PsychoSMurf

Alright my fellow jeepers, I need some advice and I hope some of you might have some experiences that you'd be able to share from as Im new to the speaker scene.

In summation, my Overall question is: is there a huge difference in the performance between the SO B8P-T and building a custom box with an 80$ range component sub? I found I can get the B8P-t for about 120$ so that was looking pretty good but I dont want to waste money on something that wont have much benefit. Are they equal in performance or should I go ahead and try to build something?

Background below:

I have a 88 xj 2 door. I just replaced front door speakers with Pioneer TS-A1375R (5-50 watt RMS) and the rear hatch ones with Rockford Fosgate Prime R152 (2-35 watt RMS). I have a Blaupunkt San Francisco 310 (22 watt RMS, 50 peak x 4channel, 4 channel preamp output) in coming in the mail.

Id like to add a bit of bass to the whole set up so I dont have to worry about breaking the component speakers (in theory). The two paths Im looking at right now are either buying a compact powered woofer or buying a decent component sub and building a custom box. I figured I can make either option fit in the spare tire (possibly sticking out a bit), as I dont want to lose much trunk space.

The powered sub is this http://www.crutchfield.com/p_777B8PT...nce-B-8PT.html It is an 8 in sub 120 watts RMS with 40-200 Hz.

The other option is would be buying a component sub (80$ price range) and bulding a circular (or hexagonal) box to fit within my spare tire in the trunk.

thanks as I am quite confused!

Bustedback

Check out the sub woofer enclosures on amazon, pretty good boxes for little cash.

KevMez

You should check this one out at http://www.rocky-road.com/xjpod.html
I would suggest what I have, but I don't know if you could find one anymore.
Bought this box back about 9 years ago, sounds awesome!

PsychoSMurf

Ill go look around for sure. I didny think of that. And those enclosures are sweet! Did your come with an amp?

KevMez

No, there was no amp included. You can score a good amp off ebay pretty cheap though.

PsychoSMurf

If i go with bulding my own sub I was thinking about going with the cheaper amazon box and just makin it work, but i figure since im always throwin stuff and people in the back I might as well try to save some space.

found this guy making these which is like what you said above but out of mdf. Im thinkin about trying to mimic it and make it for either a 8 or 10 in. These things are really cool just a bit pricey.

https://www.cherokeeforum.com/f10/xj...y-10-a-120210/

macgyver35

Check out the photo albums under my profile for another option on subs. Also, several of my earliest posts go into details on the installation and components. My sub box cost $20 to build, and the whole system only ran me about $425, including head unit, door speakers, sub, and amp. Super happy with it.

PsychoSMurf

I like what you did! I think im gonna go that route (in the plethora of spare time i have). I had though about going with a 10" (cuz im a wild 18 year old) but those 8's still look pretty freakin big! Im thinking that if I did an 8, I could design it like ya'll have it, but partition off the front part that would go above the wheel well and hide the amp in there.. how big is the average amp?

Neener

It will all depend on how much bass and how loud you want to go. Bass is addictive so unless you knowhow much you really only want...I would go bigger at first. That being said...going bigger does not mean going with a 10" vs an 8". You can get great performance out of an 8" (even a 6.5" depending on how low in Hz you need to go). What you should be more concerned with is how much air space you will have available for the enclosure. Every sub will have what are called Thiele/Small Parameters for the speaker. You will want to look at these once you know how much air space you have available and find a driver that works best for your application.

PsychoSMurf

ok do if I ended up being tight on space I could estimate a higher quality 8 being competitive with a lower price 10 then possibly.. So the theile parameters are based off of how much air space you will need? Ill go read up on that. another newbie question is about top mount depth. say for one it is 4": do I need to add additional airspace behing that 4 in? I would guess the back of the sub shouldnt touch the box.

Neener

A lot of the time you will find that:
a) cheap subs will perform just fine in an enclosure suited for thier size (usually on the large size)
b) expensive subs are built for smaller enclosures or high spl output

So it really depends on how loud you want to go...do you want to rattle your neighbors windows or do you like a balanced compliment to your existing system?

This is a great read and will teach you a lot about audio:
http://www.bcae1.com/spboxnew2.htm
This portion is specifically about enclosure types but the whole site is VERY informative. If you want the cliffnotes version just let me know and I'll try and supplement.

macgyver35

Actually, the sub I'm running is not an 8". It's a Kicker 6.5". It fits better given the limited enclosure volume, and provides pretty much all the bass I need. It starts to roll of at about 42Hz. No, it's not going to rattle the windows of the car next to you, but it will rattle your mirrors, and it provides plenty of thump (and more importantly, musically accurate thump) for my typical tunes of rock 'n roll. I'm not a rap person, so I wasn't concerned with triple decibel performance at 35Hz and below. I'm running the sub off of a 400 watt (200 watt RMS) amp under the passenger front seat. Having the amp closer to the battery allowed for the use of smaller gauge power wiring vs. having to bump up to the next size if I put the amp in the back of the XJ.

Also, check these links for some additional guidelines that if followed, can save you quite of bit of money by teaching you how to choose your sub/amp combo based on efficiency rather than pure power handling or amp output. The right sub will sound as loud on 300 watts as another sub does at 600 watts. Pay attention to the SPL rating of the sub and, provided the rest of the specs are what you want, go for the highest SPL number you can find. In effect, if you have a choice of an 85db sub or a 90db sub, all other things being equal or close to equal, go with the 90db if you can. You'll be able to use a smaller amp (saving money) and use smaller wiring (saving money) and put less load on your electrical system (potentially saving money due to undue stress and shortened lifespan of alternator/battery or having to upgrade those components).

https://www.cherokeeforum.com/f67/de...9/#post1737592

https://www.cherokeeforum.com/f67/po...9/#post1924678

PsychoSMurf

Thanks to both of you for all this info. This is helping me in thw right direction. I'm gonna go read all the links and look for some more subs so I'm sure ill have more questions. Thanks guys

Neener

As Macgyver said...6.5" is plenty if you don't need the lows of hiphop/electronica music. All good advice from him especially the talk about efficiencies and what that means to your charging system.
Like I mentioned before...it will really depend on how loud you want to go, what music you listen to primarily and what type of system you want (EG balanced or rattle my bones)

PsychoSMurf

Dang I've been reading those threads, I'm gonna have to read them a few more times lol. I see what you guys are saying though. I'm thinking if it's not to hard of a task I might go with an 8 in. I'm not a techno head and I don't want to rattle anybody unconscious, I mean I listen to mostly rock and country but I suppose it would be nice to play it deep when I need to such as taking the rough trails and highway speeds etc.
What ive gathered so far is that I don't necessarily need a huge amp and 4-6 ohms is what I'd probably want to get. Correct? Lol