Thread: My plan: am I on the right track here?

Originally Posted by soundman98

don't go by max wattage-- there are many ways they can really fudge max wattage ratings.

have you heard those speakers at all? make sure that they sound goo dto you before you buy.

also, caps are useless. search for some of 'oldspark' posts, wher he goes into detail why even a small battery is better..

Nope, have not heard the speakers yet, I'll make sure i take a listen before. What type of speakers do you recommend if I have two 10's in the back? Can you direct me to a particular product? Budget for speakers is $300.

I'll research oldspark's posts. Thanks for the direction

Originally Posted by doncarbone

what can i look at to keep myself safe? can anyone recommend a solid capacitor or possibly an extra battery to ensure i have enough power?

Why do people think they get "extra power" from a cap? Or battery?

BUT - that is in reference to the alternator being too small which is how I interpret your (doncarbone) question... "... am I in good shape in terms of power here, or will my battery get molested by the above ....".

NOTE - I was looking for miserable & crying emoticons that reflect my feeling about dishonest people (re caps & batteries)... I 'm not flaming doncarbone nor anyone else that is conned or unsure - such technicalities ARE confusing!
And FYI - soundman98's reply cheered me up. Again!


NOTHING makes up for an undersized alternator except the removal of loads.
A bigger battery merely means longer reserve time until it flattens (ie, to make it home to a charger etc). (And a cap is essentially a very small battery.)

If you mean power surges that cause voltage dips - that's another issue - and that can get complex.
EG - alternators can typically supply (at least) twice their rated current for short durations/surges.
But the voltage drops can be in the distribution (voltage drop along cables, fuses, connectors).
But that shouldn't worry a good amp - ie, hi-power audio amps have SMPS (Switch-Mode Power Supplies = dc-dc converter) which should or could tolerate voltage dips.
For dip-sensitive loads, halving the distribution resistance (cables etc) HALVES the voltage dip. Otherwise caps are recommended, but usually small AGM batteries are better (& cheaper) than multi-Farad caps for that purpose. (The small 1.2AH or 7AH AGM battery is located near the amp instead of the cap - ie, at the same close location.) [There may be situations where a cap is superior, but whilst people argue things like ESR, they have no hope of figuring out if or when a cap is superior. (LOL!)]


Back to the alternator....

As soundman alluded - the only Wattage that is useful is RMS as that provides a "true power" figure. (Peak used to be 2x RMS, but I have seen peak commonly 3x and as high as 10-times which is just ******* pointless.)
But that's likely to be a maximum power consumption - eg, full volume, high voltage, etc.

Yes - use fuse ratings or RMS (input!) power as an estimate of you max alternator power requirement and cable sizes etc....
But what is your average real requirement?


Anyhow, irrespective of sizing, how do you know if your alternator is failing to keep up?
A voltmeter! IMO a voltmeter is the only way to confirm alternator sizing.
It also allows monitoring of charge state and battery condition.
But that I will leave for you to search. I'll only repeat so much ramble....

Originally Posted by doncarbone

Nope, have not heard the speakers yet, I'll make sure i take a listen before. What type of speakers do you recommend if I have two 10's in the back? Can you direct me to a particular product? Budget for speakers is $300.

as a rule, i do not make speaker recommendations-- every speaker sounds differently then others(to some a $10 boom box sounds great, to others, a $1 million stereo system is great), so any recommendation i make would be based on my opinion, and just 'cause its my opinion doesn't make it right..

my current stereo has cost about $1,500, so the specific products that make me happy are a little pricer then what you originally indicated you wanted to spend.

the best suggestion is to take a demo disc of your favorite music to the car audio store, and listen to the different speakers, and see what fits your style.

and if the shop doesn't let you demo the speakers you are looking at, leave. i have had shops go as far as to allowing me to setup the subs in my own car to hear how they sound, and there is no reason to not hear what you are getting. it is like buying a car without test driving..


depending on how interested in speaker setups you are, you could also build your own setup using separate speakers from companies like madisound.com, or parts-express.com.

this gets a little tougher because there is really no way to listen to the speakers before buying..

i changed my front speakers for under $150(using some Dayton ND28F-6 tweeters, and some peerless brand 6 1/2" hds mids) to something that rivals the sound of $400-600 car-audio specific speakers..

the trick with this is to first learn what you desire in a speaker(loud highs, or boomy bass, etc.) and then locate the very detailed reviews that list the speakers characteristics.

a good starter site is http://zaphaudio.com/ they have tested a lot of speakers, and give very detailed results..

Originally Posted by soundman98

the best suggestion is to take a demo disc of your favorite music to the car audio store, and listen to the different speakers, and see what fits your style

i actually have a fairly eclectic taste in music -- so really im looking for something 'mutli-purpose' or fairly well rounded. my biggest concern above all else is that the dual 10" subs i'll have blasting in the trunk might drown out the speakers...which i've found from listening to a few of my buddy's systems is awesome for showing off the bass, but not very practical for enjoying the music.

having never had a sound system of my own before, what can i expect out of the 2 10's i listed above (MTX)? does anyone have these?

thanks for the response man

getting as much as i can from a online post, i also have a wide range of music tastes(from electric, to country, to rap)..

you will probably want to look for a speaker referred to as "laid back." many speakers in the budget range usually pull you in by grabbing you--usually by extremely bright highs, or overly dramatic bass- things that can sound good in a 15 second demo, but can really wear on you after hours, or a couple days of listening.

this is part of the reason for using your own music for the demo-- you should be familiar with it, so you know what to expect where (does it seem like the drummer is behind the singer, and can you hear that he is using cymbols? or does the tone of the leads guitar, or voice sound like it should, or is any of it over-dramatic?)

something i have learned to try is to try to demo a speaker way out of your budget as one of the first speakers you hear-- these speakers are usually some of "the-best-of-the-best", and should be very close to what you expect to hear with your demo cd.

from there start working with speakers less then, or around your budget, and see what different effects they have and if it is the tone you want. the easiest way to do this is to use 1 song for the entire time, and to start the section over on each set of speakers.. i usually spend at least a hour, or more doing this..

for the subs, i have feel that mtx subs are very boomy, and not very 'musical.' meaning they are great when you want to rattle windows, but not so good at soft, or gentle bass-- like in country, or classical music.

most of the brands at stores like best buy will have this tone..(mtx, kicker, alpine, kenwood, pioneer).. and before anyone complains about me being wrong, i own a pair of kicker comps, and currently runa pair of cvr's..(some day, i tell myself i will swap them out..)

for bass that is more refined, you will need to look around-- car audio specific sites, like diymobileaudio.com is a great one, just check the reviews for what everything sounds like.

i currently have been entertaining the idea of some peerless xls subs. they seem to be built very similar to my hds mids and my recent experience with the mids are very promising..


LOUD BASS: you can always tune the amount of bass your car has--the easiest way is with the gain control on the amp-- many people around me turn it all the way up...

also, something else to keep in mind is that you do not need 2 subs, many people find that 1 sub is plenty for their needs. sometimes this can allow you to spend a little more on 1 really good sub, instead of 2 mediocre subs..

there is also difference sizes to take into account.

8" are just a little extra ommph in the sound, but the speakers can run out of steam quickly if you like it loud.

10" imo, are the best well rounded subs-- they are small enough to be consistently quick and accurate(there's a physics lesson here), but large enough to mostly keep up with louder volumes--crossover setup can play a part in this.

12" they are not too far off from 10's in terms of 'quickness' but physics says that they move slightly slower due to more mass in the cone--but they are louder--due to being larger.

15" anything cheap here is dreadfully sloppy-- i have a couple of them. once you get to higher end models, they start to quicken up, but again, similar to 12's, they are slower yet, due to physics, but also louder, due to the added amount of surface area..

i think that is it for now.. now just to click "quick reply"...(congrats to anyone that read all of it!)

I just got a lot of good info for my shopping list. Many thanks to Oldspark and soundman98.

Good luck with the project!