(Topic ID: 233805)

Stern Spike Speakers and Ohms


By pindude80

10 months ago



Topic Stats

  • 10 posts
  • 3 Pinsiders participating
  • Latest reply 10 months ago by pindude80
  • Topic is favorited by 2 Pinsiders

You

#1 10 months ago

I've upgraded speakers on my past Sam systems with good results and thought it would be a good idea to upgrade the speakers on my Iron Maiden. When I went to inspect the cabinet speaker I saw it was 4ohm so I ordered a 4ohm cabinet speaker and 4ohm backbox speakers. Yesterday when I went to install the backbox speakers I saw they were 8ohm and not 4ohm like the cabinet speaker.

I hooked everything up and switched the settings for both the backbox and cabinet speaker to 4ohms. I noticed that I was barely getting anything out of the cabinet speaker but if I switched the setting to 8ohm it came to life! For the backbox speakers set on 4 ohm I have to crank the volume up pretty high, 35 or more, to get good volume, but with the factory speakers it was pretty loud at 11 or so. Do I have my settings right for the speakers I have? Do I need to go back to 8ohm speakers for the backbox?

#2 10 months ago

If I recall, the backbox speakers are wired in parallel. So, two 4 ohm speakers in parallel would be TWO ohms. That's way too low of impedance for the amplifier circuitry.

#3 10 months ago
Quoted from KenLayton:

If I recall, the backbox speakers are wired in parallel. So, two 4 ohm speakers in parallel would be TWO ohms. That's way too low of impedance for the amplifier circuitry.

I had the same thought, but wondered if changing the setting to 4ohm took care of that problem.

#4 10 months ago

Also, I would like to know if the factory setting for the cabinet speaker is 8ohm or 4ohm since it's a 4ohm speaker. The reason I am asking this is because it seems to me I remember seeing the factory setting as 8ohm but don't remember for sure and I hardly getting anything out of my cabinet speaker on the 4ohm setting.

#5 10 months ago

I would be using 8 ohm backbox speakers. That's what the factory used.

#6 10 months ago

You could overdrive the amp if you use 4ohm speakers and set it to 8ohm in settings, and go past half volume. I experienced sound cut outs when I did this.

#7 10 months ago

I've found discrepancies between Spike1 and Spike2 hardware.

Spike1 boards use 4 ohm backbox speakers and 8 ohm cabinet speaker.

#8 10 months ago
Quoted from spidey:

You could overdrive the amp if you use 4ohm speakers and set it to 8ohm in settings, and go past half volume. I experienced sound cut outs when I did this.

I had that thought also about overworking the amp. I think I'm going to stick with leaving both backbox and cabinet settings at 4ohm for now unless someone tells me differently. I am still curious what the factory cabinet speaker setting is. I would think it should be 4 ohm since that's what the speaker is but I don't know for sure since I've changed mine and it doesn't have a "factory setting" labeled for either of the settings.

#9 10 months ago
Quoted from KenLayton:

I've found discrepancies between Spike1 and Spike2 hardware.
Spike1 boards use 4 ohm backbox speakers and 8 ohm cabinet speaker.

Weird, and Spike 2 is the opposite; 8 ohm backbox speakers and 4 ohm cabinet speaker.

#10 10 months ago

When I was searching around I found this in the read me when code was updated to 1.01: Supported speaker types are "8 OHM" and "4 OHM".
The amplifier power curve is appropriately adjusted for the selected speaker type.

So, I guess it's ok to run 4 ohm speakers, even in parallel as I understand they are wired from the factory, as long as the settings are set correctly.

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