DiyMobileAudio.com Car Stereo Forum banner

1 - 5 of 5 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1
I have 2 pairs of 4-Ohm comps wired to an Eclipse CD8454 HU and a Soundstream 4.760 with a separate Zapco powering a subwoofer. The system is in the main living area of my sailboat (salon). The reason I got the CD8454 over the CD8053 is because I wanted SQ plus a low-power internal amp that I can use when I need to conserve power. There is another pair of 8-Ohm comps (outdoor speakers) in the pilothouse.

There is a 16P4T rotary switch that selects four states for channels 1-4:
A) HU Amp with salon fronts ch1&2
B) HU Amp with pilothouse spkrs ch1&2
C)SS Amp with salon fronts ch1&2
D)SS Amp with pilothouse spkrs ch1&2

The salon rears are always powered by channels 3&4, but the switch selects the HU or SS amps as required.

Problem is the 8-Ohm comps may have blown my sweet old NAK PA-304 amp, is that a reasonable guess? Or are 8-Ohm speakers just fine?
Thanks!
If not and the 8-Ohm speakers are bad for my new SS4.760 amp, then can I leave the salon fronts connected all the time and "tap in" the 8-Ohm speakers in parallel for 2.67 Ohms total when running the pilothouse speakers? SQ is not as important there but I'd rather not have to buy and install new 4-Ohms comps to replace the 8-Ohm set for several reasons; but neither do I want to blow my new sweet amp.

I've even heard my local audio shop "experts" guess for me on this one- I'd like to know what's really going on with 8-Ohms if anyone knows. Any opinions about running speakers through a rotary switch (silver contacts)?
 

·
Registered
Joined
·
7,406 Posts
I have 2 pairs of 4-Ohm comps wired to an Eclipse CD8454 HU and a Soundstream 4.760 with a separate Zapco powering a subwoofer. The system is in the main living area of my sailboat (salon). The reason I got the CD8454 over the CD8053 is because I wanted SQ plus a low-power internal amp that I can use when I need to conserve power. There is another pair of 8-Ohm comps (outdoor speakers) in the pilothouse.

There is a 16P4T rotary switch that selects four states for channels 1-4:
A) HU Amp with salon fronts ch1&2
B) HU Amp with pilothouse spkrs ch1&2
C)SS Amp with salon fronts ch1&2
D)SS Amp with pilothouse spkrs ch1&2

The salon rears are always powered by channels 3&4, but the switch selects the HU or SS amps as required.

Problem is the 8-Ohm comps may have blown my sweet old NAK PA-304 amp, is that a reasonable guess? Or are 8-Ohm speakers just fine?
Thanks!
If not and the 8-Ohm speakers are bad for my new SS4.760 amp, then can I leave the salon fronts connected all the time and "tap in" the 8-Ohm speakers in parallel for 2.67 Ohms total when running the pilothouse speakers? SQ is not as important there but I'd rather not have to buy and install new 4-Ohms comps to replace the 8-Ohm set for several reasons; but neither do I want to blow my new sweet amp.

I've even heard my local audio shop "experts" guess for me on this one- I'd like to know what's really going on with 8-Ohms if anyone knows. Any opinions about running speakers through a rotary switch (silver contacts)?

Wasn't likely an 8ohm speaker that cause the problem, more likely just an old amp... 8ohms is LESS load on an amp... so it's less likely to cause a failure..
 

·
Registered
Joined
·
1,665 Posts
I agree with Aaron. 8 ohms won't blow an amp. However, a switch like that might be able to if you switch it with the power on. If you didn't do that (or perhaps even if you did), then I vote that you just got unlucky.

You can run the speakers in parallel if you want. But you won't be able to level-match them unless you use an L-pad on one or both.
 

·
Registered
Joined
·
7,406 Posts
I agree with Aaron. 8 ohms won't blow an amp. However, a switch like that might be able to if you switch it with the power on. If you didn't do that (or perhaps even if you did), then I vote that you just got unlucky.

You can run the speakers in parallel if you want. But you won't be able to level-match them unless you use an L-pad on one or both.
8ohms will most certinly blow an amp just the same.. there aren't any 100% in this world Sir..

It's just less likely than say, a 4ohm load.. won't simply should be "shouldn't"..

That switch though, that could be another coluprit too... didn't think about that...

For the same reason relays "shouldn't" be used in a signal path, at the moment the contacts get "close" DC has a tendancy to jump the gap, but to jump the gap, voltage increases exponentionally (static charge)

That little spark can be in excess of 50kV (no joke)

So switching with ANY part of the system running could be very bad..
 

·
Registered
Joined
·
3 Posts
Discussion Starter #5
Well the relpies answer all my questions, thanks. Speaker switching while the amp is on was not something I'd thought of asking about, I was simply thinking about degraded SQ or interference within a 4P16T rotary switch. I'll have to check and see if it's a "make before break" or "break before make" to see how bad my problem is. I must admit I have switched the speakers while at lower volume.
Thanks again!
 
1 - 5 of 5 Posts
Top