sound deadening and the number of amplified speakers the car has 2 subwoofers located in the firewall which together with the shape of the footwells makes for fantastic quality sound. I’m on the same page in respect of your A8.

Good luck on getting the A2 up to the standard of music that you want.
 

bretti_kivi

Member
I looked into doing it this way as well and have decided against it. Why?

1. You can't easily decouple or fix the door card against the secondary enclosure.
2. The enclosure size is too small for the driver. I want / need 14l for the ER18RNX I was going to use. Still haven't decided.

Hertz are one of the good ones and provide the parameters for the driver; feeding this into WinISD gives me a frequency plot which basically says "no bass".
There's no issue with a leaky door, as long as the driver waves are isolated from the other side of the baffle, so the surface to which the speaker driver is attached.

Screenshot of the frequency plots: https://1drv.ms/u/s!An0o3gFKDv-ZhGUK1_gWM1JNDspK?e=rG55nR
Pink plot is box of over 140l size, and from there there's not much difference to infinity in the plot.

They're both with an approximate filter to deal with the cabin gain of the A2, which I'm assuming starts at around 57Hz due to the size of the cabin vs wavelengths. That, if you're interested, is a Linkwitz transform, with 57Hz as the starting point, and a Q of 0.707.

- Bret
 

Olerype

Member
Forget Bose.

You can come a long way simply by removing all bass from standard doorspeakers and add a separate subwoofer. A separate amplifier for the standard door speakers would also be beneficial. Much easier and cheaper than retrofit Bose also.

 

bretti_kivi

Member
so let's go back to basics.
Sound is made of different frequencies and it is transmitted as a wave.
The speaker driver makes those waves (generally) by moving a cone forwards and backwards at a frequency corresponding to the note. The size of the movement dictates the volume / amplitude of those waves and therefore the "loudness" of those sounds. We also don't measure these things linearly; decibels, the unit of loudness, is a log scale. So 10dB more is a doubling in loudness. You'll also need an order of magnitude more power to achieve this, so for a 10dB increase you'd need to up the power from 1W to 10W. Or from 200 to 2000W. Most of the time this isn't really relevant as you're listening at low levels. Your standard radio probably puts out around 14W per channel.

So if you have a specific, pure note, like an A on a piano; that's 440Hz and so the loudspeaker cone moves back and forth 440 times per second to make that sound available to your ears. It is made by pushing current through a coil which moves the coil in relation to a magnet. The amount of current pushed through dictates how much it moves and how fast the current alternates dictates the frequency,
There's a few obvious things when we start thinking about this: one is that lower sounds have lower frequencies, but our hearing isn't linear; two is that more air takes more effort to move. Also: the size of the speaker cone kind of dictates how high a frequency it can cover, and the way it's put together defines its ability to move easily - there's the surround holding the cone itself to the basket of the driver, the driver material itself, and then there's all the magnets and coils involved. These can all be tweaked for different use cases. More on that later.

The fundamental, though, is that a speaker driver is just moving air. And therefore, the first thing you need is seperation between the waves at the front of the speaker driver and the ones at the rear. Otherwise you're not going to hear very much as the waves will cancel each other out.

So the use cases for any particular driver could be one of three options: you've either got a sealed box, a leaky box, or a ported box. Drivers can be optimized for one of these and trying to use it in something else is silly unless you're deliberately trying to do something specific.
These boxes mainly have an effect on the bass response of the speaker; but remember that the car *itself* is essentially also an enclosure. This leads to something called cabin gain, and you'll get it in rooms as well. It has to do with the dimensions of the space and the waves that actually fit into that space. Anything that doesn't fit gets amplified. There's other effects on bass, too, mainly involving flat surfaces in front of, behind and maybe even next to speaker boxes - if you put a subwoofer facing the wall, you'll get different bass effects than if you put it in the corner (more bass there!) but it might be boomy at specific frequencies. This will be to do with the environment.
Back to the car: most car-specific door drivers are designed to work well in a leaky box, as that's generally what a door is. There's some air movement towards the outside world (drain ports) but the space is mostly sealed. So a driver that works well in anything above, say 14l or so, will probably work well in a door.
The thing is, though, that those drivers are of a limited size - call it 165mm for argument's sake - and that's not really compatible with loud volumes and nice bass. Why? because you're trying to move a lot of air with a relatively small driver.
If you've got a sealed box of a good size, a driver designed for that will sound nice and punchy with crisp basslines. If you decrease the size of the box, the bass response (so how low it will go) goes down and there will be a peak somewhere. If you increase the size, your bass may get better or worse again, depending on what the driver was designed for.

What Bose did and does is to tailor the response of the system to the car. They've analyzed the car and added some correction in to the amplifier, so running their system sounds better than stock. Whether it's good or not is another person's call. The thing is, they've taken into account *everything* at that point - the attributes of the drivers they use, the response of the subwoofer in the boot, and the frequency response which is delivered from the radio itself. This is all then hard-wired into the amp. I'd suspect also the "bass bump" at around 60Hz or so - it's only a 6" sub, which can't do much but if it's tuned this way, it would appear people prefer the sound as it "feels" like "more bass". (See this if you're really interested, page 5) They also use lots of tricks with driver impedance to improve headline power output while not really doing much on the electronics side (for a given load, 200W into 0.5 Ohm is similar to 100W into 1 ohm, 50W into 2 Ohms or 25W into 4 ohms.. which is about double the power of a standard 12V DC radio amp, so therefore you're getting about 3dB more output, possibly).

A better way to deal with this is DSP (digital signal processing); something like the C-DSP 6x8 isn't expensive (€250, I think), and it allows you to compensate for a lot of the issues inherent in cars. But even that's not perfect - you can polish a turd, if you really want, but it's still polished and it would be better to have a potato first or better still some aluminium to try and polish or you might be disappointed.
@Olerype is correct; removing the deep bass from the doors is a good way to stress the drivers less and it will sound a lot more effortless and clearer as a result. Putting this to a sub, driving those big waves from a big driver (most subwoofers are 8" or larger) is worthwhile.

But then we get to stereo - and there's only one sub, right? Yes. B-ut humans don't really appear to be able to locate low sounds, so up to about 150Hz or so, it doesn't really matter where the sub is and that there's only one. Yes, it can be found if it's too loud, but that's a different problem. Remember the idea that the driver's producing waves of sound? it's much easier for the higher frequencies and hard for larger diameter drivers to reproduce those - so this is why we get tweeters with really small diaphragms for the high stuff. If you listen carefully, you'll hear how little is generally coming out of them, but it's really important for lots of stuff, mainly "air" and spatial cues. The midwoofers in the doors are dealing with pretty much everything else, but they are also designed for a specific size of enclosure and without that, you'll get strange results. The plots above reflect a box size of 3.5l vs much larger. How did I calculate this? All of those parameters I spec'd earlier: the connection between cone and basket, the power of the magnet, the size of the driver, how far it can move - these all have standardized measurements, called Thiele-Small parameters. This will essentially tell you how the driver will behave in a certain type of box of a certain size; there's software for this, such as Bassbox pro, WinISD and a bunch of others. There's some seriously complex stuff involved in horns, which is why I haven't touched on them here.
So with those parameters - which some companies provide - I can model the different response of the different boxes. I have a CSS SDX10 waiting for transplant into the car. That has parameters for both sealed and ported boxes, and I've just built a 20l box which will fit nicely into the space next to the battery, sticking up a little (so I will lose the carpet). I've modelled that with lots of different boxes and this is the one that fits and seems good.
The filter I used simulates cabin gain; 57Hz is taken from the longest measurement on the inside of an A2 which was 3m something. Anything lower than 57Hz has a wave which doesn't fit and therefore gets amplified.
Additionally, a whole bunch of road noise happens at around 125Hz - and to compete with this, you'll notice GALA really amps up the bass as you drive (try turning it off in a trip and then back on again and listen for the difference!). There's also the problem with reflective surfaces all over the place - glass is bad. The sound in a car without an OSS blind is very different to one with it.
You also need to take this into account when positioning tweeters; I've wanted to put mine right at the corners of the windscreen, on both sides. But I'm hesitant to say it will work well, as there's a great big funnel and that *will* affect the sound, just like listening to speakers placed on a desk will change your perception of treble and bass, because that sound is being reflected around. Your preference is good, here, but I think it's important to understand what the speaker designer was intending to do.
If OP is happy with the sound in these enclosures, great. I simply intend to explain some of the thinking I've used in the past when I rejected the same idea.

But can't you fix all of this stuff with DSP? Sort of. Any processing introduces delays, so it's best to get it good before making it better with DSP.

A quick coda on the subject of bluetooth speakers and "How do they sound so good, then?" Solid enclosures, specifically designed for drivers; use of passive radiators instead of ports and a certain amount of DSP on-board. Add a bass hump, and I think that's most of it. For some entertainment and talking at least a little about how these are wee miracles, I can recommend this video.


- Bret
 

Olerype

Member
The Bose subwoofer is not 6” but 4,25 or 5,25 do not remember. The Bose driver itself is a joke with a small magnet and pressed steel of cheapest material. Guess the cost from China was £1. The only interesting part with the driver is that I suspect its impedance is as low as 1ohm, and that the driver is placed in a bandpass enclosure.

The Bose setup is therefor made with alot of compromizes. And at speeds above 40-50mph the subwoofer output is insuffient (due to wheel noise). There is also very few adjustments possible (no xover adjustment, individual level etc)

Remove bass from door speakers below 50-70hz as my experience is that from +80hz you will be able to pinpoint the location of the subwoofer.

Many years ago I had two Boston Acoustics Pro 10.4 (later 10.5). Each in factory recommended enclosure of 0,5 cubic feet (14 liters). Physical bass down to 20hz from a 10” and excellent sound in the Golf Mk2!

501C548A-7FCB-4A33-80A5-09A7F7E79215.jpeg


29E0C4BB-A6E4-45AF-ADBC-F8DBB344D5BD.png
 

maxufeiss

Active Member
1. You can't easily decouple or fix the door card against the secondary enclosure.
2. The enclosure size is too small for the driver. I want / need 14l for the ER18RNX I was going to use. Still haven't decided.

1. Enclosure will be put firmly in space available in door. Door card will attach directly to enclosure, you can even see places where plastic rivets will sit in. Short blacks screws should do the trick without being too noticeable. Aluminium part will need modding, but will attach to both of them. Probably some tape too to avoid any places rattle could form. Even the speaker will go in so the door card will sit between enclosure and speaker.

2. It is. And there is practically nothing to do to make that reality disappear. Without this box there would be even less volume, but it would be leaky. Leak is not large enough to translate entire door volume to usable volume. And then there would be leak to deal with, outside and inside. Door, middle layer and inner card all are pretty thin and for best performance would need heavy isolation.
At first i even thought to use space between handle and speaker location, but that would mean even more work and destruction. Removing bin etc was also discarded. So i used what i could without going too crazy with it.


But hard sealed box with powerful speaker enables lower bass at the cost of equalized power needed. And if it is not achieved, then adding subwoofer is way to go, turning off some bass from fronts if needed. I'm not very heavy on bass, but i don't want to lose vocals and other lower middle sounds these speakers should provide... Fs is kinda high for small sealed box, but same time vocals should be good. DSP would be good, but probably can live without it. And even when sub will be planned, i'll try some magic to not lose usability of car.

BUT... i'm not an sound engineer and there is possibility it turns out as disaster :D

Edit:
need 14l for the ER18RNX I was going to use
google refers to Seas speaker. Probably even larger feat to overcome, since it seems to have even larger magnet + basket (or spider or whateva...). My speaker is practically against wall, wall is around 1cm near door strap and outer ring as low as can really.
It has low Fs, but given same box size (3,5l) it will only produce 2db louder bass and lose 1db little bit higher. 2,7l box for that is like 3,5 for my speaker. That should be easy for EQ to correct.
Stepping up to 14l for seas gives it almost 10db edge over my woofer in 3,5l box in very low frequency range, so i need 8 times more power for same result if i'm correct. Given my speaker the same 14l, then 2x more power is needed.

But i'm not even sure if i inserted numbers correctly and if calculus is sound...
Black for my speaker 3,5l, green 14l.
Blue seas 3,5l, red 14l.
WpC7tDq.jpg

Whatever the case, i just don't see where that 14l could be obtained in door without massive leaks. So i'll opt for sub if needed.
 
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maxufeiss

Active Member
Today's result:
Added something inside box, amount as by gut feelings dictated.
ky7gRqn.jpg

Adding wires was good idea and after that front went under glue.
le0JlOx.jpg
Tweeter went into factory location, grille not removable without proper tools at least ;). Randomly screwed that in...
9zPPwN6.jpg

Factory grille over it, will see if someday find alternative solution or leave like that. Not liking idea of double grille.
iMa5BXa.jpg

I can hear oem screams:
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Better?
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At the moment something like that will be seen:
JABy2hu.jpg

Not the best thing to look at, but will do for moment (or forever):
NPitoXV.jpg

My overcutting got it's revenge, tried to smooth thing out but whatever... better to leave room between grilles. Might redo or modify later if i care enough.

Edit:
Box weights 2kg total, some weight was lost cutting inner door panel, some will be lost from aluminium piece, factory speakers weight probably half of new speaker set... so around 2,5kg added? Good sound deadening with new speakers will weight nearly same (guessed by my uninformed self). I'll do some of it too, but i don't need to worry about sounds generated by speaker, since it is closed off. So outer skin only or partial treatment, will see....
 
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maxufeiss

Active Member
Well, did some listening with speaker in enclosure but without door card. Should not matter much since it is a closed system.
Faded between standard left and my enclosed right. Mixed results. And i'm probably little biased by wanting it to be good :D

Bass is pretty much gone as suggested. Leak to outside is pretty much gone too.
Sound is much clearer in many frequencies and gained higher frequency range that simply does not exist in standard speakers.
Might need to rip some sound treatment out of box, somehow feels like that. (Like when listening high quality speakers and something feels missing, but is there on crappy speakers sometimes.)

Some bass is recoverable by equalizer settings but it seems subwoofer has to be planned too. Have not connected amp, so only power available was from head unit, and that was not enough for this speaker to shine.
I could regain access to door card volume by chopping off part of wood where standard door has leak room, but that would introduce back the leakage to outside and inside. Inside leakage seems to be good in this case, since by my observation one of reasons why standard speaker makes good low bass is door card acting as passive radiator + added volume... But i don't know if i want it to leak outside so much. And there would be probably massive rattles to deal with.

Standard speaker seems to be over limit when new speaker starts to slowly come alive. So i'll need to deal with amp before and then will see what changes...
Adding sub would eliminate need for them to produce low frequencies. But going by that logic, should have opted for smaller speakers from start.
(Then there will be easier option to disembowel original speaker, somehow fit 130mm or something inside, heavy sound damping + leak killing inside door where i made my box to fit and result would be nearly same as making box, if not feeded by low freq sounds. Result would stay oem look and even better vocals maybe.)

There is also option for adding bass reflex tube, but don't know if that would increase lower bass or something, that would need be tuned and calculated.
I know that my A8 Bose has similar box inside front door but with bass reflex tube and smaller speaker, so the idea of making enclosed box is not new to people who design these systems. And it probably is not feeded by very low frequencies anyway, need to listen it closely maybe. Probably has some speaker with low Fs if it has some bass too.
5pJVEB5.jpg

Well, need to copy some songs to SSD and do some more listening, thinking and equalizering...
 
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maxufeiss

Active Member
I realize that it's like Bose men knew what they were doing on A8... Surprise surprise :D

After playing around with software and some thinking in my head i realize that shoving MP165.3 in front in sealed box is pretty pointless after all. All i gain is slight upgrade to max power that i don't really need. There is quality upgrade when compared to stock (minus bass that is mostly lost). Amp can revive some bass but probably insufficient if you want to listen loudly. Maybe near oem lower ranges with much more power. Still need to wire amp for testing.

If sub is already needed, then much smarter option would be to use that 3,5l of space for any 130 mm offering. Less hassle and retained OEM look.

Best thing would be to convert box to vented, using 130mm Hertz MP130.3 as a driver. Kinda like A8 has... (or scrap box and try massive sound insulation in door cavity, plug leaks and introduce bass vent somehow in there, attach 130.3 somehow). Then use sub to take job over at around 80Hz.
Red graph for MP130.3 in vented 3,5l box:
W4NIHQt.jpg

And then there is option to scrap sealed idea, make good sauna from leftovers, introduce holes back to leaky areas and try to deal or live with those leaks. But damn that leaking is annoying.

Enough learning for today, need sleep to rearrange thoughts. ;)
 
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maxufeiss

Active Member
Well, sealed box was flawed (dumb) idea in this configuration. Lets be friendly and pretend it never existed. While i still think that's the way to go if i want to limit noise going outside and would work fine with proper sub, it is not an easy job to get it right if bass reflex is involved etc. Did not think any good way to get decent sub in there without downsides to usability.
So after some pondering and deciding to open up the box, there would be other problems to tackle if the box stayed.

Therefore box idea is scrapped altogether and decided to go more traditional route of making adapters from original speakers. Then i can also educate local people more about this fine car existing, since they might notice loud music coming out of it. They might be even pleased with my fine taste in music.

Goodbye to original speaker, don't like to break functional things, but here we go:
jAGole7.jpg

Audio fans screaming in horror:
zo2SRyo.jpg

Oh darling, would you look at that... It fits:
mNEijcC.jpg

SeTW8XV.jpg

E3RZJDC.jpg

Some of that plastic came off more afterwards, but something like that:
m0BNTZy.jpg

GryXZKm.jpg

0UKf6oi.jpg

5yd21aK.jpg

And glue added:
vFXWhsC.jpg

Did try 3 different glues and from what i bought this seemed to stick best to both materials. Locktite Power Flex Gel. My faith into glue is somewhat limited, but given contact area and having sideways contact area too, it might even hold.... probably will try to melt some plastic inwards too on top rim just in case, or add more glue....
 

bretti_kivi

Member
this should be pretty good. I'd butyl the outside of the plastic if you can...pretty much everywhere except the top where the door strap gets really close.

- Bret
 

maxufeiss

Active Member
Covered hole with fiberglass, using same superglue, afterwards added second layer with regular stuff for fiberglass, but that wont stick to plastic well. Since it's main reason was to seal any air gaps and probably sticks to first layer, i left it like that.
hlGWiAG.jpg

Wires added, and here you can see backside with rest of plastic removed, it was not glued there very strongly, so off it came.
0YMNViF.jpg

One sheet (750x500, 5cm grid) gets that much covered:
jogsCdq.jpg

Little more from second sheet, since there seemed to be enough room for it and good place for noise to enter:
L3zOBZy.jpg

Little bit felt to limit reflections:
qyPD9cC.jpg

Added additional screw under door strap (and put back holders that hold door panel afterwards)
(Had to remove around 2mm aluminium under upper hole for magnet after picture was taken, other side fitted normally):
GhX78Cj.jpg

Unmolested door panel on other side:
BfoxZk3.jpg

OJSG8rZ.jpg


Seems that slight modification is still needed, speaker movement is pretty large even without amp. But nothing that would be visible. Little bit more clearance so rubber would not be so close to door panel.
Discoloration comes from learning that superglue fumes like to find every bit of moisture there is, even slight touch with "dry" hand at rubber will be visible afterwards. Probably should have covered all of speaker top, lets hope the fumes did not alter rubber too much. Since glue is for rubber too, should be safe. For show stuff this would be really bad, but my ears don't have eyes. Will be smarter next time. Photo looks worse than reality.

butyl, plastic, door strap
There seems to be enough room on top too. Will get to that eventually.
 

Jeetesh

Member
If anything I admire the effort for the pursuit of sound perfection.

If it can be achieve without spoiling the OEM look then even better 👍👍
 
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