Audio question-need help

[Tunnel Vision]

To all you stereo Gurus,
I am having a problem with the stereo in my DCB that maybe you might be able to help me with. I don’t know jack about stereos, and DCB did replaced one of the amp’s when I bought the boat used from them.
The boat has two Rothford Fosgate amps and speakers mounted under the bow and a Sony receiver in the dash.
Here’s the problem:
While listening to the stereo for about an hour at about ¼ to1/2 of it’s volume range the system craps out, in other words the receiver is still on but all you hear is a faint sound of base coming from the woofers.
If you shut the system down for awhile or turn the volume way down it will come back and sound fine.
I have also noticed that if you keep the volume down 1/8 to ¼ of its range the thing will play all day long.
I have crawled under the bow when it shuts down and felt both amps and they are pretty damn hot.
There is also a control knob for the amps under the bow that I have tried full clockwise and full counter clockwise with no change in the crapping out department.
These are my thoughts right or wrong.
1. I have bad amp(s).
2. I need to add small dc axial fans to the amps to help cool them.
3. I have low voltage problem. My (2) 2.5 Drag motors only put out 16 amps ea. @ 7500-rpm and the fuel pumps and computers take 20 amps of that. DCB did not install volt or amp meters to verify this, so I will be installing them shortly.
4. I need to install Simon motorsports alternator kits to both motors.
Any thoughts would be greatly appreciated
Tv
:confused:

[phebus]

I had a similar problem with my Rockford Fosgate amps, and it turned out to be a voltage problem. My guess is you either need new batteries, or more batteries. The Fosgate amps go into protect mode if there is insuffficient voltage.

[phebus]

One more thing. The alternators won't put out enough voltage to make up for the draw of the stereo. Install enough batteries to power the stereo for the day, and charge them at night with a charger.

[Tunnel Vision]

One more thing. The alternators won't put out enough voltage to make up for the draw of the stereo. Install enough batteries to power the stereo for the day, and charge them at night with a charger.
Thank you, I will have them both tested :idea:
TV

[mbrown2]

My plan of attack would be the following; before you replace the amps:
-After charging your batt's make sure you are getting the proper voltage from them...they may be getting bad since the low amps they are receiving from the charging system, but they are expected to provide a source to the audio system.
- Add some fans to the amps
If it is still happening then you might want to replace the amps, I would also upgrade the charging system, but not necessarily to fix this issue.
I hesitate to tell you to add more batteries's since that adds weight and takes away speed. I run 2400 watts on our 26 with only two Oddyssey 1200 batteries and they last pretty much all day if I switch to all on both perkos...

[phebus]

The heat may also be the issue, but it is normal for those amps to run hot. When I'm cranking mine, if you were to touch them, you would burn yourself badly. They get blazing. That said, they have rarely shut down from thermal overload. I am adding fans to hopefully avoid thermal issues and for longevity. When my amps were shutting down from low voltage, turning them off, and then turning them back on would make them work (resets the protection circuit), but when played loud again or after some big bass notes the problem would repeat. My batteries weren't very old, so it was hard for me to believe they were the problem, but that was the case. If your's are getting some time on them, I would just replace them anyway and see if that takes care of your problem.

[phebus]

I'm going on here, but after charging my old batteries, they tested good for voltage, and would play the stero for a long time at low levels, but if I were cranking the stereo they wouldn't hold up for long at high levels. If I turned it off and played the stereo at low levels again it would work fine. You would think that once they reached a level that amps were going into protect, the voltage would remain low and not be sufficient, but that wasn't the case. They just wouldn't sustain high volumes or really extended play.

[mbrown2]

Phebus,
I run RF's in the 26 and mine shutdown due to heat...batt's were brand new and the two of the amps (mid/high amps) were still working....
Personally, (IMO), I think the RF amps are inefficient, get too hot and go into thermal way too easy.....(don't flame me)....they work when they work, but I would not choose them again. :rolleyes: :rollside:

[Tunnel Vision]

I'm going on here, but after charging my old batteries, they tested good for voltage, and would play the stero for a long time at low levels, but if I were cranking the stereo they wouldn't hold up for long at high levels. If I turned it off and played the stereo at low levels again it would work fine. You would think that once they reached a level that amps were going into protect, the voltage would remain low and not be sufficient, but that wasn't the case. They just wouldn't sustain high volumes or really extended play.
You are explaining exactly what happens with mine!
My thoughs were if I charge the batterys overnite it would be find, but maybe whats happening here is, the batt's have a full charge, I put it in the water and run around for a half hour or so under 7500 rpm, they loose enough charge that when the amps require it its not there, so they go in to a protection mode?
To run @ 7500 for a hour or so would be a great thrill (110+mph) but hardly possible with a 2 yr old on board.
Thanks
TV

[ROZ]

I'm going on here, but after charging my old batteries, they tested good for voltage, and would play the stero for a long time at low levels, but if I were cranking the stereo they wouldn't hold up for long at high levels. If I turned it off and played the stereo at low levels again it would work fine. You would think that once they reached a level that amps were going into protect, the voltage would remain low and not be sufficient, but that wasn't the case. They just wouldn't sustain high volumes or really extended play.
The demand the amps have all depends on your finger.... You want more volume, the amp will demand much more current and voltage will quickly become an issue with the draw...

[1stepcloser]

To all you stereo Gurus,
I am having a problem with the stereo in my DCB that maybe you might be able to help me them.
The boat has two Rothford Fosgate amps and speakers mounted under the bow.
Here’s the problem:
While listening to the stereo for about an hour at about ¼ to1/2 of it’s volume range the system craps out, all you hear is a faint sound of base coming from the woofers.
I have crawled under the bow when it shuts down and felt both amps and they are pretty damn hot.
:confused:
Based on the info given, and my experience with Rothford, it's thermal shutdown.
A voltage problem, in my opinion, would cause the sub amp to drop first as it should draw more current.
Besides, the key things here are 1. Rothford Fosgate. 2 Amps mounted under the bow... 3. ony the mid/high amp is shutting off. And I'll bet that amp is in full range.

[Havasu Hangin']

Based on the info given, and my experience with Rothford, it's thermal shutdown.
A voltage problem, in my opinion, would cause the sub amp to drop first as it should draw more current.
Besides, the key things here are 1. Rothford Fosgate. 2 Amps mounted under the bow... 3. ony the mid/high amp is shutting off. And I'll bet that amp is in full range.
I agree with 1stepcloser- those Rothfords run hot. :notam:

[ROZ]

I agree with 1stepcloser- those Rothfords run hot. :notam:
True, but not as hot as those Rockford fosgates. I hear scientist are using them as the heating divice in experiments studying the rate ice melts at -140 degrees at the artic circle... Somehow helps in the fight against global warming...

[Havasu Hangin']

True, but not as hot as those Rockford fosgates. I hear scientist are using them as the heating divice in experiments studying the rate ice melts at -140 degrees at the artic circle... Somehow helps in the fight against global warming...
True...true. I also agree with mbrown2- I wouldn't put Rockfords in a boat. On the other hand...I haven't heard too many bad things about the Rothfords... :messedup:

[1stepcloser]

I haven't heard too many bad things about the Rothfords... :messedup:
Well, other than the fact that they run pretty darn hot. :notam:

[phebus]

Complainers!!! If it wasn't for us guys that run the Rockfords (or the one's that run Rothfords), you would be complaining that it's too cold to go boating. Were just boating environmentally friendly and making pleasant weather. Givers, that's what we are. :D

[ROZ]

Complainers!!! If it wasn't for us guys that run the Rockfords (or the one's that run Rothfords), you would be complaining that it's too cold to go boating. Were just boating environmentally friendly and making pleasant weather. Givers, that's what we are. :D
You could use it to cauterize a wound as well... That make you a lifesaver :D

[1stepcloser]

Theay also make a darn nice place to warm up leftovers too.

[phebus]

Nothing like heating up a good old carne asada burrito to soak up some of the beer while your out boating. Yum Yum

[mbrown2]

What did I start with the heating and never again comments... :coffeycup :notam: :mix: :messedup:

[Havasu Hangin']

Well, to solve the inefficiency issue, you'll need to cool those Rothfords down. You'll need to change out that cheap Merc pump for a billet 2 stage rawwater pump (about $1,700) and use the second stage to cool the amps. Then, you'll need a custom billet, water-cooled heat sink (instead of the air-cooled ones) bolted to each amp. Next, you'll need a bypass regulator and two water dumps mounted to your transom. To plumb it, I suggest all steel-braided lines and aircraft fittings (you don't want any hoses breaking or popping off).
What's the big deal?

[1stepcloser]

Well, to solve the inefficiency issue, you'll need to cool those Rothfords down. You'll need to change out that cheap Merc pump for a billet 2 stage rawwater pump (about $1,700) and use the second stage to cool the amps. Then, you'll need a custom billet, water-cooled heat sink (instead of the air-cooled ones) bolted to each amp. Next, you'll need a bypass regulator and two water dumps mounted to your transom. To plumb it, I suggest all steel-braided lines and aircraft fittings (you don't want any hoses breaking or popping off).
What's the big deal?
Solving inefficiency in rothfords? Hmmm.... If that could be done, I may consider a change.....I hear thems the "hot" ticket in boats.
P.S. I have this idea for a water cooled heat exchanger that would replace the heat sink......seems no one is interested in adapting their current lines for a marine product. I say we tool up and manufacture our own line.
Whaddya think? :cool:

[mbrown2]

Well, to solve the inefficiency issue, you'll need to cool those Rothfords down. You'll need to change out that cheap Merc pump for a billet 2 stage rawwater pump (about $1,700) and use the second stage to cool the amps. Then, you'll need a custom billet, water-cooled heat sink (instead of the air-cooled ones) bolted to each amp. Next, you'll need a bypass regulator and two water dumps mounted to your transom. To plumb it, I suggest all steel-braided lines and aircraft fittings (you don't want any hoses breaking or popping off).
What's the big deal?
I read that post and the quote "polishing a turd" came to mind :boxed:

[Havasu Hangin']

I say we tol up and manufacture our own line.
Whaddya think? :cool:
Sounds good.
PS- What's "tol up"?
:D

[1stepcloser]

:notam:
So, all we need is someone to whip up the boards (Zed audio?) to our spec, I have a really crude prototype exchanger, if it works, we need someone to whip it up in some nice shiny stuff, and were in business!
Know anybody thats handy with electrical engineering?

[ROZ]

Go to China and have a few of their engineers build the amp to Zapco(or whatever company you like) specs and plumb for cooling. my last estimate was 55.00 per amp min 500 order.... You'd be surprised what they'll do for you.... :crossx:

[phebus]

But with Chinese amps, your hungry again in about an hour. :D

[1stepcloser]

Go to China and have a few of their engineers build the amp to Zapco(or whatever company you like) specs and plumb for cooling. my last estimate was 55.00 per amp min 500 order.... You'd be surprised what they'll do for you.... :crossx:
There ya go..... But I aint goin to China.... no way. I may know a guy that will though..... :wink:
We need a good name.

[ROZ]

There ya go..... But I aint goin to China.... no way. I may know a guy that will though..... :wink:
We need a good name.
ROZHANGIN'1StepCloser sounds good to me.. :cool:

[ROZ]

But with Chinese amps, your hungry again in about an hour. :D
You've been reading too many "what's for lunch" threads" :cool:
You're right though :D

[1stepcloser]

ROZHANGIN'1StepCloser sounds good to me.. :cool:
Okay.... How about "the all new from the ground up, water cooled RH1"

[Havasu Hangin']

ROZHANGIN'1StepCloser sounds good to me.. :cool:
I think "HANGIN'1StepCloserROZ" sounds better. :idea:

[phebus]

Or if it doesn't work you wil be 1stepcloser to Hangin Roz. :D

[Norseman]

ROZHANGIN'1StepCloser sounds good to me.. :cool:
It might be tough getting that long name on the label. :2purples:
How about the "RH1SC-2000 " for the 2000 watt version. :wink:
Since your going to water cool them, might as well go lots of power. Maybe a 10,000 watt amp. :eek:
Getting water cooled heatsinks is easy, so is building stuff off shore, all it takes is dollars to get started! :crossx:
And a good design, but the chinese will do that for you too, if you want them too.
Of course they like to sell them by the container load, saves shipping costs. That would be lots of audio amps... Even big oes..... :220v: