Well, I decided to build a new project based on the "Quattuor" multimedia speaker system. I was aiming for portability and I was planning to use a couple of Visatons FR8. Then I've found that those drivers are a big no no when comes the time to calculate an appropriate enclosure (the values don't make sense and are out of range, for sealed enclosures, and for ported enclosures with different alignments). Well, it seems I have to use the FR10 instead, which means, here it goes portability.

I was planning to build this project using a single control knob for volume, hence dismissing the LM1036 chip. Although not aimed for portability, Unus would still have the advantage of being cheaper than Quattuor. Also, I've found that the LM1036 introduces a bit of noise.

My question is, is Unus worth to be built, considering that is essentially just the same as Quattuor, but only with one control knob, no LM1036 and less noise?

 

I don't have an opinion, but I'm going to ask some questions that might help.

Is this something a dual pot couldn't do?

Will it have a balance control (and could it use one)?

And now for something totally different. I was testing the 555 Hysteretic Oscillator the other day, and let my boy play with it. He delighted in finding a freqency (a high note) he could hear and I couldn't. How old are you, and how good is your hearing?

 

Hello Bill,

Replying to your question, for the Unus I will use a double gang linear pot. I will use a resistor for each channel so the pot will have a perfect log behavior. I prefer this solution because commercial log pots are not perfect. I must add that the volume control that LM1036 uses is not perfect either, as it increases the volume only at the "last degrees" of the pot.

It won't have a balance control, since this project is aimed for "the lowest bid", and bass and treble controls are more useful. A balance control can be put aside.

As for my hearing, it will go up to about 15000Hz, and I'm 27 years old.

 

My hearing goes to 12kHz and I am 56 years old.

 

I don't have a clue, and I'm 52. I know it has degraded, but still works good enough.

 

Do this, Bill: Put a sine wave through an audio amp. Vary the frequency and you'll find your upper frequency cut off. I think age somehow makes our hearing less good.

 

I think we are going a bit off-topic here.

 

Only marginally, the worst audio component is the human ear, and subjective to boot. The real question is do you percieve enough of a problem that needs a redesign. We both enjoy the challange designing. My days of being an audiophile are pretty much past.

I assume this is your home stereo?

 

Is there a link to the complete plans for this? And cost of building? My n00bness didn't find anything in a quick search for 'unus'.

 

Is there a link to the complete plans for this? And cost of building?...

There are no plans on the web for this yet, because it wasn't built, as you can read in the OP. But the project is quite similar to the one entitled "Multimedia active speakers (2 x 4W)". The cost of the main board I estimate it to be around 30 to 40Eur, but you don't have to spend 4Eur buying a LM1036 chip, and for the same reason you can save some more in other components that this specific chip needs, including three pots. Also, the PCB will be 2 times smaller, saving about 7Eur.

 

Well, I decided to build it. I think that the overall price of the project is a big plus, and it will replace the "Multimedia active speakers (2 x 4W)".