So I’m confused, and hoping someone can help enlighten me over what I can find on line.
Everywhere I look I get people saying if I’m building speakers, to only use a single woofer and a single tweeter… otherwise you get comb filtering.
Yet, every where I look- even super high end $100k speakers… there are multiple same size woofers in the floor standing cabinets.
So why?
How have they solved the issue?
:frustrated:
Thanks all
Everywhere I look I get people saying if I’m building speakers, to only use a single woofer and a single tweeter… otherwise you get comb filtering.
Yet, every where I look- even super high end $100k speakers… there are multiple same size woofers in the floor standing cabinets.
So why?
How have they solved the issue?
:frustrated:
Thanks all
No one has, just that the more they comb and/or the further away we are the more our brain combines them to sum as one. Horns/WGs OTOH can be designed to sum them, so personally prefer to use them only in room corners or horn/WG loaded.
A lot of it comes down to the frequency where the overlap is occurring and the wavelength also. With long wavelengths and close spacing, there's no appreciable comb filter effect. Since the effect is related to the path length differences between the listener and the two sources and the phase difference those distances create. With long wavelengths like those in the bass range, the distances between drivers in a typical home audio speaker can't make much of a phase difference.
It's a similar issue in crossover design where people try to keep the spacing as small as possible in order to keep it under 1/4 wavelength at the cross point. Closer than that and things typically combine pretty smoothly over a decent geometric listening window (angle off-axis up/down, left/right). If you are OK with frequency response/directivity getting lumpy outside that window, you can also get away with significant spacing between drivers. Since most crossovers have similar artifacts in the overlap region, a certain amount of this effect is typically unavoidable in multi-way designs.
XSim3d will let you play around with basic models for effects like these. When you tilt the baffle is where the problems typically manifest (assuming a symmetrical layout).
This is for two 3" full-range theoretical sources spaced one foot apart at their centers, with the microphone centered between them (at the red +)
Same drivers right against each other (3 inches center-to-center)
It's a similar issue in crossover design where people try to keep the spacing as small as possible in order to keep it under 1/4 wavelength at the cross point. Closer than that and things typically combine pretty smoothly over a decent geometric listening window (angle off-axis up/down, left/right). If you are OK with frequency response/directivity getting lumpy outside that window, you can also get away with significant spacing between drivers. Since most crossovers have similar artifacts in the overlap region, a certain amount of this effect is typically unavoidable in multi-way designs.
XSim3d will let you play around with basic models for effects like these. When you tilt the baffle is where the problems typically manifest (assuming a symmetrical layout).
This is for two 3" full-range theoretical sources spaced one foot apart at their centers, with the microphone centered between them (at the red +)
Same drivers right against each other (3 inches center-to-center)
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You haven’t read far enuff.
A siingle woofer + a tweeter has some combing since (if we are talking of typoical components) the centre-to-centre of the drivers is greater than a quarter wavelength. A WAW is a 2-way aimed at evading this issue.
If you are using multiple drivers, they will start to comb as the centre-to-centre becomes larher than that quarter wavelength.
Also worth noting: combing is not nearly as bad audibility-wize as it lookls in a graph.
dave
Coincidently, I just watched a video that touched on this subject. Erin has simplified it quite a bit but overall, a good explanation.
Source is crucial. His discription is convoluted and confsuing.
Huh. Bookshelf vrs tower. A lot of misinformation.
Ideal speaker is a point source. Uniform for every sound that exits.
Coaxial, done right needs DSP.
Crossover point, mid+tweeter. He beats around the bush skirting the real issue. Quarter-wavelength and driver centre-to-centre.
His bit about multiple woofers misses the point as well. Calling it a phase issue is kindfa simplistic.
“out in time” but glosses over it.
His comments on quantity vrs quality is right but described in a confusing manner.
Generaliztion oin beaming goes back to the basik flat-piston math. The dispersion of a cone is highly dependent on the cone shape.
Comments on wide-baffle vrs narrow baffle conclude the oppossite of the common concensus i see here. It heavily depends on the execution.
Take the chainsaw to the towers to bring the tweeter down. Easier to raise your chair.
Full of confisuing and misleading comments amoung some gems.
Bigger speaker ≠ better image conclusion i agree with.
18 min i’m not gonna get back.
dave
Huh. Bookshelf vrs tower. A lot of misinformation.
Ideal speaker is a point source. Uniform for every sound that exits.
Coaxial, done right needs DSP.
Crossover point, mid+tweeter. He beats around the bush skirting the real issue. Quarter-wavelength and driver centre-to-centre.
His bit about multiple woofers misses the point as well. Calling it a phase issue is kindfa simplistic.
“out in time” but glosses over it.
His comments on quantity vrs quality is right but described in a confusing manner.
Generaliztion oin beaming goes back to the basik flat-piston math. The dispersion of a cone is highly dependent on the cone shape.
Comments on wide-baffle vrs narrow baffle conclude the oppossite of the common concensus i see here. It heavily depends on the execution.
Take the chainsaw to the towers to bring the tweeter down. Easier to raise your chair.
Full of confisuing and misleading comments amoung some gems.
Bigger speaker ≠ better image conclusion i agree with.
18 min i’m not gonna get back.
dave
Indeed, the so-called floorstanding speakers are flawed because they can only move horizontally...well, no, that's not their only limitation, since the thingy isn't perfect and the total isolation of the back wave needs a little more than a wood barrier. So sound gets out and creates more sources.
Not only that, but he kinda says that an expansive soundstage is the result of bad phase or poorer phase interactions, and that focus or clarity of the image becomes blurred as a result of this larger poorer soundstage. He also says poorer integrated speakers have bigger soundstage.
I don't agree with this sentiment. While I understand that the detriments described herein are a result of the issues he describes, he also does not say that speakers can be both good and clear at imaging and have broad soundstage without having such poor phase interactions.
While I agree that poor xover design will create issues in phasing, I believe there is a lot more to the problem and success than stated.
I don't agree with this sentiment. While I understand that the detriments described herein are a result of the issues he describes, he also does not say that speakers can be both good and clear at imaging and have broad soundstage without having such poor phase interactions.
While I agree that poor xover design will create issues in phasing, I believe there is a lot more to the problem and success than stated.
I was more specifically talking about the expansive soundstage being rooted in phase issues with floorstanding towers that are on the budget end. These issues often result in “split stage” which are clearly audible if you take the time to listen. I know I said that explicitly at least once.
Speakers that are more expensive (presumably) have good crossover integration and don’t suffer from these kind of issues, typically. I know I said that as well.
This is also why I gave the simple example of reversing polarity of one speaker in a stereo pair and listening to the effect.
Speakers behave like a uniform source at low frequency. Adding more LF drivers doesn’t change this at LF but does at MF. I mentioned this.
Also, I explicitly mentioned I was going to not discuss the obvious effect of more woofers exciting more air pressure.
Big speaker doesn’t guarantee big sound. Nor should it. And in cheaper speakers it’s almost always related to poor crossover implementation. That’s what my discussion was aimed toward.
The problem is that people want a simple answer. And it’s not simple. There isn’t always a single answer for things. Especially with loudspeakers. If you haven’t had the experience of hearing a speaker that has a split stage wrt height then consider yourself lucky. But they’re out there. And it’s super distracting when you hear it.
I attend different shows throughout the year. If you have a bone to pick then I’m happy to discuss in person.
Thanks,
Erin
On a personal note, I’ve seen some posts about me by some of you guys. I don’t know you. But you seem to not like me. That’s fine. I don’t reply to those posts. However, it is evident you let your personal bias toward me drive you to miss the things I spoke explicitly about and discussed. Otherwise, I wouldn’t see them brought up here as points of contention.
Many edits; my phone
Speakers that are more expensive (presumably) have good crossover integration and don’t suffer from these kind of issues, typically. I know I said that as well.
This is also why I gave the simple example of reversing polarity of one speaker in a stereo pair and listening to the effect.
Speakers behave like a uniform source at low frequency. Adding more LF drivers doesn’t change this at LF but does at MF. I mentioned this.
Also, I explicitly mentioned I was going to not discuss the obvious effect of more woofers exciting more air pressure.
Big speaker doesn’t guarantee big sound. Nor should it. And in cheaper speakers it’s almost always related to poor crossover implementation. That’s what my discussion was aimed toward.
The problem is that people want a simple answer. And it’s not simple. There isn’t always a single answer for things. Especially with loudspeakers. If you haven’t had the experience of hearing a speaker that has a split stage wrt height then consider yourself lucky. But they’re out there. And it’s super distracting when you hear it.
I attend different shows throughout the year. If you have a bone to pick then I’m happy to discuss in person.
Thanks,
Erin
On a personal note, I’ve seen some posts about me by some of you guys. I don’t know you. But you seem to not like me. That’s fine. I don’t reply to those posts. However, it is evident you let your personal bias toward me drive you to miss the things I spoke explicitly about and discussed. Otherwise, I wouldn’t see them brought up here as points of contention.
Many edits; my phone
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I find Erin's way of explaining very good because he describes in layman's terms for the average punter like me, please dont get me wrong but you two guys(P10 & WT) have a great knowledge basis but often when explaining things on here go way above most peoples heads making things very confusing often putting people off, I'll will stop here as I do not wish to offend.
Unfortunately, I feel Erin's pain trying to explain things simply. Sometimes there is no easy way. The other part of this hobby is trying to be accurate in explanations to the newer builder because the jargon and related terms involved make it a lot harder to understand. Sometimes there is just not an easier way to state an answer. In this hobby you sometimes have to learn more before the answer can be understood. There have been times I've read something earlier in my hobby and not understood it. Then read it again some years later and comprehended all of it. I value Erin's opinions and experiences in and around our endeavors and have learned from him as well. I hope he keeps this up.
Erin, I have nothing against you, i value your input, and in your reply i agree. We can take this offline if you have more concerns...
Erin, I have nothing against you, i value your input, and in your reply i agree. We can take this offline if you have more concerns...
No worries, Wolf. I've seen you around for a long time so I didn't take anything you said as a personal gripe with me but rather a difference of opinion.
By far the biggest struggle I have with creating content about these kind of topics is riding the line between 'not losing people' and 'providing enough information to be credible'. It's tough to make the die-hards happy while helping the newcomers not feel like they have no hope of understanding anything. The latter is more important to me. Speaking frankly, I have had a few people reach out to me and told me that my videos/reviews helped them pursue a career in audio. One fellow works for Purifi now. But for the die-hards, yeah, I get it ... I may not provide every little detail and people don't have to agree with everything I've said. I do my best to provide content that is interesting and accessible and rooted in science. Sometimes things are omitted by accident; sometimes on purpose (and I mention it, as I did in this case with the "bigger sound via more bass").
That's about it.
By far the biggest struggle I have with creating content about these kind of topics is riding the line between 'not losing people' and 'providing enough information to be credible'. It's tough to make the die-hards happy while helping the newcomers not feel like they have no hope of understanding anything. The latter is more important to me. Speaking frankly, I have had a few people reach out to me and told me that my videos/reviews helped them pursue a career in audio. One fellow works for Purifi now. But for the die-hards, yeah, I get it ... I may not provide every little detail and people don't have to agree with everything I've said. I do my best to provide content that is interesting and accessible and rooted in science. Sometimes things are omitted by accident; sometimes on purpose (and I mention it, as I did in this case with the "bigger sound via more bass").
That's about it.
I felt like you came across as a person who bought a klippel machine
and are trying to reverse engineer everything in order to figure out loudspeaker design....
Where are your loudspeaker designs?
and are trying to reverse engineer everything in order to figure out loudspeaker design....
Where are your loudspeaker designs?
" Reverse Engineering is the process of analyzing a system or component to determine its structure, function, and operation. "
This is something to do if you don't have access to the science and experts that lead the designs
We are dealing with topics that are already well covered in loudspeaker design but rather than leaning on what research has already covered, incorrect assumptions (guesses) are being presented as fact. Rather than putting those assumptions on video he should be here asking questions to the actual experts like the rest of us.
This is something to do if you don't have access to the science and experts that lead the designs
We are dealing with topics that are already well covered in loudspeaker design but rather than leaning on what research has already covered, incorrect assumptions (guesses) are being presented as fact. Rather than putting those assumptions on video he should be here asking questions to the actual experts like the rest of us.
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As mentioned easily solved with center to center spacing of drivers.
Then crossover does the rest.
Basically mount them as close as physically possible.
Little more distance is possibly at lower frequency
since wavelengths are longer.
Then crossover does the rest.
Basically mount them as close as physically possible.
Little more distance is possibly at lower frequency
since wavelengths are longer.
I’ve shared a couple in older videos. The last one I did was around 2015 or so using a KEF concentric from R500 and Scanspeak 10” Revelators (aluminum). I have a ton of pictures, measurements and LEAP simulations on the PE forum.
I stopped DIY when I found a Craigslist ad selling all the JBL speakers out of the old theater in town. I bought some cabs with dual 15’s and redesigned them for singles with the 2446j CD and the accompanying WG (can’t recall the model off the top). Have a whole video on that. Since then I got a divorce and moved. The speakers stayed at the house with the new owner since they were part of a baffle wall HT setup.
Before I got the KLIPPEL NFS I was providing raw driver tests back around 2011. Where I learned the most was car audio. I’m sure you’ll all scoff at that but maybe @Patrick Bateman can back me up here when I say that car audio can make you learn a lot about acoustics.
I've listened to and tested many designs by self-proclaimed experts. I'll leave it at that.
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I'll bow out of this thread now. Defending myself on the internet isn't something I fancy spending my time on these days. There are more positive ways I can use that time.
I'm around at shows. Let me know who you are when/if you see me in person. You can test my knowledge in person then.
Peace, gentlemen.
- Erin
I'm around at shows. Let me know who you are when/if you see me in person. You can test my knowledge in person then.
Peace, gentlemen.
- Erin
I know it seems abrasive but I think rather, you have many supporters here, and remember steel sharpens steel. Reviewing speakers has nothing to do with actually knowing the science of loudspeaker design and it disrespectful to think that one could "just figure it out" as they go. Like saying I've test drove a Ferrari and put one on a Dyno....You could test 1000 expert designed loudspeakers, that does not make one an expert loudspeaker engineer by any means. Theres plenty to study about acoustics and loudspeaker engineering that will teach you the truth. For example, In the video, it suggested that sensitivity is headroom... that is untrue and proof that some basic understandings of loudspeakers are not understood. Many choose to listen to different things, but the experts here tend to agree about a lot of the science that is basis of design, if you have 2 experts from the group commenting that "I don't agree" or " A lot of misinformation." you can be confident in their opinion as a lot of this is old information and established science.
The choice to not discuss the details with your peers and superiors just says you are worried about image. Discussion and debate brings clarity.