Sagara09

I have never been a huge audio person with my other cars. All of them have been performanced based until now. I would like to get a sub or sub but I am not 100% sure as what class amp to go with nor the rms on the sub. I am looking for something that hits lows real clear but not too overpowering, if that makes sense. I was thinking perhaps 1 12" kenwood but before i come to a conclusion, I would like to hear opinions from more experienced people. I will be going with a bandpass box as well.

Greg S

iTrader: (1)

If you are looking for something that hits lows real clear but not too overpowering then bandpass is probably not the dirrection to go, unless you plan on having it custom made and tuned for the car. In general bandpass boxes tend to be on the boomy side, especially the pre-built boxes. They have a lot of output at the tuning frequency of the port but the bass above and below that falls off quickly giving it a single note sort of sound. A sealed enclosure will usually go the lowest but requires more power than other designs to do it. It is also the smoothest sounding enclosure and the easiest to tune. Inbetween is a ported enclosure which has good upper bass and picks up more down to the tuning frequency of the port then tends to fall off below the tuned port frequency.

As for what class of amp I tend to like class D amps as they are very efficient and give you a lot of bang for your buck. The don't do as great in the midrange and highs but they are fine for bass.

As for the RMS of the sub that is probably the least important factor unless you plan on blasting the sound a lot. Somehting in the 150 and up range is usually sufficient if you are not heavily amping the rest of the system.

KaneoheKoa

I agree with Greg regarding bandpass boxes. Championed by Bose, the took the car audio world by storm in the late 80's to early 90's. No speakers to see, just large ports (amazing, sound coming out of holes with not a speaker in sight). Any distortion in the driver was filtered out by the box, creating a clean sound. Alas, they had problems (even now, and Bose still uses them)*. Narrow bass output range for one (doesn't go deep), finicky to design (change one parameter and the whole thing has to be rebuilt) and was a space hog (had to have a proper sized enclosure behind and in front of the driver). Almost gone from the home audio scene and stays in the car audio scene because it looks stealthy.

A well designed ported system will do nicely, as will a good sealed enclosure system. I do suggest upgrading the head unit and front speakers, as they are the main sound that you'll hear. A good sub will bring out the power in the music, but a good front speaker (backed by a good amp) will bring out the music with clarity and presence.

*had a customer have us install two Bose Acoustimas systems in his van, backed up by two 300w Kenwood amps. Total price was over $1800. The frequency response curve looked like the Himalayas and peaked at 98dBA. I had just installed pair of Polk 3 way separates (tweet and mids in a tear drop module) and a pair of Madisound 8's in a face to face configuration to save space (got it down to 1/4 cu ft, small for that time,). Powered by the original Punch 45 (22.5 wpc x 2). Hit 105dbA and smooth with only a 6 db ripple near the midrange crossover point. Total price: $400. The look on his face when he heard my Tercel vs. his, Priceless.

RedDragons

Agreed on bandpass boxes, they are not a good setup for quality bass. I'm not a fan of kenwood subs either btw.

From your needs I would say a sealed box, 10-12" sub approx 400-500w rms with a properly matched class D amplifier. If you want long low notes a properly tuned ported box would be the best, this would probably need to be made by a stereo shop since I'm guessing your not familiar with building boxes.

JDMJim

2 10's sealed is what you need

Sagara09

I went with this for the time being. Things will change as time goes on.
2 Kenwood KFCW-3012
Kenwood KAC-7205 1000 watt 2 channel amp
Obcon Vented sub box.

RedDragons

you would be better of running the kac-9105d amp instead. the amp you selected dont have the juice needed to power those subs which rms @ 400w each. you would be severly under powering your subs. the amp i mentioned can be run at 900w rms @ 20hm. if you wire your subs in parallel you will be able to acheive that number just make sure you keep your gain down below 50% so as not to overdrive them.

7205
9105
Subs

Always check the RMS (rated power) rating. Peak/max power is BS, you will never reach that number.

mrmondaynight

WRONG. Rms is only a thermal guideline for speakers. If your speakers have an rms of 400, you DON'T need an amp that does 400. Going from 170w to 400w should net him around 3-6db in output which isn't that noticeable in the realm of things. That amp is better suited for a pair of comps, though.

The box they're in is a lot more important than the power they're getting.

RedDragons

Well I just got schooled, my memory was a bit foggy. I forgot RMS, is root mean squared. You are correct on the box being more important. But isnt it also true you should match up your equipment? My advice was not wrong. If you have a speaker rated at being able to run 400w on it continuously you should match your equipment accordingly.

Regardless of whether I'm right or wrong. The OP should gives these a read to understand better what we are talking about.

http://www.aqdi.com/rms.htm
http://answers.yahoo.com/question/in...0075148AAhrmEV

mrmondaynight

It's good to do so to get maximum performance out of your equipment, but you don't have to. 9 times out of 10, the speakers or subs won't see all that power anyway since music is dynamic.

RedDragons

I agree, especially since most of the music people listen to in their car is download from itunes or bit torrents and most people dont know to download high bit rate mp3s. When you listen to digital music of low quality it compresses the high and low frequencies.

KaneoheKoa

With the abundance of high gig iPods and thumb drives, it's almost a crime not to use 196 data rate. All of my jazz and acoustic (read classical) is at least 196, some even higher. Alas, a lot of new music is not worth even 196. And this is not an opinion of musical taste (BTW, who is this kid, Justin Barber???).

A lot of the newer music that gets airplay (and eventually downloaded) is processed in the production mix room so there is almost NO dynamic range (difference between soft and loud). the mix is recorded as close to maximum level as possible, just so it sounds loud at any volume. And loud sells. A little old YouTube about the situation entitled "The Loudness War"
http://www.youtube.com/watch?v=3Gmex_4hreQ

RedDragons

That is what I'm talking about, compression does something similar to that. I know most of the rap on my ipod has the same produced effects as in that video. But when I throw on some Led Zepplin or some older Metallica, I want to hear the music the way it was recorded. I wish ipods supported flac and ogg vorbis without having to convert to apple lossless to play on my ipod.

JDMJim

well, eventually, compressed music will be the standard. My ipod is for the road andcruising and my CD's are for showing off. The industry is moving to nuthing but Ipods or MP3 players. it's a shame that kids think that is what sounds good. they really have no reference point to compare. Good sound to most is an earbud connected to a phone. and with I-tunes one hit wonders pushing the movement these days....

KaneoheKoa

I don't think the problem is the iPod (and digital formats in general), but in the record producers, be they big companies or garage bands with Macs. It's the drive to make the music as loud as possible all the time (and brickwalling the signal levels). I hate to admit, but when I'm in my car, I'm not concentrating on the sound, whether I had it at 96k, 196k or 256k encoding. I just want my tunes. No matter the encoding level, I DO want my soft and my loud in the music!

JDM is sadly correct: mediocre is going to be the norm. and people wonder why I still keep my CDs and LPs and Grado headphones...