Sealed box, doesn't sound good

[creyc 1]

After doing a little more critical listening of my 2 Havoc 15s in a 5.4 cu ft sealed box, I'm not really sold on the sound. My goals were a LOUD hard hitting system that sounds good on anything from hip hop to rock. Transient response and chest-thumping bass are vital to me, so I went with a sealed box initially for the sake of simplicity and a starting point to improve on.

I'm not overly impressed with the sound quality, however. It plays extremely LOW, 20Hz has my truck falling apart and my ears pressurized, but ask it to play music or a 50Hz bass line and it falls way down leaving much to be desired. Above 50Hz leaves you wondering what happened to those huge speakers sitting behind you, it's simply weak.

As a result the system doesn't sound very musical at all, and the substage mixes in very poorly with the pioneer C720-PRS components making up the mids and highs. I wonder what's the cause, either the sealed box or impedance rise or something just the nature of my tiny extended cab ranger making deep powerful bass so hard to achieve. I noticed when settings gains that voltage dropped from 64v @ 25Hz to the low 50s at 50Hz and above, all else held constant, no bass boost/LPF/subsonic.

Is it possible to build something that sounds somewhat like a rock concert inside an extended cab ranger? I've got 1800RMS and two 15's to work with...

[JimJ 11]

Isn't that good that it's weak above 50Hz or so? That's where your midbasses ideally should start, anyway...

[creyc 1]

I'm not sure, a month ago I would have agreed with you wholeheartedly.

The problem is most music doesn't go to 20 or even 30Hz. It seems like the higher frequency stuff is what really slams you, like stomping on a big kick drum. Good friend of mine has a fairly mild setup in his Explorer, but play a 50Hz sine wave over his ported 12s and its painful in his truck! Meanwhile mine is very soft in this range but kills his below 35Hz.

I know I can't reach midbass at 100-250Hz, but I thought it would hit above 35Hz. I know I will need one hell of a midbass setup to keep up. I'm thinking pro audio speakers.

[JimJ 11]

What have you currently done with the midbasses?

Once you start getting the subwoofers playing the higher-frequency kickdrum parts and such, you're liable to have the stage pull back and the sub starts getting localizable...

[creyc 1]

I understand why that will happen. But I've always crossed my subs over around 80Hz, not 50 or so that this setup seems to be. (not by choice!)

I don't know where else I could have mess up. Each havoc is sitting in about 2.6cu ft sealed airspace. I really have no idea if thats enough in a practical situation, it's within the manufacturers specifications.

[johnecon2001 82]

Have you done any deadening of your doors yet? Simply installing the mid drivers correctly could tighten and blend the sound better.

[creyc 1]

A good guy, and local installer was explaining to me that it might be 100% due to the small size of my cabin. The only odd thing here is how strong 20-35Hz comes in, in a small cab wouldn't that be the first to go?

If this is true, is there any way at all to get deep powerful bass that also hits hard in such a small truck cab? This reminds me of trying to deal with phase cancellation issues in the pro sound business, adding more and more power and speakers only makes things worse! I'm wondering if I should be approaching this from a different angle now.

As for midbass, I have the 6-3/4" midrange drivers that come with the pioneer PRS components mounted in the doors. Still waiting for my buddy with the connection on damping material. This will certainly be done soon. Maybe some LARGE designated midbasses.

[shizzzon 461]

i'm just brainstorming here but can you try downfiring the subs, trying this at different heights from the floor to see if it emphasizes the response any better?

[Tirefryr 1,742]

I think you have a cancellation issue. Give us some application specifics such as vehicle, firing direction, etc. . . Try moving the enclosure around if possible, and like others have mentioned, firing the drivers differently.

[creyc 1]

Vehicle is a 1994 extended cab ford ranger. The subs are in an 18 x 18 x 36" box sitting right behind the driver and passenger seats. The subs point forward, and fire directly into the back of the seats.

With a few easy modifications I can make the box face any direction but straight backwards. The position of the box is fixed for the most part, minus 3" of adjustment left to right.

The cab is very very small, which I don't think is helping me any. If it was a surefire bet I could fix my sound with a cut-through in the bed, I wouldn't be against that.

[Tirefryr 1,742]

Small cabs are great actually.

With my truck, I always seem to have a dead spot somewhere except for when I arrange them like so: Subs coupled in the middle of the enclosure firing forward and as low on the baffle as possible. If I move them to the left or right, or have only one driver on one side, for some reason, I have a huge cancellation issue on the other side of the truck. I think if you start firing them differently, you'll find better response. Try something for me. With them just the way they are, open your door and stick your head down by the kickpanels and tell me how it sounds down there.