Another stereo qestion
 

In order to narrow down my speaker wiring opitions,

Cockpit has 4 speakers, small sub, amp
Cabin has 2 speakers, stereo CD/DVD reciever, flat screen TV


Cockpit....
1) Do we recieve different sounds between the front and rear speakers if I were to power the cockpit speakers using all 4 channels of the amp, or just left and right? Just your plain music.

2) Cabin
....for DVD movie use. same question for non surround sound system. No front and rear difference, just left and right? No amp use in the cabin.

3) 'IF' there is a front to rear difference, is it possible to use the recievers RCA pre outs (F&R) to feed the amp for the cockpit speakers, AND also wire the cabin speakers using the recievers speaker wire, but when using the cabin speakers, have the amp turned off so the cockpit speakers are not used. I don't know if it is an either/or condition only.

I'm thinking if both speaker and pre outs can be both wired, the cabin speakers will be on a switch so when the amp is on for the cockpit, the cabin speakers are killed. And when the amp is off, those cabin speakers will be used, but only thru the recievers own power.

If there is no front to rear differential on standard music or movie playback w/o a surround sound unit.......

I will not use the front pre out and just run the 4 cockpit speakers off the rear pre outs, and then power the cabin speakers off the recievers front wires and still switch off the amp to conserve battery and shut off the cockpit speakers and also utilize the fade control otherwise.

Does any of this make sense?

Thanks

Re: Another stereo qestion
 

1) Just left and right, I don't know of any mobile amps with 4 seperate inputs

2) Again just left and right

3) You can put the cockpit amp on a switch to turn them off when not in use, but the cabin speakers will most likely stay on because you're using the head unit's on board power amps unless there's a way to shut those off seperately. (this would be a function of a menu in the headunit if it even has the capability) There should only be 2 pre outs (left and right)

You're making sense..............somewhat :drink:

Re: Another stereo qestion
 

I'm lost now. The wiring and description shows 3 preouts, for front (L&R), rear (L&R) and sub. Right now I'm only working on the output factor.

So it is possible to have both the preout and the recievers speakers wires both used? I understand by using a switch for the cabin speakers the reciever will not 'see' them, but even though the amp is turned off and no power to the rear speakers, the preout is still hooked up within the amp. I don't know if that causes a conflict with ithe reciever.

Thanks for any help. The Best Buys salespeople haven't been much help

Re: Another stereo qestion
 

On most head units, the internal amp is on whether you are using any external amps or not. There are exceptions to this (like the Nakamichi I have) but on those units, you typically have to choose to turn off the internal amp via a menu command.

Re: Another stereo qestion
 

What headunit do you have? I'll look it up. Normally there are just Left and Right but this presents a whole new ball game because it has video and sub outs. The only thing missing is Center for 5.1 But it's not anymore complicated, just more flexible.

Re: Another stereo qestion
 

Re: Another stereo qestion
 

Ok, this is what I found so far. This unit has dual zone capabilites. Use the Front Pre outs to send sound to the cockpit amp and speakers, the Rear defaults to CD/DVD. I still recommend a switch on that amp though, but if it doesn't see signal, it will shut off automatically after a few minutes. Sony calls it Zone x Zone and it will allow someone in the cabing to be watching a DVD or listening to a CD and people in the cockpit to be listening to the Tuner or Aux (satellite, I pod etc...) So if I read this right, hook up your cabin speakers to the Rear speaker wires and the hook up the cockpit amp to the Front Pre outs and of course your screen to video out. Hope this helps.

Re: Another stereo qestion
 

Sounds great.
Thank You.

Re: Another stereo qestion
 

Alright, now for the next problem..... as I see it.

I just pulled my amp and subwoofer out to see what they are.

Amp is a MTX Blue Thunder Pro 504
From MTX website:
25W x 4 @ 4 ohm
50W x 4 @2 ohm
100W x 2 bridged @ 4 ohm
what does this relate to in todays lingo so I have an idea of comparison... 200W ?



Sub is an 8" MTX Blue Thunder Legend series
All I see on it is 8 ohm writing. Can't find any power rating on it or in the MTX website archieves.
The sub is in a vented sub box that is FG to the boat inside the rear seat storage. A 10" will not fit. I have to stay with the 8" w/o major work, which I don't want to get into at this time, so the single 8" it is.
Are these still avalible? All I see are 10" and up.



I installed 4 Babbs speakers a couple yrs ago in the cockpit that are ran off the amp also.
2) 5 1/4" 4 ohm, 80 RMS
2) 6x9 4 ohm, 80 RMS


Is the single 8 ohm sub a mismatch for the amp? What is the damage possibilties?
Obviously this is not a high power system.
I believe the amp is under powered also for the 4 Babb speakers alone. I'm looking for suggestions on the required amp power needed to power my speakers and sub.... Wattage and # of channel preferences. For what it is worth, I am a total stereo illiterate person. So speak in simple terms if you would.

Also thoughts on the sub.

Once again, any suggestions are appreciated.

Re: Another stereo qestion
 

8" are still available, Fosgate makes several models. Your amount of boom boom is really $ dependent. Since you just have the one sub speaker, I would suggest looking for a powerful one and feeding it its correct power. Amp lingo is still the same today as it was back in the day. 100 watts X 2 will always be marketed as 200 watts or better yet the peak power capability of 5 million watts so people at the store go " ohhhhh, datz phat and kewl, I'll take this to da hizzie and be the shizzie". :evilb: :evilb: Anyways, tomorrow I'll look up some stuff for you and present you with some amp and speaker setups and I'll try to get costs as well. What model is the boat by the way?

Re: Another stereo qestion
 

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

Re: Another stereo qestion
 

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

Re: Another stereo qestion
 

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.

Re: Another stereo qestion
 

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?

Re: Another stereo qestion
 

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

Re: Another stereo qestion
 

Is the sub preout only for a mono amp?

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

Re: Another stereo qestion
 

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.

Re: Another stereo qestion
 

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. :evilb: :evilb:

Re: Another stereo qestion
 

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.

Re: Another stereo qestion
 

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

Re: Another stereo qestion
 

If I remember right, I believe that the REAR goes to the DVD/cabin and the front to the cockpit, try that.

Re: Another stereo qestion
 

I have switched the preouts around. No change as far as volume. That is more for the 'zone' feature.
Should I be able to go directly from my preouts to the TV in's?

Re: Another stereo qestion
 

What kind of TV, I'll look it up.

Re: Another stereo qestion
 

Sharp. It says the speakers are only 2.1 watts output.
I have tried every option with no difference. With the 2 cabin stereo speakers wired up, and the amp (rear/cockpit) turned off, There is just no volume coming froom the TV. The cabin speakers will run you out though.
My setup is that the cabin speakers are behind us when watching TV, so I thought by running the remaining preout audio jacks going directly to the TV, that the sound will come from the TV's speakers for a more realistic sound. Kinda like a center channel. Also tried differnt audio output setting in the radio setup menu, no difference either. When I have a DVD in and the volumes turned way up to hear the movie, if I hit the TV's TV/AV button changing over to regular TV mode, the volume goes thru the roof on the TV itself then. Is the audio output signal of the headunits preout, the same as what the output signal of a VCR, Video camera, CD player that would normally be connected to the TV's input? I know the TV's audio inputs worked the other day when I hooked up a home DVD player to it to try it out. But those don't have a volume control.


Thanks for all your help.


http://www.crutchfield.com/S-6HnwR5i...284LC13S1U#Tab

Re: Another stereo qestion
 

I'll be out on the water most of the day, I'll check it out tonight and see if we can get some sounds to it.

Re: Another stereo qestion
 

Here's the installation diagram for the reciever itself. In boxes #2 & #3 it clearly shows the option of the front A/V output going to a front monitor, which is what I am doing. Not just the vidoe signal, but the audio too. My wiring is exactly like the top box in #2.

http://www.xplodsony.com/XPLOD_DOWNL...all_Manual.pdf

Re: Another stereo qestion
 

Ok, either the hook up diagram is wrong or Crutchfield is. Try the REAR outputs for the DVD and see what happens. According to Crutch, the front should be run off to the "cockpit" amp. The Rear is always on DVD/CD mode and that should go into the TV, not the front outs. Let me know.

Re: Another stereo qestion
 

I tried both F&R's. No change. I did spend a nice hr on the Sony tech line this afternoon :rolleyes: . They said something about having to disable the TV's speaker amplifer. ALso talked to Bestbuys guys today. The car installer said to install a signal booster in the line between the radio and TV. That sounded more like a bandaid, but I don't want to have more gadgets plugged in anyway. At this point, I'm assuming the radio is not designed to send sound to a TV that has it's own sound amplifer, but just a set of speakers controlled only by the reciever in a 'monitor'.

SO, I just decided it would be best/safest and easiest to just install a smaller set of speakers up front where the TV will be and just use the TV as a video monitor, with all the sound going thru the reciever. At least now the sound won't be behind us with the screen in front. I can use the recievers F&R speaker wires for the cabin and just use the fade to keep the cabin speakers muted while listening to the rear.

Thanks again

Re: Another stereo qestion
 

There is NO elegant solution for what you want to do. Unfortunately your TV is looking for a Non Variable output. This is why you have to turn up the stereo to Full volume to get a decent volume out of the TV. If the unit had a pair of "fixed" audio outputs on the stereo it would work fine. Your best bet is to do what you are doing. Just use your stereo speakers for the TV. You will get much better sound this way anyway. The down side is your TV remote will not work for volume. You could get a wired remote and mount it in the back for this if you want to. If you have further questions and want to talk directly, give me a call. I worked in the audio / video business for 20 years. (847) 336-5515 My name is John.

Re: Another stereo qestion
 

John, That's the route I am now going to take. Listen thru the stereo, watch the TV. I'm going to put a switch on the 1 set of cabin speakers to turn them off when the amp is on powering the cockpit speakers. The other set can be controlled with the fader. This way I will be able to fade the 4 speakers in the cabin while watching TV, while the amp is off, so no sound in the cockpit. Peice of cake now. Thanks

Re: Another stereo qestion
 

Just got back from Jax, that is weird that the TV gets no sound from the headunit. It should. If I were there with the stuff, I could probably figure it out, but I'm not. Just go through the big speakers, it will just be better and easier in the long run. Sorry about all the troubles you been having. If I did up any additional info on your stuff, I'll let you know what I find.