Car audio build... pic heavy!

[Dumdum]

Bit of an update, I’ve mainly been spending my time doing a team members car, making the wiring neat and tidy, giving him something to look at and make his jaw drop...

ill just post pics, all rcas are home made from vandamme cable and rean rcas with a liberal coating of techflex

 

[Dumdum]

 

[Chrise36]

the top of the line focal amps are 3-4 times cheaper than the zapco ap range (the above amp is just shy of $2k I think in the states?) so I definitely would’t compare the two, (perhaps the zapco st-4/6sq maybe) but saying that I’ve never heard the focal, but I have heard the zapco and put it in the top tier against amps that cost twice as much if not more

Nice amps but too expensive in my opinion.They look a lot like DLS amps probably from the same factory.

 

[Dumdum]

Nice amps but too expensive in my opinion.They look a lot like DLS amps probably from the same factory.

Depends what you paid for them and not really any cheaper or more expensive than top of the range dls, as for where they’ve been made I couldn’t tell you, I know they are pretty damn good quality and have excellent staging and imaging for whatever reason

 

[jfetter]

-140db is tough to do with boosted automotive amps. All of the new RnD money must be going into that market segment.
Can you put up a link for info on db Drags?

 

[Dumdum]

-140db is tough to do with boosted automotive amps. All of the new RnD money must be going into that market segment.
Can you put up a link for info on db Drags?

Care to translate what you just said?
Maybe point to what you are referring to?

And if you google dB drag you will find plenty of information

 

[jfetter]

Care to translate what you just said?
Maybe point to what you are referring to?

And if you google dB drag you will find plenty of information

This plot from your pic.
I asked on db drags because I did spend many man hours looking for information a few years ago.
The trade pubs had ceased and it seemed like went away.
But sounds like it maybe has come back.

 

[jfetter]

I'll have to go see the db in knoxville.
No one wears ppe or hearing protection.

 

[Dumdum]

I'll have to go see the db in knoxville.
No one wears ppe or hearing protection.

I’ve listened to a fair few cars in my time, low bass is very different to say midrange frequencys at hi spl, I believe its to do with frequency length and the ears geometry

there are some cars that are comfy the the sense that it can be harder to breathe

when I did spl it was fairly high frequency 72/73hz (in my case, it could be anywhere between 20-80) and it was very much a sealed up cabin with the mic internal and me stood around the back with the stereo in a podium on a lead

 

[Dumdum]

Some more pictures

the roof is a fair bit deader thanks to 10cm strips with polyurethane sealant bonding them to the roof

 

[Dumdum]

The roof then got a layer of sound deadener over it, plus some closed cell foam (basically anywhere that touched and needed decoupling) and the dash sub box got attacked with fibreglass and filler to make it more dash shaped, then refitted to make sure it fitted once more

 

[jfetter]

You probably have checked, use a cheap analog sine generator and slowly sweep.
I was amazed with vibration resonance showin up.
On one MW switching power supply had ferrite beads on some components.
Sweeping they would take off like a tambourine ....
No cure except totally immersing beads in rtv.

Could make the difference between no trophy and first place.

It looking good. Lots of work.

 

[Dumdum]

You probably have checked, use a cheap analog sine generator and slowly sweep.
I was amazed with vibration resonance showin up.
On one MW switching power supply had ferrite beads on some components.
Sweeping they would take off like a tambourine ....
No cure except totally immersing beads in rtv.

Could make the difference between no trophy and first place.

It looking good. Lots of work.

One of my favourite (or least favourite if it’s mine!!) ways to find inadequacy in a stereo system is use an app on my phone which is basically a sine sweep generator, it’s amazing what you can get to resonate with specific frequencys

 

[Dumdum]

As an example of attention to detail, I have wrapped all of the wiring looms where I can get at them with tesa fabric tape, it stops them from rattling, wraps them up a little tighter, a lot of the wiring looms under the dash have the same treatment, there is no place for loose stuff in a car at the level I’m trying to attain, a single rattle will cost me marks and may detract from the soundstage, cable ties and fabric tape are my best friends!

 

[Willem]

What a fascinating alternative universe. I am not particulary interested in cars other than as comfortable and somewhat elegant transport that costs as little as possible. So I drive a very low mileage 1998 Peugeot 406 (2 litre automatic). It is a beautiful car and is a comfortable long distance driver from the Netherlands to places like the south of France, Italy, Kroatia etc, and it has to keep up somewhat on the Autobahn. At the same time it also handles nicely on narrow Italian or French country roads. My luxury was to replace the existing FM car radio with a DAB+ digital radio with bluetooth as well.... The digital radio is a clear sonic improvement and bluetooth is convenient for streaming music from a smartphone. The DAB+ digital radio sounds a bit better than the BT from the phone.

 

[jfetter]

Seems like a variable dc motor operating several Borg/Sunstrand hydraulic pumps out of phase for bass maybe can hit 180-200db. Of course mid and tweeter still electric over electric..

 

[Dumdum]

Seems like a variable dc motor operating several Borg/Sunstrand hydraulic pumps out of phase for bass maybe can hit 180-200db. Of course mid and tweeter still electric over electric..

They’ve now hit 185 with standard speakers... albeit in a highly reinforced ‘car’, when I was competing years ago the scores were just into the 180’s even the one woofer ‘cars’ were just below that point (I have been putting ‘cars’ as they are slightly removed from everyday... think 2” ballistic glass, solid steel box like interiors and the doors bolt shut, effectively a pressure chamber on wheels, there are a few pages of restrictions as to what you can and can’t do still)

 

[RayDunzl]

They’ve now hit 185 with standard speakers...

Do they make shock waves yet?

Saturn 5 night launch

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[Dumdum]

Do they make shock waves yet?

Saturn 5 night launch

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View attachment 60486

View attachment 60487

I think it’s 194 where you get effectively a perfect vacuum on the negative cycle, they will struggle to reach that I think due to cones breaking up, they use carbon and Kevlar sandwiches as cones and big neo magnets to get the motor force up to reach where they are getting to now, plus upwards of 20kw rms per speaker for 5-8 second burps

I used to use conventional paper cones to get to 164’s with 3” 8 layer aluminium coils ferrite magnets and 7-8kw measured per sub, but with neo you can make the motor more open, more efficient at cooling and have less power compression to boot with a 4” coil with more power than I could have got from a single 12v battery (that was one of my classes rules, 800cubic inch battery to keep power limited, god knows what they do now with lithium titanate cells )

 

[jfetter]

Is liquid nitrogen cooling rules legal? The vapor looks 'dangerous' too.
Nice visual.