Steriotypical Wog
Altenator in my Ford died, need a new one. 1000wrms warning :P
Hey guys, I know, it's a ford.
It's got a mitsubishi alternator in it atm and it just died (probably from trying to run 1000wrms thru it). I couldn't ever run the sterio at more than 30% because it would cut out.
I'm looking at a bigger one, the one in there is either 55a or 85a. I was told for 1000wrms and all the other electrics I may need something 130a+, my mechanic (I don't think he knows what he's talkin about) says 70-75a should be fine. Anything you guys can recommend?? I'm trying not to spend more than $200 on it.
I don't use windscreen wipers, i just use the superior handling of the STI to dodge the rain drops.
GOD
lets see.. 1000W RMS is about 1000W/12V= about 85A. At 75% efficiency, thats 113A for oyur sound system running it at MAX all the time. It will probably be on only about 50% of that power AT MOST, so about 50-60A for your stereo will be plenty, plus whatever your cars electrical system uses.
70-75W will be fine i should imagine
I think my stock alt is 85A and I have 3000Wrms worth of amps... You don't need a huge alt unless you want to completely eliminate headlight dimming, which is very expensive
1500Wrms for me and my headlights dont even flicker! and i was told i WILL need a cap.....
you will be fine, do a search on upgrading your grounds and improving your electrical/charging system.
Not a valid input....
replace it with around 85Amps. If your really desperate for huge delivery and don't want to spend much. Try getting one from a wrecked cop car.
You put you left foot in, your put your right foot in , you take your left foot out and you slide it all about!
If you have a 1000wrms system, and you think you'll even be pulling near 40amps during 'pumping' of the system.
You've got alot to learn about audio, and how loudness is measured and related to power.
Think about it, just a 3db increase in loudness needs a doubling of power.
A percieved doubling in loudness is 10db.
So that means, to make your music twice as loud, you need to double the power, double it, and double it again.
Then you have the A weighted scale, (i think its called A weighted) in other words, to make a note at say 50hz @ 100db you need ALOT more power then to make a note at 3000hz @ 100db
Take out a multimeter and measure the current draw of your system, you'll be very suprised I guarantee it.
My headlights, dash lights and interior lights dim a fair bit at high volumes but i'm not bothered by it.
My old car had a 65 or 70A alt with 1600Wrms or so total and the engine revs would drop when the volume was turned up... No idea why, but it did it everytime the volume was turned up HIGH.
are you taking the piss and being sarcastic? or serious?Originally Posted by StoneX
Serious... I couldn't understand it. I don't know if more current draw puts more stress on turning the alternator or if maybe the voltage drop was causing an electrical problem with the computer running the engine.
the more current the alt puts out the more harder it is to spin., if you want more grunt you need a high output alt.
Alt's will go into discharge if you use alot of current at idle, when spinning fast it will increase charge, it may help slightly if you reduce the size of the pulley on the alt if you idle alot listning to DOOF DOOF!.
Hey guys, I know, it's a ford.
It's got a mitsubishi alternator in it atm and it just died (probably from trying to run 1000wrms thru it). I couldn't ever run the sterio at more than 30% because it would cut out.
I'm looking at a bigger one, the one in there is either 55a or 85a. I was told for 1000wrms and all the other electrics I may need something 130a+, my mechanic (I don't think he knows what he's talkin about) says 70-75a should be fine. Anything you guys can recommend?? I'm trying not to spend more than $200 on it
Don't bother putting a mitsubishi alt back in, there is bosch direct replacment for the fords, mitsubishi alt parts are pricey.
Bosch alt are easier to sevice and replacment parts are readily available.
hi, hope im not thread jacking....
just bought a JBL GTO 7556 (6 CH amp) .... which in the set up i'll be running is:
4 x 60W (RMS) running 4x 55WRMS speakers (cant remember brand, dont care either)
1 x 300W (RMS) (bridged, running a sony 1000w Peak / 250WRMS single voice coil rated @ 4 ohms)
I've already contacted JBL to make sure the amp is able to drive a 4ohm mono speaker, as some amps will die when its bridged, cause the amp "sees" a 2ohm load... and might not be compatible, so check with your manufactuer when considering an new amp as i killed my old one i had lying around that was a 2ch bridgeable..... it couldn't handle a 2ohm mono load even tho it was connected to a single 4 ohm speaker!...
but after doing a bit of reading, im wondering a few things:
the specs say i need an 8guage wire running from the battery, which i already have, but im not sure what size fuse to put in, as the specs say the max current draw of the amp is 87A. I won't be running the amp flat out, as i only bought it for cleaner signal compared to running from my DEH-5750MP speaker connections.
Im not sure of the efficeinecy of this amp, but a link to the specs are here:
http://www.jbl.com/car/products/prod...=US®ion=USA
From what i've read, these AB class amps run in the ballpark of 50-60% effeciency... but im not sure so thats why im asking
Also, i'll be setting the gains on the amp from the head unit seperately with 0dBFS test tones i've created in Cool edit... so:
With the EQ on the head unit, the curves I like to run provide
+10dB @ 100Hz
+6.5dB @ 10KHz
The preout fom the HU is also rated @ 2.2V / 1Kohm. I know this drops due to the signal loss, and actual RMS preout put so i guess it will berunning approx 2VRMS..... so with that in mind, running a 0dBFS signal should produce 1 volt thru the preouts, and when the eq's are set to +6dB it would be producing 2V (close to, if not slightly excedding the output, creating slight clipping). So to protect my speakers, whould i set the entire range to +6dB when adjusting my gains, that way i can switch between all of my eq settings on the HU without clipping, and save from another idiot (if they ever get to drive my car) will never reach full output...and protect my speakers from being driven past Xmax?
So, for seting up the amp (with all gains lowered to start, and the HU @ fullpower, adjusting the gains up until i hear distortion, and backing off slightly, and doing the same with each (sub then high pass / full range speakers) Now, most ppl recommend to run the HU with all controls completely flat, but if i set the amp up wit everything flat, yeah... boosted eq's will now clip (?) sp adjust with the eq's already set on the HU???
Im sure i wont be running @ full power anyway, seeing as i want to keep my hearing... but just incase some one else is in my car, decides to crank it, i dont want them driving my speakers past Xmax (maximum travel), so would this be the best way to set up my gains, with my eq's already set and adjusting from there?
Im orry, i'm really new to all of this, but i've been reading every link on:
http://bcae1.com
its pretty detailed! and gives step by step on stuff, but i just wanted to ask others, and make sure im doing things ok.
So, sorry for the long post... but basically my questions are:
1: What size fuse to run in the +ve?
2: Would the above be a good way of potentially protecting my speakers from being over driven in terms of setting gains?
3: Will I need to upgrade from the stock alternator?
Thanx all.... and sorry for the noobness!
Last edited by ozzietj; 26-05-2006 at 02:09 AM.
1. 8ga only allows about 55A safely. So you need to use a fuse smaller than that, 50A would be finem, as the main fuse is just there to protect the car from the power wire shorting out. But since the amp supposedly draws 87A, i'd use 4ga just to be safe. This allows up to about 135A and you'd use a 80-100A fuse.
See this: http://www.caraudioaustralia.com/for...howtopic=42643
2. I think you're getting way too technical about setting the gains. You don't need to work out voltages and all that. Your method of setting gains is correct though. Using tones at 0dB to set gains is definitely going to protect speakers during music as music will never/very rarely get to odB. So your music will be alot quieter and you may actually run out of volume control before reaching the volume you want. I set my gains to a certain CD (can't remember now) but it was a loud recording and now when I play quiet recordings I hit full volume on the head unit well before distortion and well before i'm at a volume i'm happy with.
See: http://www.caraudioaustralia.com/for...howtopic=35875
3. No.
just a thought but your speakers and amp are matched rather well so if you want to be really exact about setting your gain to avoid distrosion/clipping then use a cro on the h/u and amp. but a much easier way would be to listen. its pretty hard to miss clipping.
also you will usually only over extend the cone (Xmax) if you have too much bass for the speakers to handle and they try to push too far, thus just set your hp a bit higher. yet again listen for the best point.
it doesnt really matter if you have your h/u and amps EQ's flat or not its just easier to hear when distorsion occurs because more of the frequency curve is being distortedthan if only a little peak is. true? having them flat just minimises any peaks there.
maybe set your hp and lp using the test tone cd. eh? a bit more accurate if other more "expensive" equipment isnt avalibal.
mate dont worry about thread jacking, if all beginners were as well spoke it would be a better place.
Not a valid input....
Thats not uncommon actually. My old subaru was running a 55amp alt and around 2kwrms. on cold mornings at idle...if I didn't dive for that volume control on start up..the first bass beat would stall the engine.
You put you left foot in, your put your right foot in , you take your left foot out and you slide it all about!
surely the alternator couldnt be providing that much resistance to the drive belt!
Who knows... Mine was a little 1.6L fuel injected 4 cyl and it was pretty obvious, just like if I turned the AC on.
thanks for the replies guys....just a thought but your speakers and amp are matched rather well so if you want to be really exact about setting your gain to avoid distrosion/clipping then use a cro on the h/u and amp. but a much easier way would be to listen. its pretty hard to miss clipping.
also you will usually only over extend the cone (Xmax) if you have too much bass for the speakers to handle and they try to push too far, thus just set your hp a bit higher. yet again listen for the best point.
it doesnt really matter if you have your h/u and amps EQ's flat or not its just easier to hear when distorsion occurs because more of the frequency curve is being distortedthan if only a little peak is. true? having them flat just minimises any peaks there.
maybe set your hp and lp using the test tone cd. eh? a bit more accurate if other more "expensive" equipment isnt avalibal.
mate dont worry about thread jacking, if all beginners were as well spoke it would be a better place.
i've contacted pioneer australia, and their going to get back to me about the output voltage from a tech who will measure it on a osilloscope for me!
Thanks for the clarifcation about xmax, and using appropiate LP/HP settings. The head units got an LP/HP on there, with a 12dB slope (and 50/80/125hz settings) so i'll be running the 4x 55W speakers @ 125Hz and up, and leave the sub to run 125Hz and lower.
I'll make up a test tone cd from cool edit pro 2..... and go from there, that way i know exactly what freq's and dB im putting it through.
Ohh, and yes, general music listening doesn't have much of a dynamic range, pop is usually around15dB or so..... with a little bit of headroom as well.. so must music you buy off the shelf will not reach 0dB. However, there are a few trance / drum and bass artists who do like to use it. One genre particularly is rap, a lot being recorded very close to, or @ 0dB for bass hits.
Im not a big rap listener.... but i do like my drum and bass.... so im not worried about reaching insane SPL's.... im only interested in clean audio output. If i want to get it louder, i'll go for larger, dedicated mono block, and 2ch amps for front and rear each and spekers to match....
but i think 55W. and 300W respectively..... even @ RMS output, will be more than enough for me.... i'd like to keep my hearing.
anyways..... one other confusion, is my dedicated subwoofer control on the head unit in addition to the equaliser??? e.g. volume set @ max, eq's set @ max (+12dB) and SW cntroller set to max (+12dB)
is that in addition to the eq?
by that i mean, if my deck (with 2V preouts) @ max volume totally flat eq's etc... produces 0.5V. if eq's are set to max this produces 1V. Now would the SW output be added to the eq, eectively giving a 24dB boost to my low freq's??? cause if thats the case.... it will clip (producing 4 volts)..am i corect?
and yeah, i am concerned with voltages, as im trying to avoid sending clipped signals from my HU to my amp.... no point listening to cliping @ louder volumes.
Im just trying to make sure, as i'd like to be able to use the full range of settings of the HU when it comes to controlling freq's and equaliser settings, rather than tuning the amp to a certain song, genre..... i'd like to know i can put any damn song in there, and have my HU set in any configuration i like, and know i wont be sending clipped signals or overdrive my speakers. And also, if some else comes along in my car and wants to listen to their cd, it saves me having to adjust the crossovers / gains for the new music, as i can just use the HU to match the music being played. It would be a lot easier simply pressing buttons and finding the right curves (or making my own) on the HU, then having to open the boot, and go through resetting the gains. Call me lazy, but i prefer to actually use the functinality i paid for on my HU. Im sure i'd look like a serious jackass declining them listening to there fav music just because my amps configured for a certain style of music. (althoguh, might be a good excuse if someone wanted to listen to opera.... *shudder* man, i hate that stuff) Sure, it might not be shitloads loud... but if i want loud, i'll just go and ride my v twin! (@ least it can be loud and i dont have to worry about being hassled by the cops, unlike car stereos....thats right officer, can you say "stock exhaust"?)
after all of this, when im driving around, im sure the general population would be more impressed if they heard my music was clean... its one thing to be putting out a crapload of dB's only to be distorted.... and in fact, i think just gives the rest of us a bad image... If we spend some serious dollars on equipment, then we should be listening to some serious quality output.... (heh, my serious dollars... the queens face has frowns... unlike my "i dont care" money i spend LOL)
anyways...cheers all
and thanks for the replies
Last edited by ozzietj; 27-05-2006 at 02:13 PM.
Alt is easy to turn with no load, when it spins fast enough to excite it and starts charging a fair amount of load is req to turn it up on full charge,
If you go to an auto elec w/shop you will see this on a test bench.
ozzietj... As I said above, you're making it too complicated for yourself and wasting some technician's time to test something that you don't need. Him telling you an output voltage isn't going to help you in anyway making your stereo "safe".
If you set your gains with a 0dB source, your speakers will be safe... You will never be able to turn your music up loud enough to clip, and alot of stuff you won't even be able to turn up to high listening levels as the gains will be set so low. Most people set the gains by ear and listen for the clipping, the only other way to do it is with an osciliscope in your car.
If you want to make it impossible for anyone else to blow your gear, you'll need to set all EQ options to maximum (+6, i think), loud to high, subwoofer level to +12 when setting your gains. Otherwise if you set them to 0 someone could adjust the EQ levels up and cause slipping on any 0dB source.
no, i dont think im making i too complicated @ all, seeing as some HU's provide clean signal @ max, some dont.... and clip. As far as knowing what the voltage is... its a simple application of mathematics...that way i can be sure of clean signal being produced when eq curves are applied. Im saying this cause some manufacturers dont take this into account on particular models.
and if you'd like to apply some more mathematics, a 540W system enclosed within that space, will be providing close to 100dB. so what if most music isnt recorded close to 0dB.... even if its 20 - 30 less.... im sure 60 to 70dB will still atract unneeded attention! (police/theives)
ohh...and usage of loudness, all that does is compensate for lower volumes, so when your HU is turned up, the loud effect reduces with more application of volume.... so, this turned on or off would make no diff, as the HU would be running @ max volume for gains setting.
dont mean to come across as rude tho... hope you dont see it that way.
but wasting a technicians time??? well, what i wanted to know was not supplied in the specifications... having purchased the product, im entitled to technical support.
i will spell this out: the only way to almost insure an unclipped signal is to use a CRO on the h/u output. then use it on the amps terminals while setting the gains on the amp. after that set the EQ (a h/u's EQ is VERY limited) with an RTA to raise and hence flatten the frequency curve. and again test the amp with a CRO to idtentify clipping.
now there is a huge problem with this again, music is not the constand amplitude of the sin-like wave formed by the test tone cd.
just because your speaker might very occasionally get fed a tiny bit of distorsion, it wont instantly kill the speaker. also your speaker is rated to X Wrms, this means that your speaker will be able to handle the stated power and possibly more.
also please remember that you cant really say i WILL have my sub LP'ed at X and the speakers HP'ed at X if you have never worked with the equipment before. even an expert/profesional like 12voltking or anyother person with such extensive experience will never just install a set of speakers that they know have sounded best at crossed-over at X because each car is different.
yes, you can apply some simple mathematics but you will get a system which will not perform anywhere near its peak.
i dont work in the car audio industry, but i have posted almost 750 posts in this car audio section, and a very little of these posts are my own personal questions.
stonex is like myself but has over 4000 posts in caraudioaustralia and has been involved in the car audio industry for 4 (?) years.
now dont get me wrong because i am not trying to be rude, but i get annoyed at people who ask for help and then refuse to accept the answers to their questions.
Yeh, your absolutely right mate... sorry all for those that have been offering their years of knowledge and experience, it FAAAAAR outweighs the little, mis understood theory i have come across, and lack of experience with different equipment. You guys are right, i cant accept that the very limited scope of eq's on HU's will adequaltely compensate for what i want to achieve acoustically in the car... after all, manufacturers would be making speakers designed for a certain x over freq, for a particular car... but even then, its all subjective, what one person likes, the other does not. And i was rather narrow mindedly basing my ideas of LP/HP settings, as i found these numbers on the HU provided the best performance combined with a rather shitty, underpowered amp (80Wx2, 120X1 or something) and poor subs @ the time, now that i've gone from elcheapo no name 2x8"'s to one 15" sub....what worked well for one, will not work well for the other. but with going to a dedicated amp, im sure those 3 numbers pioneer let you choose from (50/80/125Hz)... will most likely be no wear near what kind of cleaner output @ x freq the new amp will deiliver. After all, the HU is a HU, not a dedicated amp... so i shouldn't be expecting as much from it.
so yeah, i appreciate the inforamtion supplied. And if after i've had all this installed professionally, i'm feeling adventurous, i'll take note of the settings provided from the pros.... maybe take a photo of the settings on the amp, and note the ones on the HU, and will try that link provided on caraudioaustralia.com if i feel im seriously being hard done by. But, with the addition of dedicated amplifiers, comapared to the "stock" settings from a HU, it will be like night and day.
This did get me to thinking tho this morning for quite sometime. Seeing as there is a lot of adjustment required to get the output you desire, would it be feasible, to use 2 dedicated equalisers? by that i mean, a "master" one, compensating for the the response curves of the speakers, and another one used on top of that (as a base signal, to come as close to a flat response as i can)...to apply what ever curves to suit????
well, if thats kinda unclear.... seeing as speakers perform better @ certain points through frequency ranges... and also, in the environment they are in... could it be possible to say... using a 10 band eq, play those freq's which are tuneable on the eq.... nd using a Decibel meter... adjust it to a certain level, then move on the the next adjuster in the range.... and so on, until you end up with as close to constant output across the freq range? I know it would be even more precis using more bands in eq's./... but i dont know whats available for car audio stuff like that. I was thinking, this way, it would be easier to set the speakers close to flat response... then, using another eq after that one, to apply what ever curve you want (allowin for headroom and all the above thats been discussed)..... This would no doubt be easier to adjust by ear and feel, rather than having to take my eyes off the road, and press this button a few times, etc etc etc. Just another thought i had.......
i know, im looking for more than the average person in terms of "bah, just make it bassy/loud" or whatever.... i just kinda have a thing for quality / tuned / clean output.
thanks again all, and yeah, sorry for arcing up @ yous. I think i just need to get out more, or a job, or a gf...LOL
yep well people do use a couple of EQs like your saying. there will be anything up to a 40 band eq to flatten (raise the dips in) the frequency curve.this is done with a real time analyser (RTA). then you can have a smaller 10 band in-dash eq which you can tune to suit.
but if your thinking about EQs seriuosly and what not maybe you should consider deadening your front doors (and maybe the whole car). i can supply a pic of my doors done.
what sort of equipment are you running? you will be wasting your money for a very small improvment on an eq compaired to getting much better splits and h/u.
Posting Permissions
LinkBack URL
About LinkBacks
Reply With Quote