US1 Fountain

iTrader: (1)

Unsane, thanks.
The boat is a 32' Fever.
I'm trying to get a handle on this chit from the Crutchfield advisor for idiots. I'm still at a loss.

UNSANE

I looked up some subs for you, found a solution or 2, will get with you tomorrow, don't panic, that's what they want you to do so you'll impulse buy

UNSANE

Here's what I came up with: Let me know if you can't see the attachment. There's only a 50 dollar price difference between the 2 amps. The bigger amp will make a little more heat but will have more headroom but the smaller amp is a decent match as well. Let me know if you have anymore questions.

US1 Fountain

iTrader: (1)

Wouldn't I need a 4 channel in order to also hook up my 4) 80w Babbs speakers? Wanting to stay with 1 amp.

I don't understand on the power requirements needed for the 4 speakers.

(disregarding the sub for this part)

a) 4 speakers at 80W each, so I need a 360W amp just for the speakers

OR

b)same 4 speakers, but since 2 (2 x80W) will be lefts and 2 (2x80W) will be rights, I just need a 160W amp

OR

c) since the 4 speakers are each 80W RMS, I just need an 80W amp.

In other words, do 4) 80W speakers require an 80W amp just like a single speaker would?

UNSANE

Actually a 4 channel amp that makes 80 watts per channel, disregard the Crutch boys' and other retailers' total power rating. If each speaker is 4 ohms, which is probably the most likely case, then it would be best to use a 4 channel amp in which each channel makes 80 watts or more at 4 ohms. The spec would read like this: 80 watts x 4 @ 4 ohms, or if you hook up 2 speakers in parallel, you then create a 160 watt load at 2 ohms so then you would look for an amp's specs that read: 160 (or more) watts x 2 @ 2 ohms

US1 Fountain

iTrader: (1)

Is the sub preout only for a mono amp?

For my 4 channel amp, that preout does not get used, correct?

UNSANE

The sub pre out was kind of intended for a mono amp, but more so it is a frequency filtered output that you can adjust in the headunit. so you would use the pre outs for the cockpit amp because they are full range. You actually don't have to use the sub out for anything if you don't want, most car amps have built in management systems for subwoofers. So in short, you would not use that out for your cockpit speakers.

John 38 Scarab

US1 Fountain,
Be very careful about running your subs in parallel down to 2 Ohms. Many amps are not made to run @ 2 Ohms and will be come unstable and VERY hot. Unless the amp is made to run at 2 Ohms, I would recommend getting 8 ohm subs instead. This will bring the impedance to a nominal 4 Ohms. Many sub manufacturers make 8 Ohm subs exactly for this reason. If the am is made to run @ 2 Ohms, the amp will most likley have a spec for power @ 2 Ohms.

As for your amp power specification, Today's ratings can not be compared with ratings from years ago. The ONLY way to properly compare amps is Rated output (Watts) @ x% distortion. Even know an amp notes both these specs, they are not related unless you see it exactly as shown above. If you do not see this type of spec, the amp manufacturer can rate the maximum out put at any distortion level. Many lower quality amps will not rate their amps this way because if they did, the actual power would be a fraction of what they say. Hope this helps.

John 38 Scarab

One other thing, Your head unit has only one output for a sub because, As the frequency of sound gets lower the sense of direction and therefore the stereo effect diminishes. At somewhere around 80 Hz and below, there is no discernible left or right even if you were running your subs in stereo mode. This is why home and car systems in most cases do not have a stereo output for woofers. If you need to, you can simply use a good Y adapter to split the signal to the two different inputs on a stereo amplifier.

US1 Fountain

iTrader: (1)

John, I'm only running a single 8ohm sub to the 4 channel amp, bridging 2 channels @ 4 ohms. I was told I won't get the volume from the sub in that config, that a single 4 ohm sub would be best. I may buy a 4 ohm once I get this all installed and running to replace the 8 ohm. What is your opinion of the sub?

Anyways, on to more pressing problems

I now have the stereo hooked up.... rear pre outs going to the amp for the cockpit, and the front preout going to the A/V IN of my flat screen TV. The rear speakers(going thru the amp) sound great, but I have almost no volume coming out of the TV speakers. I have to turn the volume all the way up on the TV, and also on the stereo, and kill the amp to get 1/4 volume out of the TV.
The amp and rear speakers are not going to be used when I am watching DVD's, just the front preout feeding the TV. No amp.
Am I trying to do something that isn't meant to be? Do preouts have to go thru a amp before going to a TV? It's like there isn't a strong enough audio signal going to the TV.
Thanks