Installing amp and subwoofer with stock headunit

[kin]

Im installing an amp to the stock headunit, can someone tell me which one is the connection line out? wat modifications do i need to do? thanks~

[vividjazz]

The shocker stocker head unit has not RCA line outs. You will need either an adapter to convert the speaker output signal to an RCA signal or an amplifier with a built in adapter. These are often referred to as high level to low level adapters or speaker level to RCA adapters.

The other problem is the lack of somewhere to connect the remote power connection from the amp to the head unit as again it makes no provisions. The cheap and easy way is to run the amp's remote terminal off of a switched accessory wire. This is the wire that your radio uses. It is only powered when the key is in the accessory or run position of the ignition switch. When you shut the car off the wire loses power and the radio and amplifier will both turn off. Your amp will be on when your car is on and off when you car is off.

There is a very high chance of noise being induced into the system (can almost guarantee it) as the very low power head unit is not designed for the introduction of any amps.

Would very highly recommend an aftermarket head unit as even the cheapest units have at least 1xRCA connection and a remote power connection. For about $100 over the most basic unit you'll also get MP3 capabilities. Sound will also be better even through the 4 x 99c paper cup non-coaxial factory speakers. Oh to fit an aftermarket unit you'll need the double DIN facia, brackets and a DIN pocket/blank (to cover the other unused DIN hole).

When upgrading an audio system upgraded earthing is critical. Your electrical system is a loop.

You of course will also need to run power for the amp directly from the cars battery regardless of wether you use the factory head unit or an aftermarket.

You also have the joy of getting the factory head unit out to connect things in behind it. As well as the expected screws and clips you'll also have to disconnect the 3 air/vent control connections behind the dash/glovebox to get the unit out and you have to negotiate the 2 Honda security screws before that. Its an absolute pig of a job.

Watching what my installer went through it was worth every cent I paid (in fact even more) to have it installed by a true professional. The other benefit is if he breaks anything he has to pay to fix it where as if I break something it could get very expensive very quickly.

[kin]

hey thx vividjazz~
my amp has an rca and also got a speaker wire input. since this is only used for the subwoofer which is mono, can i connect the speaker input to just one of the door speaker?

i understand there is a unit that can sense voltage from the speaker wires and then send a 12v signal to the remote wire.. with this unit, the amp will be off when the headunit is off. can anyone tell me wat is the name of this unit? maybe i can get it from jaycar or thingysmith.

if this could be done, i will will not have to remove the headunit which will make the job alot easier

[channeldavid]

i just installed amp, sub and 2 front speakers today. (stock head unit)
How i connected the amp, same as what vividjazz say...
Remote power -> accessory cable
Sound singal -> Rear Left (+ & -), Rear Right (+ & -) from the head unit
Power (+) -> Battery (+)
Ground (-) -> there have 2 rings in the boot, near the back of rear seat. unscrew one of them, scractch out the coating under the ring on the car body (just a small area is enough), attach the wire to that area, screw it back!

[vividjazz]

kin said:

hey thx vividjazz~
my amp has an rca and also got a speaker wire input. since this is only used for the subwoofer which is mono, can i connect the speaker input to just one of the door speaker?

i understand there is a unit that can sense voltage from the speaker wires and then send a 12v signal to the remote wire.. with this unit, the amp will be off when the headunit is off. can anyone tell me wat is the name of this unit? maybe i can get it from jaycar or thingysmith.

if this could be done, i will will not have to remove the headunit which will make the job alot easier

The RCAs on the amp will probably only be inputs rather than outputs (normally case on almost all amps) so you need that line converter to change the speaker wires on the headunit to RCAs. So you loose the rear speakers (which you probably won't notice) to have the cables for the amp.

What is the make/model of the amp? Hopefully the manual is online and I can look at what those speaker wire connectors are capable of before I can comment on how or if they can be used.

I know the voltage sense thing your talking about for the remote. You can make one yourself. It is easier just to do as channeldavid has done and run off the accessory. Most people run the stereo all the time when the car is on anyway.

[ahcash]

What to know more of my options...

I want to leave the existing speakers and my door trims alone...

Is it possible to add a 4 channel amp to drive the existing speakers without rewiring to the existing speakers? In other words, using exsiting speaker cables.. run an amp in between the stock headunit and the speakers..??

[vividjazz]

ahcash said:

What to know more of my options...

I want to leave the existing speakers and my door trims alone...

Is it possible to add a 4 channel amp to drive the existing speakers without rewiring to the existing speakers? In other words, using exsiting speaker cables.. run an amp in between the stock headunit and the speakers..??

An amp needs its own power so it is necessary to run a power cable from the battery to wherever you locate the amp (most likely the boot as the petrol tank is under the seats and the amp needs to stay cool).

The amp needs to be earthed preferably close to the actual unit itself so need to sort a point to earth it to (may require scratching back paint to get a good earth at the point but there are plenty of good existing points around the Jazz).


imgboot.com/images/vividjazz/earthingmounts1.jpg

The amp needs a remote power cable to signal to it to turn on and off. As no such connection existings in the back of the factory head unit this would most easily be run straight from the ignition as discussed previously in this thread.

The speakers connect to the amp instead of the head unit in order to be amplified. So speaker wires have to run from the amp to each speaker.

In order for the factory headunit to send a signal to the speakers now that it does not directly output to the speakers it has to connect to the amp. In an aftermarket head unit this is via RCA cables. As the factory unit makes no provision for RCAs the speaker cables have to be converted to RCA to go into the amp.

To power all 4 speakers will require a 4 channel amp which has 2 sets of RCA connectors. You would convert the speaker outputs from the head unit to RCAs to run to it.

The factory speakers will not handle a lot of power. They have tiny, tiny magnets and even distort at high volume from the very, very underpowered factory head unit.

Even with this large picture you can barely see the magnet on the back of the factory speakers.


imgboot.com/images/vividjazz/midrangecomparisonmagnet1.jpg

In short you have to pull things apart and run cables to set an amp up.

You can get away without pulling the head unit out but you'll have to get in behind the speakers to rewire them thru the amp and to run the existing wires to the amp. You don't want to put joins everywhere in the cables unless you want cut out problems down the track (or worse).

If your using the factory head unit and hence not using RCA cables but a convertor remember that the converted speaker wires cannot take the same power as proper RCA cables. Thats not what they were designed for.

The wires used from the amp to the speakers should be of sufficient gauge to take the higher power coming from the amp. The existing wires are very thin as they wanted little resistance with such low power levels.

If your going to go to the trouble of putting in an amp and have to pull the door trims apart anyway (a lot easier to pull the doors apart than pull out the head unit) you might as well put in better speakers.

Split /component speakers are expensive compared to co-axials due to the additional crossovers and better quality speakers but pretty much any aftermarket speakers with the amp are going to be a marked improvement over the factory paper cups.

Also remember that sound deadening makes a huge difference around the speakers. Even just a speaker kit like the Dynamat xtreme speaker kit not necessarily the whole door kit (which obviously would cost a lot more).


_{<<edited by the admin the adjust the picture size. Original picture link remains.. hope you don't mind..>>}

[ahcash]

Thanks a lot vividjazz.. that's very informative..

In other words.. the factory speakers would not improve much with an amp added... and sourcing of good speakers to replace the factory speakers are highly recommended? I would have thought so...

Is it fair to say that if I put in an amp to drive a sub and get them to wire up all the thing now.. in a later stage, it will be easier to add another amp, draw power from the 1st amp (sub) to drive the 4 speakers?

If I am to use the existing head unit, do they (audio installation) have all the necessory connector / convertor to run cables from headunit to the amp or do I have to source them from Honda?

[vividjazz]

ahcash said:

Thanks a lot vividjazz.. that's very informative..

In other words.. the factory speakers would not improve much with an amp added... and sourcing of good speakers to replace the factory speakers are highly recommended? I would have thought so...

Is it fair to say that if I put in an amp to drive a sub and get them to wire up all the thing now.. in a later stage, it will be easier to add another amp, draw power from the 1st amp (sub) to drive the 4 speakers?

If I am to use the existing head unit, do they (audio installation) have all the necessory connector / convertor to run cables from headunit to the amp or do I have to source them from Honda?

Installer would source the RCA convertors. Honda won't know anything about them.

Best to run seperate power for each and every amp back to the source (battery) but heaps of people do chain them.

Depends on the amp for the sub. A D Class (monoblock) is only good for a sub while AB class are multichannel and can be bridged for a sub. Monoblocks are better for subs but cost. 5 channel amps are designed for your 4 speakers and a sub such as the Crossfire VR705D (4x50W RMS + 150W RMS @ 4OHM and double all that at 2 OHM with 0.02% distortion 12.5V). Or forget about the rear speakers and get something like an Audison SRx3 (2x75W + 250W @ 4OHM 13.8V and can go 2OHM)

www.audison-america.com/Products/SRX/SRX3/SRX_template_22.jpg


If you have an amp wired up for a sub then you won't have the wiring in place for the speakers as they would need to run from the amp instead of the head unit down the track.

The best sub/amp combo by itself won't sound that good with poor speakers because unless your going SPL or just rattle rattle doof doof the sub compliments the full range speakers by adding depth. You need clarity 1st.

Priorty / order of car audio upgrade
1) full range speakers
2) head unit (you need RCAs for serious amps)
3) amps
4) subs

For an easy sub upgrade just get a SAS Bazooka bass tube with built in amp.

[vividjazz]

Bang for buck you can't go past the Jaycar Response amps. They have a 400W RMS D Class amp for under $400- that can be run at 2 OHM and 1 OHM if the sub also supports it. Puts out 800W RMS at 1 OHM. Their 4 and 2 channel amps are also great value on a dollar per watt basis.

2 x 150WRMS @ 4OHM Response amp is under $250.

Jaycar also has those speaker wire to RCA convertors. They call them Car Stereo High to Low Level Converters @ $24-. They have spacer/speaker mounts for the doors to take deeper aftermarket 6"-6.5" speakers @ $10-.

[ahcash]

Once again .. thanks for the info.. I was at Jaycar on Friday .. but didn't pay attention to the above.. Might check it out again next week...

[vividjazz]

While your there have a listen to their newer kevlar 6" speakers particularly the splits.