Horn/Waveguide Questions

[mortron]

Hello all... Hope things are as well as possible given things.

As with many, I've been left ample time to ponder things and have a few burning questions regarding horns and waveguides. Unfortunately my experiences are limited and getting a frame of reference for how things sound is tricky at best.

Looking at the Yuichi A290 horn, the A480 and others of the sort has me wondering about how these sound compared to more modern waveguides like say the M2. I realize the horn and waveguide comparison is tricky, as they actually do different things in theory, but am wondering:

- how does the sound of a Yuichi type horn compare to that of a CD waveguide like the one found on the much more modern M2?

- I'm guessing directivity between the two types differ... Is there certain situations where one excels over the other?

- always considered the 1.4-1.5" throat drivers a good compromise between LF extension and HF... But don't see them used in the Yuichi type horns very much. Is there a reason?

- if going big like a 2", does the older 2445 function as we as more modern, non JBL offered drivers? Any merit to a coaxial in a Yuichi horn?

I'm not planning anything yet but trying to navigate all the options and compromises sometimes gives me more questions than answers. I understand different strokes and the sort, but just looking for a generalization of the differences, whether they're things you personally like/dislike or just general perceptions. Thanks in advance.

[JeffW]

The drivers with 2" exits like those that are used on the Yuichi have a different flare rate than the snout-less 1.5" exit drivers. I'm no expert, but it's my understanding that the flare rate of the horn and driver need to be compatible for best results.

[Robh3606]

Looking at the Yuichi A290 horn, the A480 and others of the sort has me wondering about how these sound compared to more modern waveguides like say the M2. I realize the horn and waveguide comparison is tricky, as they actually do different things in theory, but am wondering:

- how does the sound of a Yuichi type horn compare to that of a CD waveguide like the one found on the much more modern M2?

I can't say anything about the Yuichi but I do have the M2 waveguides and they are really nice and enjoyable to listen to.

- I'm guessing directivity between the two types differ... Is there certain situations where one excels over the other?

I prefer CD type horns/waveguides so I am biased. You really need to listen and decide for yourself, obviously both can sound very good but CD offers better off axis response.

- always considered the 1.4-1.5" throat drivers a good compromise between LF extension and HF... But don't see them used in the Yuichi type horns very much. Is there a reason?

I would guess the timeframe that it was developed in and what drivers were available at the time. All of the large 2" throated drivers are actually 1.4-1.5 when you remove the throat. Take a look at the 2450 vs 2450SL same exact driver except the SL is throatless. Another example is 2446 vs 2447 check the Library

http://www.lansingheritage.org/html/...p/pro-comp.htm

- if going big like a 2", does the older 2445 function as we as more modern, non JBL offered drivers? Any merit to a coaxial in a Yuichi horn?

The main difference between a 2445 and more modern drivers is the phase plug. It uses the older style like a 2441. All of the current large format drivers use some form of the Coherent Wave Phase Plug. That was first used in the 2446 CD.

Rob

[Ian Mackenzie]

Hello all... Hope things are as well as possible given things.

As with many, I've been left ample time to ponder things and have a few burning questions regarding horns and waveguides. Unfortunately my experiences are limited and getting a frame of reference for how things sound is tricky at best.

Looking at the Yuichi A290 horn, the A480 and others of the sort has me wondering about how these sound compared to more modern waveguides like say the M2. I realize the horn and waveguide comparison is tricky, as they actually do different things in theory, but am wondering:

- how does the sound of a Yuichi type horn compare to that of a CD waveguide like the one found on the much more modern M2?

It’s a subjective assessment and something you need to investigate personally. Not all people agree on what’s best subjectively. It can come down to how well either type is implemented and the impact of the listening room.

- I'm guessing directivity between the two types differ... Is there certain situations where one excels over the other?

The Yuich horns belong to the radial horn family with a particular flare rate. Typically they are 40 x 90 dispersion. In these designs fins with a particular geometric curve are used for dispersion along with the flare rate of the horn.

The wave guides use a diffraction shape of the horn throat adapter to shape the dispersion. The wave guides often have a rapid flare rate.

Sometimes a wide dispersion is advantageous but it depends on a number of factors such as your room acoustics. For example a Jbl use 60 x 90 dispersion in their consumer loudspeakers.

- always considered the 1.4-1.5" throat drivers a good compromise between LF extension and HF... But don't see them used in the Yuichi type horns very much. Is there a reason?

They are specifically designed for JBLs pro horns with rapid flare rates. The idea behind that was to maximise the flare rate in the horn throat so these drivers have a short throat. The driver resonance is much higher as a result.

- if going big like a 2", does the older 2445 function as we as more modern, non JBL offered drivers? Any merit to a coaxial in a Yuichi horn?

I would say no because those horns were designed around those drivers and the Tad 4001 drivers.
You need to have a deep understanding of how to implement the non Jbl coaxial drivers in order to make best use of these designs. It also depends on the aims of you overall loudspeaker design.

It’s subjective. Have a look at the Joseph Crowe YouTubes.

I'm not planning anything yet but trying to navigate all the options and compromises sometimes gives me more questions than answers. I understand different strokes and the sort, but just looking for a generalization of the differences, whether they're things you personally like/dislike or just general perceptions. Thanks in advance.

Your best to obtain a couple of different types and assess them yourself.
Some people rave about the old RCA drivers. Typically restricting the range of a horn or use of horns for different frequencies bands is helpful in diy audio. Attempting a wide range horn or wave guide requires a higher level of technical understanding and skill for a satisfactory result. Typically an additional high frequency driver above 8000 hertz will be more subjectively pleasing than attempting to equalise a waveguide or horn above these frequencies. Mass roll off occurs in any compression driver above 3000-4000 hertz at about 6 dB per octave. The way a compression driver and a horn or waveguide behaves at high frequencies does not necessarily live up to marketing claims.

My advice is not to expect too much out of a horn or a waveguide. For example don’t try and use a small horn or wave guide to crossover below 1000 hertz and don’t push it too high. A lot of these horns and wave guides are talk up on forum with nothing more than opinions without any practical experience with the horn or driver in question.

[mortron]

Thank you for the replies. Much of what you said confirms what I suspected.

When I look at it now, it's clear there are definitely trade-offs in many designs. Different time periods had different solutions to different problems. I would definitely like to try a 2" throws Yuichi at some point in the future as a long term goal of mine, if even just to hear one.

Is it fair to say the M2 waveguide is the culmination of all we have learned about waveguide technology to that point? I understand it's designed with a specific driver, but what about another JBL 1.5" driver? Would say a 2452 work well with the M2 guide? They're certainly much cheaper than they once were and tho still expensive, feel like the ask is worth it as far as what you get for the money. It's the implementation that is key tho, yes?

Choosing what to do is overwhelming. One could spend forever shopping for ingredients to a recipe that could turn out flopping. I try to see what works for others if even just for inspiration later down the road.

I used to be enamoured with the old woofers like 2235, but now see while they're great, newer drivers offer more in regards to refinement etc, and presume the same is true with the compression drivers, ya? I know the newer woofers have differential drive and the new compression drivers are something special, but do many of the legacy drivers hold a candle to them, or is it just chasing nostalgia? I notice the speakers Timbers made for his home use all modern (for the time) components... Even tho those are unattainable now too.

[ivica]

Hello all... Hope things are as well as possible given things.

As with many, I've been left ample time to ponder things and have a few burning questions regarding horns and waveguides. Unfortunately my experiences are limited and getting a frame of reference for how things sound is tricky at best.

Looking at the Yuichi A290 horn, the A480 and others of the sort has me wondering about how these sound compared to more modern waveguides like say the M2. I realize the horn and waveguide comparison is tricky, as they actually do different things in theory, but am wondering:

- how does the sound of a Yuichi type horn compare to that of a CD waveguide like the one found on the much more modern M2?

- I'm guessing directivity between the two types differ... Is there certain situations where one excels over the other?

- always considered the 1.4-1.5" throat drivers a good compromise between LF extension and HF... But don't see them used in the Yuichi type horns very much. Is there a reason?

- if going big like a 2", does the older 2445 function as we as more modern, non JBL offered drivers? Any merit to a coaxial in a Yuichi horn?

I'm not planning anything yet but trying to navigate all the options and compromises sometimes gives me more questions than answers. I understand different strokes and the sort, but just looking for a generalization of the differences, whether they're things you personally like/dislike or just general perceptions. Thanks in advance.

Hi mortron,

Yuichi A290 horn is internally consist of (I think) 5 small horns that would make good horizontal dispersion of the high frequency what is technical challenge while making standard horns. Usually a kind of diffraction slot is applied in the horn throat of such horn. Such type is much more difficultly to equalize, contrary to the A290 that has almost flat response from about 500Hz. So passive crossover network can be applied without any EQ.
I think using JBL aluminum diaphragm in to the drivers motors like 2446 or 2450 with A290 would satisfy all of You needs, so it would be possible to make a kind of 2-way system without many problems. Proper bass driver would be much more difficult to get. You can try 2216nd-1, 1500AL, 2235, mounted in the about 150 Lit bass-reflex box, with the crossover round 600Hz.
Some of the forum members are applied M2 horn with 2450SL/51 (476Be, 476Mg) with the satisfactory results, but a kind of UHF drivers are used. M2+D2 drivers can be applied too, but proper EQ must be applied.

regards
ivica

[Ian Mackenzie]

If you read the project M2 diy threads there is a lot of feedback there on various options with different drivers on the M2 horn. It requires an adapter.

But, be prepared to make a number of adjustments in order to equalise the horn correctly in the Dsp.

There is nothing clean cut about any of this and the end result is largely your perseverance.

It’s subjective as some people find the original Jbl drivers used in the M2 too detailed while others seen happy with it.

Read that thread carefully before you leap.

I personally would not embark on the M2 horn if it’s your first project.

There is a lot of head scratching details in setting up that wave guide with dsp.

You can get lost in the dsp trying to figure out where your going with measurements amd the subjective assessment.

Horns like the Yuichi and the improved Joseph Crowe horns are far more intuitive for diy purposes.
You don’t have to screw around with dsp endlessly and the learning curve that goes with it.


https://josephcrowe.com/collections/...s-290-biradial

[jmpsmash]

Thank you for the replies. Much of what you said confirms what I suspected.

When I look at it now, it's clear there are definitely trade-offs in many designs. Different time periods had different solutions to different problems. I would definitely like to try a 2" throws Yuichi at some point in the future as a long term goal of mine, if even just to hear one.

Is it fair to say the M2 waveguide is the culmination of all we have learned about waveguide technology to that point? I understand it's designed with a specific driver, but what about another JBL 1.5" driver? Would say a 2452 work well with the M2 guide? They're certainly much cheaper than they once were and tho still expensive, feel like the ask is worth it as far as what you get for the money. It's the implementation that is key tho, yes?

Choosing what to do is overwhelming. One could spend forever shopping for ingredients to a recipe that could turn out flopping. I try to see what works for others if even just for inspiration later down the road.

I used to be enamoured with the old woofers like 2235, but now see while they're great, newer drivers offer more in regards to refinement etc, and presume the same is true with the compression drivers, ya? I know the newer woofers have differential drive and the new compression drivers are something special, but do many of the legacy drivers hold a candle to them, or is it just chasing nostalgia? I notice the speakers Timbers made for his home use all modern (for the time) components... Even tho those are unattainable now too.

mortron, great fun to be building speakers. I have started late compare to the more experienced members here. One thing that I have learned is that while some of the older drivers have great reputation, their replacement parts are getting more and more difficult to find. So keep that in mind while trying to obtain discontinued drivers. You might end up having to do more work and money getting them fixed up.

[Robh3606]

There is a lot of head scratching details in setting up that wave guide with dsp.

You can get lost in the dsp trying to figure out where your going with measurements amd the subjective assessment.

Hello Ian

Not really with the 2450 series drivers. The M2 waveguide is not all that difficult to work with. With a passive network I was able to get a useable response with just 2 notch filters. A 2452 would be similar same with a 2453. You should able to set-up a similar result with DSP and possibly add a 3rd to bring up the last octave if needed. Here is an overlay POS did of the passive voltage drive vs the 2430 in the M2. As long as you are not looking for dead flat it should be fine.

Rob

[Robh3606]

[QUOTE]Is it fair to say the M2 waveguide is the culmination of all we have learned about waveguide technology to that point? I understand it's designed with a specific driver, but what about another JBL 1.5" driver? Would say a 2452 work well with the M2 guide? They're certainly much cheaper than they once were and tho still expensive, feel like the ask is worth it as far as what you get for the money. It's the implementation that is key tho, yes?[QUOTE]

Hello Morton

The M2 will work with the 2450 series drivers and 2452/2453. Using a passive network the only potential issue could be some last octave roll-off. Using DSP it would be no issue since you could bring the response up a bit if needed. It took only 2 notch filters to get a good passive solution. The transition with the woofer was more difficult. DSP should be similar as long as you are not going for ruler flat response.

No mater what horn/waveguide you use you will have to go through the same process. Measure, adjust and repeat as required.

Rob

[Ian Mackenzie]

Hi Rob,

If you are familiar and experienced with how to get to that point in the process Yes.

If your Not its a big ask in terms of learning how to do meaningful measurements and to drive and program DSP. Less than 1% of forum members understand how to make measurements. Probably a 1/10 of that have ever used DSP.

You have years of experience. We can’t assume that of the OP.

In my own experience as soon as l switch in Dirac to modify the response of an already flat response of a known loudspeaker you are playing God with the subjective presentation.

An on axis response measurement is not a strong indicator of how a CD wave-guide will work in a particular room. Often a flat response will sound too detailed in a typical consumer living space with a number of large flat surfaces. Real loudspeaker designs account for that. A conventional direct radiator system is more appropriate for on axis measurements. But the diy guy only thinks Flat response.

DSP is a big leap of faith in attempting a diy loudspeaker project. With the exception of home theatre l tread very carefully with EQ of any kind.

Edit . I just read your 2nd post.

If your out to have fun in diy (which we all are) and are not pitching for a superior nirvana presentation then what you end up with can be anything or anywhere as long as it goes as far as diy projects go.

If you want a superior nirvana presentation like a consumer design then it’s a more detailed and insightful journey requiring a lot of perseverance.

[JeffW]

[QUOTE=Robh3606;436115]

The M2 will work with the 2450 series drivers and 2452/2453.

2450SL, not the vanilla 2450

The 2450SL is a 1.5" exit snoutless driver, the 2450 is a 2" exit driver with the flared snout.

[Robh3606]

Thanks your right should have been more specific! Would have to modify the mounting plate for a 2451 and countersink and use flathead screws to accommodate any of the large format drivers.

Rob

[Robh3606]

Hi Rob,

If you are familiar and experienced with how to get to that point in the process Yes.

If your Not its a big ask in terms of learning how to do meaningful measurements and to drive and program DSP. Less than 1% of forum members understand how to make measurements. Probably a 1/10 of that have ever used DSP.

You have years of experience. We can’t assume that of the OP.

Hello Ian

I would dispute those numbers. I think it's a bit higher than that. As far as DSP use almost all of the projects I have seen on this and other forums of late have been using DSP. I kind of feel like the forum dinosaur using passive networks in my DIY builds. That's just my preference and it's fun!

I don't want to lead anyone down the primrose path and leave them disappointed. If you have never done any DIY before start small and inexpensive while on the learning curve and work up to more difficult projects as you gain experience.

I understand the point you are making. I am not trying to make it look supper easy just saying what's possible. We are all adults here and capable of making decisions about what kind of risks we are willing to take based on personal experience, skill and perseverance.

An on axis response measurement is not a strong indicator of how a CD wave-guide will work in a particular room. Often a flat response will sound too detailed in a typical consumer living space with a number of large flat surfaces. Real loudspeaker designs account for that. A conventional direct radiator system is more appropriate for on axis measurements. But the diy guy only thinks Flat response.

Well I disagree on that point. CD systems have very predictable in room response and power response curves which make them much more room friendly than non CD systems. As far as cone and domes the Revels are all CD designs. They are all relatively flat or slightly tilted some rising in the last octave to get a "correct" power curve. The M2 is dead flat but it's a monitor not a home system.

Most cone and dome systems are not CD so in my mind they are where off axis measurements are most important for DIY. Any CD waveguide or horn will mirror the on axis response in the power response. So with CD if you get the on axis "right" off axis will follow over that portion of the response.

The biggest issue doing DIY waveguide and horns is getting the transition through crossover smooth between the LF driver and the Waveguide and looking off axis so you don't have an abrupt DI change. You really should have good off axis measurements for that.

I agree with flat may not be right. It's not for my DIY M2 system. I am using 1db or attenuation on the waveguide. That can be with any system CD or not CD. I think most people even with basic knowledge know this and would account for it doing a DIY system.

I don't think most DIY think only flat. It's the power curve that matters most for in room response look at the Array 1400 as an example of a non flat on axis to yield a flat in-room response. Maybe I assume people have more knowledge than they do but I think most people serious about DIY know this and also have read or know about Tooles book.

DSP is a big leap of faith in attempting a diy loudspeaker project. With the exception of home theatre l tread very carefully with EQ of any kind.

I can see minimizing DSP/EQ or simply not using from a purist point of view. Any DIY system is a leap of faith that will only be as good as the work you put into it.

DSP does has advantages especially if you know what you are doing. As far as how transparent they are?? I think we can all agree they are getting better and better. To some they have no issues at all to others they don't like what they here. Only you can decide for yourself.

Rob

[Ian Mackenzie]

Hello Ian


I understand the point you are making. I am not trying to make it look supper easy just saying what's possible. We are all adults here and capable of making decisions about what kind of risks we are willing to take based on personal experience, skill and perseverance.

Well I disagree on that point. CD systems have very predictable in room response and power response curves which make them much more room friendly than non CD systems. As far as cone and domes the Revels are all CD designs. They are all relatively flat or slightly tilted some rising in the last octave to get a "correct" power curve. The M2 is dead flat but it's a monitor not a home system.

Most cone and dome systems are not CD so in my mind they are where off axis measurements are most important for DIY. Any CD waveguide or horn will mirror the on axis response in the power response. So with CD if you get the on axis "right" off axis will follow over that portion of the response.

The biggest issue doing DIY waveguide and horns is getting the transition through crossover smooth between the LF driver and the Waveguide and looking off axis so you don't have an abrupt DI change. You really should have good off axis measurements for that.

I agree with flat may not be right. It's not for my DIY M2 system. I am using 1db or attenuation on the waveguide. That can be with any system CD or not CD. I think most people even with basic knowledge know this and would account for it doing a DIY system.

I don't think most DIY think only flat. It's the power curve that matters most for in room response look at the Array 1400 as an example of a non flat on axis to yield a flat in-room response. Maybe I assume people have more knowledge than they do but I think most people serious about DIY know this and also have read or know about Tooles book.

Rob

Hi Rob,

I think your post while well informed is too sweeping in your generalised view point of what people know or don’t know or should know if they are serious about diy.

So you saying you expect people to be aware of or have read Tooles book so they can understand your post? I haven’t read it.

I can say that people who are serious about diy in other words have the means are not necessarily tech savvy in a highly detailed sense. They are generally self aware enough to get trusted advice.

The issue with you is what you think people are expected to know about Tooles Book. That’s a bit arrogant.

If you were to rephrase that to l encourage people to read Tooles book on your journey to becoming serious about diy it might be better received.