Combined 2 speakers into 1 - burning smell !!

LargeStyle

Standard Member
Hi all,

I know I'm going to get totally slated for this, but I'm a newbee in speaker technology so please bear with me....

Short version:

I basically tried using a tweeter from a Wharfedale Xarus 5000 speaker on a TDL Studio 10 speaker and I smelt a wierd burning smell from within the speaker case (I had one speaker hole empty at the time so the smell was quite apparent). It was only ran for approx 30 seconds, the smell became noticable, I immediately turned everything off and haven't tried it since. It was obvious something wasn't right, so what exactly was happening?

Long version:

The reason why I tried this is because I love the TDL's for their looks, mid and bass performance, but the treble isn't great at all, and the Xarus 5000's look worse, have bad mid performance, but the treble is what I'm after - hence the decision to swap the tweeters over and make one all-round speaker as a potentially quick fix.

Before doing all this I checked each speakers rating:

TDL Studio 10: 20-125W, 4-8 Ohms

Wharfedale Xarus 5000: 25-250W, 6 Ohms

I don't know enough about speaker ratings, but using logic these seemed "compatible", so I went ahead with it all.

Again, what was burning up, why was this happening, and what can I do (if anything) to achieve my mission?

I assume the board within the TDL (with the coil and things on it) isn't capable / tolerant enough to run the tweeter. If this is the case, can I use the boards from the Xarus's within the TDL's, or is my plan of making 1 speaker out of 2 a seriously bad idea?

Even if I used a capable board, would the extra wattage of the Xarus' tweeter effectively out perform the TDL's mid and bass speakers?

FWIW the amp used is: Pioneer VSX-LX50 (7.1 150W per channel amp). I've had this amp for a couple of years and have been constantly tweaking every setting for all that time, so I know I can't achieve any better result by any further amp tweaking. Until I learn more, I have now restored all speakers to their original state and am running both TDLs and Xarus as front speakers using the amps Surround Back system to power each pair properly - but I don't want 2 floor standing speakers either side of my tv, and I want my surround back channels again, so the current setup is a temporary fix.

Lastly, funds are near non-existent, hence homebrew tweaks, so buying new speakers isn't an option.

Sorry for the extreme noob and probably stupid questions, but as you can no doubt tell, I'm clueless with this kinda thing.

Thank-you in advance for any help / suggestions.

EDIT: I forgot to mention: the internal speaker wires for the Xarus' are red and black, the TDL's are 1x black with green stripe (what assumed was the Xarus' red) and 1x black (what assumed was the Xarus' black) - was my assumption correct, and if it wasn't, how would that affect things?
 
Last edited:

dlg78

Novice Member
Whoops!

We all make mistakes.

All you have done is assumed that as the specs are similar then all things should work fine, trouble is it is not quite that simple.

Loudspeaker driver arrays are driven from your amplifier through a crossover network, this splits the incoming signal to the various drive units. The splitting part is not as simple as bass, midrange and treble, these are done with specific values for the drive units in question, these values determine the frequency range that the driver receives and also the rate at which it "rolls off" frequencies outside of this range.

More than likely your TDL tweeters could handle lower frequencies than the Wharfedale ones, and hence installing the Wharefdales has subjected them to a bit more power than they were designed to run with. That is assuming you didn't make some kind of wiring mistake!

If you have put everything back to normal and everything works ok, then consider yourself lucky, chances are that tweeters voicecoil is damaged permanently - it doesn't take much.

It is possible to upgrade your tweeters in the TDLs, but you would need to match them to your existing crossovers or get the crossovers modified to suit, one place that springs to mind is Wilmslow Audio, who would be able to assist, obviously there is cost attached to that.

If funds are non existent then short of listening room changes, i.e. removing soft furnishings to make treble more prominent then you might have to live with it as it is.
 

LargeStyle

Standard Member
Thank-you dig78 for your kind and helpful reply.

Using the information you stated, I take it (as an extreme example) I can completely dismantle the Wharfedales and use the entire component / coils board within it to independantly control just the Xarus tweeter, ultimately running 2 sets of component boards together within each speaker. So as long as I wire every speaker up with its original relative board it should logically work, and within manufacturers tolerances, right?

Providing this is achievable (logic would suggest this is so) then I take it that all I have to concern myself with would be getting 2 control units (per speaker) receiving the same audio signal. This would assumedly not be a problem for each "combined" front floor standing speakers as I can bi-amp independantly and directly from the amp - this just leaves the surrounds to deal with (TDL Saturn 10's). For those could I effectively bi-wire the surrounds, but instead of not using the speaker terminal joining connectors I'd use them anyway (to run all but tweeters) and use the 2nd set of audio leads to run the Xarus tweeters via it's own component board?

I know what I'm thinking off is somewhat abnormal, and I'd have to completely muller one or two pairs of Xarus' to achieve all this - but the way I see it I'd rather have 1 extremely nice set of speakers as opposed to having 2 sets that I'm not happy with either of. Plus, it'll cost me nothing to achieve (other than time and effort).

As a completely alternative solution, if I had a custom component / coil board made up (by this company you mentioned), are they expensive? By doing this I could obviously leave the Xarus alone (apart from tweeter removal) and save them from mutilation. I also take it I could run the lesser powered TDL tweeter from the Xarus component board as they'd be underpowered compared to the Xarus tweeter.

Can you or anyone else please confirm or deny my wonderings, and many apologies for all my queries, I actually want to be thorough this time! If I'm asking too much out of my expectations I'll probably wave the white flag on this one, but I need clarification first to give me peace of mind, and to answer all the "what if" curiousities.

I'll wait for "the nod" before attempting more experiments :)
 

dlg78

Novice Member
Thank-you dig78 for your kind and helpful reply.

Using the information you stated, I take it (as an extreme example) I can completely dismantle the Wharfedales and use the entire component / coils board within it to independantly control just the Xarus tweeter, ultimately running 2 sets of component boards together within each speaker. So as long as I wire every speaker up with its original relative board it should logically work, and within manufacturers tolerances, right?

Providing this is achievable (logic would suggest this is so) then I take it that all I have to concern myself with would be getting 2 control units (per speaker) receiving the same audio signal. This would assumedly not be a problem for each "combined" front floor standing speakers as I can bi-amp independantly and directly from the amp - this just leaves the surrounds to deal with (TDL Saturn 10's). For those could I effectively bi-wire the surrounds, but instead of not using the speaker terminal joining connectors I'd use them anyway (to run all but tweeters) and use the 2nd set of audio leads to run the Xarus tweeters via it's own component board?

I know what I'm thinking off is somewhat abnormal, and I'd have to completely muller one or two pairs of Xarus' to achieve all this - but the way I see it I'd rather have 1 extremely nice set of speakers as opposed to having 2 sets that I'm not happy with either of. Plus, it'll cost me nothing to achieve (other than time and effort).

As a completely alternative solution, if I had a custom component / coil board made up (by this company you mentioned), are they expensive? By doing this I could obviously leave the Xarus alone (apart from tweeter removal) and save them from mutilation. I also take it I could run the lesser powered TDL tweeter from the Xarus component board as they'd be underpowered compared to the Xarus tweeter.

Can you or anyone else please confirm or deny my wonderings, and many apologies for all my queries, I actually want to be thorough this time! If I'm asking too much out of my expectations I'll probably wave the white flag on this one, but I need clarification first to give me peace of mind, and to answer all the "what if" curiousities.

I'll wait for "the nod" before attempting more experiments :)

I would tend to recommend you leave this to a professional unless you are confident, driver matching is a bit more involved than simply swapping parts here and there.

That said it is possible you could remove the crossovers from the Wharfedales, and assuming you can clearly identify which are the tweeters outputs, then you could run these in the TDL cabinets, using the TDL crossovers for bass/midrange etc.

Not sure how this would sound though, as although the Xarus tweeter would have their own correct crossover values, there is no guarantee there would be a nice match with the roll off of the midrange driver. So the sound might not be very smooth.

Places like Wilmslow Audio would be able to source much better tweeters than the Xarus ones and probably alter your crossovers to suit, or design better ones, but yes this could be expensive and you then start to wonder if simply sourcing another loudspeaker is the better alternative, getting one that you like the sound of all round would be a better alternative possibly and perhaps not much more expensive.

It's also worth asking if your Xarus tweeters are a perfect fit into the TDL cabinets? If not then you will possibly degrade bass performance too, as you might have air leakage around the tweeters on the front baffle.

To conclude, it's certainly possible (pretty much anything is) but could be tricky.
 

LargeStyle

Standard Member
Thanks again dig78!

Last night I got too paranoid that I was going to screw something up, so I restored all speakers back their original state and told myself to be more sensible and put up with the TDLs "smooth" treble, and forget about the Xarus' crisp treble (which BTW definitely provides enough treble for my liking). Now that I've just read your last reply I'm feeling most tempted to start hacking everything to bits and go for it!

I had one last major tweak of my amps settings last night too (using the standard TDL speakers) and I may've got the slightest increase in treble, but it's so slight that only say 15% of what I've demo'd responds to this tweak and sounds better, but it's still not a patch at all on the treble the Xarus tweeter can put out.

I've had a look on Wilmslow Audio website, and going by their premade crossover prices it'd be cheaper to buy another set of Xarus' from ebay purely for the crossovers and tweeters!

As for the frequency roll-off between Xarus tweeter and TDL mid driver, again using some kind of logic, I'm figureing that it'll generally sound better than either a standard TDL setup (poor high-end treble, good mids) or the Xarus' (good treble, poor mids). After all, that's why I'm thinking about doing all this, to match up the best speakers of each frequency range all running together within one set of speakers. I'm no hardcore audio purist either, so I'm guessing / hoping that a little amp tweaking will smooth out things well enough for my tastes.

As for the Xarus tweeter installation into the TDL cabinet - already measured and tested, the tweeter unit itself is pretty much a perfect match. Only difference here is the TDL tweeter has a bloody great big surround that mounts into the hole, the Xarus tweeter is as minimalist as you get, so I'll have to improvise some kind of bracket / attachment system. Either way, there won't be any significant sizing differences, and absolutely no gaps / air leaks at all.

This all should really be quite simple and straight-forward then - hack-up the Wharfedale units, trace the tweeter output from the tweeter itself, remove the tweeter and crossover, install in the TDLs - job done. Could get it all done in an afternoon, so this might be my mission for the weekend!

Unless I'm being over-confident......!

BTW. Would my bi-wiring idea (mentioned in my previous post) be acceptable to do then, as in use 2 sets of audio leads per 1 amp output so I can run each crossover unit with its own audio leads? I'm concerned that this will be cheating things too much and result in each crossover unit receiving a comparatively degraded audio signal and screw up the sound in general, or even overload the amp somehow.
 
Last edited:

dlg78

Novice Member
No the bi-wiring should work fine actually!

One question though, is it treble output that you are seeking, or better quality treble?

Your comment about the TDLs being smooth in the treble could indicate that they have softened off the response and therefore it might be a lot easier to alter their crossover boards to provide an increase in level from the tweeter, that said I imagine you can do and have been trying that from your home cinema amplifier?

There is nothing wrong with trying, if you want to take photos along the way then feel free to drop me an email and I will help if possible :)
 

LargeStyle

Standard Member
Better quality (higher frequency response) treble is what I'm after.

When I had everything dismantled the other day I very temporarily ran both TDL and Xarus tweeters outside of the speaker cabinets, so I had quite a good and clear assessment of their capabilities - the TDLs sounded like they were only doing the lower half of the "tweeting" frequencies that the Xarus' are capable of.

The TDLs are really very poor for treble, so much that I'd actually call the tweeter a mid-treble speaker. I even honestly started to think I needed to have my ears checked as they sound that inferior. I often have to wear ear-plugs at work all day, and on these days I lose treble in my ears even after my working day is done, so listening to the TDLs on these occasions is basically untolerable!

Yeah, I've tweaked the hell out of the EQ almost weekly for the past couple of years and never been satisfied, not once. The difference between TDL and Xarus tweeters are night and day for me.

My only pre-concern with this impending exchange will be if the Xarus tweeter seriously outperforms the rest of the TDLs speakers, just in terms of general output levels. The other day when I had all speakers running simultaneously in their original state (bi-amped stereo) the Xarus' generally dominated the output levels (TDLs were at a guess 70% output strength of Xarus). I'm hoping this will effectively mean I may have to actually turn down the treble for a proportionate sound, and consequently give me some extra tweaking / EQ headroom for better balancing between the tweeter and the mid-driver.

Guess there's only one way to find out!

I've almost convinced myself now that I'm going ahead with the operation, and yeah I'll take plenty of snaps in the process!

Thank-you very much again for your help so far - I'll keep you / this thread updated with my progress!
 

dlg78

Novice Member
Well at least you will have the option of adjusting the output level via your amp when the changes are made. Keep us informed :)
 

LargeStyle

Standard Member
Just thought I'd stick in a quick update...

I've completed the Xarus and crossover installation into the TDLs today. It's ultimately a better result, and so far it's been worthwhile, but it has changed the characteristic of the sound more than I thought it would.

As I said before, the TDL tweeters to me acted like a mid-treble speaker, now I have the Xarus tweeters in I'm noticing a slight lack of impact of this mid-treble that the TDL tweeter provided as the Xarus tweeters seem to operate at a generally higher frequency - so I basically have a slightly noticable gap between TDL mids high-end frequency cutoff and Xarus tweeter low-end frequency cutoff.

Doing major amp tweaking now, but I think things will eventually be ok. In my mind I'm already thinking of a backup option of actually running both TDL and Xarus tweeters in the same cabinet, which would be the best and most throrough option, but it'll need some significant cabinet modifications so I'll spend more time assessing things first before I make that decision.

As my TDL Saturn 10 surround speakers / cabinet is smaller than the Studio 10s there isn't room to add a 2nd tweeter, so I ideally want persue my original idea of just exchanging speakers, not adding more.

I'm perhaps being a tad perfectionist here, and it is currently noticably better than it was before the modifications, so I may just "settle" with things now.

Will update again soon when I've had more time with me system!
 

rayfitzharris

Novice Member
Am I right in assuming that you ran the new tweeter in the old box on it's own? ie no other driver present or one other one(mid or bass)missing?

This means that the impedance of that old box would have changed drastically and likely out of spec with the amp, it could possibly have gone below 2ohms and that would explain the burning smell, you're lucky you didn't damage the amp too.

It may well have worked out ok if you'd ran it with all drivers present..
 

Flimber

Distinguished Member
You should have done a Kramer and sealed the cabinets first before adding water in to act as coolant.
 

noiseboy72

Distinguished Member
Am I right in assuming that you ran the new tweeter in the old box on it's own? ie no other driver present or one other one(mid or bass)missing?

This means that the impedance of that old box would have changed drastically and likely out of spec with the amp, it could possibly have gone below 2ohms and that would explain the burning smell, you're lucky you didn't damage the amp too.

It may well have worked out ok if you'd ran it with all drivers present..

Not quite sure how the impedance could go down by removing a driver ?? It would go up at certain frequencies, but not down, as the inductor is in series with the LF and without this driver, it would be open circuit. The HF crossover has not changed, so it would not affect the impedance at lower frequncies than it was designed to pass.

Most HF crossovers are just a non-polarised electrolytic in series to protect the HF from low frequency content. Depending upon the specification of the HF, this crossover could be as low as 350Hz (Meyer Mica) or in the case of a small domestic bookshelf speaker with a basic tweeter, as high as 2 or 3KHz. Impedance will not be constant across the frequency range - between 100 and 1 ohms is not uncommon! Simple inductive crossovers are affected in terms of impedance if an HF unit with a different nominal impedance is used, but the effect will not be huge.

The smell of burning could be due to the tweeter overheating becuase the crossover point is too low for it, or something simpler - you pulled a cable and caused a short.

Tweeters fall into a couple of basic categories, but the electrical characteristics are broadly similar. You could even put a Piezo tweeter in place of a conventional speaker but not vice versa unless you also fitted a capacitor.
 

LargeStyle

Standard Member
Am I right in assuming that you ran the new tweeter in the old box on it's own? ie no other driver present or one other one(mid or bass)missing?

This means that the impedance of that old box would have changed drastically and likely out of spec with the amp, it could possibly have gone below 2ohms and that would explain the burning smell, you're lucky you didn't damage the amp too.

It may well have worked out ok if you'd ran it with all drivers present..
I initially ran the "new" / Xarus tweeter in the TDL cabinet using the rest of the TDL setup, as in crossover and the speakers (1 mid and 2 bass drivers). It was the general belief that running a higher rated tweeter on the standard TDL crossover was causing the overload on this crossover unit, and I obviously didn't want to risk damagaing anything hence the decision to run the Xarus tweeter from its own original crossover unit (with TDL mid and 2x bass drivers running from their original crossover unit) - all in the TDL cabinet.

In order to remove the crossovers from each Xarus I had to remove all speakers (so as to unplug the wires from each drivers terminals) and while the Xarus cabinets were completely empty (of speakers and crossover unit) I noticed the same smell that I had when I ran the Xarus tweeter on the TDL crossover unit, only the smell was a lot less prominent - I had to more-or-less stick my nose in the Xarus cabinet to notice the smell, whereas in my first (30 second long, dodgy experiment with the TDL equipment) the same smell smelt the room out quite badly, hence why I thought something was wrong!

I've completed my mission today - each TDL Studio 10 (front speakers) and TDL Saturn 10 (surround speakers) are now running in original spec apart from the Xarus tweeter (instead of TDL tweeter) running from the Xarus crossover (2 crossover units installed in total per cabinet). It took about 2 hours to completely strip down a Xarus speaker and install the tweeter and crossover unit onto the TDL speaker.

Although this has been a rather abnormal thing to do, it has worked out beautifully - I'm seriously impressed and happy with it all now. I've tweaked my EQ today to resolve the mid-to-tweeter crossover concern I had (mentioned in my previous post) and this tweak (along with running the amp in Midnight mode) has seemingly worked an absolute charm (to clarify, the concerns were caused by unoptimised EQ settings, not physical speaker constrictions). I have effectively managed to restore the general "impact" the TDL speakers originally had before my tweeter modifications, and all without comprimising either tweeter and / or bass performance!

The overall result to me is awesome - I've watched a bit of the Nicolas Cage film "Knowing" today and not only does the sound effects / action sound so solid and clear / defined, the orchestral score is amazing - in particular hearing the raspy sound of the brass section scream out (especially from the surround speakers) is almost undescribable. I've played some demos on my Xbox 360 and that is a sheer audio assault in pretty much every respect - just crazy amount of sounds / definition / clarity / and impact filling the room up completely. The "Fear 2" demo just scared the crap out of me, the sound design and soundfield in this game has to be the best demo material I've ever heard (for a game anyway).

When doing the bi-wiring installation for the surround rear (Saturn 10) speakers I was lazy and borrowed the audio leads from the surround back (Eltax) speakers (and obviously appropriately rewired the terminals at the amp, and turned off 7.1 mode - so now running 5.1). I'm so happy with the sound of everything now that I'm not going to rewire my surround back speakers in again - I think my room is too small for 7.1 as running 5.1 provides a better and more balanced soundfield. The surrounds (rears) put out so much noise now that running more speakers (that are small bookshelf jobbies) will probably be more of a gimic than an actual worthwhile thing to do.

I'm slightly regretful that I've lost the use of my Xarus speakers, which are obviously now unusable, but are kinda too good to just throw away - but it was a means to an end for my downstairs system which I use 99% of the time anyway. Anyone want 4 tweeter-less and crossover-less Xarus 5000 speakers? :laugh:

My only concern now is that I'm expecting my neighbours to bash on my door anytime now as I must admit I'm probably being quite offensive with my noise levels, and I've not even turned my sub on yet :devil:

I must thank dig78 ever-so-much. Without your input and help in general I would probably have never gone ahead with it all, and as sad as it sounds, having my "home cinema" like it is now has been the only thing that's gone right in my life at the moment - so I will forever be in your debt! I regretfully didn't have the option to take any photos throughout my mission as my only camera (my mobile phone) broke on Friday when I threw it at the floor at full-pelt (was in a bad mood that day)! I'm also well into my (subtle) lighting systems, so when I have a bit of spare cash I'm going to install some neon blue type LED strips into my setup somehow - mentioned as I'll take some pics of my setup then (if I get another camera / phone by then).

Thanks again to all (especially dig78) for the much needed help.
 

dlg78

Novice Member
I must thank dig78 ever-so-much. Without your input and help in general I would probably have never gone ahead with it all, and as sad as it sounds, having my "home cinema" like it is now has been the only thing that's gone right in my life at the moment - so I will forever be in your debt! I regretfully didn't have the option to take any photos throughout my mission as my only camera (my mobile phone) broke on Friday when I threw it at the floor at full-pelt (was in a bad mood that day)! I'm also well into my (subtle) lighting systems, so when I have a bit of spare cash I'm going to install some neon blue type LED strips into my setup somehow - mentioned as I'll take some pics of my setup then (if I get another camera / phone by then).

Thanks again to all (especially dig78) for the much needed help.

Not a problem at all :)

Read your write up with interest, pleased you got everything working ok and it really proves that hifi should be about the enjoyment factor, you certainly sound like you're enjoying your speakers now!
 

The latest video from AVForums

Podcast: Trinnov Room Optimiser: A full explanation of Trinnov and its room optimiser technology
Support AVForums with Patreon

Top Bottom