2 Head Units

**kevinlekiller** · 04-21-2005, 09:12 PM

Hi, I want to install 2 head units (one is cassette other is cd and I dont want to buy a double din since I already have the head units).

I want to use a relay to control power to the radios (I put a switch to choose between 87 an 87a).

I will plug both(the two H.U.) Left Front , Right front etc.. To my speakers(in parallel).

Anyways Heres my question: Lets say i'm using the cd H.U(no power going to cassette H.U.), will the power going out from the Left Front etc... channels damage the cassette head unit?

Should I put relays to each speaker channel's?

Thanks.

**xdjxklusivex** · 04-21-2005, 09:37 PM

hmmm thas kinda pointless to do sell em and get a double din or trash the cassette hu i havnt touched a tape in years haha

**kevinlekiller** · 04-21-2005, 10:24 PM

Its not pointless, I have a new cd player, and I dont want to throw it, has for cassettes, I dont want to copy them to my computer and burn them to cd's (the audio quality is already crap and its just gonna be more crappy) I know i'm sacrificing quality putting two h.u's but its better than putting the tape's to cd's.

The tape's I have are all old classic's that you cant get on cd.

**walky_talky20** · 04-21-2005, 10:35 PM

will the power going out from the Left Front etc... channels damage the cassette head unit?

maybe.

Whenever I ask my dad these kinds of questions he always says something like "It certainly won't be helping anything".

I beleive that would definitely apply here. If I were in your situation I would go for the multiple relays. j/k. But I think it would make an awesome "click" noise whenever you switch from one to the other.

For real I would get rid of the tape deck. If you are very ambitious you could attempt to do the switching at the LINE level. For example the cd player probably has a LINE OUT, but your tape player most likely lacks and AUX IN. You could run the LINE OUT to the place where the line signal in the tape player is - right after the preamp for the tape head. Make a switch so you can choose what is coming off the tape head or what is "hijacking" the line. This would create a sort of "psuedo AUX IN".
In other words: forget the tapes and your life will be easier!

**turbocad6** · 04-21-2005, 11:23 PM

There is software that will improve the quality of the recordings as they are converted to digital...it is defanately the best solution in your case by a long shot....as far as your question with the speaker wiring to both....the other dead head will defanatly show resistance through the unit(resistance is ohm's) & at best will just reduce the power available to your speakers, probably severly....if you must use two heads the right way would be to have one set up as master & second set up as a slave, playing through the master as an aux input.....only problem there is that the master head must have aux input...then again if your working with a crappy source to begin with you could feed the tape head unit into the cd head unit with an rf modulator....hope this helps....

**mbuchman** · 04-21-2005, 11:36 PM

Hm, I think some diodes would do the trick rather than that relay business for the speakers...

And I hope you are only switching the remote turn on on and off, right?

Their is no reason you couldnt do it, but honestly, do you even use tape enough to justify it?

Matt

**xdjxklusivex** · 04-21-2005, 11:38 PM

then if one of ur headunits have aux input why dont u take the output out of the other and run it into the one with the input it will be clear also and ull have more control over the sound

btw i didnt mean to offend you or n e thing i just ment go the easy way and get a double din with both in it

**kevinlekiller** · 04-22-2005, 04:58 PM

Originally Posted by xdjxklusivex

then if one of ur headunits have aux input why dont u take the output out of the other and run it into the one with the input it will be clear also and ull have more control over the sound

btw i didnt mean to offend you or n e thing i just ment go the easy way and get a double din with both in it

No Offense taken

I think I will go the relay way (since the aux in is already used by my xbox on my cd player)

I will only switch channels while the power to the radios are cut, this way I will prevent the clicking noise. (The only thing is that I think there will be major interferance (power going into relays + sound power going into relay).

B.T.W.: I know this sounds crazy but I have more tapes than cd's. (Lets just say I'm old school).

**Gobby** · 04-22-2005, 05:01 PM

Couldn't you get the tracks in digital format from iTunes, Napster etc??? Would be better than having an all singing all dancing carPC and then installing a Cassette Deck - kinda defeats the object to me.

**nubz69** · 04-22-2005, 06:33 PM

You will have to put a relay on all the wires including all the speaker wires. You do not want one headunit sending a signal into the other amps outputs. I suggest you do this but leave the constant and ground left alone on the HUs.