Is simply adding an amp and sub just not feasible?

[jontyrees]

I've searched the forums, and not come up with a whole lot of info on this. What I'm gathering is that the low frequency roll off applied by the HU as volume increases cannot be bypassed without using some kind of signal processor to restore the level. All I really had in mind was to drop in a sealed box 10" sub I have sitting around, and be out the door with just the cost of a small mono amp (RF Prime 250w for ~$100, accepts speaker level signal) and power/ground amp kit - say another $20. I was going to just tap into the rear speaker wires, use the amps speaker level inputs, and be done.

Is it just not worth doing because of the low freq roll off?

 

[jontyrees]

I've searched the forums, and not come up with a whole lot of info on this. What I'm gathering is that the low frequency roll off applied by the HU as volume increases cannot be bypassed without using some kind of signal processor to restore the level. All I really had in mind was to drop in a sealed box 10" sub I have sitting around, and be out the door with just the cost of a small mono amp (RF Prime 250w for ~$100, accepts speaker level signal) and power/ground amp kit - say another $20. I was going to just tap into the rear speaker wires, use the amps speaker level inputs, and be done.

Is it just not worth doing because of the low freq roll off?

Question popped into my mind...are all the speakers subject to the low freq roll off? I read somewhere that the fronts do at least get a full range signal, is that the case? If so, I could tap into them for a signal to the sub amp. I understand the parcel shelf 6x9 subs are already low passed and subject to the roll off.

 

[hawkeye18]

You will need one of these:

http://www.amazon.com/dp/B004CTBYGE

Then you will be good to go with everything else you mentioned.

 

[jontyrees]

You will need one of these:

http://www.amazon.com/dp/B004CTBYGE

Then you will be good to go with everything else you mentioned.

Hey thanks for the link - that is exactly what I'll need. How is it that there is no such thing as a simple car audio project though - lol! Seems like there's always a need to buy something else. Question though, how do you power this box? Does it require a separate power cable from the battery, or do you just tap into the same power cable as the amp? I imagine you ground it to the same spot as the amp.

 

[hawkeye18]

Hey thanks for the link - that is exactly what I'll need. How is it that there is no such thing as a simple car audio project though - lol! Seems like there's always a need to buy something else. Question though, how do you power this box? Does it require a separate power cable from the battery, or do you just tap into the same power cable as the amp? I imagine you ground it to the same spot as the amp.

It will require its own +12v source. You can buy a power tap for amps fairly easily and cheaply - 4ga in, 2x 8ga out, etc. etc. On the '95 I am running 2ga wire from the battery to the trunk where it goes into a power distribution block that offers 2x4ga, 2x8ga and 2x12ga power taps out. It will also need a remote wire just like your amp, but you can run the head unit's remote wire to this unit, which has a remote out that then goes to your amp.

Factory stereos are getting more sophisticated, as are most electronics. It's the price of the game.

 

[Boggus]

Now I don't have the Sony system in my SHO and that's what I did. I replaced th front speakers with better components then added a single 10" sub and 2 channel amp.

 

[jontyrees]

It will require its own +12v source. You can buy a power tap for amps fairly easily and cheaply - 4ga in, 2x 8ga out, etc. etc. On the '95 I am running 2ga wire from the battery to the trunk where it goes into a power distribution block that offers 2x4ga, 2x8ga and 2x12ga power taps out. It will also need a remote wire just like your amp, but you can run the head unit's remote wire to this unit, which has a remote out that then goes to your amp.

Factory stereos are getting more sophisticated, as are most electronics. It's the price of the game.

If I do this, I'll probably end up getting a distribution block, but what really is the difference between running two long power cables from the battery + to the amp and to the LOC, running one to a ditro block and separate ones to the amp and LOC, and running one cable to the amp with another one coming off the amp 12v input to the LOC? Not trying to be argumentative, just trying to better understand the situation. And save $10 for a distribution block or a long power cable. I can see a fused distro block for separate amps, but does this box need to be fused separately?

 

[hawkeye18]

One of the constraints one runs into when running power cables from the engine compartment to the trunk is physical space; the laws of physics dictate that one 2ga cable takes up less room than two 4ga cables. Furthermore, having a bunch of cables snaking from your positive terminal looks ugly - the more you have, the worse it looks. Plus, generally you want to put your main fuse as close to the battery terminal as possible (to minimize the length of unfused wire), and if you have a bunch of cables going to the amp, each of them needs to be fused.

As far as splitting the power wire from the amp to the LOC, I'm sure that could work, but I generally avoid splicing high-current wires as a rule, because if anything goes wrong with the splice, it tends to go wrong real quick. I am an avionics technician, though, and I probably have higher standards of wiring work than most people. There is nothing physically wrong with splicing the wire off the amp.

I would want to run the biggest wire I could from the front to the back; it's not so much for current handling capability so much as future-proofing. The amp setup I'm running in the '95 barely calls for a 4ga wire from the battery - a 2ga wire is total overkill. However, if I decide it's not loud enough (which is liable to happen at any time), I really wouldn't want to have to rewire the damn car just to run a bigger amp...

 

[SHOrod]

the laws of physics dictate that one 2ga cable takes up less room than two 4ga cables.

Calculating the Circular Mil Area (CMA) will help explain this phenomena.

-Rod

 

[hawkeye18]

Calculating the Circular Mil Area (CMA) will help explain this phenomena.

-Rod

Yeah, that! I would've remembered that last night but I was friggin' super drunk then. It does seem that my grammar gets better the more I drink... :/

 

[jontyrees]

As far as splitting the power wire from the amp to the LOC, I'm sure that could work, but I generally avoid splicing high-current wires as a rule, because if anything goes wrong with the splice, it tends to go wrong real quick. I am an avionics technician, though, and I probably have higher standards of wiring work than most people. There is nothing physically wrong with splicing the wire off the amp.

...

I have spare distribution block now that I think about it - that'll work.