speaker question (a quick one)
speaker question (a quick one)
Author
Discussion

gib6933

Original Poster:

5,278 posts

261 months

Wednesday 17th September 2008
quotequote all
i have no idea where i should ask this, i don't think we have a speaker forum eek

right i am messing around with a small amp and 2 speakers i have pinched out of the tin snail (landrover discovery). i have taken them out of there box thingy that sat on the rear door and i have wired the amp into another car radio, now with everything wired up and the speakers in my hand they are distorting. my question is are they distorting because they need to be in a enclosure or will it be something to do with all the magical electricky that is going on in the amp?


Sorry I have had a drink so I may be talking in riddles.

jez

Morningside

24,147 posts

259 months

Wednesday 17th September 2008
quotequote all
Have you got their polarity correct?


Rav

3,084 posts

260 months

Wednesday 17th September 2008
quotequote all
Check the impedance of the system.

Car speakers are usually 4 ohms and thus must be connected to an amplifier that has 4 Ohms impedance at its output.

Also check how you have wired the speakers, seperate channels and live / earths?

zcacogp

11,239 posts

274 months

Wednesday 17th September 2008
quotequote all
Could be one of many things.

Crap speakers/need a box/crap amp/crap source. The source, amp or speakers can all cause the distortion.


Oli.

andyquantum

13,204 posts

234 months

Wednesday 17th September 2008
quotequote all
It's to do with ohms and impedance yes

gib6933

Original Poster:

5,278 posts

261 months

Wednesday 17th September 2008
quotequote all
Hay there is nothing wrong with little jez!!!
Oh sorry impedance
I think this is going to be out of my league for what I am going to get out of it frown. I shall make a small box for them tomorrow and see if it helps. Thanks trying to help me smile

andyquantum

13,204 posts

234 months

Wednesday 17th September 2008
quotequote all
I think from the sounds of it, you're trying to put twice the amount of power that the speakers are expecting, and so they're distorting

Change the speakers or amp

DennisTheMenace

15,605 posts

298 months

Wednesday 17th September 2008
quotequote all
Which landrover ? is it part of a factory upgrade system ? if so it wont be compatible with any other audio system .

gib6933

Original Poster:

5,278 posts

261 months

Wednesday 17th September 2008
quotequote all
its a very early disco when we got it the radio was broken so i fitted a cheep and nasty thing from halfords witch meant the rear bass speaker did not work, so I took the door apart and took a line off a rear speaker and used that for an input into the amp and it worked fine (actually brilliantly).

Anyway the disco has had its day now and I wondered if I could butcher it into my z4 as it has the standard tiny radio. I started this thinking it would be quite easy, I never wanted to go down the big boy racer bass box its just that this was such a light weight and small package.

Edited by gib6933 on Wednesday 17th September 22:31

koenig999

1,667 posts

262 months

Wednesday 17th September 2008
quotequote all
You can't use the output from one amp / unit as the input to another amp. it
will be too much current and volts and watts and that.

Does the source you are using have a line out rather than a speaker out? use that it it has it.

Or use a resistor bridge to drop the volts and current

or buy another head unit.

Koenig

Simpo Two

92,952 posts

295 months

Wednesday 17th September 2008
quotequote all
The car radio already has an amplifier in it, so by adding another amplifier you're overloading the speakers by a massive amount.

Take the amp out and wire the speakers straight to the car radio (which is how it was before you dicked about with it!)

DennisTheMenace

15,605 posts

298 months

Wednesday 17th September 2008
quotequote all
gib6933 said:
its a very early disco when we got it the radio was broken so i fitted a cheep and nasty thing from halfords witch meant the rear bass speaker did not work, so I took the door apart and took a line off a rear speaker and used that for an input into the amp and it worked fine (actually brilliantly).

Anyway the disco has had its day now and I wondered if I could butcher it into my z4 as it has the standard tiny radio. I started this thinking it would be quite easy, I never wanted to go down the big boy racer bass box its just that this was such a light weight and small package.

Edited by gib6933 on Wednesday 17th September 22:31
If its like the 1/3/5 series they have a midrange in the door tweeter in the dash and a bass unit under the seat (bit odd they are trying for a thumper effect) the stereos ive heard in the 3 series sound a bit pants same as the 1 and the 5 , sod trying to add anything to it , go to a car audio specialist and see what can be done with the standard headunit to keep teh OE look if your not fussed go aftermarket , it will sound loads better .

Pigeon

18,535 posts

276 months

Thursday 18th September 2008
quotequote all
gib6933 said:
i have no idea where i should ask this, i don't think we have a speaker forum eek

right i am messing around with a small amp and 2 speakers i have pinched out of the tin snail (landrover discovery). i have taken them out of there box thingy that sat on the rear door and i have wired the amp into another car radio, now with everything wired up and the speakers in my hand they are distorting. my question is are they distorting because they need to be in a enclosure or will it be something to do with all the magical electricky that is going on in the amp?
So you've got the same speakers wired into the same amp in the same way as they were in the car, and you are driving the amp in the same way just from a different radio?

The only difference is that the speakers were in a closed box of some sort and are now sat in free space?

I think the problem is that they need to be in a box, they need the enclosed mass of air in the box to provide some resistance and prevent the cones moving too far.

900T-R

20,406 posts

287 months

Thursday 18th September 2008
quotequote all
Pigeon said:
I think the problem is that they need to be in a box,
Indeed. Take theam out of an enclosure (or 'infinite baffle' and you'll cause an 'acoustical short' where the pressure waves in front of and behind the speakers are cancelling each other out. So in order to be able to hear something you crank uo the power - result: distortion.

Edited by 900T-R on Thursday 18th September 04:39

gib6933

Original Poster:

5,278 posts

261 months

Thursday 18th September 2008
quotequote all
well i knocked up a box today and plugged it all in and

still wasn't working frownbanghead

So sod it! i will put up with the tinny radio.

Thanks for all your help.

waiting for the "i told you so" now lol