Stereo help, I FINALLY have the pictures.

[Markstanco]

A few weeks ago I was asking for help with a problem, I cant get the sound "out of the storage" area. When I open the hatch, it sounds beautiful. Closed, it is very quiet.

I have a Rockford Fosgate http://www.rockfordfosgate.com/products/ez2rockford/ModelInfo/ModelInfo.asp?ItemKey=10065585&CategoryDesc=Punch%20Subwoofers (P312D4) woofer, and a P6001bd amplifier for it http://www.rockfordfosgate.com/products/ez2rockford/ModelInfo/ModelInfo.asp?ItemKey=10063527&CategoryDesc=Punch%20Amplifiers

So I am fine on power. The box it is in is very well built, and sealed completely (no port, I dont want boomy sound).

Anyhow, some of you wanted to see some pics to help me get the sound out. I can not mount the speaker top side for obvious reasons, but just wanted some ideas. Thanks in advance!

http://myweb.cableone.net/markstanco/starboard%20driver%20helm.JPG

http://myweb.cableone.net/markstanco/low%20port%20side%20rear.JPG

http://myweb.cableone.net/markstanco/port%20side%20front.JPG

http://myweb.cableone.net/markstanco/starboard%20side%20rear.JPG

http://myweb.cableone.net/markstanco/port%20side%20rear.JPG

[Christian]

So I am fine on power. The box it is in is very well built, and sealed completely (no port, I dont want boomy sound).


Old wives tale, but thta is another subject

Just figure out the internal volume of the storage area MINUS the box and port it, and create a 5th order enclosure

You could probably get by with a 3" port x whatever lenght is needed, andthat should fox your issue.

or you could go 2 x 2" ports an dit would be easier to hide.

Provide the measurements and there are ton of us on here who can provide port specs.

Just my .02.but I now run a sealed 12"and ported 12".it provides a nice blend, the ported is ported at 27 hx, so it rolls off at 40 and the dealed has a natural curve at about 43 so it make a nice, natural bump, and it is not boomy at all [smilie=whip]

[Markstanco]

that is interesting Christian... I have HEARD of 5th order, but have no idea what it is or how it functions.

As for the storage area, it is HUGE. a problem with finding the volume inside it I also store a lot of stuff in there are well (backup anchor, about 7 fenders, deflated tube, "noodles", etc.) I plan on going to the boat tonight and can take some measurements, just let me know what to do/look for, and I can of course take more pictures. :)

Will this affect my internal volume significantly? Also, this 5th order you are describing... will it still have issues getting the sound out?

[Markstanco]

no you dont slip to page 2!!! :mrgreen: :mrgreen:

[Markstanco]

BTT for Christian....

[Josh]

Christian is right, bandpass will rock with the right volume and port. 5th order is when you have an inductor in line with the speaker to help with high-freq rolloff. You can go 4th order, which is the same design, just no inductor, if your amp has a good built-in crossover, or you you are using an external xover. Bandpass will give you more throw of pressure ie volume outwards when placing the enclosure in another enclosure.

[Markstanco]

good lord what in the hell did you just say. :oops:

[Josh]

Bandpass is a very effective way to "vent" the sound (pressure) outwards so you hear it better. A bandpass box has a chamber on both sides of the woofer, and with 4th and 5th order- sealed on the back side, and vented in the front.
So, basically, you need to allow the air pressure created by that woofer to vent into your cockpit somehow. A prefab ported box will more than likely sound much better than what you have now. You can buy prefab bandpass boxes also, but that might be hard to find one to fit your space requirements.

[Markstanco]

I really have no space issues at all. The area below deck is 5' X 7' X 2' (approx with the tape measure). So, no space issue at all.

Now, if I go with a bandpass box, how is this going to get the sound out better then the way it is now? Am I not getting something here? (probably so)

[Christian]

Christian is right,



Hell even a broken watch is right twice a day

Basically it is taking the box you have now and playing it into a larger box, and prting that outer box out to the world ( boat ) that will allow you to have natural low end roll off of a sealed box, and the natural high end limiting of a ported enclosure. The problem is that the volume of the outer box changes when you add fenders, life jackets etc.

What may be easier is finding a way toport the current encloure through the compartment in a traditional ported enclosure deisgn, and done right will sound good, but will require alittle geometry to figure out the correct port size vs length.

A port, in basic terms is a helmholtz resonator, picture yourslef blowing over a coke bottle and having the pitch change as the volume in the bottle changes, that is how a port works. it accentutaes the frequency at a certain point and rolls off naturall one octave above and below that frequency.

enough of audio dynamics 101 and back to your issue.

if you can get pcis of thebox, in its enclosure,I am sure Josh and I can come upwith a design to make it a lot more gooder, as can others, but since we are kind of geeky and have responded [smilie=trink39]

[Markstanco]

I should have known you were going to say that. I can run out there in the morning for a few pictures, and can put a tape to it for some measurements.

I STILL do not know what to do about getting the sound out though, you can see in the 3rd pic the vent I have already added. It is about 2 feet from the speaker, but it has to travel around a corner to vent the sound out (if that makes sense).

[Christian]

when venting a speaker the lenght is as important as the diameter of the port. if you an a 4" tube 2 feet your porting frequency would be below audible frequencies :)

We can get you there but we need to know the distance from the closest side of the box to the closest flat surface oif the boat where you could place a port


here are a couple of shots from my boat, one ported, one sealed

lots of places to add subs you never thought of [smilie=061.gif]

[Markstanco]

Christian and Josh..

Thank you guys for racking my brain! I pulled the boat to a marine stereo guy today and he had a great idea....

He is going to make a fiberglass box poured in to an area that I didnt think was possible, (actualy didnt know you could do this) and should sound great. We will see.....

Promise to take some pics afterwards (will be a while, travelling till the end of August on the West Coast).

[Christian]

lots of places to add subs you never thought of



It is amazing what you can do with someone elses vehicle :mrgreen:
it will turn out great, fiberglass is easy to do,a nd it is a hell of a lot easier to do than MDF or Medite in a marine enviroment

Glad you were able to get it worked out

[Josh]

Good luck! Wish we could have helped more!

[bconley]

Dang Josh I am with you all of the time and I don't think you have shot that much knowledge my way ever about how to make my stereo sound better. Anyway Mark you were definitely in great hands with those 2 guys. I know Josh is very knowledgeable about that stuff and it appears Christian knows his way around that stuff as well. Good luck! [smilie=042.gif]

[Markstanco]

Good luck! Wish we could have helped more!

Send me some money and we'll call it even. [smilie=265.gif]

You guys WERE helpful and I thank you. Scheduled for Monday for them to pour the mold.

[Josh]

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