Ceiling speaker amplifier to mono circuit.

[roganty]

Yes. You do seem extraordinarily determined to cut your nose off to spite your face.

I asked for some advise, I got a resounding NO, what gives?

It's one transformer with three windings. The Web page describes the wiring. There are inputs for the left and right speaker wires from the amp, and a single output to connect to the mono speaker.

Yes, and the reviews for it are outstanding. (Link)
I particularly like the first one where he advises using 8ohm resistors in series with each channel.

I'll just carry on with my original plan and hook the speaker to one output and mono the source in software.

Thanks for your help

 

[roganty]

Apologies if I am missing an obvious reason why you can not do this.

But why not buy a single ceiling speaker that contains two speakers so you can use both channels?
Sfk

A stereo speaker was my first choice, but after some initial searches (and false hopes) I went with a standard single speaker.

The reasons was: it was going into a small room, so audio quality and a loud volume wasn't important; I was also after a small speaker (I ended up with a 4" diameter speaker)

 

[Lucid]

I asked for some advise, I got a resounding NO, what gives?

You were given a NO on your plan to somehow sum the two channels with a resistor or resistors, that's all. You were given two viable alternative solutions in the first reply of your thread. What's your problem?

It was clear from your opening post that you hadn't grasped the important differences between line level input signals and speaker level signals. Despite several of us telling you the same thing, you still hadn't understood it by post #10. This was about a day and a half later, and you posted yet another line level summing solution.

Yes, and the reviews for it are outstanding. (Link)
I particularly like the first one where he advises using 8ohm resistors in series with each channel.

Granted, if the instructions are (or were) inadequate then that's a cause for concern. However, what you asked for was a way to make the stereo speaker outputs of the Bluetooth amp in to a mono signal to drive a single speaker. I gave you two such solutions. @kentishman gave you a third way, using the software to make the source signal mono, and I think that's a very elegant solution, but you pooh-poohed it.

We even discussed the consequences of your idea of running one channel of a stereo mix and how you'd lose part of the audio that was mixed to be on the other channel. I have my doubts as to whether you fully grasped that concept too.

I think the bottom line here is that you're miffed that your original plan won't work. The sensible thing would have been to cut your losses and get the right speaker.

Oh, and as for your disparaging remark that you shouldn't have asked in a DIY forum; thanks for the insult, but FYI this forum is home to some really clever bods, business owners and generally techie types.

 

[Lucid]

Apologies if I am missing an obvious reason why you can not do this.

But why not buy a single ceiling speaker that contains two speakers so you can use both channels?
Sfk

Yep, and already suggested in post #2. But that's a sensible answer and roganty didn't want to hear that.

 

[roganty]

You were given a NO on your plan to somehow sum the two channels with a resistor or resistors, that's all. You were given two viable alternative solutions in the first reply of your thread. What's your problem?

It was clear from your opening post that you hadn't grasped the important differences between line level input signals and speaker level signals. Despite several of us telling you the same thing, you still hadn't understood it by post #10. This was about a day and a half later, and you posted yet another line level summing solution.

Granted, if the instructions are (or were) inadequate then that's a cause for concern. However, what you asked for was a way to make the stereo speaker outputs of the Bluetooth amp in to a mono signal to drive a single speaker. I gave you two such solutions. @kentishman gave you a third way, using the software to make the source signal mono, and I think that's a very elegant solution, but you pooh-poohed it.

My reply in post 3 was supposed to have been sarcastic/tongue-in-cheek.
What I think I'm missing in that post is a smiley face after the crying emoji.

This was also on post #3: (emphasis is mine)

I had hoped not to spend too much on this, so I might just end up hooking a single speaker up to one channel and make do.

So by post #3 I was already resigned to mono on a single channel. [Edited]

The edit in post #10 was a wondering out loud moment, and not something I was going to do and way past anything I'm prepared to do electrically.
I was searching for stereo-to-mono transformers and that happened to pop up, and, like your original alternative; that also used transformers.

So I asked.


Wish I'd never bothered.

We even discussed the consequences of your idea of running one channel of a stereo mix and how you'd lose part of the audio that was mixed to be on the other channel. I have my doubts as to whether you fully grasped that concept too.

I think the bottom line here is that you're miffed that your original plan won't work. The sensible thing would have been to cut your losses and get the right speaker.

Oh I got that I would lose part of the audio.

And for the record I wasn't bothered that my original plan wouldn't work. I had hoped that it would, but I was unsure on if/how it would which is why I asked here.

Oh, and as for your disparaging remark that you shouldn't have asked in a DIY forum; thanks for the insult, but FYI this forum is home to some really clever bods, business owners and generally techie types.

Oh I get that.
My remark was directed at the fact I might have got a more measured (less terse) response from a more specialised forum.

(Edited to clear up my meaning)

 

[roganty]

Yep, and already suggested in post #2. But that's a sensible answer and roganty didn't want to hear that.

A stereo speaker was my first choice, but after some initial searches (and false hopes) I went with a standard single speaker.

The reasons was: it was going into a small room, so audio quality and a loud volume wasn't important; I was also after a small speaker (I ended up with a 4" diameter speaker)

 

[Lucid]

So by post #3 I was already resigned to mono.

How exactly can you be "resigned to mono" by post #3 - as if that was some kind of 2nd best solution - when your reason for starting the thread was to find a way to convert to mono in the first place? [Don't bother answering, it was more of a rhetorical question]

The edit in post #10 was a wondering out loud moment, and not something I was going to do and way past anything I'm prepared to do electrically.
I was searching for stereo-to-mono transformers and that happened to pop up, and, like your original alternative; that also used transformers.

Transformers get used for a variety of different tasks in audio applications. 600 Ohms is used in some professional audio line level signals and in higher-end headphones. The fact that the page shows a solution which happens to use transformers, and that includes "stereo to mono" doesn't make it a solution for speaker level signals.

Wish I'd never bothered.

Hmmm... no comment

My remark was directed at the fact I might have got a more measured (less curt) response from a more specialised forum.

I've played this game enough times to know the script very well. Someone enquires about doing something, but they don't understand the fundamentals of what they're asking, and they've seen something but they haven't realised it's unsuitable (see first point), and they're usually working on sod-all budget .... stop me when this sounds familiar.

We then end up with a six page thread going all round the houses to come back to what was usually said a few times by knowledgeable contributors posting on page #1. In short "The thing you want to do can't be done with the solution you've found (or at the budget you've set). Here's how to do it. " I cut out the usual BS and gave you what you needed straight away.

You conveniently forget that you're the one asking for our help and to benefit from our knowledge and our time to help you solve your problem. Now you're moaning is wasn't dressed up in pretty language and that we wouldn't pander to your fools errand!?! Tell you what, I'll give you a refund of what you paid for the accurate advice you received. Oh, wait....

 

[roganty]

How exactly can you be "resigned to mono" by post #3 - as if that was some kind of 2nd best solution - when your reason for starting the thread was to find a way to convert to mono in the first place? [Don't bother answering, it was more of a rhetorical question]

Ok my bad, I could have worded that better.

So by post #3 I was already resigned to mono on a single channel.

Transformers get used for a variety of different tasks in audio applications. 600 Ohms is used in some professional audio line level signals and in higher-end headphones. The fact that the page shows a solution which happens to use transformers, and that includes "stereo to mono" doesn't make it a solution for speaker level signals.

Thank you for that clear explanation.

Just out of interest, what size transformer (if any) could be used for speaker level signal?
(It's just idle curiosity [we know what happened to that cat])

I've played this game enough times to know the script very well. Someone enquires about doing something, but they don't understand the fundamentals of what they're asking, and they've seen something but they haven't realised it's unsuitable[...]

I'll stop you there

We then end up with a six page thread going all round the houses to come back to what was usually said a few times by knowledgeable contributors posting on page #1. In short "The thing you want to do can't be done with the solution you've found (or at the budget you've set). Here's how to do it. " I cut out the usual BS and gave you what you needed straight away.

Your post #2 was fine.
It was your post #4 that got me. A simple "NO" would have done.

Page two now, but it's doing wonders for my post count

 

[roganty]

[duplicate deleted]

 

[Lucid]

Just out of interest, what size transformer (if any) could be used for speaker level signal?
(It's just idle curiosity [we know what happened to that cat])

It depends on the application and the power handling required.

Typical domestic stereo gear is generally designed to work with a 4-16 Ohm load. Some stuff such as the all-in-one home cinema kits were designed with 3 Ohm speakers in mind.

KEF's decision to have a 1 Ohm load transformer makes sense in this context. Padding the resistance with additional resistors to suit the amp's expected load range means that the transformer is, within reason, universal. That's handy from a sales perspective for them and for the installers. It means less inventory is required to cover a wide range of applications.

Your post #2 was fine.

It was your post #4 that got me. A simple "NO" would have done.

Post #4 was written in response to your post #3. You're right, a smiley or wink might have helped change the tone of how your post came across.

As for just writing "No", aside from the forum rejecting very short posts, personally my view is that one word answers aren't that helpful to the enquirer. Giving an answer which explains why some other solution might work better is far more informative.

 

[SFK]

Anthony,
Yes, sorry I missed that you wrote that you had already considered using a single Stereo speaker.
If you do find a solution please tell us as I would be interested to see what you decide to do.
Regards SFK

 

[roganty]

Just out of interest, what size transformer (if any) could be used for speaker level signal?
(It's just idle curiosity [we know what happened to that cat])

It depends on the application and the power handling required.

Typical domestic stereo gear is generally designed to work with a 4-16 Ohm load. Some stuff such as the all-in-one home cinema kits were designed with 3 Ohm speakers in mind.

KEF's decision to have a 1 Ohm load transformer makes sense in this context. Padding the resistance with addition resistors to suit the amp's expected load range means that the transformer is, within reason, universal. That's handy from a sales perspective for them and for the installers. It means less inventory is required to cover a wide range of applications.

Now this is the type of conversation I had imagined when I started this thread.

Post #4 was written in response to your post #3. You're right, a smiley or wink might have helped change the tone of how your post came across.

Sorry about that.

 

[roganty]

Yes, sorry I missed that you wrote that you had already considered using a single Stereo speaker.

That's alright, it's easy to miss something in all that has gone on in this thread.

If you do find a solution please tell us as I would be interested to see what you decide to do.

I can recommend a ready made product by KEF

 

[roganty]

Hello @Lucid

This little 'idea' is still playing through my head [don't ask, it'll be replaced soon!]


I understand that this will not work with speaker level signals.

But what if the resistors were replaced with appropriately sized resistors? (like these wirewound resistors*)

Or is it still a defiantly not?


*These resistors match the output of the amp I have (15w @ 4ohms)

 

[winston1]

No.