mgoedeke said:
There's nothing wrong with using regular tweeters in a waveguide. The big problem that I see is mounting a dome tweeter to a horn designed for a compression driver. As, you can see, the ways to do this are all a bit of a hack. Nothing wrong with using compression drivers either. Though, they generally are not designed for the same qualities many people look for in 'hifi'.
bg40403 said:
Well, don't let me stop anyone. I was just trying to point out that it's not as easy as it might appear. You have an easier way to make or cut a waveguide? You've got me intrigued.
A dome tweeter will in most cases fall short on the potential of a waveguide because it is not likely to produce a sufficiently well defined wavefront at the throat resulting in HOM and not have sufficient clean output potential for my liking (Though I'll admit that I am a fan of Prosound type cone drivers)
How many compression drivers have you heard that fell short on your expectations on a waveguide? The waveguide/horn itself is the biggest contributor to the sound (Because of the mouth reflections and HOM) and the limitation with OS Waveguides is generally thought to be the device at the small end. There are quite a couple of very nice comps available thesedays and personally after I took the dip have never looked back on dome tweeters.
In my perception the biggest problem with a dome is the poor bottom end. A dome strains pretty quickly. Adding a waveguide will certainly improve matters. Those that have tried it seemed to be enthusiastic about it and I suspect it is because the waveguide reduces distortion at the lower end of the range. Lower excursion probably gives less spectral contamination overall. Of course HOM's will be an added problem, but the overall result may be an improvement.
But I support Martin's position about domes vs compression drivers. I'm done with domes. For a punchy and dynamic sound I would go for a 12" (at least) HE midbass and compression driver / waveguide. That is if space is not a limitation.
BTW I have listened to Martin's system some time ago. The typical glare that I associate with a dome trying to reproduce material with a wide dynamic range just was not there. Keep in mind that he used fairly low cost drivers and no waveguide yet. The bass was great too. I'm not accustomed to hear that level of articulation from 6.5" and 8" LE drivers.
Martin if you are reading this, hope we can talk waveguides again soon. I've just been busier than originally anticipated.
But I support Martin's position about domes vs compression drivers. I'm done with domes. For a punchy and dynamic sound I would go for a 12" (at least) HE midbass and compression driver / waveguide. That is if space is not a limitation.
BTW I have listened to Martin's system some time ago. The typical glare that I associate with a dome trying to reproduce material with a wide dynamic range just was not there. Keep in mind that he used fairly low cost drivers and no waveguide yet. The bass was great too. I'm not accustomed to hear that level of articulation from 6.5" and 8" LE drivers.
Martin if you are reading this, hope we can talk waveguides again soon. I've just been busier than originally anticipated.
Hi Hennie: but of course. Will send you a mail. I have been stuck in Pietermaritzburg of all places...
[OT]
The reason why a dome is louder on a waveguide is very simple: directivity.
My PA doesn't sound too shabby in the home heh? It is however reasonably compromized, but the next system will be a home-design, 12" + 1" or 1.4" (2-part waveguide) (argh, I wanted to get rid of the old stuff on the shelf in a conventional 3-way set first, but what the heck) I have a couple of Ideas that might fit into my budget and look, well, different.
[OT]
The reason why a dome is louder on a waveguide is very simple: directivity.
My PA doesn't sound too shabby in the home heh? It is however reasonably compromized, but the next system will be a home-design, 12" + 1" or 1.4" (2-part waveguide) (argh, I wanted to get rid of the old stuff on the shelf in a conventional 3-way set first, but what the heck) I have a couple of Ideas that might fit into my budget and look, well, different.
First I want to thank you all for posting your opininons!
Thank you bg40403 for sending me your topic adress!
I can't use a 12" because I can't build a large volumed box!
I want something around 40-45L!
An 8" would probably do the job in such a small box!
CA22RNX needs very large boxes ~100L!
So isn't suited for the job!
Any other suggestions?
Thank you bg40403 for sending me your topic adress!
I can't use a 12" because I can't build a large volumed box!
I want something around 40-45L!
An 8" would probably do the job in such a small box!
CA22RNX needs very large boxes ~100L!
So isn't suited for the job!
Any other suggestions?
My fascination with waveguides began when I saw examples of Amphion and other speakers which included waveguides. I'm already an idiot for making speakers, which my wife calls my "toys"
An alternate to making the waveguide would be the reverse form, so that multiples of a profile could be made indefinitely.
I can use the formulas to calculate a profile longhand. What I need ( Scratch that...what is needed for all of us who are interested ) is a routine to plot the profile full scale in some readily available software... Excel, maybe?
With that we could get on to considering the other compromises that may be a part of this type of construct.
I hope what shows through is my conviction that this is worthwhile and I need some help to push it along.
I have stacked layers of mdf for mounting on my wood lathe to turn. I'm able to work to tolerances measured in thousandths, which exceed the seasonal stability of hardwood. Maintaining tolerances this close requires a more homogenous material such as baltic birch, apple ply, a complex stacked lamination and/or to a lesser degree, mdf
An alternate to making the waveguide would be the reverse form, so that multiples of a profile could be made indefinitely.
I can use the formulas to calculate a profile longhand. What I need ( Scratch that...what is needed for all of us who are interested ) is a routine to plot the profile full scale in some readily available software... Excel, maybe?
With that we could get on to considering the other compromises that may be a part of this type of construct.
I hope what shows through is my conviction that this is worthwhile and I need some help to push it along.
bg40403 said:
Of course. I realized after I posted that it was probably very similiar to how Duevel makes their "horns": http://www.cd-konzert.de/details/E-speaker-built.html . Sounds like it is very similiar.
I am planning to use waveguides on my Arvo Pärts dipoles. Inspired by none other than AJ. I have both the steel sound and MCM waveguides and plan to use the Seas H1212. I'd be interested in anything you come up with Ed.
Could you be bribed to make one extra pair of waveguides on your lathe for lil ol' me?
Could you be bribed to make one extra pair of waveguides on your lathe for lil ol' me?
Part no. 54-580
Then there is the steel sound waveguide which is an inch larger. Both would need some grinding and modding to work with the Dayton or the SEAS as they were meant for compression drivers.
Then there is the steel sound waveguide which is an inch larger. Both would need some grinding and modding to work with the Dayton or the SEAS as they were meant for compression drivers.
Alexnick said:I need an 8" guys!
Post #19 : http://www.diyaudio.com/forums/showthread.php?postid=735931#post735931
Konnichiwa,
Here is how I PERSONALLY would approach this kind of speaker.
First, the tweeter. Dome tweeters suck. Ring Radiators suck. Inverted domes suck. Okay, you can add waveguides, but in the end there is a hard limit as to what you an get. The problems these contraptions have are to numerous to start with.
With the ready and fairly cheap availability of large format ribbon/planar drivers from China you have little excuse to use a dome unit these days. The problem you have with ribbons is an excessively wide horizontal dispersion, which of course calls for a Waveguide. I should think a nice 10-12" wide tractix waveguide machined from solid wood should do the trick. If you judge the depth right you also get pretty decent time alignment with the woofer.
As the 4" long ribbons are already in the 100db/W/m class and given that our waveguide is likely to bump up efficiency by another 4 - 6db our upper midrange/treble unit has plenty of SPL available so it can be crossed over quite low, when coupled with a more normal woofer, the driver would need to be padded down MASSIVELY (in the region of 12 - 16db) so an autoformer inductor in the treble crossover is probably a better choice than a resistive divider.
As woofer there are not that many options, I would not go below a 10" unit, Seas has a nice quite high efficiency 10" which can be made to play very well, there is also the Chinese (swanspeakers.com D10.8) copy of a famous danish brand driver. Put them into a suitable floorstanding enclosure, voila, decent LF extension in room to below 30Hz should be doable.
I think the result should be a system with a sensitivity in the high 80's or lower 90's and pretty decent LF extension. For laughs and giggles place a second LF section above the ribbon with waveguide making a very tall speaker with around 95db/2.83V/1m sensitivity and plenty of dynamic range.
Sayonara
Alexnick said:
Here is how I PERSONALLY would approach this kind of speaker.
First, the tweeter. Dome tweeters suck. Ring Radiators suck. Inverted domes suck. Okay, you can add waveguides, but in the end there is a hard limit as to what you an get. The problems these contraptions have are to numerous to start with.
With the ready and fairly cheap availability of large format ribbon/planar drivers from China you have little excuse to use a dome unit these days. The problem you have with ribbons is an excessively wide horizontal dispersion, which of course calls for a Waveguide. I should think a nice 10-12" wide tractix waveguide machined from solid wood should do the trick. If you judge the depth right you also get pretty decent time alignment with the woofer.
As the 4" long ribbons are already in the 100db/W/m class and given that our waveguide is likely to bump up efficiency by another 4 - 6db our upper midrange/treble unit has plenty of SPL available so it can be crossed over quite low, when coupled with a more normal woofer, the driver would need to be padded down MASSIVELY (in the region of 12 - 16db) so an autoformer inductor in the treble crossover is probably a better choice than a resistive divider.
As woofer there are not that many options, I would not go below a 10" unit, Seas has a nice quite high efficiency 10" which can be made to play very well, there is also the Chinese (swanspeakers.com D10.8) copy of a famous danish brand driver. Put them into a suitable floorstanding enclosure, voila, decent LF extension in room to below 30Hz should be doable.
I think the result should be a system with a sensitivity in the high 80's or lower 90's and pretty decent LF extension. For laughs and giggles place a second LF section above the ribbon with waveguide making a very tall speaker with around 95db/2.83V/1m sensitivity and plenty of dynamic range.
Sayonara
Some sims - standard WINISD stuff:
Driver: PHL 4530 12"
Tuning freq: 47Hz
Box size: 57.7l
-3dB: 51Hz
Efficiency: 94dB
Driver: Volt BM251.3
Tuning freq: 50Hz
Box size: 27.5l
-3dB: 55Hz
Efficiency: 93dB
Driver: SEAS P25REX
Tuning freq: 24Hz
Box size: 247l
-3dB: 21.5Hz
Efficiency: 93dB
Driver: SEAS CA26RE4X
Tuning freq: 36Hz
Box size: 49l
-3dB: 42Hz
Efficiency: 90.5dB
Driver: SEAS CA26RFX
Tuning freq: 34Hz
Box size: 73.4l
-3dB: 36.6Hz
Efficiency: 94dB
Considering a 20m^2 room with European style construction and ample room gain I would say the SEAS CA26RE4X looks like your ticket. I'm not too clued up on ribbons so ask KYW.
If I was doing this for myself I would go for the PHL with a Geddes type waveguide crossed at 1200Hz, alternatively a Volt BM251.3 crossed at 1500Hz for a smaller enclosure. Treble driver could be Oberton D2544, B&C DE250 or Beyma CP380/M. I would add an LE sub for the last octave and use it with EQ and time delay in a nearfield position to combat room boom. It could be a tube or a coffee table type sub, with the tube sub placed just behind the listener being my preference.
Nearfield subbing is generally undestimated but it does reduce room boom considerably due to the nearfield effect. The Geddes type waveguide is said to remove the weaknesses associated with compression driver/horn combinations (HOM's) although I have not built one yet.
I would avoid too low tuning and too much excursion on the main bass driver.
All that because you said punchy bass....
If you can afford a sub the scope for the main bass driver opens up considerably. There are many 12" HE midbass units suitable for cabs < 45l.
But in the context of your original requirement I think the new SEAS will be great. Except maybe price.
Driver: PHL 4530 12"
Tuning freq: 47Hz
Box size: 57.7l
-3dB: 51Hz
Efficiency: 94dB
Driver: Volt BM251.3
Tuning freq: 50Hz
Box size: 27.5l
-3dB: 55Hz
Efficiency: 93dB
Driver: SEAS P25REX
Tuning freq: 24Hz
Box size: 247l
-3dB: 21.5Hz
Efficiency: 93dB
Driver: SEAS CA26RE4X
Tuning freq: 36Hz
Box size: 49l
-3dB: 42Hz
Efficiency: 90.5dB
Driver: SEAS CA26RFX
Tuning freq: 34Hz
Box size: 73.4l
-3dB: 36.6Hz
Efficiency: 94dB
Considering a 20m^2 room with European style construction and ample room gain I would say the SEAS CA26RE4X looks like your ticket. I'm not too clued up on ribbons so ask KYW.
If I was doing this for myself I would go for the PHL with a Geddes type waveguide crossed at 1200Hz, alternatively a Volt BM251.3 crossed at 1500Hz for a smaller enclosure. Treble driver could be Oberton D2544, B&C DE250 or Beyma CP380/M. I would add an LE sub for the last octave and use it with EQ and time delay in a nearfield position to combat room boom. It could be a tube or a coffee table type sub, with the tube sub placed just behind the listener being my preference.
Nearfield subbing is generally undestimated but it does reduce room boom considerably due to the nearfield effect. The Geddes type waveguide is said to remove the weaknesses associated with compression driver/horn combinations (HOM's) although I have not built one yet.
I would avoid too low tuning and too much excursion on the main bass driver.
All that because you said punchy bass....
If you can afford a sub the scope for the main bass driver opens up considerably. There are many 12" HE midbass units suitable for cabs < 45l.
But in the context of your original requirement I think the new SEAS will be great. Except maybe price.
Konnichiwa,
PERSONALLY, and when operating on "accept no compromise" principles I would use a 15" Fieldcoil Magnet Woofer/Midrange and a Raven R3 Tweeter with modest waveguide mounted in a semi-coaxial arrangement using a dipole enclosure.
If I had to do this on a limited budget I'd be tempted to use the Swans D10.8 woofer (which is basically a decent copy of the 10" Dynaudio used in the Shun Mook Speaker, which is excellent) and a Fountek NeoPro 5 ribbon in a sealed or EBS aligned vented enclosure.
Sayonara
Alexnick said:
PERSONALLY, and when operating on "accept no compromise" principles I would use a 15" Fieldcoil Magnet Woofer/Midrange and a Raven R3 Tweeter with modest waveguide mounted in a semi-coaxial arrangement using a dipole enclosure.
If I had to do this on a limited budget I'd be tempted to use the Swans D10.8 woofer (which is basically a decent copy of the 10" Dynaudio used in the Shun Mook Speaker, which is excellent) and a Fountek NeoPro 5 ribbon in a sealed or EBS aligned vented enclosure.
Sayonara
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