Well, we got something productive out of the debate (eventually) which is what forums are about, so I can't see a problem myself. Er, Ron is not known for screaming, exaggerating, or trying to cause problems for other people last I checked... not sure what that's about. 
Hence his irony.
OK, baffles. Everything's a compromise -it simply depends which you select. Step-loss is not quite the same as shape, so I'll briefly deal with them separately.
Step-loss is well understood & related to width. The transition from 2pi to 4pi radiation space, and the apparant loss of SPLs below this point at the listening position (due to less energy being directed forward) occurs at a frequency which is determined by 4560 / baffle-width in inches. Adding an extra baffle wider than the front of the cabinet allows you to push step-point downward to a point where cabinet gain takes over, the two cancelling each other out, without needing electrical compensation etc.
Baffle shape and it's effects are a different issue, and something Ron in particular has put a lot into over the past few years. First up, attached is p23 from Harry Olson's Acoustical Engineering, which shows the effect a number of different baffle-shapes can have on a wavefront. In addition, wavefronts tend to take on the shape of whatever it is they happen to be travelling across. Ergo, a baffle can (indeed, it should) be regarded as a separate transdusor in its own right, with it's own main and secondary sources of radiation. We can use this to our own ends if we wish / have the ability (that's where software like The Edge, Ron's private stuff, and the new versions of Martin's MathCad worksheets that he's currently working on come in). Because to use one example, we can use the baffle, as well as for shifting the baffle-step point downward, to help shape the frequency response of the speaker system.
Hence his irony. OK, baffles. Everything's a compromise -it simply depends which you select. Step-loss is not quite the same as shape, so I'll briefly deal with them separately.
Step-loss is well understood & related to width. The transition from 2pi to 4pi radiation space, and the apparant loss of SPLs below this point at the listening position (due to less energy being directed forward) occurs at a frequency which is determined by 4560 / baffle-width in inches. Adding an extra baffle wider than the front of the cabinet allows you to push step-point downward to a point where cabinet gain takes over, the two cancelling each other out, without needing electrical compensation etc.
Baffle shape and it's effects are a different issue, and something Ron in particular has put a lot into over the past few years. First up, attached is p23 from Harry Olson's Acoustical Engineering, which shows the effect a number of different baffle-shapes can have on a wavefront. In addition, wavefronts tend to take on the shape of whatever it is they happen to be travelling across. Ergo, a baffle can (indeed, it should) be regarded as a separate transdusor in its own right, with it's own main and secondary sources of radiation. We can use this to our own ends if we wish / have the ability (that's where software like The Edge, Ron's private stuff, and the new versions of Martin's MathCad worksheets that he's currently working on come in). Because to use one example, we can use the baffle, as well as for shifting the baffle-step point downward, to help shape the frequency response of the speaker system.
Attachments
Scottmoose said:Well, we got something productive out of the debate (eventually) which is what forums are about, so I can't see a problem myself. Er, Ron is not known for screaming, exaggerating, or trying to cause problems for other people last I checked... not sure what that's about.
Have to explain then. "Lot of screaming, no noise" is a metaphor, not screaming as in angry. Ron claimed that tested and proofed evidence in his work is essential, but obviously in this case he has none of that, while Horst has. Then it's a strange statement at least for me. Contradictive as I wrote in my former post.
Enough now, go on with the subject instead.
Scott
I'm aware of Olsen's work, and still can't see any benefits of having round or square baffles with the driver in the middle.
Re Ron's work there is in fact no contradiction. If you re-read Ron's posts re his software, you'd note that he can't give graphs of the type that are directly comparable to those you're familar with, because it's not that sort of programme. It doesn't produce graphs like, say, Martin's MathCad worksheets, AJ Horn, WinISD or others. Ron's spent 4 decades working with wavefronts, including for military applications, so he knows what he's talking about. He has proof in the physics, but unless you know how to interpret figures relating to the balancing of wavefronts, resonances, pressure and thermal energy losses, there's little point in him presenting it, because it'd be like ancient Martian to most people, myself included. Martin King can probably follow it; I certainly can't. However, I understand enough to appreciate that it works, and for example, I've done my best to model cabinets using different flare constants for different expansions in MathCad, and things do indeed improve. It's not that surprising.
To give one example, if I understand it correctly, Ron has used a conical final expansion section in some of his cabinets like the Austins. Conical is known to produce the lowest distortion (a fact found in any physics textbook). The price though is that it is the least efficient of any horn profile. So, he takes a different approach. He uses a more efficient flare for the initial stages and a low distortion flare for the final stage, to get a compromise offering mostly the best of both worlds. That's heavily simplified, but you get the idea. Sneaky, huh?
Re the baffles, as I explained, in general terms baffles can be used to adjust step-point, and to significantly tailor the frequency response according to what you want to achieve. The driver being in the middle is neither here nor there -you place the driver in what's optimal for a specific driver / cabinet / baffle combination.
The round baffles were more a homage to TC than anything else. The BIB generally doesn't benefit massively from them, though this varies according to the driver / cabinet / baffle combination and shapes. Some drivers beam more than others, and the surface wave / wavelaunch can have less obvious effects than other combinations. YMMV as ever.
To give one example, if I understand it correctly, Ron has used a conical final expansion section in some of his cabinets like the Austins. Conical is known to produce the lowest distortion (a fact found in any physics textbook). The price though is that it is the least efficient of any horn profile. So, he takes a different approach. He uses a more efficient flare for the initial stages and a low distortion flare for the final stage, to get a compromise offering mostly the best of both worlds. That's heavily simplified, but you get the idea. Sneaky, huh?
Re the baffles, as I explained, in general terms baffles can be used to adjust step-point, and to significantly tailor the frequency response according to what you want to achieve. The driver being in the middle is neither here nor there -you place the driver in what's optimal for a specific driver / cabinet / baffle combination.
The round baffles were more a homage to TC than anything else. The BIB generally doesn't benefit massively from them, though this varies according to the driver / cabinet / baffle combination and shapes. Some drivers beam more than others, and the surface wave / wavelaunch can have less obvious effects than other combinations. YMMV as ever.
Thanks Scott!
I have read Ron's explanation and I understand (or does not, I'm not an martian. Hmm, my wife thinks so sometimes) what Ron has stated about his program. It is more measurements of the Frugal horn that's missing compared to Horst's horns. No doubt that his are documented.
Anyway I leave this subject now. Life is calling
Peace brothers and sisters!
I have read Ron's explanation and I understand (or does not, I'm not an martian. Hmm, my wife thinks so sometimes
) what Ron has stated about his program. It is more measurements of the Frugal horn that's missing compared to Horst's horns. No doubt that his are documented.Anyway I leave this subject now. Life is calling
Peace brothers and sisters!
I know that feeling. My ex insisted I must have been from somewhere else, not of this world.
I don't deny the value of measurements -as you know, I'd be one of the last to; and Horst has done very well in taking such pains to have his boxes measured. Leaving aside financial issues, the main problem with the Frugel-Horn, as I've mentioned before, is that you have to know / keep in mind what it is you're actually measuring.
In anechoic or 1/2 space conditions, the Buschorn, and the Frugel-Horn, simulate, and measure, in a rather mediocre fashion. But these conditions are not only not representative of a listening environment for any loudspeaker, they are misleading for a cabinet which actually uses the room as part of it's expansion. If you remove the room, as you do in an anechoic chamber, or a 1/2 space environment, you also remove a major part of the cabinet you're measuring, so aside for very limited use for development purposes, you might as well not bother. The best way to look at it is this. Picture an unfolded horn. Would it be a fair test if I got out the old chain-saw, and chopped the end off it, then measured the mutilated horn? Of course not. But the analogy is pretty exact: that's what measuring a corner horn without a corner is like.
This is the same reason that BIBs simulate poorly, but perform much better when damped to taste, and positioned in-room (I believe you can testify to this yourself Peter!). They were roundly criticised by many people, myself included I'm ashamed to say, after TC posted his write-up, because everyone fell straight into the trap of plugging their dimensions into the modelling software, and completely forgetting that what we were doing was modelling a corner-horn without the corner, which is a pretty major part of the design. They're called corner-horns for a reason. (though the BIB has so much QW gain that it can get away with just a rear wall, if suitably damped and you don't mind working the driver harder than it would otherwise be).
Just to make life even trickier (you wouldn't expect me to make it easy would you? ) as all rooms are different, placing a pair of corner horns into my living room corner and taking a measurement is going to produce a different set of results to those we'd get if we did the same thing in your living room. This is one of drawbacks of corner-horns, although more than compensated for by their advantages of large image-scale & dynamic ability for driver-size etc. As ever, YMMV. There are only different sets of compromises in speaker design, no rights or wrongs, assuming the cabinet is correctly designed to one or more sets of these compromises. We can try to minimise the drawbacks our choice entails if possibe, but this is not a major priority; that we're designing a particular type of enclosure, whatever it might be, means that we've accepted these negative points to some degree or other.
Hope that helps
Scott
I don't deny the value of measurements -as you know, I'd be one of the last to; and Horst has done very well in taking such pains to have his boxes measured. Leaving aside financial issues, the main problem with the Frugel-Horn, as I've mentioned before, is that you have to know / keep in mind what it is you're actually measuring.
In anechoic or 1/2 space conditions, the Buschorn, and the Frugel-Horn, simulate, and measure, in a rather mediocre fashion. But these conditions are not only not representative of a listening environment for any loudspeaker, they are misleading for a cabinet which actually uses the room as part of it's expansion. If you remove the room, as you do in an anechoic chamber, or a 1/2 space environment, you also remove a major part of the cabinet you're measuring, so aside for very limited use for development purposes, you might as well not bother. The best way to look at it is this. Picture an unfolded horn. Would it be a fair test if I got out the old chain-saw, and chopped the end off it, then measured the mutilated horn? Of course not. But the analogy is pretty exact: that's what measuring a corner horn without a corner is like.
This is the same reason that BIBs simulate poorly, but perform much better when damped to taste, and positioned in-room (I believe you can testify to this yourself Peter!). They were roundly criticised by many people, myself included I'm ashamed to say, after TC posted his write-up, because everyone fell straight into the trap of plugging their dimensions into the modelling software, and completely forgetting that what we were doing was modelling a corner-horn without the corner, which is a pretty major part of the design. They're called corner-horns for a reason.
(though the BIB has so much QW gain that it can get away with just a rear wall, if suitably damped and you don't mind working the driver harder than it would otherwise be). Just to make life even trickier (you wouldn't expect me to make it easy would you?
) as all rooms are different, placing a pair of corner horns into my living room corner and taking a measurement is going to produce a different set of results to those we'd get if we did the same thing in your living room. This is one of drawbacks of corner-horns, although more than compensated for by their advantages of large image-scale & dynamic ability for driver-size etc. As ever, YMMV. There are only different sets of compromises in speaker design, no rights or wrongs, assuming the cabinet is correctly designed to one or more sets of these compromises. We can try to minimise the drawbacks our choice entails if possibe, but this is not a major priority; that we're designing a particular type of enclosure, whatever it might be, means that we've accepted these negative points to some degree or other. Hope that helps
Scott
Have to explain then. "Lot of screaming, no noise" is a metaphor, not screaming as in angry. Ron claimed that tested and proofed evidence in his work is essential,
I also mentioned "codes". The problem is some codes are in error. This much alike conventional equations used for horn design. If you change the operation parameters then the old equations can be in error.
Code error: ASTM A435,A578 which are American established codes for the ultrasonic inspection of rolled carbon steel. They were written in the mid 50s. There is a basic flaw in the evaluation of signals. I did some investigation into the problem and the error is not addressed because the group will not admit that the wrong evaluation does exist and has existed for over 50 years.. I have incorporated the British codes in place of the American codes to great effect.
All i am stating is that just because a set of rules or equations are currently used or in effect does not mean that they can be applied to all conditions.
Scott! Sneaky is my middle name,you cant beat physics, but you can sometimes find a way around it.
ron
I also mentioned "codes". The problem is some codes are in error. This much alike conventional equations used for horn design. If you change the operation parameters then the old equations can be in error.
Code error: ASTM A435,A578 which are American established codes for the ultrasonic inspection of rolled carbon steel. They were written in the mid 50s. There is a basic flaw in the evaluation of signals. I did some investigation into the problem and the error is not addressed because the group will not admit that the wrong evaluation does exist and has existed for over 50 years.. I have incorporated the British codes in place of the American codes to great effect.
All i am stating is that just because a set of rules or equations are currently used or in effect does not mean that they can be applied to all conditions.
Scott! Sneaky is my middle name,you cant beat physics, but you can sometimes find a way around it.
ron
YIKES! I started this thread because I am a newcomer to the world of horns. There were some unanticipated problems with the sound of my new Frugals, and I could not find concise nor much FH-specific tuning information in the threads; I needed the advice of experienced persons. Such is the plight of an "early adopter."
For those you whom are more experienced, perhaps my needs will shine a light of what "after the sale" assistance it takes to produce a successful DIY project for the masses...which I believe is what the FH project is all about. In the heat of creative excitement, designers are often anxious to move on to the next exciting project, and beginners like me are left puzzled as to why the project did not satisfy quite as promised...or was at least implied. Simple footnotes, like the tendency for an undamped FH to sound "cuppy"- and what to do about it...are nearly as important to a newbie, perhaps more, then the design of the main product itself. Other examples are explanations, and perhaps subjective descriptions of what the various levels of build achieve. Is the SupraBaffle really necessary? What does it do to the sound? Same questions go for the rear deflectors. By asking such questions in this thread, I have finally come to an understanding of the FH that makes me feel confident I spent my precious hobby time and money in the right place. I was not so sure before I started this thread, where the experts so graciously bailed me out of my knowledge gap.
For the FH to become a true classic "Volks-kit" in the speaker world, I suggest that the information I sought be maintained somewhere on the FH web pages at Planet 10. It could be presented as a rather terse builder's FAQ or in some other other format. And...why not include a single sheet of these tips with every kit? It could touch on the following topics:
1) Driver break -in time, why...and the resulting difference in sound.
2) Compression chamber damping/tuning...why, and how to do it
3) Speaker positioning...what results to expect of various, "typical"setups (mine are not in corners...so NO bass!)
4) Build levels...some people might need a basic explanation as to what BSC is all about and what the rear deflectors REALLY do (they do not just extend bass, I have been told).
Am I overly ignorant or dumb? No. Am I being overly picky? No, I dont think so...not in the context of something that people are going to pay $$ for, and spend a LOT of precious time building and/or tweaking. I mean...there ARE alternatives to the FH, I recently saw that Madisound sells a Fostex-designed flat pack horn kit at just $95 per speaker. Say what you will, but it is in the market as an alternative.
My comments are not meant to be taken as a harsh criticism of this wonderful grass-roots effort. To the contrary...I remain excited (and now satisfied) with what I have done...and learned in the process thanks to Dave @ Planet 10, Chris, ScottMoose (I love that name) and others.
I hope that this thread will answer the questions and sooth the frustrations that other horn newbies might face, as they too decide to build FHs.
Thanks all,
Dennis
San Diego, CA
For those you whom are more experienced, perhaps my needs will shine a light of what "after the sale" assistance it takes to produce a successful DIY project for the masses...which I believe is what the FH project is all about. In the heat of creative excitement, designers are often anxious to move on to the next exciting project, and beginners like me are left puzzled as to why the project did not satisfy quite as promised...or was at least implied. Simple footnotes, like the tendency for an undamped FH to sound "cuppy"- and what to do about it...are nearly as important to a newbie, perhaps more, then the design of the main product itself. Other examples are explanations, and perhaps subjective descriptions of what the various levels of build achieve. Is the SupraBaffle really necessary? What does it do to the sound? Same questions go for the rear deflectors. By asking such questions in this thread, I have finally come to an understanding of the FH that makes me feel confident I spent my precious hobby time and money in the right place. I was not so sure before I started this thread, where the experts so graciously bailed me out of my knowledge gap.
For the FH to become a true classic "Volks-kit" in the speaker world, I suggest that the information I sought be maintained somewhere on the FH web pages at Planet 10. It could be presented as a rather terse builder's FAQ or in some other other format. And...why not include a single sheet of these tips with every kit? It could touch on the following topics:
1) Driver break -in time, why...and the resulting difference in sound.
2) Compression chamber damping/tuning...why, and how to do it
3) Speaker positioning...what results to expect of various, "typical"setups (mine are not in corners...so NO bass!)
4) Build levels...some people might need a basic explanation as to what BSC is all about and what the rear deflectors REALLY do (they do not just extend bass, I have been told).
Am I overly ignorant or dumb? No. Am I being overly picky? No, I dont think so...not in the context of something that people are going to pay $$ for, and spend a LOT of precious time building and/or tweaking. I mean...there ARE alternatives to the FH, I recently saw that Madisound sells a Fostex-designed flat pack horn kit at just $95 per speaker. Say what you will, but it is in the market as an alternative.
My comments are not meant to be taken as a harsh criticism of this wonderful grass-roots effort. To the contrary...I remain excited (and now satisfied) with what I have done...and learned in the process thanks to Dave @ Planet 10, Chris, ScottMoose (I love that name) and others.
I hope that this thread will answer the questions and sooth the frustrations that other horn newbies might face, as they too decide to build FHs.
Thanks all,
Dennis
San Diego, CA
Diogenio said:
NO! I don't think you are being overly picky either Dennis! I'm sure I speak for Dave & Chris too when I say that this is exactly the sort of feedback and constructive criticism / suggestions from builders that was wanted and hoped for. The FH is open-source; this is what it's all about.
Your suggestions all make excellent sense to me. An FAQ page or similar is a very good idea indeed, and including a couple of sheets with this information on in FH kits is also a valuable notion. From your description, it sounds like they're working as they should be for you now? Hope so. Please don't hesitate to get in touch if you have any other issues / need further help, and to let us know how you got them adjusted to your taste. Best regards & enjoy the music
Scott
Scott:
The Frugals are "making music" for now. I have not changed any of the damping from my original polyfill stuffing experiment. Vocals still sound a BIT cuppy on certain CDs, but I now know what causes this and can accept it for a few weeks more.
Dave is sending me SupraBaffles and I will build some deflectors too. I will not change CC damping until I install the baffles, as those will change it all anyway.
With my 2A3 the results are VERY impressive...some of the best sound I have ever had in my system. Even sounds pretty good with a Sonic Impact "T" amp...a bit edgy, more sterile...but I probably need to insert an ohm or two of series R to simulate the 2A3 output DF.
A very cool speaker project (and so tiny!) .
Thanks for your help.
-Dennis
The Frugals are "making music" for now. I have not changed any of the damping from my original polyfill stuffing experiment. Vocals still sound a BIT cuppy on certain CDs, but I now know what causes this and can accept it for a few weeks more.
Dave is sending me SupraBaffles and I will build some deflectors too. I will not change CC damping until I install the baffles, as those will change it all anyway.
With my 2A3 the results are VERY impressive...some of the best sound I have ever had in my system. Even sounds pretty good with a Sonic Impact "T" amp...a bit edgy, more sterile...but I probably need to insert an ohm or two of series R to simulate the 2A3 output DF.
A very cool speaker project (and so tiny!) .
Thanks for your help.
-Dennis
All i am stating is that just because a set of rules or equations are currently used or in effect does not mean that they can be applied to all conditions.
Ron
I know this in my own work, reality has a tendency to show it self when repeated constantly, despite theory, which means lack of good theory for every application.
Scott
Women are wonderful but different, the moment one realise that life is easier. It's just to accept othervise it ends up like in this thread!!!
And yes, I agree it is more difficult with corner horns. After more than 16 homes I'm fully aware of that. But it is possible to interpret behaviors in bass for example, or depth for that matter, with the anechoic response with the corners in mind.
As you say yourself, "max flat alignment is not so interesting for me anymore"
Oops, it fell in a lot of posts while writing. Leave the thread now for the thread owner
For me and my many rooms, in general a sloping curve towards the fs has worked best.
Cheers
Ron
I know this in my own work, reality has a tendency to show it self when repeated constantly, despite theory, which means lack of good theory for every application.
Scott
Women are wonderful but different, the moment one realise that life is easier. It's just to accept othervise it ends up like in this thread!!!
And yes, I agree it is more difficult with corner horns. After more than 16 homes I'm fully aware of that. But it is possible to interpret behaviors in bass for example, or depth for that matter, with the anechoic response with the corners in mind.
As you say yourself, "max flat alignment is not so interesting for me anymore"
Oops, it fell in a lot of posts while writing. Leave the thread now for the thread owner
For me and my many rooms, in general a sloping curve towards the fs has worked best.
Cheers
Diogenio said:
I well know what cuppy is... something i have don't like to put up with. Our 1st build of the A126 was cuppy. Our comments & fixes helped Ron actually find where that was coming from in the physics.
Neither of our FH builds had problems with cuppiness... early prototypes were sans sB and those didn't sound cuppy either.
In the BD-Pipes we built the cure was just getting enuff hours on the driver (and*). In the A126s it was a larger CC (pushing the crossover to the horn down, adding the requirement for a supraBaffle), with the mFonken increasing the cabinet width helped (still a tiny bit compared to the larger Fonken, but that is a compromise that will likely have to be made for the size -- and the Fonken is a hard standard to hold something up to -- you almost need to go OB to get less boxy).
Other things that have helped are making sure the rear of the driver is stream-lined. This is particularily needed on the 126 with its monster magnet (we are attempting to cure some driver related issues on the similarily magneted FF125) -- the *RS 40-1197/FE103 also really benefitted from the stream-lining.
Dennis -- are your 126s as they came out of the box?
dave
PS: sBs were in the mail yesterday.
Diogenio said:
Hey Dennis, I'll share here what I learned building my FH level 3's. My original posts can be found in the Frugel-horn thread, warts and all.
After initial prototyping, building basic boxes, and the final build, the one overriding factor affecting the sound of the FH's was the CC size. Adding a suprabaffle was next in importance. Everything else was a distant third. So before you go worrying about break-in, damping, or stuffing, get the CC size where you need it to be. I bet I pulled my drivers (FE108 EZ) over 100 times throughout this process. I even built an AB switch to compare the two speakers against each other. For my drivers, a CC of 1.8-1.9L was perfect. I discovered that I could hear a difference with as little as 3 cubic inches when doing AB testing. For your driver, a CC of 1.8L would be too small, but I suggest taking yours down to 2L to start and then make 10% changes to find out which direction you should go. Adding a suprabaffle will affect your CC size, too. The larger the suprabaffle, the larger your CC can be. Keep tweaking it until you are happy with the sound. You may find that you don't even need damping/stuffing (I didn't)
Having said all that, the FH is a good, extremely flexible design for the average room at average volumes. I'm sure you won't be disappointed if you keep that in mind, and yes, they are magical when you get them just right.
Doug
Dave:
My 126s are dead stock...right outta the box. I know they need some work (and break in!), but I wanted to get a baseline sound first, so put them in as-is.
"Streamlining..." by this do you mean filling blu-tack in the void formed by the front facing ridge of the magnet and the basket?
I'll be looking out for the SBs...
Taperwood...you are very patient. I'll never pull my drivers more than a dozen times! Current CC size is (I believe) 2.35 L, as shown on the plans at Planet-10. That is...if the beta kits were sent out with the same CC size, and not changed last minute. I did not measure actual CC volume.
-Dennis
My 126s are dead stock...right outta the box. I know they need some work (and break in!), but I wanted to get a baseline sound first, so put them in as-is.
"Streamlining..." by this do you mean filling blu-tack in the void formed by the front facing ridge of the magnet and the basket?
I'll be looking out for the SBs...
Taperwood...you are very patient. I'll never pull my drivers more than a dozen times! Current CC size is (I believe) 2.35 L, as shown on the plans at Planet-10. That is...if the beta kits were sent out with the same CC size, and not changed last minute. I did not measure actual CC volume.
-Dennis
Diogenio said:
Yes.
The fill on the trailing edge is not as critical. Also at least a piece of wool or cotton felt (1/2" or more) on the back of the magnet -- or more elaborate but reported to work well is a piece of stryrofoam (or such) shaped into a cone shape (yellow hi-lite -- as illustrated by this pic based from one from the Bowers & Wilins site http://www.bowers-wilkins.com/display.aspx?infid=1159&terid=1232
dave
Attachments
Dave:
For the unwashed amongst us...what does this "streamlining" achieve...less reflected energy coming back through the cone? What has been your subjective response to this tweak...describe how it changes the sound? Is the effect subtle, moderate, or WOW?
This is the kind of stuff we newbies are hungry to learn...
-Dennis
For the unwashed amongst us...what does this "streamlining" achieve...less reflected energy coming back through the cone? What has been your subjective response to this tweak...describe how it changes the sound? Is the effect subtle, moderate, or WOW?
This is the kind of stuff we newbies are hungry to learn...
-Dennis
Diogenio said:
Not subtle at all... i consider it mandatory on any driver*. Instead of being reflected directly off the flat face of the magnet immediately back thru the cone, the waveform is sent off to the side (and in a blurred manner because the ductseal is soft and will never be a flat surface). Waveforms that are longer will flow around the rear driver structure with less diffraction (which can go back thru the cone). The idea is to have anything off the back of the cone take as long as possible before it has a chance to get back out thru the cone -- this both delays it in time (if long enuff then our ear.brain can tell it is a reflection and will ignore it) and to diminish the energy.
* which is why we may not encounter some of the same issues (before we ever install a driver (even some that we have never seen before) will get some minimum tweaking).
dave
How the heck did that post twice...?
Time to tweak the driver a bit.
OK, I'm off to get some Blu-Tack adhesive putty (I'm too lazy to try and find a source for duct seal here in San Diego). Blu-Tack sems to be a similar material, and it does not dry out either. Maybe it is just repackaged duct seal, sold at 10X markup for the retail market...?
Any S. Cal readers out there know where to get Ideal duct seal?
-Dennis
Time to tweak the driver a bit.
OK, I'm off to get some Blu-Tack adhesive putty (I'm too lazy to try and find a source for duct seal here in San Diego). Blu-Tack sems to be a similar material, and it does not dry out either. Maybe it is just repackaged duct seal, sold at 10X markup for the retail market...?
Any S. Cal readers out there know where to get Ideal duct seal?
-Dennis
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