Hi,
Thanks for reading my post.
I came across something that I don't know how to "translate" into the real world.
On parts express, there is a waveguide that has a minimum frequency response. I notice that every waveguide has a frequency range listed.
My question is about what happens if a speaker is crossed below the "minimum" that is shown for the waveguide.
Is that where the "honk" sound comes from in horn drivers? I mean, is that honk created by improperly matched crossover frequencies on those drivers? (edited: because this was me rambling)
This is the waveguide that got me to thinking about it: https://www.parts-express.com/Dayton-Audio-H08RW-8-Round-Waveguide-1-3-8-18-TPI-270-308
Thanks again for reading my post.
Dan
Thanks for reading my post.
I came across something that I don't know how to "translate" into the real world.
On parts express, there is a waveguide that has a minimum frequency response. I notice that every waveguide has a frequency range listed.
My question is about what happens if a speaker is crossed below the "minimum" that is shown for the waveguide.
This is the waveguide that got me to thinking about it: https://www.parts-express.com/Dayton-Audio-H08RW-8-Round-Waveguide-1-3-8-18-TPI-270-308
Thanks again for reading my post.
Dan
Last edited:
You are freely mixing horns with waveguide.
Definitely not the same.
https://techtalk.parts-express.com/...s-the-difference-in-a-waveguide-and-a-horn-nm
Horn is typically large diaphragm moving against small throat.
Waveguide is directivity control, but there is typically no compression chamber.
Definitely not the same.
https://techtalk.parts-express.com/...s-the-difference-in-a-waveguide-and-a-horn-nm
Horn is typically large diaphragm moving against small throat.
Waveguide is directivity control, but there is typically no compression chamber.
I'm going to reword my question because you are not answering what I'm asking...
That is what I'm wondering about.
I am not mixing terms... I meant to say "waveguide." The link I included clearly has the word "waveguide" in it. That is why I used the word "waveguide" and I posted the link so you can see what caused me to be confused.
It seems like you are just looking to argue. What's the point? You could have just ignored the post if you didn't know the answer.
Hi,
What happen below recommended cut off for waveguide: like TNT stated you loose directivity control ( you tend to omni). Not sure about 'loading' but you certainly won't gain any.
As there is a cutoff, there is a filter so there is an attenuation ( and relatives: phase relationship change). The interesting point is it is minimum phase so can be manipulated through eq.
That said you'll have the same issue that with any radiator: xmax and distortion will certainly limit what is achievable through this kind of manipulation.
What happen below recommended cut off for waveguide: like TNT stated you loose directivity control ( you tend to omni). Not sure about 'loading' but you certainly won't gain any.
As there is a cutoff, there is a filter so there is an attenuation ( and relatives: phase relationship change). The interesting point is it is minimum phase so can be manipulated through eq.
That said you'll have the same issue that with any radiator: xmax and distortion will certainly limit what is achievable through this kind of manipulation.
Thank you for addressing my actual question.
I suppose you are right about the efficiency becoming negligble. I wonder if it just gets distorted, because, clearly sound "will" still come out of the horn, lol.
I'm going to buy some and test them to see what happens when it is crossed lower. I'm really curious to see what happens.
Not sure, a waveguide often (but not always) narrow the dispersion or unifies it over a larger FR range. But it is wider towards lower frequency - which is the behaviour of a bass as well... so not the opposite really as I see it...
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Thank you.
Regarding the attenuation, I suppose that would really be the most obvious audible problem. That's a really good point.
I'm going to test it and see. I'd like to see what happens if I cross a quarter octave lower, to crossover from an 8-inch mid-woofer, which should beam somewhere around 1700hz if memory serves...
Well, let me look.
Had to look it up. Speed of sound in inches divided by driver size in inches. Since I don't believe the drivers will be exact, just as well to approximate it. So, ~13500 divided by ~8 is 1687.5hz, which is where the 8" should start to beam, and where it should already be crossed over... I was close.
Sorry, I got off topic a little there. I'll be interested to see how it tests out.
Thank you. I was thinking about how it starts to introduce the distortion at the edge of some sort of frequency range. So, what I was thinking is that a woofer starts to break up, on the way up to those frequencies, and the WG starts to break up as it goes down towards lower frequencies. That's what I meant by opposite of the woofer beaming.
Thanks again.
The issue will not be the waveguide but the compression driver: for example if 1" might be ok from 1.2khz but few will accept lower. I think a Bms could be usable to 800hz if you are reasonable about spl ( domestic application) but it would already be a stretch in my view.
As you use the cd on the lower range it can produce you might reach xmax and don't have enough headroom left so higher potential distortion, while with direct radiator it might not be the case.
You'll have to ponder both. I see your thinking about directivity match.
Usually it is the other way around: let mid direct radiator directivity behavior dictate the 90* ( or other angle) where the waveguide directivity match. In other words the woofer 'lead' the xover requirements. This way you have higher 'clean' spl potential ( the cd is not xmax limited, the woofer have higher headroom potential)
I think it makes more sense for reason previously exposed but nothing stop you to try by yourself, just makes sure you cross the woofer in a frequency range where it is still radiating omni as you don't want any 'waistbendeing' in the directivity behavior.
The sharper the "cut-off" (the drop of acoustic impedance) of a horn, the higher is the chance that it will resonate badly near this frequency. It's pretty plausible that this makes at least a part of the "honk", as it's often ignored (or measured in such a way that it disappears). The problem is that the acoustic impedance is almost never shown so the only way to be sure is to measure the device properly yourself. Then the only real limitation will always be the driver used, mainly its excursion, given the SPL requirements - the same as with any other transducer.