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I'm running an old school Alpine MRV-1505 2 channel amp, I'm thinking of running Kicker CompVR 10" subs in my trunk. I don't want to go any larger because I'm tight on air space. I've calculated enough airspace for these two subs, I'm just curious is I need something stronger for subs or will these match well with this amp?
-TheImpalaMan
http://narbi.free.fr/manuels/Amplis/Alpine/MRV-1005.pdf
They should work okay - the amp is rated for 900W RMS bridged at 4-ohms at 14.4V and 600W RMS bridged at 12V - however, it only has one 80A fuse, which implies it would do about 550W.
It will work for the 800W RMS subs whether it is 550W or 900W, but I'm not sure what power to realistically expect out of it.
Be sure to get the DVC-4-ohm CVR subs so you can wire them for 4-ohms at the amp and bridge the amp.
Hope This Helps!!!
Anyone else have suggestions?
2002 Ford Focus JVC KD-A815 Sony CDX-GT410u Sony XT-100HD HD Tuner Stock speakers, no amp, no subs
I did get the DVC-4-Ohm CVR 10" subs and they work well. My power wiring is solid, I'm running a 200amp alternator along with an Optima Red-Top battery. But I think I'm still going to have to add a capacitor to the system. Whenever the bass hits, the voltage drops at the amp down to 11-12 volts. As far as my wiring goes, I'm running a 0/1 gauge power wire from the battery to the trunk which hits a 3 way distribution block. From the block I'm running a 4 gauge power wire to each amp (2 amps total) along with a 4 gauge ground for each amp running through the trunk floor to the vehicle frame.
Any suggestions on the size/brand of capacitor I should get for the sub amp? Or should I get one for both amps? Thanks in advance for any helpful info.
Generally rule of thumb for the capacitor is 2.0-F per 1000W RMS of subwoofer amperage. More won't hurt but will cost more, less could be more strain on the electrical or not fully solve the problem.
TheImpalaManMy power wiring is solid, I'm running a 200amp alternator along with an Optima Red-Top battery.
Have you upgraded your Big 3 wiring ?
Yes, I had a custom battery harness made when I got the 200amp alternator.
The positive battery harness has 0/1 gauge wires going to the starter and alternator with a 2 gauge wire going to the underhood fuse box.
The ground battery harness has 0/1 gauge wires going to the engine block and to the vehicle's frame with a 2 gauge wire going to the body.
Top terminal harness made by innovativewiring.com.
So now I'm shopping around for a 2 fared cap...any suggestions?
Are there any caps out there that you can dial in the desired voltage to the amps? the Alpines I'm running require 12 volts, but provide better wattage at 14.4 volts.
Thanks for the info so far everyone....good stuff here.
TheImpalaManSo now I'm shopping around for a 2 fared cap...any suggestions?
TheImpalaManAre there any caps out there that you can dial in the desired voltage to the amps? the Alpines I'm running require 12 volts, but provide better wattage at 14.4 volts.
Stinger did introduce a 16.8 volt alternator and a corresponding 7 cell 14 volt battery, but the whole idea never caught on and probably caused more problems than it solved. the batteries looked pretty cool, tho.
the cap will have approximately the same voltage as the voltage feeding (or coming from, when the engine is off) your battery. there is no adjustment possible, whatever voltage it gets, it gives. good news is, you're probably close to 14.4 volts anyway whenever the engine is running (i'd say 13.8V is about the a minimum expected in a healthy charging system).
basically, they give 2 power ratings to reflect the difference between engine running (14 or so volts) and engine off (12 or so volts). if you play the amp(s) with the engine off, they will run off the battery (typically 12 to 12.5V) rather than the alternator (typically 13.9 to 14.4V). with your wiring upgrades, you will most likely be at the higher end of the 13.9-14.4V range. alternators must have a higher potential (voltage) in order to charge a battery. 14.4 is kind of an industry standard, but your alternator's output may vary and that's normal.
J Ro,
I need a cap because while the vehicle is running, and the bass hits, I measured just under 12 volts at the sub amp. The lights dim, etc. When the stereo is off and the vehicle is running, I get a solid 14.4-14.6 volts from the alternator to the battery. From what I've read, a cap will prevent the rest of the system dropping voltage when the bass hits. My original goal, when doing the alternator and wiring upgrades, was to prevent having to buy a cap. But the Alpine is just drawing so much juice that the rest of the system suffers. I would get a second battery, but don't want to add much more weight to the vehicle.
that seems extraordinarily odd to me. this problem may be explained by a weak connection somewhere between the amp and the battery. a 600 watt amp should not be dropping the voltage so much (i've got a 900 watt amp that can barely flinch the voltage with the stock alternator in my Scion... it's class D, but i'd say that's approximately comparable). MECP guidelines are there should never be more than a 0.5V difference between the voltage measured at the amp terminals and the voltage read at the battery terminals...
that being said, it's pretty easy to isolate whether the vehicle's charging system (alt and batt) is the problem or the wiring is the problem. take your DMM and measure the voltage seen across the battery terminals during periods of high bass demand. are you getting a similar drop in voltage?
a more direct way to measure voltage drop is to do the following:
to test for voltage drop on the power connection, connect one probe from your DMM to the positive battery post(you might use a set of jumper cables as an extension)and the other to the positive input on your amp. note that you are not using the negative at all, because you are measuring the difference in potential from the battery to the amp. this is only a check of the wiring and the associated connections. set your DMM to DC 20volt if it is manual ranging. with the amp playing loudly, the DMM reading should not exceed 0.5 volts. if it does, you have a problem with the power lead. to check voltage drop on the grounds, move the probes to the amplifier ground and the negative battery post, or a known good ground on the chassis. again, a jumper cable is handy for extending the leads from the DMM's probes.
I will run these tests when I get home and let you know the result. I do remember testing the vehicles voltage from the battery to the amp and there was a .2 voltage difference from the measurement at the battery and the measurement at the sub amp. I will post the results after the testing this evening. Thanks for the help.
you've already done this check??? i'm rather impressed...
well, due diligence is called for, so do it again for both the power and ground in the manner i've explained. with all that copper, i wouldn't expect it to be a wiring issue, but it's something we have to eliminate before going into deeper diagnosis. be sure to check both the POS and NEG wiring individually.
thinking on it some more, you didn't say you did the check during periods of high demand (loud bass playing). maybe you did, maybe you didn't, but this check doesn't mean much if you simply turn the key... you've got to play some hard rock or some other bass-heavy music (a test tone would be preferable) for it to really mean anything.
Using your advice, here is what I tested.
car off - Battery only Results = 12.6v
car off - Probing amps power/ground at amp connection Results = 12.4v
car running w/stereo off - Battery only Results = 14.4v at idle
car running w/stereo off - Probing amps power/ground at amp connection Results = 14.2v at idle
car running w/stereo on with heavy bass - battery only Results = 11.8v at heavy bass load
car running w/stereo on with heavy bass - Probing amps power/ground at amp connection Results = 11.6v at heavy bass load
Now i broke out the jumper cables and connected the positive to the battery and ran the jumper to my trunk. With the car running w/stereo on with heavy bass.
Results = between beats I got a .4v difference - during heavy bass I got a 3.4v difference.
With the vehicle turned off, I checked the continuity of the circuit using the jumper cable on the positive of the battery. The DMM probes went to the jumper cable while the other went to the battery connection on the amp.
Results = 0.2 ohm (that connection should have tested the entire lead circuit from the battery to the amp.)
With the vehicle still off, I checked the continuity of the ground circuit by placing the jumper cable to the negative of the battery. The DMM probes went to the jumper cable while the other went to the ground connection at the amp.
Results = 0.2 ohm (that connection should have tested the entire ground circuit from the battery to the amp.)
Let me know if I missed something. Thanks again :)
J Ro
I can take pics of the setup if you'd like and post them if I can. Let me know.
TheImpalaMan Now i broke out the jumper cables and connected the positive to the battery and ran the jumper to my trunk. With the car running w/stereo on with heavy bass. Results = between beats I got a .4v difference - during heavy bass I got a 3.4v difference.
this is not good, not good at all. 0.5 volts is acceptable. i don't know if you tried the same thing with the ground, but a 3.4V drop indicates a problem with your power wire. now it's not necessarily the 0/1 wire itself, but it could be if it has become oxidized (rusty). more likely, there is a weak connection to your distribution block, the under-hood fuse, or to the battery terminal.
the impedance check (0.2 ohms) is a little less telling, but also higher than expected for a 0/1 gauge wiring run. try an impedance check on either side of each connection (touch the probes of the DMM to the input and output side of the distribution block, the under hood fuse, and the battery terminal connection. all should be approximately zero). i'd wager one of these is the source of a 0.2 ohm resistance.