View Full Version : Crossover question?
Could anyone help me figure this out? If i'm running 3 amps for (tower,interior, and sub) and each amp has a crossover switch on the back for lows, highs, and all...do I need external crossovers as well? Or will those suffice by themselves?
Could someone also recommend a distribution block for stereo equipment and also ballast pumps? Thanks in advance
Thrall
03-11-2010, 12:42 PM
If the amps have internal X-overs, which most do, then you don't need an external X-over unless you want to start doing fancy stuff, like with a Wetsounds 420 ? (PA system, more control over individual speaker fade, etc.
Regarding dist blocks, check out my pic in the Elect section "amp dilema"
I got those blocks from sonic electronix online. Used a fused block for the amps + and reg blocks for the start batt + loads and both - hookups.
My head unit CMD4 has 3 pr of pre-outs (front, rear and no fade). I chose to run the front outputs to the sub amp first, as it has a pass thru, then output from sub amp to the boat speakers amp, with 2 RCA splitters to get to 4 ch from 2.
I ran the rear pre outs to the tower amp. This allows a simple F to R fade adjustment to keep the boat spkrs and sub volume down when the tower spkrs are cranked up.
Just running it in the garage, I haven't had any problems with the line out signal being strong enough to run the sub and 4 channels with the pass thru and splitters. It's loud and clean and I haven't tuned the amp sens levels or mid/sub x-over frequencies on those amps.
TMCNo1
03-11-2010, 01:57 PM
The title scared me, I was afraid it was a Ann Landers/Dear Abby alternative lifestyle question. :rolleyes:
First off...TMCNo1...no alternative lifestyle crossovers to worry about haha!
and Thrall...i'm using a Bazooka MPA-1000b PA system, and a Clarion EQS746 equalizer to control a mono Autotek SM1-1000 and two SM4-1000 for the interior and tower speakers. I wanted to control the sub, interior and tower volume seperately.
Thrall
03-11-2010, 06:58 PM
So you're planning on an external X-over?
I think that's the only plausible way to control volume of 3 or more different sets of speakers with most head units.
Could anyone help me figure this out? If i'm running 3 amps for (tower,interior, and sub) and each amp has a crossover switch on the back for lows, highs, and all...do I need external crossovers as well? Or will those suffice by themselves?
Could someone also recommend a distribution block for stereo equipment and also ballast pumps? Thanks in advance
Don't connect anything with motors to your audio system's power wiring. Make the connections for the pumps at the battery, so you can use it as a filter (which it's really good at).
Also, what head unit do you have? Most have front/rear fader and many have a subwoofer output.
The boat came with a Kenwood KDC-225MR head unit. It only has one set of RCA outputs in the back. I thought i could run the head unit output to the equalizer, and then hook the 3 amps up to the equalizer. Will that work? To be honest...this is my first stereo system install ever...so i'm completely open to suggestions or even diagrams and what size wire to use and where.
Thrall...your question is my question haha...do I need them? If they are built in already...why do I need more...and do they go before each amp?
JimN...I was planning to have a separate distribution blocks for just the pumps because i have 9 of them lol...but I was trying to figure out which ones to use.
The boat came with a Kenwood KDC-225MR head unit. It only has one set of RCA outputs in the back. I thought i could run the head unit output to the equalizer, and then hook the 3 amps up to the equalizer. Will that work? To be honest...this is my first stereo system install ever...so i'm completely open to suggestions or even diagrams and what size wire to use and where.
Thrall...your question is my question haha...do I need them? If they are built in already...why do I need more...and do they go before each amp?
JimN...I was planning to have a separate distribution blocks for just the pumps because i have 9 of them lol...but I was trying to figure out which ones to use.
What is the make/model of the equalizer? If it has sub out, front and rear out and a fader, it should be all you need.
Power wire for an amp is the only thing that you really need to be concerned about. Speaker wire isn't a big deal unless the speakers are far from the amp and in a boat, they aren't. The equalizer doesn't need heavy wire, either. You can connect it to the same power wire as the head unit and then, ground it to the case of the head unit. If it has an illumination lead, use the blue wire under the dash.
Power and ground are the two most important connections in any electrical circuit. If you're installing the amp(s), you need to put a fuse or circuit breaker within 12" of the battery positive terminal. The negative cable doesn't need a fuse.
Thrall
03-12-2010, 08:58 AM
I would say you don't "need" a crossover in it's traditional sense for frequency adjustment, because the amps have hp/lp and X-over frequency adjustment.
You do need one however to separately control output to each amp if you want to control volume separately for each amp/load because you only have one set of RCA outputs.
The other option is to hook up your speaker level outputs to the F and R amps, some amps will accept speaker level inputs, but this is not the preferred clean sounding method.
For dist blocks, draw up a diagram of what input and output wiring you have or need and then size up a dist block accordingly. 9 pumps? What for?
EarmarkMarine
03-12-2010, 10:40 AM
kbob,
The amplifier's internal active crossover networks are all you'll need. In today's electronics external corssover units are mostly a thing of of the past.
However, the Clarion EQ has a build-in lowpass filter (*either 60 or 90 Hz) that cannot be defeated. Set it at the 90 Hz point and do not redundantly use the lowpass filter built into the subwoofer amplifier. The other amplifiers' highpass filters will be engaged as normal.
While the fixed 90 Hz crossover of the Clarion EQ is not optimum for every sub in every boat, its as low as a setting as you would ever need with a normal six sub in an open environment. You may still set your highpass filters 20 to 25 hertz higher without any ill effect, if need be.
Since the equalizer has siz discrete outputs you will only need one set of RCAs from your source unit.
David
Earmark Marine
EarmarkMarine
03-12-2010, 10:52 AM
kbob,
The amplifier's internal active crossover networks are all you'll need. In today's electronics external crossover units are mostly a thing of of the past.
However, the Clarion EQ has a built-in lowpass filter (*either 60 or 90 Hz) that cannot be defeated. Set it at the 90 Hz point and do not redundantly use the lowpass filter built into the subwoofer amplifier. The other amplifiers' highpass filters will be engaged as normal.
While the fixed 90 Hz crossover of the Clarion EQ is not optimum for every sub in every boat, its as low as a setting as you would ever need with a normal six sub in an open environment. You may still set your highpass filters 20 to 25 hertz higher without any ill effect, if need be.
Since the equalizer has six discrete outputs you will only need one set of RCAs from your source unit.
David
Earmark Marine
Good deal, thank ya'll for the help, I really appreciate it. I'm using 9 Tsunami pumps are for my 3 ballast bags...probably over kill...but i figured go big or go home lol! Anyway, i'll save that for another thread. I'll try to draw up a stereo diagram this weekend and post it and see if I have everything I need.