DIY bluetooth speaker

[audioguru]

The Visaton speaker in the same enclosure as a woofer has its cone pushed around by the airflow from the woofer which causes the Visaton to distort what it plays and causes a big hole in the enclosure that cancels bass from the woofer. Put the Visaton in a sealed off part of the enclosure causing its resonance to be about 250Hz or 300Hz then use a capacitor to cutoff at about 2kHz to 3kHz. Then since it has a cone its high frequencies will be in a narrow beam.

 

[SentinelAeon]

Yep, that is what i plan to do. I was even toying with the idea of using capacitor at like 200Hz instead of 2000Hz. I know that would mean both woofer and visaton would play the same frequencies making it uneven. But that would mean also this part of spectrum would be a lot louder resulting in louder speaker. Sound quality vs loudness, hmm

 

[SentinelAeon]

Ok, so my dad is excited about my idea for his speakers. He wants the speakers to be able to play in 2 rooms at once. That means left and right speaker in each room. I draw up a simple scheme to give you an idea. I want to use a bluetooth amplifier for this, since like i said, he doesnt have amp, wants it to be as compact as possible and having an option to use bluetooth on mobile phone to play music is an added bonus.

He wants a separate control of music in each of the rooms. So for instance, if he wants to only listen to music in room 2, he will simply turn on the volume in room 2 and turn it off in room 1. It would even be an added bonus if he could control speakers in room 2 from both room 1 and room 2.

So there are a couple of questions i need to solve. Do i use only 1 stereo amplifier ? Do i connect 2 sets of speakers to each channel in parallel (and make sure amplifier is strong enough for that ?). Or do i buy an amplifier with option to connect 4 speakers ? Do i separate audio receiver (3.5mm jack and bluetooth and then separate amplifier) or use combined ? Do i even use a small bluetooth board or maybe buy some small already made amplifier of compact size ?

This time i am not on such a tight budget, i would say i can have like 100€ or 150€ budget. I was thinking of using dayton + visaton in each of the 4 speakers. Visaton gives much bass in small enclosure. And i can make the enclosure very small since i dont really imagine my father liking to much bass, like i said he listens only to classical music.

Alright guys, help me out

 

[audioguru]

A separate volume control for each room indicates a separate amplifier for each room since the volume control is at the input of its amplifier.
But if each room does not need separate volume then the speakers can be switched on and off with a switch and a single amplifier must have spec's that it can drive both sets of speakers in parallel.

 

[SentinelAeon]

Yeah, i kindof came to the same conclusion as you. So basicaly i have this two options:

1) separate amplifier in each room, each with his own volume knob. And then i would send audio from 1 receiver to two amplifiers (if thats possible ?)

2) 1 amplifier and 1 receiver, volume control in room 1 and in room two only a button to turn the speakers on and off

 

[audioguru]

A Bluetooth receiver can drive many amplifiers.

 

[rjenkinsgb]

Or put the amps in the loft/attic - that's where my setup is for whole-house audio.
Just add a volume control in each room if needed, or use voltage-controlled volume ICs between the receiver and amps, so you don't have to run long audio cables.

I'm part way through redoing my whole-house system to stereo everywhere, from the mono system I built 20 years ago when I first moved here.
Only a couple of pairs of speakers and amp inputs from the mixers are connected in at the moment as I'm still rewiring rooms, as I get time.

The amps are ebay TPA3116D2 stereo modules, modified for balanced input as I posted a few months back on here & with extra heatsinking; they work very well, using an old industrial 24V 10A supply.



The XAP800 mixers higher up in the rack are superb for multi-room setups, they have 12 inputs & 12 outputs each that can be cross-connected or controlled either by a computer serial link, or by creating preset scenes that can be selected directly by switches.
And they are often only around 20- or so on ebay, to give facilities that cost thousands in branded audio gear.

With mine, they also handle mics for voice control and echo cancellation on those so they ignore music etc.

 

[SentinelAeon]

Thank you for your reply and please, stick here with us, a lot is going on all the time.

Right now i think i will go with 2 separate amplifiers and 1 receiver. I read a lot about dayton tcp 115 and everyone is saying it gives a lot of bang for buck, probably the best budget speaker i can get, not sure i need its strong bass for classical music though, but maybe i can make smaller more compact enclosure and have F3 at like 80 or 90Hz. But for upper frequencies, i am not sure i should be using the cheap 4 dollar tweeter from aliexpress. Will have to do more research. Maybe i could even find a full range speaker and avoid using separate woofer and tweeter. Maybe some visatons? I think i will need to test how classical music sounds on speakers with bass. Well to be honest, i listen to it all the time on my big speakers with lots of bass and it sounds just fine. But for some reason i just cant imagine myself listening to rachmaninoff on my bluetooth boomy speaker.

 

[SentinelAeon]

Ok i was playing around a bit with different speakers, just for fun. So i remembered i have 4 visaton FR 8 4 ohm laying around, i never got to use them. So i imported them into my QSpeakers app that i like. And well, i have to say i was surprised. This speaker, if u read its data, has no bass whatsoever. But watch what happens if u put it into a ported box. Ofcourse this is not enough bass for someone who wants to listen to techno. But what about Bach ? Mozart ? Granted we would like a flat line, not this wavey nonsense. But in this price range without making speakers stupidly crazy ?

 

[rjenkinsgb]

For general listening speakers, have a look at dual-cone units intended for car door fitting.
They are fairly cheap and often fairly good overall frequency response; I used a pair many years ago to replace the chassis in a nice pair of cabinets I was given that has one code damaged & they were better than the original units

Examples:

dual cone for sale | eBay

Find great deals on eBay for dual cone. Shop with confidence.

www.ebay.co.uk

These are one type being sold in that list - £17 a pair & they supposedly have response from 35 Hz to 20 KHz, with pretty decent efficency.

Car speaker, 16cm Dual cone car speaker CS-J610X • JVC U.K.

Perfect upgrade to your standard car speaker, JVC CS-J610X, 16 cm Dual cone speaker for powerful dynamic bass.

uk.jvc.com

 

[audioguru]

In the ported little speakers, I think the increased output at a few hundred Hz will sound "boomy" and the missing bottom 2 octaves will sound bassless."

Dual cone speakers produce inter-modulation distortion of the high frequencies. The power rating is a joke (hundreds of Whats!) and the frequency response spec means nothing without saying its deviation from being flat.

 

[SentinelAeon]

I will test it out just for the sake of fun, i really really wanna see how it sounds. When i create a 3L enclosure for my new speaker, i will test it in that one. Boomy because of mid might be problematic. But do u think missing bottom 2 octaves would be a problem when playing classical music ? I guess i will have to see and hear. As for the other speakers, even if they are fine, there is no data to calculate the enclosure, and i dont feel like testing my luck again as i did with my first speaker, doubt i will ever get that lucky again.

 

[audioguru]

Google says that a classical cello plays down to 65.4Hz and a common classical double bass plays down to 32.7Hz. Google says that a classical kettle drum and bass drum go from 60Hz to 100Hz. I play classical music recordings sometimes and the bass is important.
Tiny speakers can't doo dat.

 

[SentinelAeon]

Hmm, well you convinced me. I guess there is no way around using the daytons for the lower part. Now remains the question whether i should use the visaton FR 8 for the upper part, i could cap them at around 3000Hz. I know they are far from perfect but for some reason i would like to belive they sound better than 4$ aliexpress tweeter. And while i will have to check with dad what the budget is ... i am pretty sure it wont be higher than 100$ or 100€ for 4 speakers and an amp. So if 4 daytons cost 60€ and amp is 5-10€, then i have 30€ for 4 high frequency speakers which is less than 8€ a piece, even those FR 8 i have cost more.

 

[audioguru]

You will need to test the Visaton speaker in a fairly small enclosure to see that the enclosure does not affect its high frequency sounds.

 

[SentinelAeon]

Well if i used combination of dayton and visaton, the enclosure size would probably be around 2L. I would put visaton in a separate box to protect it from the woofer. The problem with music is that one thing is a graph, you can see frequency response there and it tells you something. But you can never be sure that nice graph means it will be pleasant to listen to it and that messy graph will result in a very bad speaker.

One thing is for sure, when i make the speakers, if i am not happy with them i will not give them to my dad, instead disasemble them and try another route.

 

[audioguru]

All speakers I have bought, made or modified have good graphs and sound good.

 

[SentinelAeon]

Yes my friend, but see, i am pretty sure that when we talk about buying speakers, we arent in the same budget class. I always try to do what i can with what i have.

My friend just messaged me today saying he would like to have some nice speakers at home and his budget is about 60€. Since 10€ will go to the amplifier, the question is. Can i get a nice set of speakers for that 50€ that will sound better then if i make them myself. I know there are many nice sounding speakers outthere. But i tried quite a lot of speakers before i settled for this hitachi 1978 speakers i currently own. And this speakers really sound nice to me, very pleasing. When i tried some other speakers on my amp, it was just horrible, horrible. The difference was so huge that in a second i said, terrible. And to be honest, i didnt try any expensive speakers but for 2 sets of speakers, i remember they were from a stereo system that wasnt the cheapest out there. They cost probably in the area of 400€ each and u can get stero system here new for 100€ or less.

 

[audioguru]

Budget?? But I had a good job which allowed me to buy just about anything. I could reach most of the money that grew on the trees around me.
I never paid credit card fees and I got rid of the mortgage on my home fairly quickly. My car monthly payments had no interest owing.
Now that I am retired I get seniors discounts on most things I buy.

 

[gophert]

Budget?? But I had a good job which allowed me to buy just about anything. I could reach most of the money that grew on the trees around me.
I never paid credit card fees and I got rid of the mortgage on my home fairly quickly. My car monthly payments had no interest owing.
Now that I am retired I get seniors discounts on most things I buy.

No debt? Then you were, obviously, NOT doing your fair share to keep the great Canadian economy going. Surely you could have spent more by filling up empty rooms with crap or buying higher end than needed!