Are DIY Bluetooth speakers practical?

[Keldog]

Among audiophiles (most here) and purists, is there any interest in marrying old and new tech?

I learned how to convert vintage stuff to completely wireless, powered bluetooth speakers. I've since perfected true stereo pairs of speakers. I can play my phone, television/bluray or ANY audio source through a nice set of KLH Seventeens I've converted. They are totally portable and I can put them anywhere (even outside during a cookout) without running speaker wires or even having any stereo equipment. I like them, not just for the sound, but for the aesthetics and decorative value of a vintage pair of cabinets. Far better than a puny little, purple speaker no bigger than a soup can (although they are good for the bathroom). I'm also confident I can do this with any vintage speaker. Everything is internal and you wouldn't know it's been converted. I've even kept the legacy wiring intact so I can still connect to a stereo in the traditional sense.

While building these, I didn't find anything related on this forum as a whole. Why? Is it a stupid idea? Is there no interest? Is it impractical?

 

[swechsler]

Probably mostly no interest. In earlier years Bluetooth rightly got a lot of flack due to its low bandwidth; however, newer versions are a lot higher, and as background music you probably wouldn't notice anyway.

However, your setup does raise some questions (I've seen at least one article showing how to do what you did, more or less):

Are your speakers battery powered? If so, what kind of batteries are you using and what's their runtime? What's the output of your amps (output power requirements would probably make converting inefficient speakers impractical)? And how do you distribute left and right channels with no wires between the speakers?

 

[drbiggles]

I've got great interest in doing just that, and I've done a little research as well. In fact, I have a pair of little Ampex speakers that I'm restoring at the moment and they'd be a perfect candidate. For me, I simply don't have the available cash to buy the bluetooth bits for the conversion. But when I do, I will be doing the same thing with some of my rigs.

Biggles

 

[Keldog]

Are your speakers battery powered? If so, what kind of batteries are you using and what's their runtime? What's the output of your amps (output power requirements would probably make converting inefficient speakers impractical)? And how do you distribute left and right channels with no wires between the speakers?

I use a separate amp/bluetooth module with each speaker. All of the Youtube DIY videos show single speakers because current technology in most phones and iPods only allows one bluetooth device to be paired at a time. However, I have found a workaround by attaching a transmitter/splitter to my phone and I can pair both speakers individually. This will change in the future because current Galaxy S8 phones have bluetooth 5.0 technology that lets you pair multiple devices. It's a hardware thing.

As for left and right channels, it's an easy wiring trick. Each module has left and right channels to wire the speakers. I wire one speaker to only the right channel and the other speaker to only the left channel on each separate amp module.

I use 12v battery packs (8 AA alkalines) that are external. I can also connect the amps (which are internal) via A/C adapters to save on batteries. Rechargeable Li-Po batteries can be used but they don't have the same output as standard alkaline batteries, though rechargeable would be preferred if you want wireless and play them a lot. The amp can be powered with only 9v of power as well.

The amps come in 50w (25w + 25w) or 100w (50w + 50w) configurations along with adjustable dip switches (21.6db, 27.6db, 31.3db, 33.6db). It may require different cap values for the speakers if you want to fine tune them.

My next project will be to build a self-contained amp and battery pack that can be simply wired to any speaker via the terminals. No hassle with opening up the speaker.

 

[Keldog]

I've got great interest in doing just that, and I've done a little research as well. In fact, I have a pair of little Ampex speakers that I'm restoring at the moment and they'd be a perfect candidate. For me, I simply don't have the available cash to buy the bluetooth bits for the conversion. But when I do, I will be doing the same thing with some of my rigs.

Biggles

It cost me less than $50 for all of the parts.

 

[swechsler]

I doubt you're running anywhere near 50 watts, let alone 25, with a AA battery supply, otherwise your batteries would be dead in only a few minutes. Luckily you don't need much power for background music, but if you tried to play them loud, I suspect you'd quickly hit the limits of your power supply. If you have an ammeter, you could put it in series between the battery pack and the electronics to see how much current you're actually drawing.

 

[Keldog]

I doubt you're running anywhere near 50 watts, let alone 25, with a AA battery supply, otherwise your batteries would be dead in only a few minutes. Luckily you don't need much power for background music, but if you tried to play them loud, I suspect you'd quickly hit the limits of your power supply. If you have an ammeter, you could put it in series between the battery pack and the electronics to see how much current you're actually drawing.

I never considered it. It sounds the same with A/C as it does D/C. I only assumed by the advertised ratings on the modules. I've never fully tested the run time on battery. It's mostly still in the novelty stage.

 

[drbiggles]

It cost me less than $50 for all of the parts.

Thank you for your input and what the cost is, it's appreciated! I've got a Galaxy S8, so it's nice to know I've got some technology buried in there I can tap into.

The vintage speakers I work with are quite efficient and generally won't need more than a watt or 3. For general listening levels, .5 of a watt is all I use.

Biggles

 

[Keldog]

Thank you for your input and what the cost is, it's appreciated! I've got a Galaxy S8, so it's nice to know I've got some technology buried in there I can tap into.

The vintage speakers I work with are quite efficient and generally won't need more than a watt or 3. For general listening levels, .5 of a watt is all I use.

Biggles

Already having an S8 should save about $12 since you won't need the transmitter/splitter.

 

[swechsler]

I never considered it. It sounds the same with A/C as it does D/C. I only assumed by the advertised ratings on the modules.

These sellers tend to exaggerate the capabilities of their products (I know the modules that you're talking about).

 

[alteclipsch]

I have an orphan KLH Seventeen that I powered with a cheap vivitar Bluetooth mono amplifier that I butchered by removing the speaker and hooked the wires to the Seventeen. It worked well for about a week and the battery died permanently. I've thought about trying a Bose speaker but i don't know the impedance of its speaker and it's more money than I want to invest on a whim. Any suggestions for a mono Bluetooth amp?

 

[Keldog]

I have an orphan KLH Seventeen that I powered with a cheap vivitar Bluetooth mono amplifier that I butchered by removing the speaker and hooked the wires to the Seventeen. It worked well for about a week and the battery died permanently. I've thought about trying a Bose speaker but i don't know the impedance of its speaker and it's more money than I want to invest on a whim. Any suggestions for a mono Bluetooth amp?

I haven't tried a mono amp. My first experiment was with a single stereo amp connected to a 3-way Fisher. Most DIYers using old speakers connect one channel to the tweeter and woofer and the other channel to the midrange. That obviously won't work on the 17 since it's only a 2-way.

 

[swechsler]

I haven't tried a mono amp. My first experiment was with a single stereo amp connected to a 3-way Fisher. Most DIYers using old speakers connect one channel to the tweeter and woofer and the other channel to the midrange. That obviously won't work on the 17 since it's only a 2-way.

Why would you do that? Just sum the outputs and connect to a single channel amp.

 

[alteclipsch]

Why would you do that? Just sum the outputs and connect to a single channel amp.

What does sum the outputs mean?

 

[Keldog]

Why would you do that? Just sum the outputs and connect to a single channel amp.

Ummm....to experiment....I was just copying the DIYers I saw and wanted to test the first amp to see if it was worth pursuing. Plus, I don't have a single channel amp. Plus, plus....I'm obviously not an electronics expert. I just piece together hardware and **** and learn as I go.

 

[donprice]

While building these, I didn't find anything related on this forum as a whole. Why? Is it a stupid idea? Is there no interest? Is it impractical?

I would guess that a fair percentage of of AK members don't know much about the pieces, parts, and prices to execute the project...so they are just unaware of the options. Some would consider it a sin to hack up a speaker (even if that is the only thing keeping it out of the garbage). Some of us already have speakers just about everywhere we could take one. As noted above, others have no interest in bluetooth (or any modern technology it seems at times).

Posting a build thread with pictures might help get the idea out and let the haters hate. Quite frankly, the powered and wireless (except AC adapter) conversion would be an excellent way to bring the beauty and sound quality of vintage speakers to the iGeneration that has little or no interest in a stack of components, crates of media, and a rats nest of wires. Soundbars aren't winning the sales race because they sound better...

Placing the amp/receiver (and optional battery pack) in a project box mounted (velcro) to the back of the speaker might make the mod far more acceptable to the typical AKer as it avoids hacking holes into the cabinet and is easily transferred to another speaker...or pulled off for modification....or whatever.

 

[Keldog]

I would guess that a fair percentage of of AK members don't know much about the pieces, parts, and prices to execute the project...so they are just unaware of the options. Some would consider it a sin to hack up a speaker (even if that is the only thing keeping it out of the garbage). Some of us already have speakers just about everywhere we could take one. As noted above, others have no interest in bluetooth (or any modern technology it seems at times).

Makes sense. Modification is really no more surgical than recapping a speaker. The power wire only requires a hole the size of a 14 gauge in a well-placed, discrete location.

Posting a build thread with pictures might help get the idea out and let the haters hate. Quite frankly, the powered and wireless (except AC adapter) conversion would be an excellent way to bring the beauty and sound quality of vintage speakers to the iGeneration that has little or no interest in a stack of components, crates of media, and a rats nest of wires. Soundbars aren't winning the sales race because they sound better...

I'd like to do that sometime. That was a main intention of the build. To blend vintage beauty with modern convenience and tech. I don't really see it going past the novelty stage, though.

Placing the amp/receiver (and optional battery pack) in a project box mounted (velcro) to the back of the speaker might make the mod far more acceptable to the typical AKer as it avoids hacking holes into the cabinet and is easily transferred to another speaker...or pulled off for modification....or whatever.

As stated earlier, it's in the works. Instead of hacking multiple speakers, I plan on a portable pack that simply plugs into the existing speaker jacks. Nothing disturbed on even the finest of speakers.

 

[tyella]

Speaking to the mating of old and new tech, I put this TPA3116 bluetooth amp together last year. It sounds pretty darn good! I used an old 8 track player, covering the old slot with some vintage grill cloth. Not as elegant as an internal install, but it mates well with old gear. There's even a remote control and FM, if you're into that!

 

[swechsler]

How could you hack up a classic 8-track player like that?

It's easily worth tens of dollars!

 

[soundmotor]

Among audiophiles (most here) and purists, is there any interest in marrying old and new tech?