Audio question
 

Im looking to upgrade my stereo system in my 93 accord... Had two 12" l7s running off a 1100 watt amp... Long story short, I'm in the process of upgrading to two 15" Memphis m5... Gonna be ran off two 1200 watt amps ( hifonics ) my question to u guys is... Do I get a second battery such as a Kinetik with high amp hours or get a high output alternator??? :cool:
Sorry it's my first time posting ...

one isnt really a substitute for the other. what model hifonics are you buying?

Two brz1200.1

Do you have a Wagon?

How are you going to properly fit 2 - 15's in the trunk?

To answer your question, you should start with the Alt first.

Agreed,
Start with the big 3, a new main battery (AGM with high reserve capacity), and a new alt.

Crispin
Its a coupe... From my understanding each sub needs 3.27 cubic feet... We took measurements just yesterday... They were pretty happy with the size of the trunk but were gonna contact their rep to see if he recommends doing any tweaks to the size of the port for that same reason. I told them they can use the whole trunk and if they needed to we can cut a slot out of the rear deck to to fire the port up at the back window but they said that wasn't a good idea =/

As for the alternator...
I've found a few on line... I sent a email to Ohio generator and found some other ones such as power bastards, load boss, and some other kat named nathan peddicord ... The electrician at work told me to rip my a/c and put an additional alternator in... Wasnt too sure about that one lol
But I'll look into a better battery as well ... I already have a optima but compared to them Kinetik and other audio batteries its far from the greatest ... Thanks

I bought an 180 amp alt from ebay and it does well especially for the price paid.

I am running a box that is just over 6 cubic feet (including port) for a pair of 12's and it just barely fits.

Now you can build the box in the trunk like neophyt just did but getting 2 -15's with a proper port is hard to do.

Now if you are planning on going sealed well that is just silly, you would be better off building a proper box for the 2-L7's

Here is how a 6 cube box looks in the trunk, not much room left in the trunk

Attachment 18519

Thats massive, I bet it sounds nice!!!
My l7s are ported and sound really good... The same kat I'm buying my 15's from made my box for them...Yeah no sealed boxes here lol even thou I use to have two 12" cvr in my 2001 gt that way =)
I hear what ur saying thou, my boy put two 15" 9500 in his blazer recently and the box is fkn huge... So if they call me Tuesday or I show up and they tell me they can't get it right I think ima be posting some 15's for sale on Craigslist lol

Do u remember what seller u bought the 180 alternator from
I think ima have Nathan from excessive amperage do mine if he has time. $350 isn't to bad... Load boss has a alternator for $180 but couldn't find any reviews so I'm a little sketchy

excessive is a great alt. and they stand behind their product. I bought one and later decided to switch it to an external reg. I shipped it back and all I had to pay was to ship it to him. nate rewired it at no charge and overnighted it back to me without charging me for the shipping back.

also there is a little over 9 cubes in the trunk of an accord. my box for my two 15s is right around 6.5 cubes after displacements. the only real problem is the port is going to be a little small if you do it the same way I did. I have 62 sq in of port.

also on the battery I got a deca intimidator. not as flashy as an xs but has the same power ratings and is agm. it was like 180 before shipping.

I paid $130 shipped for my alt with a 1 year warrenty.

I am trying to get you to understand the size of our trunks.

That box has a net of just over 2 cubes per driver.

You will not be able to get a box with over 3 cubes per driver plus port, wood, and driver displacement unless you build the box in the trunk.

Looking at Neo's build that is something I would never do.

Plus I can slide my box forward and get my spare tire out (which I just had to do 2 weeks ago when i had a blowout on the interstate)

very true. if you want 15s the box is semi permanant. gonna need a recip saw to pull it out. and you will definately loose the stock location of the spare tire.

if you do them straight across the front and do a aero port out the deck. you may be able to have the box short enough to stand the spare tire up in the rear of the trunk. you will either have to cut into the top of the box or get shallow mounts for the rear deck or come up with another creative way to get them in there.

and in all honesty you could probably get just as loud with a single high end 15. I am a gpi dealer and by the time my car is finished it is intended to be a demo car. so impressive looking is almost as important as the volume and sq. there are trade offs to be accounted for for everything. my two 15s are the way i went for more than just one of the reasons. it was a decision that I decided would be best for my goals.

what are your goals with putting two 15s in the car? if it is just loud, I think it is important to be aware that there are people hitting 150s with a single 10.

I agree, I know that I'm going to have to give up my entire trunk to fit the subs properly ... That's the first thing I told my boy at his shop, spare tire and all he can have it. I had my mustang box built inside the trunk as well after my 12" cvr in a sealed box wasnt cutting it... Lost it in an accident thou... Sounded decent with two 12" m3 running off a 1000 d... Anyhow, I rember having a 8" bazooka tube, 10's, a few sets of 12's and now I just wanted to own my first pair of 15's =)
Don't plan on competing even thou i would like to know what it will do on a meter after everything is done... Now that I think about it, they haven't had a db drag or any kind of sound off in years around here.

But thanks neo, I'll see if nathon has time to build me a alternator...
I'll try to upload some picture of everything once everything comes in...
I'm all ears to advice, thanks everybody!!!

completely understandable. I think if that is what you want then go for it.

So I finally installed all my equipment but I'm not sure how to upload pictures... I'm using my iPhone can it be done? Im kinda of a square at these type of things lol Can anyone help me post pics plz

I will pm you my email addy.
Send them to me and I will post them for you.

here are the pictures of the install

http://i139.photobucket.com/albums/q...-10r/photo.jpg
http://i139.photobucket.com/albums/q...10r/photo3.jpg
http://i139.photobucket.com/albums/q...10r/photo2.jpg
http://i139.photobucket.com/albums/q...10r/photo1.jpg

Definetly looks like a solid box to me. Whats the air space per driver on that thing? Looks a little small. I was under the impression you needed more air space if your going ported?

Not too sure bro... Each woofer had a recomended gross air space of 3.4cf but how he figured out the specs for both of them firing out the same port I have no idea lol sound awesome thou!!! Jack did a hella of a job!!! Taking it back to be carpeted and for some sound dampening material ... My poor car is gonna fall apart lol

Also installed a alternator from "EXCESSIVE AMPERAGE" ... Works great! ( thanks Nate )

Oh and thanks "CRISPIN" for posting the pictures for me!

nice work, guys

to answer tylers question. you do need more airspace for ported boxes. doesnt look terribly small, maybe a little. it seems like as the box grows in size air space starts adding up quickly, especially in cube style boxes. you have to remember you only loose the wood thickness. when the pieces are close together then that .75 or 1.5 in border eats a lot of space. once you get some significance size you add airspace quickly and dont loose much space to material.

"more airspace to go ported" is relative.

box volume Vb affects the overall Q of the system. for SQ, you typically shoot for a Q of 0.707.

A friend told me ported boxes only really add 3db increase is actual volume. How accurate is that?

kha, I would assume that going for 2 15s they are going for spl not sq. generally speaking a manufacturer will suggest a higher box volume for a ported box than for a sealed box is what I was meaning.

tyler, it is hard to say it adds 3db. there are a lot of factors that affect how loud something is. also the louder you already are the harder it is to get that 1 db gain. at 100 dbs you can turn the volume knob up a little and gain a db at 150 you can not gain an entire db as easily. ports also are not standard. one port is not the same as another just as one box is not the same as another and one car is not the same as another.

THe common theory is that a vented box gives a 3dZb addition because the rear wave combines with the front, but after traveling some distance to be in-phase with the front. Also, you get more excursion compared to sealed.

Depending on the design, you can get more than 3dB compared to sealed.

People say they want SPL, but they use the system for music every day. Even a Q=0.707 will be stupid loud.

I wasnt necessarily arguing with you kha, I am sure you know more about the tuning than I. I was just speaking generally suggested airspace is higher on a vented box.

also what a meter reads is not always the same as how a system is interpreted by the ear. a system doing the same number at a lower frequency, at least to me, seems much louder.

agreed. we're a team here. no worries. just adding information into the mix.