View Full Version : Added an amp for the new type-R
04-11-2012, 08:06 AM
Just got my Alpine SWR-12D4 sub and power distribution blocks so it was time to add on to the amp rack. I'll apologize in advance for the lack of Excile audio in the system. lol. First rack I've done but think it turned out pretty clean.
Maybe tonight I'll do some box building.
04-11-2012, 09:26 AM
I am concerned about the stiffening capacitor in the context of a boat. Here is why. Normally a cap is used in a daily driver where the cap is always connected to the battery supply and is always charged. Caps come with a resistor so that you can slowly charge them at the initial installation. In a boat you are disconnecting the cap from the supply with each and every storage event and then violently introducing the discharged cap to the supply. This results in eventual but certain damage to the cap which in turn makes it a distinct liability to the charging system rather than an asset.
Also, keep in mind that a stiffening cap can only prop up the voltage for a fraction of a second at a maximum level equal to but no greater than the voltage of the supply (battery or battery/alternator). It cannot raise voltage or even sustain voltage past a brief transient. So it's not solving the primary supply challenges associated with boating.
However, if you want to keep it, then add a bypass switch plus the appropriate resistor value and slow charge the cap before each re-connection to the supply before each outing.
you da man
04-11-2012, 10:25 AM
^^^ yeh, what David just said lol. Great, free advice for you.
04-11-2012, 12:03 PM
Interesting... thanks for the response. I left the cap in the system as it was wired in from the original owners installation, guess it's just window dressing. If I understand you correctly, as long as it's attached to battery all the time it shouldn't be a problem once it's charged and hooked back up? I understand that I'll need to discharge and recharge before and after winter storage. I do not disconnect the batteries during the season as we use the boat about 3-4 days a week on average. On the charging/discharging side of things, the manual references a bulb supplied for this process. As I am not the original owner, I have no such supplied part. Any suggestions on how to do this (resistor) safely? Not sure what size would be adequate. Other than that, would there be any other concerns? I was really only worried by the grounding part of the system but thanks for adding to my concern.
04-11-2012, 02:43 PM
A bulb or resistor serves the same purpose as it allows the cap to charge slowly. The value would be roughly the same for all caps. Although very small, a cap always pulls a bit of current to keep it charged. But it is still parasitic so I would disconnect it when in long term storage. 3 to 4 days doesn't sound like a major concern. There's nothing like measuring the voltage before and after the 4 day span. That will clear things up for sure. The capacitor needs to be as close to the amplifier primary terminals as possible in terms of cable length and number of connections so that is another reason why it's impractical to have it on the battery side. Personally I would remove it because I do not believe that you will hear an audible benefit in your particular situation. But if you satisfy this dis/charging issue then it really can't hurt you.
04-11-2012, 05:28 PM
Thank you for that info. For the moment I believe it'll stay the way it's set up as I'm anxious to have it all back together by this weekend. When i get around to building a platform/moving the batteries forward and off the ground for storage purposes I'll look at re-wiring as it'll be needed at that time anyways. Hopefully this won't cause any other issues as the system already includes a second battery and switching relay. As for the wiring, there is direct power feed from cap to soundstream amp that is less than 1.5' in length. I believe the longest run of any of the power or ground wires in this setup is about 18-20". The grounding concern stemmed from mixed diagrams I've come across. Some show the amp grounded back to the cap then cap grounded to battery, some show distribution blocks. The above has each amp and cap grounded back to distribution block then block back to battery. That should be the last question. Thank you again for your help and when I look at stepping up to play with the big boys I'll make sure to give Earmark a call.
04-11-2012, 09:23 PM
All grounds are common so none of your schematics should be in conflict. It is true that both the pos. and neg. terminal of the cap should be very close to the amplifier primary terminals. Source electronics should reference their ground closest to the other components in the signal path rather than the battery IF the battery(s) are a great distance from the amplifiers. If all are in close proximity there isn't much of an issue. It's important that the cable gauge is large enough to have sufficiently low resistance to nullify the high current components from modulating the supply of low current components and eliminate most sequencing concerns. Keep short direct paths when possible. And that is about it.
04-12-2012, 08:03 AM
Thanks David it's been both helpful and informative. Gauge should be good as I'm not running anything smaller than 4 in the above picture. The main power and ground to the block are actually 2.
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