Attention Raffi and Till (Roemhild)

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#3
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
 
#4
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?
 
#5
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
 
#7
hi

my first try:

BL-Horn

length: 0.95m
throad: 95cm²
opening: 2800cm²
volumen: ~40liters
 

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#9
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
 
#10
Audio_idiot said:
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
Click to expand...


Hi


I will try my best and post the result tonight.


cya Till
 
#14
Roemhild said:
hi

my first try:

BL-Horn

length: 0.95m
throad: 95cm²
opening: 2800cm²
volumen: ~40liters
Click to expand...


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
 
#15
Audio_idiot said:
Thank,

The cureves looks ok to me, but will the dip between 250hz to 500hz have any effect on the mids?

Cheers
Click to expand...

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".




ConExp said:



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
Click to expand...


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
 
#16
Scottmoose said:
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?
Click to expand...


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.
 
#20
Tyimo said:


What do you mean? Where?? Klangform Akustiks or Hornlautsprecher or Impulse??

Tyimo
Click to expand...

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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