there's nowt wrong with being factually correct, whereas waking round with yer head up yer own arse will get you nowhere fast
bass driver specs
- Thread starter Russell Jupp
- Start date
This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
there's nowt wrong with being factually correct, whereas waking round with yer head up yer own arse will get you nowhere fast
Russell Jupp
New Member
- Posts
- 242
- Location
- Devon
WTF??? The question is, could any of you have offered the desired info? Forgive me for seeming confused, but I asked a simple question, and seemed to get comments from folk, (excepting m link and st dan) that were of no use whatsoever. I consider this to be a complete waste of everyones time. I don't search threads and make pointless comments on subjects that I have little knowledge about.
ming
SPACE TWOT
- Posts
- 11,977
- Location
- PLANIT ZOG
Youve upset ma Mutt. . . . . .yer bastid he's sencertive [eeze er furra bread]
yes of course, but as i'm a lifelong tractor/series owner i'd break out with a itchy rash if i helped a Freelanderer
Russell Jupp
New Member
- Posts
- 242
- Location
- Devon
Russell Jupp
New Member
- Posts
- 242
- Location
- Devon
Youve upset ma Mutt. . . . . .yer bastid he's sencertive [eeze er furra bread]
yeah right....I'm sure this guy is on drugs.....
mono78v
New Member
- Posts
- 106
- Location
- nottingham
Hello, thought i'd join in the fun.
I don't know for sure but i'd put my money on your speakers being 4 ohm. very few car bass drivers are 8 ohm and i've never come accross any which are 16 ohm. (not saying there aren't any, i just haven't come across any) most car bass drivers i've played with in the past are 4 ohm.
As for audio being AC or DC, i'd say it was more comparatable to AC, because its an alternating siginal. If you look at an audio siginal on an oscilloscope it will be an alternating sine wave.
I don't know for sure but i'd put my money on your speakers being 4 ohm. very few car bass drivers are 8 ohm and i've never come accross any which are 16 ohm. (not saying there aren't any, i just haven't come across any) most car bass drivers i've played with in the past are 4 ohm.
As for audio being AC or DC, i'd say it was more comparatable to AC, because its an alternating siginal. If you look at an audio siginal on an oscilloscope it will be an alternating sine wave.
SysFX
New Member
- Posts
- 18
- Location
- Under a Freelander
As long as the electron flow does not change direction then its just wobbly DC.
ming
SPACE TWOT
- Posts
- 11,977
- Location
- PLANIT ZOG
Russell Jupp
New Member
- Posts
- 242
- Location
- Devon
Mrs Ming . . . . . . .eeze avin a go agin
Really sorry Mrs Ming, but if ee culd tell i where tiz Mr Ming getz 'is grass from, 'twould be proper...
Russell Jupp
New Member
- Posts
- 242
- Location
- Devon
Thanks...i know nothing at all about car audio (hence the post), all the stuff Ive ever worked with is large PA stuff, zilliions of watts etc. As a bass guitarist, I have my own setup, but its all multi drivers, large format 8 / 16 ohm stuff.
I will source a couple of 4 ohm drivers and hope for the best!!!
Cheers,
Russ
Russell Jupp
New Member
- Posts
- 242
- Location
- Devon
Gentlemen, I think we should consider this thread closed for business. Most of you have been most helpful.
Sean, however, is noticeable by his absence (maybe he is busy with his nasty rash).
Never mind.
Cheers,
Russ
Sean, however, is noticeable by his absence (maybe he is busy with his nasty rash).
Never mind.
Cheers,
Russ
Russell Jupp
New Member
- Posts
- 242
- Location
- Devon
i bailed after this comment[/quote
TFFT
Missing Link
New Member
- Posts
- 653
- Location
- Colchester, Essex
This is getting silly but....
The last thing you want as the output of an amplifier is any level of DC, wobbly or otherwise. This would produce a continuous current flow through the speaker even when there is no sound which 1st would generate more heat and 2nd bias the coil in one direction distorting the sound pressure waveform.
The output of an amplifier is AC pure and simple with zero volts across the speaker terminals when there is no sound. Car audio has a severe constraint on its design due to the fact that the amplifier only has nominally 12 volts to generate the output. Domestic audio has rectified mains which in theory gives it 300volts to play with. In practice a common rail (nothing to do with diesels) voltage in good audio is + AND - 30 volts. Cars dont even have any negative voltage. There are a number of charge pump and inverter circuits to overcome this which even baffle me. It is because of this function however that all modern car stereos etc come with a warning not to ground or common feed either of the two speaker terminals. 25 years ago when I 1st worked in car audio you could with the cheap units.
Speakers are always classified as having an impedance rather than resistance. If you take a multimeter and measure the resistance it will be lower than the rated impedance. This is because a multimeter applies a dc voltage to the voice coil which is just a long thin copper wire to dc. During the test it will also generate a small magnetic field and it will remain until you remove the meter probe.
However to AC (audio) it is continually building and collapsing the field in the magnetic coil which takes energy so opposes the current flow more as if the resistance is higher. The trouble is this AC resistance varies according to the frequency of the AC, being higher at higher frequencies (some caveats to this). We use the term impedance to indicate that there is two components to the value. In the case of a speaker the impedance is the dc resistance added to the AC resistance at a nominal frequency, if I remember correctly at around 2/3 of the frequency range.
As a rough guide because most people only have a multimeter the dc resistance of a speaker of car audio/domestic audio is between 2/3 and 3/4 of its impedance. This is close enough to distinguish between the common values. Remember this is of the speaker itself, be wary of crossover units when working with an enclosed speaker cabinet.
A crossover unit allows multiple speakers which are designed for specific frequency ranges (high, mid, bass) to be fed only the range they are optimised for from a single source. Subs are not included because normally they require so much energy to work they have a separate amplifier.
The reality is that the acoustics in a car are so bad to call any form of audio hi-fi is wrong, I am not such a purist that I believe 100 strand oxygen free copper speaker leads are essential but I can tell if bell wire or telephone cable has been used (no bass). As long as it sounds good to your ears who gives a ****!!! (but that could be said about all of the above)
The last thing you want as the output of an amplifier is any level of DC, wobbly or otherwise. This would produce a continuous current flow through the speaker even when there is no sound which 1st would generate more heat and 2nd bias the coil in one direction distorting the sound pressure waveform.
The output of an amplifier is AC pure and simple with zero volts across the speaker terminals when there is no sound. Car audio has a severe constraint on its design due to the fact that the amplifier only has nominally 12 volts to generate the output. Domestic audio has rectified mains which in theory gives it 300volts to play with. In practice a common rail (nothing to do with diesels) voltage in good audio is + AND - 30 volts. Cars dont even have any negative voltage. There are a number of charge pump and inverter circuits to overcome this which even baffle me. It is because of this function however that all modern car stereos etc come with a warning not to ground or common feed either of the two speaker terminals. 25 years ago when I 1st worked in car audio you could with the cheap units.
Speakers are always classified as having an impedance rather than resistance. If you take a multimeter and measure the resistance it will be lower than the rated impedance. This is because a multimeter applies a dc voltage to the voice coil which is just a long thin copper wire to dc. During the test it will also generate a small magnetic field and it will remain until you remove the meter probe.
However to AC (audio) it is continually building and collapsing the field in the magnetic coil which takes energy so opposes the current flow more as if the resistance is higher. The trouble is this AC resistance varies according to the frequency of the AC, being higher at higher frequencies (some caveats to this). We use the term impedance to indicate that there is two components to the value. In the case of a speaker the impedance is the dc resistance added to the AC resistance at a nominal frequency, if I remember correctly at around 2/3 of the frequency range.
As a rough guide because most people only have a multimeter the dc resistance of a speaker of car audio/domestic audio is between 2/3 and 3/4 of its impedance. This is close enough to distinguish between the common values. Remember this is of the speaker itself, be wary of crossover units when working with an enclosed speaker cabinet.
A crossover unit allows multiple speakers which are designed for specific frequency ranges (high, mid, bass) to be fed only the range they are optimised for from a single source. Subs are not included because normally they require so much energy to work they have a separate amplifier.
The reality is that the acoustics in a car are so bad to call any form of audio hi-fi is wrong, I am not such a purist that I believe 100 strand oxygen free copper speaker leads are essential but I can tell if bell wire or telephone cable has been used (no bass). As long as it sounds good to your ears who gives a ****!!! (but that could be said about all of the above)
