udailey, it needs some time to get used to. a good starting point is to type in the parameters of some design posted in this thread, then press ctrl+h to open the tapped horn design tool and just play with the paramters. press "ok" on occasion and see how the parameters in the main window correlate to the ones in the tool.
Have you looked at the phase plots of the DSL subs? If you compare the TH50 to other subs, it has qiute the different phase plot, spanning over 400 degrees of phase shift between 20 and 100hz in a more or less straight falling line while the DTS20 or TH115 have alot less phase shift and also a different kind of curve, which has a minimum in the lower half of the operating band. Someone know why?
Had a few helpful emails. Thanks a lot guys.
I followed everyones advice and was able to come up with this so far.
This is assuming that the Sd is right, but when I change Sd anyway it can vary by as much as from Sd of 300-500 and it changes hardly at all.
edit: So I did not get into anything but the SPL graph that you see.
I did not mess with the variables on options "chamber, driver, or other". Maybe I should have but so far I dont know what they are. I have to read that HornResp Class thread further.
Here is my pic:
I followed everyones advice and was able to come up with this so far.
This is assuming that the Sd is right, but when I change Sd anyway it can vary by as much as from Sd of 300-500 and it changes hardly at all.
edit: So I did not get into anything but the SPL graph that you see.
I did not mess with the variables on options "chamber, driver, or other". Maybe I should have but so far I dont know what they are. I have to read that HornResp Class thread further.
Here is my pic:
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The plot looks good, but in practice I don't think it would work. The mouth or opening of the horn is 1/3 or less the Sd. It would be something like a weird bandpass. Maybe it would work but I'm not sure it would technically be a TH.
S1 is the throat area, or the area of the closed end. S4 is the mouth, or the only opening.
Start with S1 at 175 or so, and S4 at 700. Adjust L12 to something like 5-8. Try L34 something like 20 or so. Go from there.
Before doing that fix the driver specs so they are what was posted. That will be closer than what is in the pic.
When adjusting s1, s4, L12 etc easiest is to just use the wizard.
S1 is the throat area, or the area of the closed end. S4 is the mouth, or the only opening.
Start with S1 at 175 or so, and S4 at 700. Adjust L12 to something like 5-8. Try L34 something like 20 or so. Go from there.
Before doing that fix the driver specs so they are what was posted. That will be closer than what is in the pic.
When adjusting s1, s4, L12 etc easiest is to just use the wizard.
Duh? What the heck am I missing here?
Why is it I cannot seem to get more than 101 db at 100hz out of a 3015lf in any of the dozens of tapped horns I've built?
I can get 104 below that, and above that. I tried short horns, long horns, big ones small ones, chambered, compressed. is it the driver? Hornresp says I should have 103 but I never seem to get it. Most of the time they come in at 98db at 100hz regardless of what hornresp predicts.
Folding issues maybe?
AAARRRGGGHHHH!.
Why is it I cannot seem to get more than 101 db at 100hz out of a 3015lf in any of the dozens of tapped horns I've built?
I can get 104 below that, and above that. I tried short horns, long horns, big ones small ones, chambered, compressed. is it the driver? Hornresp says I should have 103 but I never seem to get it. Most of the time they come in at 98db at 100hz regardless of what hornresp predicts.
Folding issues maybe?
AAARRRGGGHHHH!.
Well, it can't be the cab if the frequency doesn't move with varying box alignment and I don't see how it could be the various drivers as some are bound to be different from others spec-wise and a 100 Hz WL is way too long for it to be a self reflection, so lacking any other info this implies a measuring anomaly.
GM
GM
Off a bit. Isobaric doubles the effective mass/motor strength and since compliance is inversely proportional to mass and equivalent Vb is proportional to compliance, the effective Vas is halved. IOW, halve Vas, double Mms, Rms, halve or double Re/Le if wired in parallel/series, Bl is unchanged if wired in parallel or doubled if in series.
HR uses Mmd though and doubling it doesn't work out for whatever reason, so I just input 1/2 Vas and halve or double Re/Le if wired in parallel/series, then (re)calc Mmd, Bl, Rms.
GM
HR uses Mmd though and doubling it doesn't work out for whatever reason, so I just input 1/2 Vas and halve or double Re/Le if wired in parallel/series, then (re)calc Mmd, Bl, Rms.
GM
Agree, 100%, a reversed taper stuffed TH (tapped BP-TQWT) works IMO surprisingly well, lesser in room localized due to the screening effect of the terminus , if can be made small enough.
In the late spring this year I helped a friend of mine to smooth out his in room noticeable FR dip centered around 30 Hz.
A simple corner placed BP-TQWT (208 L internal volume/ 217 cm tall) was designed using two inexpensive Talon 12” drivers.
See pictures 1(11) to11(11)
Later I also designed a smaller BP-TQWT in order to improve the low frequency SQ of my son's PC-speaker setup that were equipped with an old ill-designed PC-sub branded ELTAX , = an 8 inch driver in a 11” cubic BR box.
When comparing this old type of sub with the the BP-TQWT, the over all SQ improved to be almost blame/flaw-less .
See pictures 1x(10x) to 10x(10x)
Input requirements for the substituting sub were: It should have similar low (in room less than 40Hz) and upper end (about 120 Hz) extension and possible to be placed easily below the desktop.
My son has a smaller 'boys room' and very little space to accommodate a larger sub elsewhere in the room, floor footprint left over is less than a 10” x 12” square situated next to a door close to a room corner.
This place was found to be more optimal 'room filling' than placed under the desktop using the older BR sub but earlier not chosen as the BR speaker was easily 'localized'.
OTOH, the low distorting BP-TQWT integrated well almost anywhere in the room without any noticeable localization or other disturbing cues.
Two left over 8” Audes drivers: Audes-75W87-4 were chosen to be used in series, placed in a small footprint BP-TQWT box (10.3”W x 7.1” D x 47.25”H; in cm = 26.2 x 18 x 120) using a 80 cm^2 single port tuning the box to about 27 Hz, damping material included.
A tapped horn would not be practical as the driver type is of a low Qts and a low fs and would if built be of a much larger size for a similar low frequency cutoff.
Instead the BP-TQWT were designed using about a 2.6/1 taper and the 2xSd/ (port area) to about 5/1,see the pictures or the simulation. Smaller port area (< 80 sq cm) was tested but loaded the paper coned drivers to much and causing compression artifacts at excursions lower than x-max.
b
1(11)
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Hi I am bjorno's son Rickard, his diyaudio account is deactivated, he need help to get the account activated again.
"Sorry for the delay!
While posting pictures to this tread I was locked out because I changed my mail address.
At the same time my new mail server went down for unknown reasons but is working again.
Still no contact with DIYAudio.com, can somebody help?
Here are the promised pictures: 8(11) and 1x(10x) to 10x(10x)
b"
8(11)
"Sorry for the delay!
While posting pictures to this tread I was locked out because I changed my mail address.
At the same time my new mail server went down for unknown reasons but is working again.
Still no contact with DIYAudio.com, can somebody help?
Here are the promised pictures: 8(11) and 1x(10x) to 10x(10x)
b"
8(11)
Attachments
