Fitting car-type radio

[paulrossall]

Existing car-type radio in boat has expired and I want to fit radio out of my old Volvo. Boat has 4 speakers each states 60 watt max, 8 OHM. Car had 4 speakers each states 60 watt max, 4 OHM. Can anyone tell me whether it is ok to connect new radio to the 8 OHM speakers? What significance is the OHMS?Thanks

 

[HaraldS]

You can connect the 8 Ohm speakers without problem. However your radio will only deliver full power with 4 Ohm speakers. It will probably still be plenty loud, and that also depends on the speaker efficiency.

Inversly, taking a radio that is designed for 8 Ohm and connecting it to 4 Ohm speaker could overload it.

 

[LadyInBed]

Ohms are what the Impedance of the speaker is measured in.
(Impedance is like Resistance but takes into account the phase angle in a.c. circuits)
You have a few options:

1 Buy new 4 ohm speakers – relatively expensive

2 Wire two of the speakers together (in parallel) (and the same with the other two) – this will give you standard stereo as opposed to quad (you wont be able to adjust the volume on each individual speaker) but I defy you to tell the difference, especially if you parallel up the diagonal speakers. You will also loose max power output from each speaker but lets hope you don’t wind them up to 60 watts!

3 Ignore the mismatch, and just connect the existing speakers to the stereo – Modern solid state power output from the stereo will probably cope with the mismatch. You may get a little distortion, but are you listening to (or want) hi-fi.

 

[Strathglass]

Won't do any harm it may be a little less loud.
The wiring in your boat will probably add more to the impedance seen by the radio than the difference between using 4 and 8 ohm speakers. That is unless your boat speaker wiring is heavy duty HI-FI type.
Just change the radios over and it should work fine.

Iain Simpson

 

[bedouin]

As the previous posters have stated. yes it will work without risk of damage to anything. It is possible that your existing set up already has two 8 ohms wired in parallel - so the radio thinks it is driving 2 x 4 ohm speakers rather than 4 x 8 ohm speakers. No real problem with that except that sound quality will suffer.

In general if you wire up 8 ohm speakers in place of 4 ohm ones you will only get half the power out of the radio (probably not too significant - the ear's response to volume is not linear so twice the power does not equate to perceived volume of twice as loud - that takes about a factor of 8)

More significant however is that if they are 8 ohm speakers they are probably domestic hi-fi speakers rather than car speakers - this means that they may well be comparatively inefficient; again this would impact the volume at which you can play the system.

 

[ColinS]

Re: Another tack

Found an AIWA mini system last year for £70 or so with a 12v socket in the back. CD/Tape/Radio combined, plus remote control for those moments when you cannot leave the helm at shipping forecast time. It only has 2 speakers, but who needs surround-sound in a boat?
Only drawback was the 12v adapter which took a couple of months to obtain and cost £15.
Sits on a shelf held down with Velcro, as do the speakers.

 

[bedouin]

Re: Another tack

Could you post the model number - I've been looking for one of those for ages for a very similar reason.

I don't think they are popular since having a single-rail 12V supply restricts the power you can put out.

 

[paulrossall]

Re: Another tack

Where did you buy this? Why did you need a special 12V socket, can`t you just stick a supply into the radio? Again the model number would be usefull. Thanks

 

[ColinS]

Re: Another tack

I will get the information this weekend when I get to the boat.
As far as the power socket goes, from memory it is soldered on to the circuit board and is therefore not easy to get at. I didn't want to invalidate any warrenty at the time, so I got the adapter. This has a small centre pin which is not common with all other types, such as the power for a CD Walkman.
Mine had to be ordered from Germany.

 

[Guest]

Re: Another tack

I have considered buying exactly that model for my boat. What is the sound quality like? The thing that cost an extra £15 , was that just a special plug or something fancier?

 

[ColinS]

Re: Details

The system is made by AIWA and is model LCX-337K.
Sound quality is adequate for the type and price of system, maybe a bit short on bass, but ok on a boat.
I have lost the 12vdc power adapter part number, but it can be found in the system handbook (which I have mislaid as well). As mentioned previously, this item is a special costing circa £15, and can only be bought through an AIWA dealer. It has a cigar lighter plug on the other end.