Are you able to take some REW measurements Mick ? If so perhaps that will give us an indication of what is going on.

Hi Dritz,

Yes I probably could do that, but I'd doubt it would be worth the effort at this stage. If I could hear some potential, then I'd get the mic out, but 'Potential is waaaaay in the distance. I'll change the, source and amp and see if they perk up a bit. ATM sounding like a very large transistor radio, and that's being rather kind.

That is no good.at all.

I would.be interested.in the.measurements though.

Kye could you take.some measurements?

OK, had another listen tonight, this time with a much higher quality front end. Audio Research pre/power, Stello Transport/Dac combo, with Audio Metallurgy interconnects. And low and behold we have a WINNER!! 'THE ABSOLUTE WORST!! DIY SPEAKER IN THE WORLD!!'If your reading Kye, YOU GOT ME!!, well done mate, very clever, and devious. I tip my hat to you.

So does anyone want 8 speaker drivers? Only 4 slightly used, for about 4 minutes. It would've been less than a minute, but I couldn't find the remote to hit the 'STOP' Button quck enough. Also One built speaker enclosure, and a second one ready to be screwed together? Take home a BARGIN TODAY!! Nothing more to pay.

I hope it wasnt a joke as that is very poor form.

Not too sure what else it could be Drizt? Anyone remotely interested in HiFi, would laugh at this effort, I know I did, I still am. Very

Embarrassing. I certainly wouldn't let anyone from my local audio club listen to them.

Perhaps it sounds good to kye?

It would be interesting to see kyes measurements to see what he is actually getting from his speakers.

Perhaps it sounds good to kye?

Not sure how to answer that. I'd actually be content with 'Good'.

Edited March 5, 201214 yr by Mick35
typo

Mick, I'm not suggesting this is a total solution, but try building the second speaker box and listening to the speaker as a stereo pair and with a sub woofer to warm up proceedings. I really can't understand how anyone can totally judge a speaker's merits listening to one box. Whenever I have listened to just one box, well, all you get is one half of the picture (actually the effect is less than that). The beauty of point source drivers is their lock tight stereo imaging and other good aspects of dipole behaviour as in the case of Kye's project, such as a freedom from boxiness. You are just not going to able to appreciate any of this, listening to one speaker box.

I do appreciate that you are disliking the transistor radio sound of the Altronics whizzer cone driver, but IME they all sound a bit like this when put into a open baffle arrangement (even the expensive Lowther, Fostex and Corals I have tried). Adding a competent woofer brings a lot of balance to the sound. Also, Kye's room looks to be quite cozy and the speakers are close to the wall so it could all be loading up quite nicely in there.

A lot of assumptions, but maybe some solutions too ...

Regards,

Steve.

Edited March 6, 201214 yr by Steve M

Not too sure what else it could be Drizt? Anyone remotely interested in HiFi, would laugh at this effort, I know I did, I still am. Very

Embarrassing. I certainly wouldn't let anyone from my local audio club listen to them.

Have you checked that the inductor is properly wired up to the bottom 2 drivers i.e. you are only getting bass through them?

You could try and position them hard up against the wall or place a piece of wood over the back to partially seal the enclosure. Does it start to sound more balanced that way?

Hi Steve,

I've listened to these drivers before, had a pair for many years. And at the time, I found their musical qualities to show no potential in any area of the fequency range, certainly nothing like a Coral, Fostex or Axiom, they have a certain something in tonality that can be addictive. So I packed them up and put them away. That's until Kye's way of thinking, sparked a new intrest for me in these drivers, hence I jumped at the chance to build. Back then though, a pair of these drivers sounded wrong, and now 4 sound just as wrong, will 8 be the magic number? So Yes I will build and then listen to the other channel in stereo, that's only fair, and I did build a pair after all. And seems as though we have two opposing opinions with regards to the sound quality, I'm willing, once I've built the other channel, to lend them out to someone else here in Brissy to judge the sound for themselves, in their own room with their own equipment.

Have you checked that the inductor is properly wired up to the bottom 2 drivers i.e. you are only getting bass through them?

You could try and position them hard up against the wall or place a piece of wood over the back to partially seal the enclosure. Does it start to sound more balanced that way?

Yes and Yes, all wired correctly and properly soldered (but I will recheck when I wire the other channel) I will push them up tighter to the wall, and see how that goes. The sound is balanced, but it's the 'Tone' that's all wrong IMHO. With only the one channel working, I'm not interested in image or soundstage at the moment, one thing at a time. I'm listening for tonal qualities of this driver.

OK another update from this evenings listen. These speakers definitely need a tweeter, which I've now added. For the time being the tweet I've chosen is a HiVi RT2C-A Planar Isodynamic Tweeter, it's about 94-95 db, I bought these whilst on special for $30ea about 2 years ago, you'll pay quite a bit more money nowdays though. Keeping in mind that if wide lateral dispersion is important to you, look elsewhere - ribbons/isodynamic tweeters 'beam' like lasers, not a concern for me as it's just me in the sweet spot. ATM using a 1uf cap on the tweet, Not bad, but needs improving. There's just something about the midrange tone and the bass, that's going to be harder to manipulate, to my taste, but for tonight, a positive step forward, sounding much cleaner, with a more refined top end, and some definition and separation to the midrange. I'm happier at this point, much more work to be done though. Potential is edging closer.

Hey Mick, I actually built a pair too and have the same conclusion as you. Tweeter is definitely required with these speakers. Comparing these with the fostex, the clarity n fizz is lacking in the top end.

I've got mine crossed fairly high and the bass is definitely there, but there are spikes in the midbass where a particular note would boom. It might be the way it is positioned currently, loading up against a rear wall. will try different positions later on.

Not having spare pair of tweeters, I was thinking of using a fairly affordable VIFA XT25 ring radiators. What do you think?

Some basic measurements are needed to salvage the project else you are working in the dark.

You could also try disconnecting one of the top 2 drivers and see if that makes a difference. Running 2 tweeters in parallel at such high spacing will result in comb-filtering and deep nulls off the vertical axis.

With a project like this I can see a number of issues. The first is that with a driver such as this, there may be some inherent limitations. Firstly, being a budget low cost driver without high end pretensions, there isn't likely to be much attention paid to a low distortion motor. It's probably something standard. There may also not be much attention to cone breakup issues. Add to this a stamped basket and whizzer cone - those things have issues. They can do all kinds of things wrong. The really bad ones are often in built-in ultra cheap car audio setups, and I suspect cone breakup (and amp distortion at clipping) causes that horrendous painful sound when cranked up. If you try to run this fullrange, you are going to be running the driver into its breakup range, and the whizzer cone while adding top end may also add issues of its own.

Now try to work without any measurements and you are really in the dark. You might see high Q sharp peaks in response suggesting cone breakup in the passband. That would then give you some feedback as you might seek to treat it and tame it, and also feedback regarding whether your crossover is solving the problems. You might also have a rising top end which can account for a "midrange glare" you can sometimes get from these drivers.

OK, had another listen tonight, this time with a much higher quality front end. Audio Research pre/power, Stello Transport/Dac combo, with Audio Metallurgy interconnects. And low and behold we have a WINNER!! 'THE ABSOLUTE WORST!! DIY SPEAKER IN THE WORLD!!'If your reading Kye, YOU GOT ME!!, well done mate, very clever, and devious. I tip my hat to you.

Mick, you win a prize for the best post of the week!

I haven't stopped laughing since I read it! Kye did have a question mark in the title so it's no surprise to me it sounds like it does. Still, it's great you made the effort to give it a go and see what *might* have been the greatest DIY speaker in the world. I think there is real potential in line arrays but I don't see them as a simple solution; and a lot more of the physics needs to be considered.

Hey Mick, I actually built a pair too and have the same conclusion as you. Tweeter is definitely required with these speakers. Comparing these with the fostex, the clarity n fizz is lacking in the top end.

I've got mine crossed fairly high and the bass is definitely there, but there are spikes in the midbass where a particular note would boom. It might be the way it is positioned currently, loading up against a rear wall. will try different positions later on.

Not having spare pair of tweeters, I was thinking of using a fairly affordable VIFA XT25 ring radiators. What do you think?

Very Nice RLDK, glad to have you onboard. Nice to have a third pair of ears. Also glad your ears agreed with my initial thoughts too, PHEW!! They certainly do need some top end support, and by adding a pair they will begin to 'Shine'. The Vifa XT25 is a nice sounding tweeter, well worth the coin, provided you can get them with a nominal 8 ohm impedance (To keep it simple). If they don't then a Zobel crossover network will need to be designed, but this will probably be the case with most tweets, even 8 ohm ones, as there impedance curve will vary. An actual measurement of the tweets is needed, to compensate. You could try a pair of those tweets wired in series (For 8ohms) for each channel and place them back to back. Linkwitz does this with the Orions, and I've heard this arrangement on some dipoles before and liked the effect. I can't do this with my ribbons, so well worth a try, even though it won't be perfect, you'll begin to enjoy the sound far more. I may even give this a go at some stage.

Some basic measurements are needed to salvage the project else you are working in the dark.

You could also try disconnecting one of the top 2 drivers and see if that makes a difference. Running 2 tweeters in parallel at such high spacing will result in comb-filtering and deep nulls off the vertical axis.

But I like to listen in the dark LOL! but your right, measurements are a must, I haven't said I wasn't going to do them. Just having some fun fiddling around, just to see if these drivers hold any qualities I haven't heard before, I think they may. As Kye mentions ' they are not flat, and you can hear it.' I agree. Measurements all in good time, but time is my enemy ATM.

With a project like this I can see a number of issues. The first is that with a driver such as this, there may be some inherent limitations. Firstly, being a budget low cost driver without high end pretensions, there isn't likely to be much attention paid to a low distortion motor. It's probably something standard. There may also not be much attention to cone breakup issues. Add to this a stamped basket and whizzer cone - those things have issues. They can do all kinds of things wrong. The really bad ones are often in built-in ultra cheap car audio setups, and I suspect cone breakup (and amp distortion at clipping) causes that horrendous painful sound when cranked up. If you try to run this fullrange, you are going to be running the driver into its breakup range, and the whizzer cone while adding top end may also add issues of its own.

Now try to work without any measurements and you are really in the dark. You might see high Q sharp peaks in response suggesting cone breakup in the passband. That would then give you some feedback as you might seek to treat it and tame it, and also feedback regarding whether your crossover is solving the problems. You might also have a rising top end which can account for a "midrange glare" you can sometimes get from these drivers.

Hi Paul,

Yep 'Cheap and nasty', but at this stage the 'Nasty' bit may not be what it seems, I hold hope. Custom Phase plugs, basket dampening, all possibilities I suppose, depends on how far one wants to take it. I did get an improvement by changing the gasket material I used behind the driver when I fixed them to the baffle. Initially I used a rubber impregnated with cork, changed to a soft squishy foam used for door seals, instant difference in sound. I may get an improvement with some basket dampening as well? I know the dampening worked well on my Emminence alphas. I'm all in the dark at the moment, until I measure, Maybe Kye could chime in here at some point?

Mick, you win a prize for the best post of the week!

I haven't stopped laughing since I read it! Kye did have a question mark in the title so it's no surprise to me it sounds like it does. Still, it's great you made the effort to give it a go and see what *might* have been the greatest DIY speaker in the world. I think there is real potential in line arrays but I don't see them as a simple solution; and a lot more of the physics needs to be considered.

LOL! I call it how I hear it. I like to be honest. The flipside is true also. If things improve, then so will my opinion. ATM I'm happier about what I hear from these drivers. Sounds are improving.

I added phase plugs to some Vifa P17 drivers, and a glue mod that was published on DIY audio. It was a good sounding driver to start with, I can't say I really noticed a real difference (probably would require less time between). It takes some effort to do the phase plugs, especially attaching them concentrically - manufacturers often don't do well with that one. These things can be fun to try, although I wouldn't hold out too much hope. The fundamental motor design remains. I'd say the biggest area to investigate would be related to the whizzer cone. Could be worth trying coatings like dammar, and treatments to the whizzer, even removing it. Check out Troels Gravesen's mods of drivers on his website - you'll find food for thought there.

Especially doing 8 phase plugs BUGGER ME!! The magnet gap will no doubt have some resonance issues, some dampening here, only on the outside, and the baskets may improve things?, but obviously not the entire solution. I'm yet to open one of these drivers up, at $15 bucks a pop, cheap to learn something. Forgot about Troels will check it out, Thanks paul.

I'd expect the basket would be one of the least audible changes you could make. Dealing with the whizzer is probably the biggest, treating the cone next.

Very Nice RLDK, glad to have you onboard. Nice to have a third pair of ears. Also glad your ears agreed with my initial thoughts too, PHEW!! They certainly do need some top end support, and by adding a pair they will begin to 'Shine'. The Vifa XT25 is a nice sounding tweeter, well worth the coin, provided you can get them with a nominal 8 ohm impedance (To keep it simple). If they don't then a Zobel crossover network will need to be designed, but this will probably be the case with most tweets, even 8 ohm ones, as there impedance curve will vary. An actual measurement of the tweets is needed, to compensate. You could try a pair of those tweets wired in series (For 8ohms) for each channel and place them back to back. Linkwitz does this with the Orions, and I've heard this arrangement on some dipoles before and liked the effect. I can't do this with my ribbons, so well worth a try, even though it won't be perfect, you'll begin to enjoy the sound far more. I may even give this a go at some stage.

I think I have given up on it to be honest... went and bought a pair of shl5 instead...