Lo-pass filter for speaker simulation....

[rb]

Hi Guys,

I am wondering how complex it might be to build one of these?

I guess those spkr sim boxes on the market use a lo-pass and some other eq-ing to get a speaker/cab sound.

I don't need the "other eq-ing", just the lo-pass....

Anyone know what frequency they typically shelve (if that is the correct term). I am guessing they allow everything up to about 5 or 6k thru...Does that sound right?

Is it possible to build a simple circuit that does this with a pot controlling how much the "shelved" frequencies are attenuated?

TIA for any advice/help!

[newey]

Runoffgroove has a couple of speaker sim DIY projects:

www.runoffgroove.com/condor.html

runoffgroove.com/mreq.html

These are both more complex than what you seek. They are both rated as "intermediate-level" projects.

There are many other similar ones out on the web. Most of these involve more than just a lo-pass filter to try to match (as closely as possible) the response curve of a given speaker. This means a Hi-pass filter as well, and some amount of boost, to simulate overdriving the speaker.

Far be it for me to discourage anyone's DIY thoughts, but you may want to consider that you can buy a cheap 7-band EQ from Dano for $30 USD:

guitars.musiciansfriend.com/product/Danelectro-DJ14-Fish-and-Chips-7Band-EQ-Pedal?sku=151873

Which would probably give you all the EQing you could want, at a price not much more than you could DIY one for, unless you already have the necessary bits on hand.

[ashcatlt]

You may think I'm silly, but I've found that these things
tend to fail in just such a way as to provide a certain amount of speaker simulation. They are neither flat nor clean, and can be suprisingly convincing.

If you need it to end up as a 1/4" plug, you can plug it into one of these and get even more coloraton and saturation from the cheap transformers.


PS - clic the pic, it is imperative that it be the RadioShaft brand (or something similarly crappy). Shure and some other reputable manufacturers sell these, but I'm afraid they'll be too hi-fi for what we're trying to do.

[rb]

Thx for the ideas guys.......still wondering if there might be a way to mount a simple tone pot on the gtr which could roll off everything above about 5 k?

[sumgai]

Jun 22, 2010 19:42:32 GMT -5 rb said:

Thx for the ideas guys.......still wondering if there might be a way to mount a simple tone pot on the gtr which could roll off everything above about 5 k?

If I've used JohnH's GuitarFreak spreadsheet correctly, you'll be wanting a capacitor valued at 0.0005mf, or 0.5nf. Use this in your tone control, or in a separate "sim control", your choice. Just be aware that the effect on the tone is subtle, to say the least

HTH



sumgai

[rb]

Thanks Sumgai - btw, would you mind posting a link to JohnH's spreadsheet please!

TIA

[newey]

rb-

Here you go, from our Reference section:

guitarnuts2.proboards.com/index.cgi?board=reference&action=display&thread=3627