10 replies to this topic

[RXimpreza]

im looking at getting 2x 10 HE subs, but i have noticed that there is both ROCKFORD FOSGATE RFP3810 PUNCH HE 10" and the Rockford Fosgate RFP3410 Punch HE Sub 10 , now so far the only difference i have noticed is the ohm impendence, what does this mean??? also would i be better off getting the higher ohm woofer???
cheers craig

[HISPL]

Higher impedance woofers suit amps that can't handle low impedance loads.

When you wire two subs in parallel the load is half that of the singular woofer (assuming that they are the same impedance) This means that if your amp is not stable running two ohm mono you can purchase two 8ohm woofers and wire them in parallel for a 4ohm load.

You should easily be able to find an amp that will run at two ohms mono. (two 4ohm woofers in parallel) most class D mono amps are happy running at this sort of impedance load.

It all depends on the amp you plan to use.

Building a good car stereo system is a big balancing act. You need to match everything just right to get the most out of it.

Go the 4ohm and get yourself a nice big class D mono amp and an xtra battery for the boot.

[RXimpreza]

balancing act... your not wrong.... really i have no idea as to amps... but will now have a look at class d.... is this better than running a 2 channel bridged to mono???
cheers craig

[HISPL]

Not nessacerily better.

The type of amps that are generally mono are called a class D and these are just more efficient.
(Some others exist but as far as powering subs go this is pretty common)

These amps draw less curent for a given output and can generally handle lower impedance loads.

I would reccomend if you are looking at a really powerful D class amp that you also get a battery and dedicate it to the audio system.

I have posted on other threads about this.

One unfortunate downfall of the class D architecture is that they seem to be a little more fragile when you experience voltage problems.
(IE anything less than 11v)

I think the advantages of D class amps outweigh the disadvantages in most circumstances.

Sony, Kicker, Crossfire, Kenwood, MTX, JL Audio and many others all make mono amps that are worth considdering.

Personally if you are looking at "bang for your buck" I think the Sony XMD1000P5 is great value if you have looking at a modest system that will provide the amp with a 2ohm load it does 900wrms into 2ohms and sells on the street for $800 or less.

While you are looking for an amp check out the price and do some quick calculations. anything under $1 per watt is generally good value and as the amps get more powerfull the ratio generally gets better.

Best of luck with your balancing act!

[RXimpreza]

cheers boys thanks for the info
craig

[BlackRain]

2 rockford Punch HE 10's? A pair of entry level subs would hardly call for an extra battery in the boot. In my opinion, installing a second battery to run a pair of HE10's would be the biggest waste of time and money. I'd recommend you keep that money in ur wallet to cover the cost of a nice amp.

You can easily throw in a Class D amp that runs 1000wrms @ 2ohms (which would be more than enough for your two rockfords) and u shouldn't have any problems provided you are set up with sufficiently sized power and ground cables.

[Bassaholic]

HISPL said:

One unfortunate downfall of the class D architecture is that they seem to be a little more fragile when you experience voltage problems.
(IE anything less than 11v)

This is not exactly true.......

I also agree with BlackRain, with two Rockford He 10s, you will hardly need a battery in the boot...

[HISPL]

I didn't think subwoofers drew current from anything???

It is not the subs that draw the current it is the amp.

It is a big advantage having a battrey deicated to the audio system in your vehicle.

Any D class mono amp that is going to draw a heap of current should have an xtra battery in the boot.

Some manufacturers are going to b voiding warranties if their amps are not installed with a battery within a certain distance.
(Crossfire 4 1)

This is just a reccomendation from me.

[BlackRain]

Subwoofers don't draw anything...we're not stupid.

Anyone can tell we're alluding to the fact that the power required to run these little subs won't neccesitate a big amp and hence won't require a second battery.

But if you'd like it spelled out to you then there you have it.

Personally, I hope you don't recomment stuff like that to your customers.

[HISPL]

Well personally I wouldn't but he was going down the track of getting two MRD500 amps and running them to half their potential. May as well go the MRD1000 and run it properly.

Can't have too much power, you can always turn the sub level down.

The battery is something I see as a nessesity when you but a mono amp int hat is 1kw or more.
Just my opinion thats all.
Guys @ Crossfire seem to agree with me too.
(Either that or I agree with them LOL)

[Bassaholic]

HISPL said:

Some manufacturers are going to b voiding warranties if their amps are not installed with a battery within a certain distance.
(Crossfire 4 1)

By Whom (Is it the crossfire techs in Australia that said this?), Who else and Why?

I don't believe it, unless there are no engineers working for these manufacturers.