DIY bluetooth speaker

[audioguru]

Did you find an article that shows the "magic" different dimensions of the width, height and length of an enclosure to avoid standing waves?

 

[Mickster]

Golden ratio.

 

[SentinelAeon]

No, i didnt, i am taking small steps, otherwise there is to much information at once and i get confused

 

[audioguru]

The rough "golden ratio" is 1.6 x 1.0 x 0.6.

 

[SentinelAeon]

I will keep that in mind in my next build, though that will complicated things further, just look at the list of things i need to do now for the enclosure:

1) calculate the correct enclosure volume and port size in QSpeakers
2) calculate the volume of port, batteries, amplifier, speaker and vires and add this volume to enclosure volume
3) find an app to calculate enclosure volume and try different sizes
4) try to match the golden ratio
5) suicide

There is probably an app that will, for a given volume, calculate the perfect enclosure. If there is not, i will make one !

 

[audioguru]

Try this app:

 

[SentinelAeon]

Tnx, will give it a go. Btw, do u see any problem of simply glueing the tweeter to box enclosure as oposed to drilling a hole for it and putting it inside ?

 

[audioguru]

The tweeter should have a grille so that little kids don't collapse its dome. It might look funny outside the enclosure.

 

[SentinelAeon]

Its not my responsibility to take care of children xD But you are right, those speakers are usualy used around drunk people. The speaker i use has both its domes collapsed because people just trip around and catch themselves on my speaker.

I am really happy about finding out that dayton TCP115 does what i need it to do, its decently loud and really packs a punch. When i get the 4 ohm version which will gve me another 5dB, which is 40-50% more loudness, it will be great. I think i will build many speakers around it. I just wish there was a simple way to turn stereo into mono so i wouldnt have to have woofer on 1 channel and tweeter on the other.

Btw this dayton and tweeter combination, they are both 8 ohm and i am thinking that maybe tweeter needs a resistor in series, it might just be to loud.

 

[audioguru]

Most tweeters are much louder than woofers.

 

[SentinelAeon]

I know, that is why i am thinking whether to put a resistor or not. I will have to listen to it and decide what sounds better.

But i will say it once again, this daytons pack a punch, they really are strong speakers. They move this plastic enclosure around the table and really give this BOOM feeling and they also go very low, for that price range. I think 4 ohm version will be my speaker of choice, in combination with some cheap tweeter. I hope to finish the wooden speaker today since this thin plastic clearly. I will report how it goes !

 

[SentinelAeon]

Ok, i mostly finished the wooden enclosure. Bass is good. I am waiting for glue to dry, then i have to fill more holes and sand it. Its not vibrating that is good. But sadly the dimension is less portable than it was before. Let's hope i can still sell it at least for some profit.

Wood is kind of messy to work with in my small workshop, i really need to get a vacuum for dust. And i need to buy thiner wood, plywood would be perfect.

 

[SentinelAeon]

Ok here is a quick test, as usualy, mic wont pick up the bass but its really really deep. Its shaking everything that isnt screwed in my workshop. Very happy. And i still got more holes to fill.

 

[SentinelAeon]

I have a question. QSpeaker program which i like, always seems to give me certain port diameter. I can manualy change its diameter to bigger or smaller and it adjusts length accordingly but if i change enclosure size or resonant frequency, it will change to this "default" port diameter it likes. Its usualy 3.20cm. So my question is, what is special about this 3.2cm diameter ? Do i lose something if instead i have port of 2cm diameter? Because that would be a LOT better for me since port will be shorter and will take less space so there is more space for other components.

 

[audioguru]

The little woofer is moving so much that it is modulating the high frequencies it produces. Which is another reason for a crossover that removes high frequencies from the woofer.

A port needs a certain volume. If you make its diameter less then its length must be longer. Some of my ported speakers have its port go parallel with a side then is bent to continue parallel with the rear.

 

[SentinelAeon]

Can you explain what you mean that it is modulating the high frequencies and why is it bad ?

As for coils to do a crossover. Do i need some special kind of coil or can i just pick the correct value i need and order it ?

 

[audioguru]

I hear intermodulation distortion and doppler frequency shift of the high frequencies from the little woofer being modulated by its severe low frequency movements.
I was given for free my crossover coils from a local high end speaker manufacturer. Guess what? Suddenly my newest speakers sounded wrong and had the wrong crossover frequency so I measured the high end speakers at their showroom and they had the same problem. I measured their inductance and it was wrong. They thanked me but do not know how many nice looking but bad sounding speakers they made and sold.
A crossover coil has an air core that does not saturate and thick wire (low resistance) with enamel insulation.

 

[SentinelAeon]

I cant pick what u said. I can only hear rattling and noises from things in my workshop since the woofer shakes them.

Btw, the calculators i used, the smaller the diameter of the port, the shorter it is.

 

[gophert]

I cant pick what u said. I can only hear rattling and noises from things in my workshop since the woofer shakes them.

Btw, the calculators i used, the smaller the diameter of the port, the shorter it is.

pit seems like you are more concerned with volume than accurate reproduction of the audio signal. Not that there is anything wrong with that but at least clarify your goals to allow members to focus their answers to your goal.

 

[SentinelAeon]

It's not as simple as that. My first goal was to make any bluetooth speaker and was very impressed that i could do it. And my first 2 speakers were very very loud. I was satisfied wih the speakers but my friends were very obsessed with bass. So because of them, my next goal was to make speaker with bass, remain loud and be very cheap. And it seems with last 2 speakers i accomplished loud and good bass.
Now the speaker sounds good to me. But since audioguru noticed something that i couldnt, since he obviously know a lot more bout audio than me, i was wondering what he noticed. So logical next step is to improve sound quality.

I am learning as i go. And while attitude of some (not you gophert) in audio comunity was in lines that i barely have a RIGHT to make my own speakers until i know all the theory, i belive i have a right to make fun things, do mistakes, learn as i go (afterall its my time and my money i spend).

So to sum it up, i would love to know what intermodulation distortion and doppler frequency shift is and how it sounds, so i can correct it, as audioguru mentioned i can do that with cutting woofer from playing high frequencies.