butterbeer2fd

Sup guys I've been researching a bit for my subs and amp, I plan to run a JL audio W3 with a Kenwood KAC-8105D. Right now I don't have a sub enclosure, but I've seen them run anywhere from 15 bucks to like 80 dollars, is there any difference?

I contacted a local car audio shop and they told me that cheap ones could actually fall apart but I want to hear it from you guys and see if there really have been any stories of cheap enclosures collapsing. I only plan to run my subs at around 300W RMS if that makes a difference how much vibration the box has to take itself lol.

Do you guys recommend any certain enclosures? The local shop is asking $65 just for an enclosure and it exceeds my budget but I'd rather spend extra for quality parts.

Thanks!

davidhseo

You get what you pay for. Get the quality box for your sub and you'll see why you paid extra for it. It's like getting a turbo kit on your car and trying to decide whether a 2.25inch exhaust is better or a 3inch.

mhart

what brand is the better box? usually cheap boxes are made of partical board wood and good ones are mdf. also what size sub? is the box ported or sealed? a sheet of mdf is about 30-35 dollars, then add in the glue and carpet and screw or nails and $65 isn't a bad deal on a box.

Rand The Man

Depends on what kind of tunes you jam, if your looking for rap and hip hop wobble you'll want to go with a Vented box, if your going for rock go for a sealed one. If anything try craigslist I'm sure you'll find something!

butterbeer2fd

haha I listen to a little bit of everything (from rap, trance to country) except for classical. From what I read on the internet sealed boxes hit cleaner but not as hard as ported boxes? I'm more of a quality over quantity guy so I think I'd go with a sealed box. I'm going for a 12" sub...I might just go with JL audio's sealed W1 since they made the box specifically for that sub and it's trustworthy!

Another question...I actually meant the JL audio W1 matched with the Kenwood KAC-8105D. Is this a good combination or is my sub going to be overpowered? Here are the specifications:
12" JL Audio W1v2 - 300 W RMS @ 4 Ohms, 600 W Peak
Kenwood KAC 8105D - 300 x 1 RMS @ 4 Ohms, 500 x 1 RMS @ 2 ohms, 1000W Peak

ken9

Kenwood don't see to be under-rated at 2 ohm 1000 watt peak.. LOL..but should be good for that sub but is it DVC or SVC..

Rand The Man

You'll be fine even if you bridge it just don't jam your bass all the way up. My guess is you haven't had subs before, so I'll save you some money, unless you dont mind replacing your sub for melted voice coils you need to break the sub in for 3 months then adjust the tune after that leave it for another 6 months and then go to your final tune, I always suggest tuning your head unit before tuning your amp. Best head unit for tuning is pioneer hands down.

1fastvtec

I ran that exact amp in my old Accord, and its def underrated. The best enclosure you could have is a custom one built for your car and your sub. Like the guys stated also, you'll have to decide on whether you want ported or sealed. Each car has is own inside frequency, so its best to tune the enclosure based on each car. I hate pre-fabbed boxes. Most of them are junk.

butterbeer2fd

Hmm gotcha, yeah this is my first sub so I'm kind of clueless haha. It's supposed to be a SVC sub...I just don't want to overpower my sub cause I'm worried about blowing it out but I can cop the Kenwood amp for a pretty good deal. I believe the sub I'm lookin at is SVC.

I'm planning to run this on the factory deck so I'm not sure if I can tune it haha but I'm not really one of those guys to blast the crap out of my subs I just want enough to rumble my seat.

I'm not really sure what bridging it means LOL I'm getting it done at a trustworthy shop here in norcal so I'm letting them do all the work.

Edit: Just did a quick google on bridging...my amp is a monoblock and I believe you need 2 channels or something?

Rand The Man

Bridging can be internal or external depending on the application. Since thats a mono block, if the sub is bridgeable it will have 4 terminals instead of 2. Idk how running it off the stock head unit is going to work so great being as there is no tuning for subs what so ever unless there was a pre-existing sub or a subwoofer option for the vehicle. To 1fastvtech: I've seen my share of crappy pre fabbed boxes, and you are correct most of them are junk, but the place I go to out here in Illinois has great pre fabs and they usually give me a box for 50 or 60 bucks, although Ive brought them thousands of dollars in customers!

fcm

As mentioned, one of the diff. between a good box and a bad one is material, a good box will be made with MDF, [the thicker the better] another factor is build quality, things like how it is put together, [glue, glue and nails or glue and screws] if the box is "braced" or not, is the MDF sealed or not, [MDF is a porous material].

The box needs to be the correct size, [internal volume] for the sub for best results, and the correct "shape", EG; a 1cuft box should not be 12"x12"x12", a cube, it should have as many non parallel sides as possible and diff. HxWxD.

Your sub, the JL Audio 12W1v2 comes in a SVC 4ohm or a SVC 8 ohm, you will need the SVC 4 ohm if you are going to use the Kenwood amp, 1x300W RMS into 4 ohms.

Your best bet for a cabinet is the loaded JL Audio box, [if that is what you meant by, "...I might just go with JL audio's sealed W1", JL sub boxes are well built and it will be the correct size for the sub.
A sealed box is also the way to go, for best results over a wide range of music.

The Kenwood amp is technically a little underpowered, you would be better off with something like a 1x325W-1x350W RMS into 4 ohm amp, as it is always better to be overpowered then it is to be underpowered, more speakers are blown by underpowered amps then by overpowered amps, it is not the wattage that blows the speaker, [speaker is rated at 600W peak] it is distortion, [clipping] that blows speakers, it is much easier to drive an underpowered amp into clipping then it is to do so with an overpowered amp.

With that said, the Kenwood amp will do the job, and as mentioned, braking in the sub before you drive it hard will not only extend the life of the sub, it will also sound better.

The one improvement You could make, [it will cost you] is to use the 12W1v2-8, the SVC 8 ohm sub, [should be the same price] and find an amp, [more expensive] that is 1x300W RMS into 8 ohms. [1x600W RMS into 4 ohms] it will improve SQ, [tighter, more accurate bass, better linearity and the amp will run cooler].

Back to the box, if you want to buy a pre built, look for an MDF box, using at least 3/4" MDF, buy one that is a little bigger then you need, the 12W1v2 needs a net internal volume of 1.25cuft for a QTC of 0.733 and an F3 point of 41.7Hz, so you get the pre built with an internal volume of more then 1.24cuft, [lots of those around] use up the extra volume by installing bracing, [1"x1"x1" blocks glued along all inside seams] then seal the MDF, [inside] with a wood sealer, [I use fiberglass resin] then run a bead of silicone along the seams, you can make a very good quality box from a not so good cheaper box.
One more thing if you buy pre built, make sure the mounting hole is the correct size, it should fit the speaker perfectly, a 12" pre built box has a mounting hole that will fit a lot of 12" subs, the JL Audio 12W1 uses an 11.0625" (281mm) mounting hole, a mounting hole that is bigger will making mounting and sealing the sub very difficult. 94

butterbeer2fd

^You hit it spot on. Thanks man!
And yeah I was going to go with the sealed box from JL audio themselves.

As for the amplifier, is it THAT bad to run my current setup? My only problem is that I've already exceeded my budget lol, do you guys have any suggestions on good amps within that range? I'm really new to the whole car audio scene so I honestly don't know which companies are good or not good like Crunch or Kenwood.

EDIT: What do you guys think about Rockford Fosgate? I found this one that seems pretty fitting it's 1x320W RMS @ 4 ohms
http://www.sonicelectronix.com/item_...1-Amp-Kit.html
HOWEVER, it is a Class A/B amp and not a Class D like the Kenwood...I didn't read much on that but from what I did see Class D is supposed to be better in terms of overheating? Or that Class D uses power more efficiently or something than Class AB lol.

One last question here, I don't need a capacitor do I? I like to just chill in my car and listen to music a lot (can range from 30 minutes to 1 hr) but I don't want my car battery to die from that lol.

edzy

The sub is 125w so the 8 ohm version can work, too. I'll go for the 8 since it'll be less stress on the amp.


Subjective at best

It's always better to have more, but under powering doesn't blow subs, clipping does. The 2 don't collorlate(spell check) with each other.

builthatch

a box built via a program that yields a box design based on the specs of the driver and your favorite type of response will be ideal - if you do it yourself, it can be reasonable. oh, and i don't know what's out there now but back in the day and with this latest box i built, i don't use terminal cups. i drill a hole, run the wires out from the sub, and terminate with high quality big gauge male spade connectors. then i seal the hole well.

fyi i found that factory sub box recommendations can be quite a compromise.

for instance, the alpine type r 12 i've been running in my mazda for the past 3 years had a factory ported box reco of 1'-2', with their (alpine) optimum design at 1.5'.

however, i designed a box with winisd and the flattest response was yielded using 2.5'. i was not entirely sure i was doing it right since it was my first foray with such a program - the size seemed so big, so i had a pro design a virtual box with the same response request and his box came out the same specs and porting - 2.5'

i agree. as long as you are careful with "the *****" and tune it right, just like a boosted car ; )

there is a process, OP, for setting gains. it is pretty failsafe.

you can keep an underpowered sub happy. people bagged on me for using two channels from a pdx 4.150 to drive my type r 12, until they got in the car...

edzy

They do this for a reason. Those tiny boxes they recommend are peaky as hell and usually peak around the 40+hz area where it'll be it's loudest. Kids want loud, not flat...that's why manufacturers do that.

butterbeer2fd

Hmm sounds good I'll go for a legit box.
You guys have any suggestions for any good amps that run a little over 300x1 @ 4 ohms? The Kenwood sounds like a great deal but reliability and doing it right always comes first for me.

Edit: I think I'm going to go with the Rockford Fosgate amplifier (class a/b amp). I read up and here's what i've conluded:

Class D amps: Uses electricity more efficiently, sounds pretty much like a class A/B amp
Class A/B amps: Uses more power (and therefore more strain on alternator, etc), supposed to be better in terms of sound quality but to the ear it isn't a noticeable difference.

^^If any of that info is wrong then let me know!

Rand The Man

Power Acoustic makes some good amps there are a couple not huge name brands that were the gate way to the industry.

edzy

Power Acoustic is one of the worst brands in car audio.

fcm

Pt, [thermal] for the 12W1v2 is 300W, recommended power is about 130 W continuous.
The 8 ohm on that amp would be underpowered, would be driving amp into constant clipping.

For a guy, [audio no0b] looking for a pre-built box, who listens to a wide range of music, the sealed box is the best way to go, that's not subjective, that's the smart thing to do.
Yes, that sub would "sound better" in a slot port box, good luck finding a pre-built that would work.

What part of, "it is distortion, [clipping] that blows speakers, it is much easier to drive an underpowered amp into clipping then it is to do so with an overpowered amp" did you miss? 94

edzy

if what u say was true, every time you had the volume on anything but maximum, you'd fry something

now, what clipping does is "chop" the top and bottom of the wave making it square. some will tell you that "square wave" will damage the speaker, regardless of any other conditions. clipping an amp or speaker, normally, will not damage anything.

so what kills speakers? overpowering them or calling them to do things they can't for too long a time. overheating the coil beyond its capability is the short answer. the "RMS rating" is only a thermal guideline determined by limited testing, after all. if you give a "500w" speaker "500w" it's fine. the problem comes when you overdrive the amp through a non-judicious use of the gain and volume *****. that square wave with the tops missing...the position of the wave moves towards the upper and lower limits making the amplitude larger [the wave appears wider, that is, more "info" the amp has to reproduce]...therefore requiring more from the amp...and letting the magic smoke out of the speaker.

here's the long version if you'd like to peruse it http://www.bcae1.com/2ltlpwr.htm the very last line way at the bottom is crucial

butterbeer2fd

Hmmm...okay so would it'd be okay to use a 320x1 amp on a 300W RMS sub.

As for "tuning" your gain *****, do shops usually do this for you when they install your amp? I've looked up some ways to "tune" your subwoofer but they were all done on aftermarket head units. Do you guys have any links how to tune your amp/sub combo for a factory head unit? Thanks!!

Here are all the ***** I would have on my amp http://images.sonicelectronix.com/im.../r5001_ak4.jpg

fcm

You will have no problem with a 1x320W RMS into 4 ohms amp, if you use the 4 ohm driver.

edzy tends to get very "technical" and technically he is correct, but in the real world things are a little differant, case in point, I have replaced more blown car speakers over the last 35 years on underpowered systems then I have on overpowered systems, [by a very wide margine].

Tuning, [amp gain] the amp is no diff. with the stock HU then it is with an aftermarket HU, turn gain down on amp, turn volume up on HU, as far as it will go and still sound good, [no distortion/clipping] but no more then 75% or 3/4 volume, make sure bass and treble is "flat", [in the center] slowly turn up the gain on the amp untill you can hear the sub, leave it like that for a week to allow sub to brake in, after a week or so, repeat the above but turn amp gain up as high as it will go with the sub still sounding good.

Use a good bass test disk, or music with good clean bass. 94

edzy

That wasn't the amp's fault, though. Stupid user/installer caused that by jacking the gain up.
If you can afford it, always go with more power.

OP, read this.
http://www.mobileelectronics.com.au/...howtopic=35875

butterbeer2fd

Hm okay gotcha...as for the other three settings on the amp, there is "Frequency (hz) low pass only", "punch bass", and "phase" Any idea what these do?

When you say set bass and treble "flat" do you mean flat on my factory head unit?

And lastly...my amp comes with a remote volume control at the driver's reach. When tuning the amp, what should I do with the remote volume control? Turn it up or down before I tune the gain?

builthatch

low pass only will be where the cut-off is for the bass frequencies. if you set it at 80hz, then anything below 80hz will "pass" through the amp and on toward the sub.

punch bass...that is probably some sort of bass enhancement at a given frequency. i don't know anything about it, maybe the others do, but i do know i'd probably not use it. if the enclosure is properly designed and the system is tuned, i'd assume you would not need it.

phase, as i've understood it, is when the speaker sees the signal to help make a seamless blend from subs to mids. that is something else i've never adjusted, just left it at zero.

and yes, flat would mean everything at "0"