Has anyone ever attempted this? I'm not an engineer, but it seems to me that not everything has been done in terms of making a truly full-range driver capable of large SPL figures without a subwoofer. 
Here's my thinking: a 12" cone with a XBL2 motor (the one with two back-to-back voice coils to reduce inductance) (2" voice coil?) could provide high excursion and low inductance, so adding a whizzer cone would extend the usable frequency range up to maybe 12khz.
At the same time, in a ported alignment, this driver could give output to probably 40hz or maybe even below. While this isn't quite reference range, it's enough for PA applications--no coincidence, this is my goal. 
To cover the frequencies above 12khz, a peizo horn could be attached to the back of the driver and horn-loaded through the pole piece and whizzer cone. I suspect this would be enough to reach all the way up to 20khz.
Since the woofer part would be an inductive load, and the peizo part capacitative, it's possible, I think, to design the thing so it wouldn't require a crossover; just hook both elements up to an amplifier. I like this idea a lot.
If it turns out that the bass isn't enough, we'll add a DIY parthenon to get enough extra thump.
What do the engineers in the room think?
Here's my thinking: a 12" cone with a XBL2 motor (the one with two back-to-back voice coils to reduce inductance) (2" voice coil?) could provide high excursion and low inductance, so adding a whizzer cone would extend the usable frequency range up to maybe 12khz.
At the same time, in a ported alignment, this driver could give output to probably 40hz or maybe even below. While this isn't quite reference range, it's enough for PA applications--no coincidence, this is my goal. To cover the frequencies above 12khz, a peizo horn could be attached to the back of the driver and horn-loaded through the pole piece and whizzer cone. I suspect this would be enough to reach all the way up to 20khz.Since the woofer part would be an inductive load, and the peizo part capacitative, it's possible, I think, to design the thing so it wouldn't require a crossover; just hook both elements up to an amplifier. I like this idea a lot.
If it turns out that the bass isn't enough, we'll add a DIY parthenon to get enough extra thump.
What do the engineers in the room think?
These things characterise a driver able to produce low frequencies:
heavy diaphram
rigid suspension
long excursion
And these thing characterise a driver able to produce high frequencies:
light diaphram
loose suspension
short excursion
So you see it would be a impossible task to produce the perfect full-range speaker.
Lowther unit come close, but suffers the great disadvatage that they absolutely have to be hornloaded.
heavy diaphram
rigid suspension
long excursion
And these thing characterise a driver able to produce high frequencies:
light diaphram
loose suspension
short excursion
So you see it would be a impossible task to produce the perfect full-range speaker.
Lowther unit come close, but suffers the great disadvatage that they absolutely have to be hornloaded.
Ron, I think you misunderstood my reference to horns... the peizo element would be horn-loaded through the pole piece (so it would be a very unusual pole piece!) and the whizzer (since the whizzer is rather horn-shaped already) but the dynamic part--the woofer part--is not horn-loaded.
This probably isn't the optimal solution for making large amounts of sound in a small space, but AFAICT, it hasn't been tried yet in this combination.
This probably isn't the optimal solution for making large amounts of sound in a small space, but AFAICT, it hasn't been tried yet in this combination.
Small volume and low frequencies dont go hand in hand. Best is a 2 way, a seperate bass driver in a cab tuned for 40Hz then rolled off and a full ranger in a cab taking the hand off starting at < 200Hz and extending up. Lets face it, a wizzer cone in a FR is very near a mid and a tweeter. Kinda sorta like a co-axial without the added crossover. To me anyway a rear loaded horn with a single FR driver with a wizzer is more like a 3 way without electronic (<----NOTE!) crossovers. Even though there are designed in mechanical crossovers.
However its still my choice.
ron
However its still my choice.
ron
for sympathy,
try the Full Range driver forum
http://f18.parsimony.net/forum31999/
cheers.,
Pete McK
try the Full Range driver forum
http://f18.parsimony.net/forum31999/
cheers.,Pete McK
Well, why try to make a full range driver that doesn't need a subwoofer when nobody has even made one that's anywhere NEAR being pefect to even cover the range above the subwoofer (to use WITH a subwoofer)???
Plenty of subwoofers do a fine job that it's not really needed to try to replace them by lowering the range of your main speakers. The range they cover is not nearly as critical as the range that covers human voice & instruments.
The human ear + brain is not nearly as discerning below the frequency range of the human voice. It makes sense to focus your efforts where the results have the most impact.
Plenty of subwoofers do a fine job that it's not really needed to try to replace them by lowering the range of your main speakers. The range they cover is not nearly as critical as the range that covers human voice & instruments.
The human ear + brain is not nearly as discerning below the frequency range of the human voice. It makes sense to focus your efforts where the results have the most impact.
Ever hear a Lowther?
Better yet ever hear a Lowther driven horn with a SET?
I have here some polk audio monitor speakers that i use to test my amp designs. They CLAIM a +/- 2 db flat FR. They also sound like crud.
Sometimes it isint a flat FR that counts , its the total sound.
Phase is not an issue with a wizzer if its designed correctly.
At present i have Fostex Fe-206e drivers in a TQWT, waiting for me to get off my lazy butt and finish the design for a rear loaded front firing 50Hz horn.Sure i could design and build a 40hz horn as the Fs of the 206e is well within the range. But then i would have to let the horns live in my apt and myself live in a pup tent.Besides i probably would get evicted.
ron
Better yet ever hear a Lowther driven horn with a SET?
I have here some polk audio monitor speakers that i use to test my amp designs. They CLAIM a +/- 2 db flat FR. They also sound like crud.
Sometimes it isint a flat FR that counts , its the total sound.
Phase is not an issue with a wizzer if its designed correctly.
At present i have Fostex Fe-206e drivers in a TQWT, waiting for me to get off my lazy butt and finish the design for a rear loaded front firing 50Hz horn.Sure i could design and build a 40hz horn as the Fs of the 206e is well within the range. But then i would have to let the horns live in my apt and myself live in a pup tent.Besides i probably would get evicted.
ron
ron clarke said:
No I haven't heard a Lowther. There are a lot of speakers I haven't listened to that I should. I've been pretty dissapointed with most speakers I've heard in the last 10 - 20 years. Here's one that I liked a lot http://www.revelspeakers.com/products/overview.asp?ID=1 - until I put on the Matrix soundtrack and they fell flat on their face (not literally). The top end of the spectrum is beatiful on those speakers, but throw heavy bass at them and the run home to mommy (unless it was the $10,000 giant fancy-assed amps the store was running them with?).
Yeah I know, flat does not nesc. indicate good. But not flat does indicate not good, to some extent. I was asking 'cause a dip/bump in the response somewhere around a few khz could indicate a phase problem with the whizzer.
The back of the whizzer and the front of the whizzer are in opposite phase, if both sides are not "exposed" to the listener then I don't think it is a "whizzer", at that point, it needs a new name because it is significantly different.
I don't imagine a whizzer could be "properly designed" such that the frequency response is not significantly different from different listening angles. Of course, that is an issue with most speakers. But, if you have to sit within a relatively small "sweet spot" then you almost may as well just use headphones...
reply
How about the Eminence Beta 12LT dual cone fullrange with freq range of 45hz-10khz and put that in a rear loaded horn cab.And put a piezo ceramic disc on centre of whizzer cone and connect it ,with small pin sized holes, thread wire though to terminals. The speaker will now reproduce 40hz-20khz very good for a 12 inch dual cone fullrange and piezo disc.
How about the Eminence Beta 12LT dual cone fullrange with freq range of 45hz-10khz and put that in a rear loaded horn cab.And put a piezo ceramic disc on centre of whizzer cone and connect it ,with small pin sized holes, thread wire though to terminals. The speaker will now reproduce 40hz-20khz very good for a 12 inch dual cone fullrange and piezo disc.
Whizzers do have phasing issues, especially the Lowthers, PM6A shown. A whizzer with no phasing issues is one that's so well damped it's just dead weight.
GM
An externally hosted image should be here but it was not working when we last tested it.
GM
Sorry GM, you know i have a great respect for you and your knowledge , but my present wizzer containing 206e is by far one of the better drivers i have heard.
The non wizzer Fe-168e was a disaster, it was actually painful to listen to, had a tiny sweet spot and i just didnt like the sound.All i am stating is , that if there is a phase problem, i cant hear it.And if i cant hear it then its acceptable to me.
I have heard lowthers and even though they were IMO lacking in bass, one of the most musical and realistic sounding drivers i have ever heard.
ron
The non wizzer Fe-168e was a disaster, it was actually painful to listen to, had a tiny sweet spot and i just didnt like the sound.All i am stating is , that if there is a phase problem, i cant hear it.And if i cant hear it then its acceptable to me.
I have heard lowthers and even though they were IMO lacking in bass, one of the most musical and realistic sounding drivers i have ever heard.
ron
I spent a few weeks trying to design a good piezo tweeter, no luck, some were OK but none seemed really great. Maybe the old Motorolla piezo elements we had are not the best? They looked the same as the ones I'd seen on the Iconoclast's tweeter.
Parts Express sells some Piezo (pizeo? forgot the spelling, durh..) horn tweeters with a little paper cone on them in the chamber behind the horn, maybe you could just take that assembly out and us it. They were really cheap, don't remember the part # though.
Parts Express sells some Piezo (pizeo? forgot the spelling, durh..) horn tweeters with a little paper cone on them in the chamber behind the horn, maybe you could just take that assembly out and us it. They were really cheap, don't remember the part # though.
Well GM i have my wizzers dammared quite a lot. I ran some FR curves and when i do i hook up the scope to watch the sine wave.I can see a phase shift at a given Hz, the wave trace broadens.
When i was using (about 2 years ago) the B-20 the waveform spread about 3ms and actually showed as a seperate wave with a different amplitude.I dammared them(about 6 layers) and had no luck, so i finally cut the wizzer off and crossed to a tweet.The B-20 phase shift i could hear.
With the dammared wizzers(3 layers) on the 206e i see no such thing or hear it.However i didnt run any curves before i modded the drivers so i actually have no comparasion base.
ron
When i was using (about 2 years ago) the B-20 the waveform spread about 3ms and actually showed as a seperate wave with a different amplitude.I dammared them(about 6 layers) and had no luck, so i finally cut the wizzer off and crossed to a tweet.The B-20 phase shift i could hear.
With the dammared wizzers(3 layers) on the 206e i see no such thing or hear it.However i didnt run any curves before i modded the drivers so i actually have no comparasion base.
ron
Hmm though, I do have to admit once you get over 10Khz or so being terribly flat shouldn't make much difference as long as there aren't any super high spikes until you get over 20Khz... (regarding extending the trebble with a piezo tweeter on the pole piece...)
So then, a driver that covers from 200 Hz to 10 Khz, low distortion, at least 90 db sens.... But, alas, the smaller the radiator is the better the dispersion is...
I HAVE a design that solves these problems, but I don't have the funds to build it.
So then, a driver that covers from 200 Hz to 10 Khz, low distortion, at least 90 db sens.... But, alas, the smaller the radiator is the better the dispersion is...
I HAVE a design that solves these problems, but I don't have the funds to build it.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.