hey guys i just got some new subs for my car. i used to have 2 mtx thunder 6000 12" with some junk pyrimid amp well the speakers cracked so i just bought 2 rockford fosgate 10" punch 3's. supposedly they are pretty good and the guy from rockfords tech support said don't run anything under the rockford p8002 amp but recommends the 100002 amp. so i'm going to go with the p8002 for now. then i'm ordering my new custom box from a speaker shop they wants 220 bucks anyone build them here for alittle cheaper?

edit: also my other question is should i have a capacitor for this setup? what exactly do they do?

i haven't bought the rockford 8002 amp but the cheapest i have found it was 615 at the local best buy. ikes sound has it for 358.. what is the catch? something that cost that much money for sale for only 358 sounds fishy to me?

 

I bought my amp from ikesound and was very satisfied. They are much cheaper than electronics stores, but there are probably some shipping costs added too. I doubt there's anything wrong with it.

 

yeah i would for sure run a cap if i had those subs. basicly what it does is that when your stereo is running it charges up and when you subs hit hard instead of pulling power from the amp the cap blows all of its charged up power and thus saving ur amp and you battery. it is really worth it.
(Battery - cap - amp - speakers)

 

its common for car audio to be marked up well over 500%. buy it from ebay or ikesound and reap the beneifits

I've ordered plenty from etronics.com, great results, shipping is like 15 bucks

good luck

 

Anyone know what ESR is????

 

clue us in

 

The power that is stored in a cap only last for a second or so and then the cap becomes something else that needs to be charged and starts to bring the electrical system down even more due to this.

Try upgrading the power wire from your altenator to your battery, and the ground from the battery to the engine, and battery to the body of the car. Use atleast 8 gauge, but 4 gauge would be better off.

 

alright cool then i'll probably just go with ikes sound.. one more question is do they have warrenties or can i buy a warrenty rigth from rockford fosgate? i heard if i buy a product of theirs i can buy a warrenty for it incase something happens it can be fixed

 

well I'm pretty sure a capacitor is always a good thing for your car, it levels out the peaks in power surges. your alternator will last longer, plus if you keep the cap close to your amp you will have more instantaneous power for when your amp needs it.

hey needaz, what is a good ESR rating for a cap? I heard a rumor that Lightning Audio makes some okay caps, but I honestly don't know... I'd love to just get some cheap one and toss it in.

 

I bought 2 bp1200.1s off ikesound for around 255 bucks each. The place was ok. Only thing I disliked was they made me email them a picture of my driver license and credit card, before they would ship out my amps. They never mentioned anything about that ahead of time and then they made me wait till I could get the picture to them before they would ship items that had already been charged on my account.

Caps are a "quick fix" method, basically it won't fix any major power drain. LOL, trust me I know I was sucker'd into that hole before I have a 1.0 farad cap on each of my jbls and I'm also running 2 batteries I still drain them both to 9.0 volts in 3 minutes or so of hard thumping. That's also with good alternator wire (0 awg) and 0 awg ground and powers linking up the batteries and with the car running at 2000 rpms with a overdriven alternator pulley.

This would be what I would do: Buy your stuff put it in, upgrade your alternator to battery, battery to ground, and etc when you do your wiring job, and then see if you still have a problem. If there's a problem look around for options.

If you search on the forum here you'll find we all preach higher output alternators because our stock ones put out 105 amps at most (that's at highway speed) so you figure you're only getting 50 amps or so idling for the whole electrical system.


As for ESR I knew the lower the better, but I had to look up the actual meaning (Please don't flame me if I'm wrong about the defiintion).

I stole this from ESR means how well a capacitor passes AC while blocking the DC, and the lower the ESR the better.

 

Lightning Audio caps are suppose to have a low ESR. That's the brand I own basically mine are just a fancy digital read out of volts at my amps still usefull though.

Here I found this in an on-line store selling Lightning Audio caps:

Ultra low ESR < 0.0015 Ohms. +/- 20% Tolerance

So you're talking about 0.0012 to 0.0018 Ohms range.

---EDITED--- for ? answer
Warranties from ikesound.com are normally from ikesound only, due to the fact they are not an authorized dealer on any items. From what I was told when I bought mine. I have the regular warranty that the brand name would offer only I have to ship it to ikesound for claims since it's not authorized dealer they can't give me a direct factory warranty. They said they would still repair or fix it on their own.

 

whoa... the capacitor is NOT intended to increase your battery life, ... its just their to "smooth" out the current draw spikes from the battery/alternator

it can provide a short burst of high-amperage power for your amp, and the idea is that the capacitor will have enough time to charge back up by the time your sub hits again.

you didn't get "suckered" into getting an amp... it helps the charging system out, and can provide a cleaner power input to the amp.

 

The only thing with that kind of markup is the small trinket crap and wire. Electronics and speakers never have over 100% markup, and that's only if the shop is charging full MSRP.

 

I can get the memphis audio 1800D on the net for like $250 after shipping.

every local store sells it for over $1200

what the crap is that? sounds like way more than 100% markup

 

I was really hopping that Jim would chime in on this. Being an engineer I’m sure he would be better versed to handle this question. I just let the Z-meter tell me when it’s to high . It was one of his posts that made me consider this and it’s effect in the mobile audio world in the first place.
ESR= Effective series resistance. (usually measured in m ohms, 0.000.)
ESR is how much resistance there is “in the way” of the electrons to the plates. The lower the better. “If it’s so low, what the big deal?” If we look back at ohms law (E=IR) we can see that at vary high current levels even a small resistance can develop a problematic voltage drop (in the cap). Where are you using these “stiffing caps”? Well at the amp of course. And do these car audio amps pull a lot of power? YES. That’s why people are using caps to start with. The cap is only needed when the amp is pulling peak current. Well this is when that extra resistance to the plates is the biggest problem. It creates an internal voltage drop before the electrons can get all comfortable hanging out on the plates. Effectively “slowing down” the charge rate by increasing the R in the RC time constant. Remember that when a cap is discharged it has a vary low resistance, this means more current to charge it. As it charges, current goes down and the effects of ESR are reduced. Just like with the RC time constant.
And as the cap gets old, the ESR will increase some. The biggest factor in how much and how fast it increases is heat (and thermal changes in general). This is often seen in switch mode supplies. And increasing ESR problems become vary noticeable in video circuits, I hate video circuits with bad caps. These large “stiffing caps” also have increasing ESR problems over time relating to pore build quality.

If I made a error, I apologies, and flame away…

 

so the cheaper, say, 15 farad caps, probably have a very bad ESR? I've never personally seen a system that needs more than 3 farads. If the rule of thumb is about 1 farad for 1,000 RMS watts.

I always figured that the ESR made a big difference, just not exactly what the difference was.

 

I've never in my life seen a markup like that on audio equipment. Keep in mind that Memphis works very hard to keep their product off the internet and out of unauthorized sales people, which means that if it's on the net, it's either stolen, b-stock or grey market product. You can't use that crap as a comparsion because you have no idea where it came from.

Of all the products I've sold (Pioneer, Sony, JVC, Kicker, Rockford, PPI, Kenwood, Alpine, Boston Acoustics, Infiniti, and a ton of others), dealer cost was at or slightly higher than 1/2 of MSRP. Typically the products were sold under MSRP. Our markup was typically between 70% and 90% on most products.

Now, keep in mind that super high volume retailers like Best Buy and Circuit City have contracts with manufacturers that allow them to buy high quantities directly from the factory at prices below typical dealer cost. This luxury is unfortunately not available for the typical brick & mortar retailer who has to buy his stuff in low quantity through factory reps at the normal dealer cost.

A lot of retailers on the internet sell brands like Pioneer and JVC because those brands don't care who sells their stuff. They will warranty anything. Retailers buy this stuff and ship it out the door sometimes at a margin as low as 10% above cost. Then you run into brands like Memphis, JL and Eclipse who realize that to sell quality products, you need quality retailers with sales people who actually know something and give a damn. Because of this, they have strict policies to make sure their products sell only through their authorized channels. Unfortunately, some of it still finds its way online, usually void of serial numbers so that the "authorized" person that's passing this stuff to the unauthorized guy doesn't get in trouble. This product could also be stolen product or B-stock. But either way, with no serial numbers, you can bet you're not getting it waranteed.

 

Of the 15 farad caps I've had experience with, the ESR was so high that the cap was virtually useless as a power reserve device. A normal 1 farad cap was as beneficial if not more beneficial in an installed application.

 

at Alpha Audio in Austin, Texas... the Memphis 1500D is $1000

the 1100D is $500-$750---It's been a while since I asked them.

would you guys say that the Hifonics 1500D is similar to the Memphis 1500D? I thought it was interesting that they had very similar specifications.

the Hifonics 1500D can be had for $220 off ebay... not stolen, with a 1 year warranty.

if I bought an amplifier off ebay, I'd use the ebay insurance, its like $10 and you can buy 1,2,3, or 4 year replacement plans... it's like a best buy warranty on steroids.