I'm going to start a project

[Boarder]

That's what I thought but AC is going to push AND pull won't it? Only DC will have polarity.

[Bitter]

16 hours ago, Unimportant said:

That JL300/2 is a standalone amplifier, most of those indeed have the necessary voltage booster on board to deliver the claimed wattages. However; we're talking about a plain head-unit here, and a cheap one at that. I have never *EVER* seen a headunit with a voltage booster on board for the amp in over 40 years, not even the expensive ones. 

Without it, the best you can muster is 4.5W RMS single channel or 18W RMS bridged on a 4 ohm speaker with a 12V supply, that's just math. Class D or not does nothing to help in this respect. So the numbers on all those headunits are meaningless peak values or just lies.

 

Now, that does not mean it won't be loud. The problem is audio amplifier output numbers have been exaggerated for so long (I remember tiny PC speaker sets which claimed 300W P.M.P.O - Where P.M.P.O is yet another bullshit metric - they were really 1W RMS) that most people can't imagine how loud a few real RMS watt's can be (very). But that is another issue.

So every one, Kenwood, JBL, Sony, Alpine, etc are all in a conspiracy to lie when they say 18-20W RMS per channel? I don't have a working non OEM head unit laying around to measure the output on, but I find that hard to believe. What about the CEA rated units like the Pioneer AVH-290BT, 14W RMS per channel by 4 channel at 1% THD, that's a bit more than 4.5W per channel. Clearly most are being rated at higher THD like 5% to inflate the RMS wattage numbers, but even so most are in the 15+W range.

[Unimportant]

7 hours ago, Bitter said:

So every one, Kenwood, JBL, Sony, Alpine, etc are all in a conspiracy to lie when they say 18-20W RMS per channel? I don't have a working non OEM head unit laying around to measure the output on, but I find that hard to believe. What about the CEA rated units like the Pioneer AVH-290BT, 14W RMS per channel by 4 channel at 1% THD, that's a bit more than 4.5W per channel. Clearly most are being rated at higher THD like 5% to inflate the RMS wattage numbers, but even so most are in the 15+W range.

18W RMS is the max. possible with a 12V supply and a 4 ohm load with push-pull as I've already said multiple times. So if Kenwood, JBL, Sony, Alpine, etc output 4 push-pull channels (simplified: 8 channels internally bridged to 4 outputs) then yes, they can do 4x 18W RMS. However, you can't bridge them again after that. You can't "bridge a bridge". 18W RMS is the end station without boosting voltage.

 

Most head units have claims of 4x50W or even higher ridiculous numbers written on their front. Those are useless peak values that can be massaged any way they like.

 

Since the OP says he's going to bridge his outputs that implies his head unit has single ended outputs, otherwise you would not be able to bridge them externally. So he has max. 4.5W RMS per single ended output and if he bridges 2 outputs he's got max 18W RMS. That's a far cry from the 120 Watt per channel the OP was hoping for in an earlier post - That is all I'm pointing out.

 

But again, 18W RMS can be plenty loud.

[Bitter]

Ah I understand now, actually 8 channels and some fudge room for THD with the ratings.

[Boarder]

18W RMS per channel is plenty. I'll be happy with dat. 

 

At listening level it should be hi def.

[Boarder]

Talk about brain racking looking for a decent set of speakers on a budget. I thought I had a set but after plowing through dozens of models on Amazon I finally found a pair. I'm going 6.5" instead of 5.25".

 

https://www.amazon.com/Skar-Audio-RPX65-Coaxial-Speakers/dp/B01BFK1X4A/ref=cm_cr_arp_d_bdcrb_top?ie=UTF8

 

 

 

[Bitter]

Coaxial? I see room for tweets.

[Boarder]

They're on the speakers.

[MrJoosh]

On 4/26/2019 at 2:36 AM, Boarder said:

They're on the speakers.

They are, but component speakers are always better than their coaxial counterparts...

[Boarder]

They are but these speakers are going to look cool. 

 

Out for delivery today. 

[Boarder]

They're in and I see what you mean about the cage. It's separate from the housing. I didn't know they separate.

 

Here's the stereo:

 

 

Here's the speakers (showing one):

 

 

The PSU:

 

 

Some tools:

 

 

Let's see how it fits:

 

[Boarder]

Bench tested.

 

 

[Boarder]

So far today... still working.

[Boarder]

Painted!

Let's see how it look installed. It's a coincidence that the paint matched the cones of the speakers.

Cutting a straight line with a dremel is tricky even with the guide but by the time I cut the bottom part of the hole I got the hang of it.

[Bitter]

You can secure the radio 'cage' with some L brackets and rivets so it won't wobble around inside the box. Also baffling the inside so the two speakers are separate will really improve the sound quality since playing in stereo may mean that the two speakers aren't playing exactly the same things at the same times and may be cancelling each other on their back sides.

[Boarder]

Glue works. 

[Boarder]

Nearly finished. Waiting on the antenna cable before I can close it up but here it is.

 

 

[Boarder]

After a couple more mistakes I'm finally done! 

This radio pulls in stations that's out of town so it's weak and mostly static.

 

https://www.youtube.com/watch?v=NyEVRb4mcLc&feature=youtu.be

[Boarder]

Just got a Mahogany panel. Same project but with new stereo and speakers. 

[Boarder]

Forgot the pics: