LM386 and speakers in UMD question

[thearkman2009]

I have a question on how this should/could be done.

I actually dont use the LM386 much, so maybe someone else could tell me how this would be done best.

I have the LM386 put together for the sound mod.  Its not connected to any form of output right now, in fact, its not even in the PSP, its all on breadboard right now.  I have 2, 8 ohm, 0.5 watt speakers from a laptop I want to put in the UMD area.  I want to also have the speakers filtered so that only the lower frequencies are let through to the speakers, so in essence, they act as "subwoofers".  Anyone able to draw me a rough diagram of how it would be done and what the values of any components would be?

[Blazinkaos]

ooo so u want to add more speakers plus the lm386 theres a thread on it umm i have to find it cuz i did the same thing

[thearkman2009]

Yep.  I looked for one that would tell me the resistor values and stuff like that, but never found one.  I might have been looking in the wrong places too.

UMD door is going to have a custom style jewel (using some of the plastic parts that make up the LCD screen from a phat), blue LEDs, 2 big speakers that are LED lit, and possibly some sort of digital info display.  I have not made my mind up completely, but I know what I WANT to do.  lol  Again, I wont devulge ALL the details yet, but keep your eyes peeled, I have some sweet stuff planned.

[Blazinkaos]

yea its some where in am theres a couple diagrams

[thearkman2009]

I just tried to install my LM386 mod today, and came across a couple problems:   

I wired it up EXACTLY as showed, except for the fact that on the one wire coming from the speaker, I used 200k ohm resistance instead of 191k.  Does that REALLY make a difference?  Because once hooked up, it lit up VERY bright, but the problem is, is that is STAYS that way.  Now when I put my finger on one of the connections, the LEDs suddenly get very dim, and almost turn OFF.  Now, in this state, when I play some music, they pulse VERY nicely.  But as soon as I let my finger off the wire, they are back on full brightness.  ALL my connections are perfect, no leaks, or shorts, and I had the unit apart down to the LCD cage, thats all.  What the  !

Second, I may not be the first to have this issue, but my direct contact trigger LEDs (to the RIGHT speaker) turn OFF when there is some kind of specific pressure to the area on the faceplate right above where the speaker is.  Could the LCD cage be making a short?  The speaker still works, but the LEDs no longer light!   

Third, I connected the LM386 the same way as I did for the LEDs, but swapped the LEDs for a single 8 ohm, 0.5 watt speaker.  It was LOUD, but VERY distored, and full of white noise.  What did you guys use as a filter to clean up the sound?   

[Ben.]

That resistor might not matter.. as they are pretty close.

And with the direct contact ones, it maybe the lcd cage, or the face plate it too tight..? Try sticking some insultaing tape over the bear connections..

[Blazinkaos]

No YES it does matter it wont work if you dnt have the 191k if you cant the exact 191 thearkman then do this get 2 k resistors that will equal up to 191k  for example i cnat find them either so i went to this electronics store and got a 11k  and 180k that will work if you do that.

[jakxxx]

I have a 180 and and 11 but when I measure them it is only 188k will this work?

[thearkman2009]

I have a 180 and and 11 but when I measure them it is only 188k will this work?

If your using a multimeter to check the resistance, it will be a bit off (tolerance).  Check the resistors using the color bands to get the values, and you should be good.  If the resistors are 180k and 11k, then YES, it will work.

[Blazinkaos]

yea hes right dnt worry if ur multimeter dnt read it still works i tested it several times.

[jakxxx]

thanks guys thats what I thought

[Blazinkaos]

np