Speaker Replacment

A project log for Positive Grid - Spark 40 Teardown/Mods

This project is to document the teardown of the Positive Grid Spark 40 Amp, the internal components, and any cool mods!

michaelsheaffermichael_sheaffer 09/12/2020 at 02:213 Comments


I decided to try out these Morel 2-way car audio 4" speakers, as they looked to be the right dimensions.  And voila, they fit perfect, even the mounting holes lined up just enough to use the already existing screw holes.

Even the crimp connectors are the standard for these car audio speakers, so it was a quick removal of the old ones, and install the new ones, 30 secs to replace each. 

So, adding these speakers definitely added much more high range, the treble is much clearer and streaming music sounds so much better...

BUT, I do feel the amp in this unit is really underpowered for the design.  You really can't get it that loud, if it just had at least another 25W per channel I think it would be so much better.  Anyhow, even though it doesn't get real loud, it did really clear up the sound spectrum...


Jonathan Tarbay wrote 09/14/2020 at 11:40 point

Ho Michael,

Just found the forum where I found that Spark has A MAXIMUM SOUND PRESSURE LEVEL

116 dB SPL @1

I’m guessing that might be one of the reasons why the new speaker doesn’t sound nearly as loud? I’m not well versed on speakers so if I’m reading this wrong let me know!


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michael_sheaffer wrote 09/14/2020 at 12:04 point


I haven't tried with my guitar again, since it's still torn apart on my work bench.. lol...

but seeing those discussions, it seems like this thing really does get much much louder.. the loudness I was seeing was the same with the Morels or the stock...

but ya know, I can't even remember if I also played with the main volume knob!  haha... I was always tweaking the small 'music volume' knob but not the main volume, as I 'thought' it didn't do anything in BT streaming mode...

but now thinking about it, I really can't remember if I double checked that!  I will check tonight when back home from work...

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Jonathan Tarbay wrote 09/13/2020 at 21:46 point

That looks great! Have you tried the amp with a guitar? I wonder how the 2-way speaker sound with guitar. Do you notice if the amp is less loud with this speakers than with the stock speakers? I believe I saw somewhere that the sensitivity of the original speakers is something around 112db which would be much louder than most 4" speakers I have been seeing online. I tried looking for the page where I found that information but can't find it! 

Thanks and enjoy the amp with the new speakers!


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