Does anyone here think Waveguides are not a good idea?

I don't think i've heard a bad word said about waveguides but just wondered if anyone here doesn't like them? And if so, why?

I realise they are a good idea when trying to mate a small tweeter with a large 8" or bigger woofer but what if the woofer is only 6" or smaller? Assuming you time-align the speakers and take care of edge diffraction by chamfering the edges with a big chamfer. All things being equal, is it possible that a non-waveguide tweeter could sound better than one with a waveguide?

I also know that you get less distortion with a waveguide but would it be audible if you got say 10dB less distortion?
 
All things being equal, can never be. Some people here do prefer domes to waveguide setups, but I think the consensus is that waveguide/horn design is "where it's at" compared to "cone n domes". Not only do you get the lower distortion (more than 10dB in most cases), you get very high efficiency which helps with dynamics, and a more controllable front lobe, helping mitigate the problems with room acoustics.

Crossing to a small woofer is fine, but the idea is to match directivity at the crossover point, which means 12"s and 15"s in most big waveguide systems. This allows you to have the narrower, more controlled pattern down to below 1kHz.

Dome tweeters usually do the top octave better than compression drivers, due to the small diaphragm, but those advantages disappear below 10kHz.
 
fatmarley, you are missing the point.
A loudspeaker cabinet IS a waveguide.
The cabinet itself constrains the output of the drivers into a beamwidth that's 180 degrees wide.

So you can't avoid loudspeakers with waveguides; they ALL have waveguides. The only difference is the following:

1) What is the angle of the waveguide? For instance, a direct radiator on a flat baffle constrains the output into a beamwidth of 180 degrees. A compression driver on a ninety degree wide 'waveguide' will be constrained to 90 degrees.
2) How low does the waveguide go? This will largely be dictated by the dimensions of the waveguide.


I own a set of Summas, and IMHO the cabinet of the speaker is just as important as the waveguide. (Hint: that roundover isn't just cosmetic.)
 
I'm also a fan of waveguides, simply because you cannot beat the dynamics in a 2 way designs.
You can match directivity, you can match sensitivity as well and this helps alot the xover.

pic9.jpg
 
Some waveguides work well.

001_zps9b053815.jpg


And you want to match directivity at the crossover point.

8" woof crossed 24db LR @ 2khz to the mcm round horn (54-580) discontinued, but I think diysoundgroup sells them now.
Denovo DW-62S - Denovo Waveguides - Waveguides DIY Sound Group

and yes, the foam made a difference, detail improved, more so than a speaker wire swap. I wouldn't have thought it would have made any difference.

But the 4ohm 93db woof is about 17db quieter than the jbl compression driver............

Norman
 
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mayhem13

Member
2008-09-22 4:37 am
Some waveguides work well.

001_zps9b053815.jpg


And you want to match directivity at the crossover point.

8" woof crossed 24db LR @ 2khz to the mcm round horn (54-580) discontinued, but I think diysoundgroup sells them now.
Denovo DW-62S - Denovo Waveguides - Waveguides DIY Sound Group

and yes, the foam made a difference, detail improved, more so than a speaker wire swap. I wouldn't have thought it would have made any difference.

But the 4ohm 93db woof is about 17db quieter than the jbl compression driver............

Norman

How do you like the Silver Flutes?
 
There is no such thing as a generic "waveguide". The term, afaik, refers to a broad class of structures that are intended to control beamwidth, but are not as concerned with driver loading as are classical horns.

So, you can't just say "waveguide" and have a whole lot of meaning.
Good or bad would depend on the specifics of the "waveguide" structure and design as well as how it mates with the driver.

The idea that one can merely slap a commercially available "waveguide" onto the face of any given driver - especially a dome tweeter isn't quite going to yield a predictable result at all.

Using a compression driver is yet another combination that requires careful consideration to get truly good results. Look at the Geddes thread to see just how deep and complicated it actually is...

_-_-
 
yea, waveguides some use loosely as horns. To me horn really manipulates dispersion (usually giving a lift in highs on axis).

Waveguides seem to be smoother shaped and have less reflections, ideally short too.

I need to get the "round the horn" article. In there they graphed shorter horns having less reflections in the high end than larger but better designed horns. I thought I saw a spectrograph of a seos horn and it didn't have the mouth to throat reflection. See post 406.

Hey guys...we need a little rallying here...


I'm using the 4ohm 8" silver flute and love it. Not much bass with the low qts. But sitting on the floor helps the baffle step. Many say the hivi or dayton is better, I've not heard them. But for a $37 Silver Flute driver, it's good. I like the wool cone. The resonance doesn't bother my ears, granted I'm already 6db down at 2khz due to the crossover. It has a smooth sound but not poly cone soggy smooth sound. Just nothing that seems offensive. Even trapping resonances in drivers, it may measure flat, but the resonance rings over in time, and the resonance can be set ringing by a frequency 1/2 octave and 1/3 octave lower. Any cone creates a harmonic distortion, and when a harmonic falls at the cone's resonance, the cone rings again.

I loved the 6.5" also, but I need a bit more cone area (I'm a 2-way fan detesting crossovers in the male voice range). I run my 2-way wide open. And I don't have any domes laying around, but I recommend the now un-obtanium 6.5" shielded 8ohm. We used a silver flute 2-way as reference for a diyaudio, maybe 7 years ago. Awesome sound for minimal money. Now that's diy !!!!!!!!!!!

Oh, that's a jbl 2407.

Norman
 
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