Build your own Multiamped "Floobydust" system for less than 100 dollars.

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Kimbal@EFT

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  • Posts: 3
Hi All;

I am new to this forum but not new to Audio and Electronics. I am a qualified Electronics Technician by trade and have the ability to repair and redesign equipment if needed so for myself this was a great chance to do some experimenting. Experimenting which has permently changed my own view of what I consider to be a quality audio system.

Here I want to place this small note of interest for those who may be struggling to get quality sound at a small price. I have for some time been out of work and barely having enough income to survive. But at the same time have had an insatiable desire for a quality sound system, which has never wained. So this is where I got clever.

I went around to all the local opportunity and junk shops and bought up as many stereo amplifiers I could get. These were selling for about $10-30 dollars each and having power outputs as high as 50watts RMS per channel. Many were much lower but still of reasonable power rating. All in my case were discrete solid state amplifiers from the 1970's and 80's period.

Again I did the same with the speakers and found some reasonably sized enclosures all with 8 inch drivers for the bass. in all I have four STEREO amplifiers totaling about 150 watts RMS per channel or 300 watts in all. From this I sources a belt drive turntable and at least 2 equalizers, one 7 band and the other 10 band.

I hooked the equalizers to the inputs of two of the best amplifiers and padded them out to filter the best band for the speakers on their output. The other two amplifiers were simply Tone Control adjusted for best bass and mids. I had four pairs of speaker boxes ( all but one pair were two way the other pair was 3 way ), with all acoustically phased and stacked from floor to ceiling on each side of the lounge room like two massive speaker columns. None of the gear was exotic or high end. All of the equipment was low to mid end gear of its period.

I also fitted a dedicated Computer for MP3 down loads and a CD player. The lot cost me less than $100 dollars Australian including the speakers and computer.

But "my God" the sound "quality" was incredible. What a vast difference from a standard stereo with two speakers. The sound was so loud I could hear it clearly, without any audible distortion for at least three house blocks up the road. I placed an old Oscilliscope on each of the amplifier outputs to monitor their clipping levels to attain the best sound level for drums and other high transient passages.

The only think lack9ing was decent Sub wooffer to fill in the bottom end, but even so the bass was incredible considering I was using at least eight 8 inch drivers in total.

The sound was clear clean and full of grunt. The bass was quite gutteral considering the speakers I was using and I had no shortage of headroom of transient response.

So in conclusion. A multi-amped set up is definitely the way to go and with active equalizing before the power amps and each speaker dedicated to its particular band. The stereo separation and imaging is so much better with a set up on this arrangement. The more amps and speakers "the better".

In fact I jokingly said to my wife that I would expand the system to cover the entire lounge room wall with speaker stacks all made from low-fi amplifiers just to see what sort of sound quality could be attained with cheap gear.

I would be interested in others comments on this and if such a set up has been done by anyone else on the same idea. If your on a real tight budget this is the way to go if you want any half decent sound system. Great for parties and those who like loud hard rock music as I do. I also found it sounded very good with pipe organ music and various classical pieces played on the turntable.  In fact many people dump these amps and speakers on the front hard rubbish collection each year; so you may score a few freebies in the process as I did.

Cheers.

     

Taterworks

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  • Posts: 52
Any system can be equalized 'flat' in the frequency domain, whether composed of $100k super-speakers or a pile of sub-$50 junk.

Whether that system can continue to play with low distortion at the desired listening volume while behaving well in the time domain is another matter entirely, and that seems to be what separates true 'hi-fi' gear from mid-fi junk, and that's without bringing power compression and dispersion into the mix.

Personally, I'd send all that junk back to the Goodwill or whatever second-hand store you bought it from, and spend the money on a pair of decent two-way monitors. If you must have something second-hand, there's always Audiogon, or (*cringe*) eBay. There's a good reason why all this stuff costs real money*. If you're not sure what gear to buy, then feel free to ask; opinions are never in short supply in hi-fi.

(*This statement is true to a point. When you get to the point where spending more money seems pointless, you've found your ideal 'value' point, though keeping an open mind is always nice - your view of what is 'enough' may change.)

Kimbal@EFT

  • Jr. Member
  • Posts: 3
Any system can be equalized 'flat' in the frequency domain, whether composed of $100k super-speakers or a pile of sub-$50 junk.

Whether that system can continue to play with low distortion at the desired listening volume while behaving well in the time domain is another matter entirely, and that seems to be what separates true 'hi-fi' gear from mid-fi junk, and that's without bringing power compression and dispersion into the mix.

Personally, I'd send all that junk back to the Goodwill or whatever second-hand store you bought it from, and spend the money on a pair of decent two-way monitors. If you must have something second-hand, there's always Audiogon, or (*cringe*) eBay. There's a good reason why all this stuff costs real money*. If you're not sure what gear to buy, then feel free to ask; opinions are never in short supply in hi-fi.

(*This statement is true to a point. When you get to the point where spending more money seems pointless, you've found your ideal 'value' point, though keeping an open mind is always nice - your view of what is 'enough' may change.)

I agree with what you have to say, but this was rather an experimental pursuit. I was quite impressed with the sound improvement gained in this set up from so called junk audio gear.

I have also been out of work and money is also another issue, hence I don't have the luxury of owning a pair of $10K dollar speakers, or whatever. Like so many others, in a perfect world I would have the best technically available.

Speedskater

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  • Kevin
A quick note on the word "Floobydust".

In the 1976 National Semiconductor - Audio Handbook  the word "Floobydust" is defined as:

"Floobydust" is a contemporary term derived from the archaic Latin miscellaneus, whose
disputed history probably springs from Greek origins (influenced, of course, by Egyptian
linguists) - meaning here "a mixed bag."

Later in 1991 Bob Pease (Staff Scientist at National Semiconductor) defined the word in his
Book "Troubleshooting Analog Circuits" as:

"Floobydust" is an old expression around our lab that means potpourri, catch-all, or miscellaneous.  In this chapter, I'll throw into the "Floobydust" category a collection of philosophical items,  such as advice about planning your troubleshooting,  and practical hints about computers and instruments.

Bob Pease now uses the word in his columns in Electronic Design Magazine.

Kimbal@EFT

  • Jr. Member
  • Posts: 3
A quick note on the word "Floobydust".

In the 1976 National Semiconductor - Audio Handbook  the word "Floobydust" is defined as:

"Floobydust" is a contemporary term derived from the archaic Latin miscellaneus, whose
disputed history probably springs from Greek origins (influenced, of course, by Egyptian
linguists) - meaning here "a mixed bag."

Later in 1991 Bob Pease (Staff Scientist at National Semiconductor) defined the word in his
Book "Troubleshooting Analog Circuits" as:

"Floobydust" is an old expression around our lab that means potpourri, catch-all, or miscellaneous.  In this chapter, I'll throw into the "Floobydust" category a collection of philosophical items,  such as advice about planning your troubleshooting,  and practical hints about computers and instruments.

Bob Pease now uses the word in his columns in Electronic Design Magazine.

Well thats pretty well what I have and where I got the original word from - since I also had the National Audio Handbook many years ago. "A mixed bag" of whatever audio gear I could find and readapted it into a potpourri sound system. Mind you, I have not just used any old crap amplifier, I do have some half reasonable amplifiers from the period, but nothing exotic. And bring it into modern times, I even have an old Pentium 4 computer adapted as a music library to drive the system when CDs and records are not being used. Great for parties, where nobody gives crap about the perfect sound.

JLM

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  • The elephant normally IS the room
One of my audio epiphanies was auditioning passive versus active versions of small ported 2-way standmounted Paradigm speakers.  About 10 years ago they offered a passive version (Studio 20, $800/pair) and active version (Active 20, $1600/pair). 

There was no comparison!

The Actives were much more dynamic and had a flatter frequency response, but the biggest difference was the bass.  OMG!  It was really deep and strong.  Passersby couldn't believe that we weren't running a subwoofer.  Easily worth the cost difference just to save the cost of the sub, power amp and/or speaker cables, let alone the overall sonic improvements.

Paradigm also sold an Active 40 that used a 2nd woofer for deeper bass, but that would only be needed in very large rooms or home theater applications.

Wayner

Sounds like you've made the best out of your particular situation. Bravo!

I have several 1970's vintage Marantz receivers that will make the Outlaw RR2150 sound like a POS. Even my Marantz 2220B with a pair of Paradigm Atoms is very musical (I have this system out in my garage). Of course, for real power, I can bust out the Marantz 2385 with 185 watts RMS per channel (with discrete transistors). This receiver crushes anything. Very loud (and clear) with volume at 8 o'clock.

Wayner :)