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Discussion Starter · #1 ·
Hows it going everyone, new to the forum. I'm looking for a set of 15" woofers to put in my truck, had a set of db drive k9s that blew up. Wasnt impressed with the ouput, sq was fairly good.

Anyways the setup is an 01 gmc single cab, fiberglass box with about 4.5ft of airspace shared. the box is very rigind and airtight. I have a true clean 2500 watts or so at 2 ohms. I want decent sound quality,and I dont like subs that cant stretch out to 120hz or so. mounting depth cant be much more then about 7.75".

So whats out there for around $600 new or used?

Main two I'm looking at now is the massive hippo, or the Fi ssd. the massive is a bit more sensitive, the fi has more xmax... on the fence about which will really be more important. having a hard time finding much info on iether of those subs, or any recomendations at all for sealed 15s. Dayton HO wont handle enough power before anyone suggests it lol. Ive had little luck on car audio forums as most everyone just has a huge boner for tiny drivers and ported boxes for some reason lol.

12,039 Posts
Yes I'm tired of small subs too.

I've been in this game long enough to know that no amount of subs and amps will ever make a basshead happy. It's called upgraditis for a reason. ;)
Price and implementation-practicality seems to be the only limiter upon a bassheads dreams.

Anyone can get 175db+ *if you are willing* to make a van with 4" thick bulletproof windows and 1ft thick solid-metal doors and walls with 80 2ft bolts holding it shut. (implementation-impracticality ;) )

As for boxes, various box designs have several pros and cons. I don't want to get into it all but:
-Folded horned subs have the most SPL (6db louder than even ported) but has the worst bandwidth (generally 15hz to 60hz only) and are fairly large too (you'd need a van).
-4th and 6th order bandpass boxes are no better than ported, so there is no sense in talking about them.
-Generally ported 18's have the best combination of output, efficiency, and bandwidth.
-Sealed is only good when you are trying to play frequencies below 12hz or are constrained to a small box (sealed boxes require a 30hz LF shelf-boost because their -3db point is usually 30-40hz, which extends them to ~4hz.)
-IB is basically like sealed, but more efficient. You can't easily put an IB in a car (if at all), more like a bus or full-sized audio trailer, so it's not worth talking about.

Obviously applying a 20-30hz HPF will allow you to push a lot more power into a sub before it bottoms out, regardless of the box it is put in.

As far drivers:
Don't be so quick to judge a sub based solely on its watts handling.
Besides 1kW vs 2kW is only 3db. (Important if you are competing with a TermLab I guess.)

Every T/S parameter is equally important; if it wasn't, then nobody would bother to take such measurements.

For a daily driver, your best bet is to model the various drivers you have available to you in the box type and volume you own using winISD.
(I'm pretty sure people who compete, model their stuff too.)

I think once you start modelling, you'll see that the 4.5 sealed box is the limiting factor here. (You'd have more SPL and options with 18's. You'd be happier in the end.)

The FI SSD-15 is 8 inches mounting depth.
The MH-15 has a mounting depth of almost 9 inches (Too much?). Its sensitivity seems to be 97db, which I have a hunch that that is a completely made-up number (highly unusual).

If money and box weren't an issue, as far as 15's go you'd be hard pressed to beat a Sundown Z v.4, I'd recommend you save your money for that. It's mounting depth is 12 inches though so you'd have to remake a box.

For frequencies above 45hz, this is the best driver you will find:
For stuff below 45hz:
the older Soundstream XXX-18's, TC LMS-18's, RE XXX-18, Sundown Zv4-18, UXL-18, and SI HST-18 and SI-24 is generally regarded as some of the top-reigning subs (with a price tag to match).
Anything less is simply that...
(and if it ain't, then it needs to be added to my list then ;) )

2 Posts
Discussion Starter · #3 ·
I appreciate some unbiased input. If space weren't a constraint i would be all about a ported 18, I have a dayton classic ported to 28hz in 15ft sitting in my living room and I absolutely love it on only 300watts. In tight spaces though, my thinking is that maximum cone area and maximum power handling is my best bet to get the most out of a limited space.

the added efficiency of a ported box in this set up doesn't mean so much to me because I really have a ton of power to play with. that amp is a monster it smoked the k9s which are rated for 1000rms after about 10 seconds of music. I believe its closer to 2800watts at the voltage I'm providing it.

yea the massive drivers just don't come with enough info. Those rating have to be bogus, 2000rms AND 98db (assuming 2.83v, doesnt even say?) 15mm xmax... I doubt it. my last subs (jbl p1222) were rated 96db 1w1m and I have to say they were very loud on only 1000watts. but they didn't really handle the power and sounded like mud with most music. I dont see a heavy duty woofer with 2 spiders like that being so efficient.

the way the backplate is on the fi with its 8" depth would work. sundown doesnt make anything that would fit their huge. I would love a set of Idmax's but again too deep... I could possibly fit an 18" but the surround may hit the seat track.

to give you an idea of the box, trust me its the biggest box in all existence for this particular truck. I pulled out all the stops for this one. It's molded to the floor and back cab and is only 1/4" thick fiberglass braced like crazy. pre fab boxes for thes trucks are .75 to 1ft per sub. to give you an idea of what im working with.


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