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JW
01-04-2004, 12:29 PM
I think I can squeeze four 6X9 speakers into my new boat, but the front pair will have to be housed in boxes. Does anyone have experience with the pre-made boxes you can get at Best Buy? $30 for the pair, and they come with the stuffing so I can tune the sound. What does the boxes do to the bass frequencies? Do they lose a lot? Or will a decent pair of 6X9's still rock OK in those boxes?
Thanks!

ncst8er
01-04-2004, 01:13 PM
It's been a while since I designed any speaker boxes, but the short answer is that you can't predict exactly what will happen without detailed info. on the speaker, however the following general statements will be true:

1. If the front and back of the speaker are not isolated from each other in some way, the energy from te back will cancel the energy from the front (especially bass).
2. The smaller the box volume, the more it will raise the frequency that the speaker folls off at (less low end bass).
3. If the stuffing is fiberglass matting or some other non-rigid sound-absorbing material, then installing it makes the box seem larger to speaker and will improve bass response up to the limit described in #4 & 5.
4. Speaker are designed with a certain volume in mind and if the box volume is larger than that, then the bass response will extend lower, but will not be even (resonant points, booming at certain frequencies).
5. Concerning #4, at some point the speaker will "unload", leading to violent excursions and speaker damage.

As a general rule, it's better to be too small that too big, since too small will only lead to less bass; while too big gives poor sound AND can damage the speaker. In the case of the boxes you're referring to thay are porbably not big enough to hurt the speaker even with the stuffing added. If you notice booming or the speaker excursion being excessive, then remove the matting to make the box acoustically smaller (again this is assuming the stufffing is not rigid volume filler since I've never seen that used, but it could be used to reduce the acoustic volume further).

Jimbob
01-04-2004, 04:14 PM
Back many many years ago I made some boxes for some 6x9 speakers as small as possible in order to fit on the rear deck of my'69 Chevy. Because they were so small it really killed the bass response, just as ncst8er says. So when I went to use them years later behind the seats of a Ford Ranger I put some mat in the boxes and added some 1" louvered vents (4) to the boxes and while it did help get more bass it still was no near what it should be.
The premade boxes at Best Buy are larger that what I built so they should be a little better, but since most car speakers are made to use the doors or trunk space as their enclosure, your bass response will still probably be stiffled some. You might want to add a port to the box to help let it "breath" some for more bass. A general rule of thumb is a sealed enclosure will give a "tight" bass while a ported one will give some boomiest to it. In fact, some bass sound waves will emit from the port.
I'm about to use my 'ol boxes in my boat as I'm putting a stereo in this winter. I'm gonna add some volume to the boxes by adding a 3/4" plywood front to it to mount the speakers to and add some bigger ports, as well as some stuffing. Some bed pillow fill stuffing you can find at Wallymart works just fine.
Sorry got a little wordie here. Good luck to us both on our quest for big bass out of lit' boxes!:p

JW
01-04-2004, 05:00 PM
It sounds like I'll have to play with the boxes some to see how they sound. Knowing the typical 6X9 is a deck/trunk mounted speaker, I was afraid of coil heating in the small boxes since the woofer movement would be restricted. If I cut ports carefully, I should be able to refill them in case I get too much air movement :D
The rear 6X9's will fit into my engine well ( it's an I/O) like a car rear deck, so the bass should hit hard. The fronts are going to be in the boxes, but under the dash in front of my feet so maybe the bass will hit hard there too.
Goal is to later add a sub, only if needed

Jay R.
01-04-2004, 05:03 PM
I've got a pair of JVC 3 way 6X9's in my check and they hit pretty hard. I picked up some roadgear boxes al walemart. about $15 each so about the same price. definatly premade box the way to go!

175checkmate
01-04-2004, 05:18 PM
I have used them, not to bad. Used foam to tune them. Be sure to run them to an amp. Give them the juice they deserve.

2fast4mom
01-04-2004, 05:28 PM
My 2 cents...

6x9 speakers are a classic case of "let's design the speaker to fit the car".

The elliptically shaped cone is pushed by a circular shaped piston (voice coil). Thus you inevitably get a faster transient response across the narrow portion (6") than the long portion (9"). The cone thus flexes at high excursion, massively distorting the bass frequencies.

Boxes, without the air volume present to load the woofer down to the resonant frequency spec (and you won't get any lower than this spec, no matter what!) will exacerbate this problem.

Before you go invest in boxes and / or 6x9's that are bound to leave you less than impressed, you might consider a powered subwoofer for up under the dash, facing the bow of the boat (if possible). This arrangement will 1/4 or 1/8 space load the subwoofer, and you'll get water-rippling bass. Leave the mid's and highs to smaller (6") coax speakers that you can mount elsewhere in the boat. You'll have a bi-amplified system, and be much happier with the result.

Check out www.bazooka.com for such stuff...hope this helps!

Lou

JW
01-04-2004, 05:42 PM
I'm going for bigger 'hit' on a lower budget. I'm starting with four 6X9's, and adding amps and subs later if I have to. I've had the smaller round speakers, and they just don't bang. 6X9's bang hard, and will barely fit where I want them :D . I'll be bi-amplifying and adding a sub ONLY if the four 6X9's aren't enough. I have a head picked out that will run the 4 speakers, and will use the line level outputs for a sub/amp combo later :D

Starting price looks to be about $350 total for a decent CD head unit plus four 6X9's and a pair of boxes.

Best Buy and Etronics.com all the way!!!!!!!

pyro
01-04-2004, 08:46 PM
I have to agree. Even small speakers like 5.25" can still sound good if you get a 6.5" powered Bazooka sub for the low end. Use an amp for the mains that has HPF/LPF and start with it set to High-pass around 60-70 Hz and adjust from there. The sub will hit everything below the crossover point, just tune the HPF so there's no notch or peak in the bass response. You could make some small boxes for mains, but 5.25" speakers can fit just about anywhere. 6X9's sound good in cars because they're usually mounted "free-air", using the rear deck as a baffle, eliminating the low-end rolloff associated with the undersized sealed boxes.

Jay R.
01-04-2004, 09:51 PM
I've got an 8" sub on an amp in a box. even wih that off my 2 6x9s hit hard! you'll like it. but i recomend all four in boxes.

bulldogdaddy
01-05-2004, 02:49 PM
was thinking about incorperating subs into the deck supports under the bow of my boat. but will the excesive wave jumping and so forth break the speakers?

Jay R.
01-05-2004, 04:41 PM
probably not. would be worse on the speakers to mount facing up and down as opposed to frount and back. sound better that way as well.

Jeff_G
01-07-2004, 02:23 PM
So what you guys are really saying is.....

Pretend I know nothing about radios and speakers. I know very little so help me here.

I have a 17' closed deck boat with a small lay down cabin. The receiver is mounted through the wall under the dash. Like a glove box. I have 2, 5.25" speakers. I can either mount them in the wedge shaped little boxes they are in or I can mount them through the cabin wall on either side of the boat under the dash.
Which way would be better?
Should they have an enclosure around them on the back side. Inside the cabin?
Should I pair them with 2 additional speakers next to them or using the wedge boxes mount them in the rear of the boat, about 5 feet back?

Just want to listen to a few cd's while cruising down the river.

pyro
01-07-2004, 03:49 PM
The boxes sound nice, but they take up extra space.

Regarding panel-mounting: "phase cancellation" occurs when sound waves from both the front and back of the speaker each collide and cancel out a band of tone, mostly bass frequencies. When the factory mounts 6.5" speakers in the side panels too close to the edge of the panel is when this happens the most. It is not as noticeable with 5.25" speakers because they're smaller, and they don't have tons of low-end response anyway.

The farther the speaker is mounted from the edge of the panel, the better it will sound. It's OK to mount them in the dash or side panels this way as long as you do it right.

A pair of small speakers with good tweeters and a small powered sub will sound great in anything.

ncst8er
01-07-2004, 08:56 PM
Pyro is pretty much "right on". As he said, further away from the edge of the wall reduces phase cancelation. Also closer to a perpendicular surface reinforces the bass (IF it is a hard surface like fiberglass, wood, etc., so it reflects sound). Again it is possible for the speaker to be damaged if it unloads, but that is unlikely to happen with a 5.25" speaker since it will generally be too heavily dampened for this to happen, but it could happen to a larger/ soft suspension speaker with a lower resonant frequency. With regards to placing additional speakers, a second pair should be located in a different location, not adjacent to the first pair since they can influence each other negatively if they have not been designed to be used as a pair.

Jay R.
01-07-2004, 10:34 PM
I agree with the two previous so you don't think this is a contradiction. i just think that the boxes will always sound better even if it takes up exra space. you can always find unsed space and even the wedge boxes will be enough to be noticed.

Reese
01-09-2004, 06:53 PM
generally sound like ****, primarily because 95% of them mount their speakers in an open panel (no box of any kind) placing them in the gunwale or front deck area.

All "public announcement", "DJ", or boat type speakers need some kind of box (usually ported) to give them much chance of reproducing the bass sounds (100 Hz. or less) that most of us like.

I don't like the sound of trying to use a single subwoofer to cover up the deficiency of a panel-mounted speaker or even an enclosed box speaker in an open environment like a boat.

It is more work to build a ported box for each midrange speaker enclosure but the sound is much better. Of course most of us are just as happy with four panel mounted speakers and that's okay too...different strokes as the saying goes.

2fast4mom
01-20-2004, 12:32 AM
A ported box will always lend some emphasis to a given resonant frequency, which can be a desirable effect--or not!

Further, a subwoofer should be just that...SUB frequency compensation below ~40 Hz, not trying to make up for deficiencies in any other drivers, but to augment frequencies not possible to be reproduced by smaller drivers having higher resonant frequencies.

I have two Hafler powered reference monitors in my studio, and my boat stereo sounds better. With good design and thoughtful application, a boat stereo CAN sound great and fulfill the requirement to be heard above the engine at WOT.

Just my opinion!!

MirageSmack
01-20-2004, 12:56 AM
Your remark about the ****ty sound in a boat because speakers mounted in gunwale. A few questions.

I have a Mirage Ski Racer that was raced and I plan to add a system. The gunwale is the only true place I can mount rear 6x9 speakers. I planned to mount them in boxes on the gunwale brace about near the rear seat. Facing forward, in angled boxes. Also front speakers somewhere, don't know where. My options are limited becasue I will not cut holes in the boat itself, just a few screw holes in gunwale braces. Any ideas?

If I can find another center console to cut up, I was going to mount some smaller front speakers in the side of console, basically facing out from the middle, slightly angled toward the seats. Is this okay?

This is all greek to me. I thought the boat stereos just sounded worse because of the open air setup on a baot vs. a vehicle.

2fast4mom
01-20-2004, 02:14 AM
Can you post any pictures of the interior of your boat? Would be glad to consult on it......

Lou

MirageSmack
01-20-2004, 04:45 PM
When I get a chance, 2FAST I'll see what I can find. I know I don't have pics of the gunwale area, but I have the front. I'll get back with you. Thanks for the reply. Smack

Reese
01-20-2004, 11:28 PM
are convenient and simple to install...they also are not exactly the best approach to really good sound...it all depends on what you want and how much time you're willing to spend getting it right.

Component speakers give you several advantages over regular 6x9's especially in the area of flexability...you can put the tweeter in a much better location (closer to ear level) and the box can be tuned because the manufacture (vifa, scan speak, etc) include the speaker specification.

I'm using four component speakers in my boat...two ported boxes were custom made to fit the underside of the front gunwale...the two rear speakers were placed under the rear bench seat...they were also ported. Keep in mind that the tweeters all all flush mounted on the gunwale at ear level. The only negative with some component speakers is that you have to build a crossover network in order for them to work.

Ported speakers will produce the most volume with the least distortion of any other design. Even the most expensive head units will only put out 25 watts per channel (continuous).

Sub woofers are great and I love em...but outboards are horrible when it comes to alternator output and I just don't feel comfortable driving them too hard or too long.

Here is a pic of the back seat area...good luck with your project.

Techno
01-21-2004, 06:26 PM
If you want a 6x9 skip the box. Boxes are only needed for bass. I'm talking technical bass not the low end of the mid range.
A speaker asked to reproduce all the frequencies of human range does not play bass. What there is of it can't be heard.
The isolation of the front and back wave will help but on the bottom end install don't really matter. A speaker cup or anything will do almost the same.

I suggest as a good "cheap" system. Round speakers.
A coax with an amp. You can add a woofer later if wanted.
Or a mid range with seperate tweeters.
The biggest advice is buy name brand items even if the wattage or speaker size isn't as "good" as the cheap stuff. It will outperform them anyway. Same price speakers... the name brand is 4" and 20 watts the cheap one is 6" and 80 watts. The 4" only needs 2 watts to work while the cheap 6" needs 20 watts. Little things like that. The 4" sounds good while the 6" sounds like crap.

The tweeters are so tiny they can be put in prime location on the dash and aimed diagonaly people wise. The screw hole would be the hole for the wire instead covered up by the glued on tweeter, or velcro. A 3/4" disc is all they are.

Location. Forget the car locations, these are extremely bad locations. The goal is to have all the speakers in front of you and aimed at you. A boat has a vast, in most cases location in the prime area. At your feet. Plenty of room to install easy to get to and the right spot. Even the woofers or subwoofers are better in front than behind.
Think home stereo and not car stereo.

Boxes may help a non bass speaker but not by much. Isolation does about the same without the cost or weight penalty.
True boxes are dense particle board, thick and thus heavy.
Woofers need box VOLUME. Stuffing increases the boxes apparent volume to a point.

chynewalkr
01-21-2004, 07:01 PM
good point on speaker location in front, i had never thought of that comparison to home systems. plus if your boat travels faster than the speed of sound and your speakers were in the back you would never here them:D

MirageSmack
01-21-2004, 07:57 PM
Hell, my boat is a '92 and has never had sound. It is exactly the way it was when it left the hands of Brad Collins in Texas.

Maybe I'll just keep it that way and just listen to the motor!!

My problem is that I don't want to cut a single hole in the boat. And then I want the hole thing to be totally removable, thats why the use of boxes. I have wingnut type fasteners that are 4 inches long, so I can quickly unscrew the boxes from the gunwale braces. I hope to mount the stereo and front speakers in a console between the legs of the front seat passengers. The console is totally removable, and I would need some type of quick connects.

I do not want to be stuck with all the weight. It cost too much to build HP in the motor, and I don't want to piss it all away with weight. Cheap and free horsepower!

BTW Reese, I always like the way those back seat systems look. Yours looks sweet. It just isn't an option for this boat. Thankd for the info......Smack

Techno
01-22-2004, 09:17 PM
Semantics. I'm using boxes as shorthand for a woofer box built out of particle board or that DMO or whatever stuff. Both kind of lousy for marine use.

Back to what you want. Get or make some enclosures. Make them out of whatever you want. Light or cheap, won't matter. Boxes would kind of suck for what your doing, heavy and lousy material for a boat.
You don't have to drill a single hole. Put a saddle like thing and clamp them on the brace. Something like a built in C-clamp.
Forget about a head units wattage output- they cheat, like running your OB at 11 k. Get whatever you like and some speakers, I still suggest at least 4. Some head units have remote controls, either wired or wireless. Some have an optional deal to mount to the steering wheel. or on the console This gets rid of the head unit install, it goes anywhere. It also don't matter what it looks like anymore. Trade the glitzy head units price for a decent quality amp. A rockfort phosgate at 20 watts is more like 200 watts, a little goes a long way. Any of the quality amps.
Or later add an amp for those speakers, and then a woofer in a box or a stand alone like bazookas and an amp. Increase it as you want.

The tweeters can be mounted to a bar or stalk, a finger. Your imagination. This can be velcroed to the back of the dash or coaming. If this finger is a flexible adjustable thing it can even be aimed. Cheap, easy and removable. The finger or support itself should be glitzy though. It looks like it should be there thing. Mounted on the back side of the boats finish but sticks out where it can fire at you.

I've mentioned velcro. There are 2 kinds. the hook and loop and a single side mushroom. Also is material They have near permanant stainless steel stuff too. But way $$$.

For power I will say the taboo phrase. A seperate battery. This can be one of those portable jumper ones or an installed one that can be yanked out. Don't know if a cycle battery would have the oomph or not but are light.

Or get a boom box:cool:

pofarm
02-05-2004, 08:32 PM
Regardless what you decide to do, make sure the boxes aren't made of particle board or any other pressed-board material. These will fall apart pretty fast if they get wet.