| Scottmoose |
I did some basic dimensions for something similar here: http://www.diyaudio.com/forums/show...5247#post975247
See post 6. It's not drawn, and this is a rough 1st pass -I'm currently, amongst a few other projects, working on a more refined version. No drawing -that you'd have to do for yourself, but the dims needed are there. Might be of use anyway.
Regards
Scott |
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| ConExp |
Thanks Scott,
Interesting. I designed a double horn (to enable large mouth), rear fairing (for corner loading), based on the parameters of the Fostex factory design (for the 206esr), this is kind of huge – 2 meter high.
I run simulation using Hornresp 10.0 (with very similar parameters) and got different results than you. There is a dip in the FR at ~100Hz. Once more, if I “force” the path length between the direct radiator and the moth to be short (50cm or shorter), the dip vanishes.
Any additional thoughts?
Thanks |
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| Scottmoose |
It sounds huge!
Without knowing the exact dimensions you were using, it's difficult to say why you're getting the dip. I don't know HornResp very well, and I have suspicions about it's accuracy -I use Martin King's MathCad worksheets instead.
I'm probably being more than usually stupid, but I'm not sure about the sort of horn you're modelling -was it a BVR type, or a (sort of) doubled version of the Factory horn? |
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| GM |
Greets!
Assuming I understand the question........ IIRC Hornresp assumes a straight FLH without a rear cover (no compression chamber), so it calcs the dipole cancellation between the driver and mouth whereas MJK chose to assume for ease of programming that the mouth and driver's output is emanating from the same point, ergo no dipole cancellation, only pathlength differences through the horn.
Is the distance from the driver to the mouth ~68" (~173 cm)?
GM |
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| Roemhild |
Hi
sorry I havent been here for a while.
| quote: | Originally posted by ConExp
Hi,
(.....)
Could you draw a first guess of a BLH for FE206ES-R using your design concept?
Thank you, |
sure I will try to make a design tonight and post it here.
regards Till |
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| Roemhild |
hi
my first try:
BL-Horn
length: 0.95m
throad: 95cm²
opening: 2800cm²
volumen: ~40liters |
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| Scottmoose |
| Nice response. I'll have a look at that in MathCad over the next day or so out of interest. |
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| Audio_idiot |
Hi Roemhild
I'd been following your design concept since last year. I believe it's an excellent concept and just couldn't resist to build one for experiment.
Unfortunately, I do not have any of the drivers you simulate, the only decent pair of drivers I have is as follows:-
Coral Flat 6B
Parameter
Fo 68Hz
Qms 5.671
Qes 0.433
Qts 0.402
Vas 31.346 L
Could you kindly do a BL-Horn of your resonance theory model for me please.
Cheers |
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| Roemhild |
| quote: | Originally posted by Audio_idiot
Hi Roemhild
I'd been following your design concept since last year. I believe it's an excellent concept and just couldn't resist to build one for experiment.
Unfortunately, I do not have any of the drivers you simulate, the only decent pair of drivers I have is as follows:-
Coral Flat 6B
Parameter
Fo 68Hz
Qms 5.671
Qes 0.433
Qts 0.402
Vas 31.346 L
Could you kindly do a BL-Horn of your resonance theory model for me please.
Cheers |
Hi
I will try my best and post the result tonight.
cya Till |
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| Roemhild |
heres what I´ve got for the Flat6:
BL expo horn
length: 65cm
throat: 70cm²
opening: 1950cm²
chamber: 25ltr |
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| Audio_idiot |
Hi Roemhild,
Thanks in advance for the effort.
Cheers |
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| Audio_idiot |
Thank,
The cureves looks ok to me, but will the dip between 250hz to 500hz have any effect on the mids?
Cheers |
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| ConExp |
| quote: | Originally posted by Roemhild
hi
my first try:
BL-Horn
length: 0.95m
throad: 95cm²
opening: 2800cm²
volumen: ~40liters |
Roemhild,
Thanks so much for your response.
Some more questions:
1. The driver Fs is 42Hz, won’t you try to take the FR lower?
2. As I understand, the FR plot is a combination of the direct radiator and the BL horn (180 degree out of phase plus delay)?
Thank you again |
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| Roemhild |
| quote: | Originally posted by Audio_idiot
Thank,
The cureves looks ok to me, but will the dip between 250hz to 500hz have any effect on the mids?
Cheers |
Hi Audio
No not really. In most cases the room makes more problems than the speaker FR. I dont know if your room has a breakein at this frequency or not. For example my room has a problem with 150Hz. All my speakers have a dip in this range. Noone has ever heared that dip. But after I have shown the FR most people suddenly heared that "problem".
| quote: | Originally posted by ConExp
Roemhild,
Thanks so much for your response.
Some more questions:
1. The driver Fs is 42Hz, won’t you try to take the FR lower?
2. As I understand, the FR plot is a combination of the direct radiator and the BL horn (180 degree out of phase plus delay)?
Thank you again |
Hi ConExp
to 1) I never go under the FS of the driver. If you try so the driver will have a bigger amplitude at this frequency with out a benefit. The driver can't play deeper as its FS. Only way to get the driver deeper is with a actve correction.
to 2) yes.
regards Till |
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| ConExp |
| quote: | Originally posted by Scottmoose
It sounds huge!
Without knowing the exact dimensions you were using, it's difficult to say why you're getting the dip. I don't know HornResp very well, and I have suspicions about it's accuracy -I use Martin King's MathCad worksheets instead.
I'm probably being more than usually stupid, but I'm not sure about the sort of horn you're modelling -was it a BVR type, or a (sort of) doubled version of the Factory horn? |
I’m sorry for the confusion, definitely my mistake.
1) First design was based on the factory design with the following modifications: 1) double horn 2) mouth to the back 3) the last portion of the horn (~30cm) expands rapidly to provide a mouth of ~4000cm^2. (I don’t know how to post the design pic. here so for the moment I’ll skip it ) For this design Hornsep predicts very ugly response.
2) Another approach was the Bl-horn “Roemhild” style. I played around back chamber of 50L, length of 1m to 1.5m and throat of ~0.5Sd. for this I got the said deep around 100Hz. After I saw your parameters (0.2*Sd etc) I run it with Hornresp and got relatively flat response, Bravo.
Now I need to decide between the three options: 1) the big rear moth version of the factory design 2) BL-horn or 3) BIB (easy to build etc).
Thank you all for your great help. |
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| Tyimo |
Hi Till!
I sended a private mail to you. I was asking for some help to understand a strange design: the Impulse H6.
Greets:
Tyimo |
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| qi |
| quote: | Originally posted by Tyimo
Hi Till!
I sended a private mail to you. I was asking for some help to understand a strange design: the Impulse H6.
Greets:
Tyimo |
Nice speaker on thier web page! |
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| Tyimo |
| quote: | | Nice speaker on thier web page! |
What do you mean? Where?? Klangform Akustiks or Hornlautsprecher or Impulse??
Tyimo |
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| qi |
| quote: | Originally posted by Tyimo
What do you mean? Where?? Klangform Akustiks or Hornlautsprecher or Impulse??
Tyimo |
If you go to the Impulse H6 web page, the picture I posted is over on the right.
It is a "spin-off" called Aspara Acoustics
Don't get me wrong.
I LOVE the Replikon!
It is still my favourite of all the designs I have seen |
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| Tyimo |
Hi!| quote: | | I LOVE the Replikon! |
Me too!!!!:)
But, I need very much Till's help to understand the Impulse horn design's theory.
Please Till!!!! Answer to my question! Bitte, Bitte.....!:D
Greets
Tyimo |
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| planet10 |
| quote: | Originally posted by qi
Nice speaker on thier web page! |
That is one of the most elegant uses of a Decca London (?) ribbon tweeter i've seen.
dave |
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| qi |
YES, YES...
That's a real stunner!
The system that really hooked me on this stuff (years ago) was a an MIT professor's (Cambridge Ma)...
Tweeters -- Decca Ribbons (horn loaded)
Midrange -- Quad Electrostatics
Sub -- Concrete TLINE
He was playing Miles Davis
I was a BELEEEEVHA |
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| Tyimo |
Raffi and Till, are you out there??
Tyimo |
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| Audio_idiot |
Hi Roemhild,
You listed CORAL 8A70 as one of your favourate driver,Plainly out of curiousity, what did you use them in? In your new theory too? and what is the box design?
I think I can get my hands on a pair of those...
Thousand thanks
Cheers |
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| Roemhild |
| quote: | Originally posted by Tyimo
Hi Till!
I sended a private mail to you. I was asking for some help to understand a strange design: the Impulse H6.
Greets:
Tyimo |
Hi Tyimo,
I havent heared anything about the H6. I havent seen ist until now. All what I got are the same infos you have got from the official page.
Sorry can't help here.
regards Till |
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| Roemhild |
| quote: | Originally posted by Audio_idiot
Hi Roemhild,
You listed CORAL 8A70 as one of your favourate driver,Plainly out of curiousity, what did you use them in? In your new theory too? and what is the box design?
I think I can get my hands on a pair of those...
Thousand thanks
Cheers |
Hi
the 8A70 is one (if not the) favourite fullrange driver I have got. I have had them in a 25ltr sealed volume together with a 15" bass. I have had it in a 55ltr BR and in a backloaded horn.
Right now I have got it together with a Fostex W300A-II. The coral is in 25ltr closed, the Fostex in a new designed TML.
http://www.diyaudio.com/forums/show...&threadid=77544
regards Till
P.S. if you can get me a second pair too please do it!! I need 3or 4 more for my soround system. |
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| Tyimo |
Hi Till!
Thanks.
Did you get the e-mail what I sended? I attached the enclosure plan to see the "horn" size.
Greets:
Tyimo |
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| Roemhild |
Hi Tyimo
no sorry didn`t get it. was it a zip-file? Maybe my firewall blocked it.
greets Till |
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| Tyimo |
Hi Till!
I sended to your e-mail address what I seen in the hornlautsprecher.de web page. It was nor Zip-ed.
Now I cann't see your web page! It is not working! I get the message: "Hier entsteht eine neue Internetpräsenz !"
Please tell me to which e-mail address should I send the drawings again.
Greets:
Tyimo |
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| Roemhild |
| quote: | Originally posted by Tyimo
Hi Till!
I sended to your e-mail address what I seen in the hornlautsprecher.de web page. It was nor Zip-ed.
Now I cann't see your web page! It is not working! I get the message: "Hier entsteht eine neue Internetpräsenz !"
Please tell me to which e-mail address should I send the drawings again.
Greets:
Tyimo |
Hi Tyimo,
the Hornlautsprecher-page is under construction (and under my name)
please send the plan to: roemhild ->at<- einklang-audio ->dot<- com |
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| Tyimo |
Thanks Till!
I will send in some minutes!
Tyimo |
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| Tyimo |
Hi Till!
Did you get my e-mail with the plan?
Tyimo |
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| Roemhild |
| quote: | Originally posted by Tyimo
Hi Till!
Did you get my e-mail with the plan?
Tyimo |
Hi Tyimo,
yes I have got the plan now and I will takje a look at it this week. Right now I am very busy and have not time for nothing :mad: |
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| Tyimo |
Hi Till!
O.K. I will wait.:)
Maybe the most important question is how works an expo horn shaped reflexport-tube???
Greets:
Tyimo |
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| Scottmoose |
Pretty much the same way as a normal reflex tube. As you know, when vent cross-sectional area increases, so you need to increase length for a given alignment, assuming of course, nothing else changes. Also, if you have a flared vent, which starts narrow and expands, it needs to be longer than the equivalent straight port. The narrower the initial opening, the longer the vent needs to be.
So in these cabinets, as in the more usual sort of small vent bass reflex enclosure, the length, throat area and mouth area of the vent (or horn, if you prefer) is chosen to provide the correct reflex tuning and passband for it's action. The difference is one of degree, so the flare type (exponential or whatever) is selected & tuned for lowest vent distortion. At least, that's the way I see it. GM, Martin, Dave or Ron (or any of our other experts) will be able to explain the physics of it far more accurately than I can. And probably rip me to pieces in the process. Be kind to me guys!
What do they sound like? If done well (& Raffi & Till are very good at these), pretty good, assuming you are using a reflex box as your baseline, and base your technical assessment on that. Compared to their small vent reflex brothers, they couple to the air much better, as you'd expect, and present a far larger image of the sort of scale you'd usually associate with a decent horn design. A well designed horn will slaughter them in some areas of course, but then, a good horn usually beats reflex boxes anyway in these subjects (low distortion, high efficiency, control of the driver athigh levels etc.), so that's no great surprise. On the up side, these big vent reflex cabinets counter with (usually) deeper bass for a given box-size before room-boundaries are brought into consideration, and ease of construction, just like their small vent brothers. Each has it's own trade-offs, so it's apples & oranges really. |
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| Tyimo |
Hi Scott!
| quote: | | Pretty much the same way as a normal reflex tube. As you know, when vent cross-sectional area increases, so you need to increase length for a given alignment, assuming of course, nothing else changes. Also, if you have a flared vent, which starts narrow and expands, it needs to be longer than the equivalent straight port. The narrower the initial opening, the longer the vent needs to be. |
Thanks! I knew it. I think I have to re-edit my question:
How can I calculate the HelmHoltz resonant frequency of a known Vb Box with a known sized expo horn shaped reflexport-tube?
For example:
Vb: 25L
vent lenght:45 cm
vent throat: 120cm2
vent mouth: 435 cm2
flare type: expo
| quote: | | So in these cabinets, as in the more usual sort of small vent bass reflex enclosure, the length, throat area and mouth area of the vent (or horn, if you prefer) is chosen to provide the correct reflex tuning and passband for it's action. The difference is one of degree, so the flare type (exponential or whatever) is selected & tuned for lowest vent distortion. At least, that's the way I see it. |
I think you mean the BLHs of Till and Raffi, but my question was about the Impulse H6. This speaker is a "bit" different from the Replikon...:)
Greets:
Tyimo |
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| Scottmoose |
Sorry, brain not working. :whazzat:
Re the vent, plug the parameters into one of Martin King's BLH worksheet[s], which will show it clearly enough.
Scott |
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| Tyimo |
| quote: | | Re the vent, plug the parameters into one of Martin King's BLH worksheet[s], which will show it clearly enough. |
Yes. It was the first what I did, but the result was so poor, that I cann't believe it is true for this kind of speaker. In the reality it is playing music awesam good!!!
Tyimo |
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| GM |
Greets!
Human hearing is only acute over a fairly narrow BW, otherwise our audio systems would be limited to ~ a phone's BW since a wide BW speaker system's distortion alone would make it unpleasant to listen to, not to mention all the added distortion a typical room adds.
Indeed, I'm convinced it's the harmonic distortion of horns, certain box alignments and driver's FRs that makes them sound so good to some since it 'colors' the sonic presentation in our acute hearing BW just right, like foods rich in fat does to our sense of taste or 'hot' color biased TVs, etc. to our sense of sight, etc..
GM |
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| jamikl |
| Hi Tyimo, nice to see somebody else looking at those older impulse Horns. There was a little discussion about them here a few months back. The layout of them is unusual in that they do have a large filter chamber but it is the whole height of the enclosure, tapering from wide at the top, though not evenly, down to narrow at the bottem which becomes the throat. The horn is then directed up to the top, turns over and comes back down to the bottem like an upturned BIB but not as long. Probably a quarter wave. The mouth at the bottem, full width and deth of the enclosure almost, then appears to be 3 - 5 cm above the ground. Is this mass loading the horn? Does the layout of three folds full height in the box have some sort of resonating effect? The three folds are the filter chamber and the two horn folds. Seems to have been very impressive at its time. |
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| Tyimo |
Hi jamikl!
| quote: | | There was a little discussion about them here a few months back. |
Could you tell me where??
| quote: | | The layout of them is unusual .... |
Yes, very unusual. It's design method is contradict to every "classic" design rules!
I think I need to open a new thread for this questions.
Greets:
Tyimo |
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| Tyimo |
Hi Till!
Did you find something??????
Tyimo |
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| Roemhild |
Hi Tyimo,
to be sincerely, I have no plan if this horn works and why it should sound very good. Dont understand me wrong I belive you that they sound good. I have heared a lot things that shouldn`t work but they do and that very good too.
Here is my simulation with your parameters:
From my point of view the chamber is a bit too small.
scottmoose has given a good answere. It is a thing between a BL-Horn with a big chamber and a usual BR. I would call it a HornReflex.
Here you can see 5 different way how I simulateted one driver.
Black Line is a usual BR
Green Line is a BL-Horn with 1m lenght and a 3200cm² opening area.
Blue Line is a "regular" BL-Horn with a chamber of 3 ltr.
As you can see there is now real differece between a BL-Horn with a big chamber and a BR.
sorry for my late response
greets Till |
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| Tyimo |
Hi Till!
Thanks for the simulations. I got the same with the MJK's Mathcad sheet.
| quote: | | I have heared a lot things that shouldn`t work but they do and that very good too. |
Yes, I think this box is in the same category.
I have an idea about the heard good bass reproduction.
Philips used it in little "sub"bass-boxes: they tuned the box to strong 80Hz reproduction because they said the human ear and the brain will add to the missed lower frequencies. Forexample: We here in the reality strong 80Hz and the brain will imagine that also some 40Hz and even 20Hz was played!
Sorry for my bad english. I hope you can understand the basic "psicho-acoustic trick".
Greets:
Tyimo |
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| Roemhild |
| quote: | | Sorry for my bad english. I hope you can understand the basic "psicho-acoustic trick". |
Hi Tyimo,
yes I know what you mean and that sounds realistic to me. Otherwise why do we like the bass in cars even when they dont play deeper that 60/70Hz?
greets Till |
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| Tyimo |
Hi Till!
| quote: | | Otherwise why do we like the bass in cars even when they dont play deeper that 60/70Hz? |
Yes!:)
Totaly another question:
What is your favorite amp? I know your favorite drivers already! :D
Greets:
Tyimo |
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| Roemhild |
Hi Tyimo,
right now I have got a single-ended-class A MosFet amp (similar to a Pass Aleph)
my new project is a 6-channel amp with the Aleph-X. I have 6 of the PCB's out of the diy-audio group buy.
I will use them for a full active system ( one amp for the tweeter, one for the midrange and one for the woofer).
greets Till |
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| Tyimo |
Hi Till!
I would liket to ask you one more unanswered question:
How could be calculated the Helmholtz resonance with horn shaped duct in a BR box???????????
Greets:
Tyimo |
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| planet10 |
| quote: | Originally posted by Tyimo
How could be calculated the Helmholtz resonance with horn shaped duct in a BR box??????????? |
It can be modeled with Martin King's software. I have been working with Scottmoose on a family of BVRs and that is what he is using (BVR = Big Vent Reflex = Replikon-style box)
dave |
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| Tyimo |
Hi Dave!
Thanks!
| quote: | | It can be modeled with Martin King's software. |
Yes I know and I did it already, but I would like to know is it possible to modify the original Helmholz resonance's equation fo this kind of duct shape????
Tyimo |
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| Roemhild |
| quote: | Originally posted by planet10
It can be modeled with Martin King's software. I have been working with Scottmoose on a family of BVRs and that is what he is using (BVR = Big Vent Reflex = Replikon-style box)
dave |
Hi Dave,
you are 100% right. I allways said that for me a BL-Horn is nothing else than a BassReflex. In my way of building BL-Horns I can shorten the horn and reduce the opening area without any bigger differences. Only the sound will change a bit. I personaly like BL-Horns (or name them BR with a big Port or HornReflex or how ever) more than a BR.
In this simulation you can see what I mean
the blue line is a "normal" BL-Horn
| quote: | Originally posted by Tyimo
Hi Dave!
Thanks!
Yes I know and I did it already, but I would like to know is it possible to modify the original Helmholz resonance's equation fo this kind of duct shape????
Tyimo |
Hi Tyimo,
I have no formula for that but if you make the hornmouth bigger you have to make the length and throat bigger too.
greets Till |
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| Tyimo |
Hi Till!
| quote: | | I have no formula for that but if you make the hornmouth bigger you have to make the length and throat bigger too. |
Yes, I know.
Thanks!
Greets:
Tyimo |
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