how bad a starting point is this?

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how bad is this for a starting point for a rear-loaded horn for my fane 12" drivers?

this is about the best i've managed with a physically planned box and the subsequent numbers for it plotted in hornresp. its 'tuned' high to keep the size manageable and to hopefully match the subwoofer assistance (i think). the path offset is due to a suprabaffle i was going to play with, but the path difference doesn't make all that much difference.

thanks for your help :)

An externally hosted image should be here but it was not working when we last tested it.
 
thanks for the reply. its for use in a fairly large room in my home (music+movies), where smaller drivers just aren't big enough to fill the room. i bought some MA drivers to try out in a little bass reflex box, they sound pretty good but they just don't have enough presence for the high ceilings etc.

this is the plot for a TQWT (right-side results), is this a more favourable set of results?

if not can you link me to, or post results for what a favourable rear-loaded horn/TL/TQWT would look like in hornresp so i can try and modify a design to the driver so its suitable.

thanks for your help.

An externally hosted image should be here but it was not working when we last tested it.
 
Last edited:

GM

Member
Joined 2003
Hmm, IIRC, MA doesn't recommend horn loading its drivers and TLs won't give you the LF gain required to help fill up a large room. I'm not even sure they can make enough mids SPL for HT at any distance required for a larger screen.

Regardless, I don't consider this new alignment acceptable either. Search the forums for the replicon horn [I've lost the link]; its Excel designer calculates a traditional BLH that you can input into HR or one of the other horn designers.

GM
 
Hmm, IIRC, MA doesn't recommend horn loading its drivers and TLs won't give you the LF gain required to help fill up a large room. I'm not even sure they can make enough mids SPL for HT at any distance required for a larger screen.

Regardless, I don't consider this new alignment acceptable either. Search the forums for the replicon horn [I've lost the link]; its Excel designer calculates a traditional BLH that you can input into HR or one of the other horn designers.

GM

i am not planning on using the MA drivers in a horn, i wish to horn load my 12" full range drivers.
 
can someone please show me what a useful hornresp plot looks like for a big FR driver? the eminence beta 12LTA for example. even a small driver in one of the mk3 frugal's that have very good feedback would do, i just need a visual representation of what is considered 'good'.

i got the easyhorn spreadsheet calc and the numbers it gives me seem rubbish. huge volumes and rubbish combined responses (to my eye), although the sheet might not be working correctly, which is why i need something correct to base my tinkering around.

thanks for your help.
 
BLHs interact with the room far more than simple sealed, reflex alignments unless the room is small auditorium size, so while I can give you one, it may grossly mislead you.

Note too that HR calculates ~ 'ideal' values, making peaks, dips grossly exaggerated [just look at the various TH sims Vs measured], so short of comparing to measurements, it takes a bit of experience to 'see' the likely real world response in just 2pi [half] space with in-room response requiring much more. Much better to pay MJK $25 and use his BLH MathCad SS with the provided demo version to do sims of whatever alignment you 'slide' design in HR's Wizard since it allows one to selectively damp it as well as show some simple in-room predictions.

Post your driver data, calculations..............

GM
 
BLHs interact with the room far more than simple sealed, reflex alignments unless the room is small auditorium size, so while I can give you one, it may grossly mislead you.

Note too that HR calculates ~ 'ideal' values, making peaks, dips grossly exaggerated [just look at the various TH sims Vs measured], so short of comparing to measurements, it takes a bit of experience to 'see' the likely real world response in just 2pi [half] space with in-room response requiring much more. Much better to pay MJK $25 and use his BLH MathCad SS with the provided demo version to do sims of whatever alignment you 'slide' design in HR's Wizard since it allows one to selectively damp it as well as show some simple in-room predictions.

Post your driver data, calculations..............

GM

please do post one, i'm not going to base anything from it, i just want to see as a lot of the literature is quite hard to understand without more visual representation.

how do i get the sheets? are they easy to use?

the drivers are

http://www.fane-acoustics.com/downloads/FANE_Sovereign_12200LT_Specs.pdf

i know they're not ideal (eminence beta 12lta unavailable at time) but i wanted something cheap to start with that would be similar to the end product i would build once i felt i could comfortably shape a system to the sound i want from the end product. like i said earlier i tried some of the MA drivers in one of the suggested enclosures and it just wasn't what i wanted as the thing is just too small to be relevant to my learning. so whereas my end product here will probably not be all that great, i will be able to play with them in various enclosures i make learning to woodwork and tailor sound along the way.

which calculations do you want? the hornresp readouts?
 
which calculations do you want? the hornresp readouts?

The easyhorn and its HR sims. Note though that if this is Soho’s SS, it’s not a designer per se, but a template designer to input into HR, then use the Wizard to try and get a desirable alignment.

Here’s a ~100 L 23 Hz hyperbolic BLH designed for corner loading a CSS FR125S, though simmed in 1 pi to get a more realistic plot. Worked quite well once damped, with usable output to ~32 Hz:

GM
 

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No tutorial needed for a basic sim, just click on a driver spec or cab dimension value to highlight it, type in the new value, move to the next field, etc. or hit enter each time. I don’t have his more recent sheets, but the older ones auto calcs Qts, so check it. Scrolling down the page causes it to auto calculate all the fields. Seems to me one of MJK’s docs ‘walks’ you through an example for room boundary section.

I assume you’re using the MC8 demo, which doesn’t allow you to save your work, but you can copy/paste a record of it into a WORD or similar doc.

GM
 
The easyhorn and its HR sims. Note though that if this is Soho’s SS, it’s not a designer per se, but a template designer to input into HR, then use the Wizard to try and get a desirable alignment.

Here’s a ~100 L 23 Hz hyperbolic BLH designed for corner loading a CSS FR125S, though simmed in 1 pi to get a more realistic plot. Worked quite well once damped, with usable output to ~32 Hz:

GM

if possible could you give me a brief description of what sets that design apart from the ones i bundled together please? just so i can get an eye for it. that is the unstuffed plot from hornresp yes not from MJK's mathcad sheet? once the line is stuffed that curve would smooth out into a nice arc?

No tutorial needed for a basic sim, just click on a driver spec or cab dimension value to highlight it, type in the new value, move to the next field, etc. or hit enter each time. I don’t have his more recent sheets, but the older ones auto calcs Qts, so check it. Scrolling down the page causes it to auto calculate all the fields. Seems to me one of MJK’s docs ‘walks’ you through an example for room boundary section.

I assume you’re using the MC8 demo, which doesn’t allow you to save your work, but you can copy/paste a record of it into a WORD or similar doc.

GM

i've got access to the entire set of sheets.

i've just printed out the 50page walk throughs for a back loaded horn and a transmission line and will have to start slugging through the reading.

thanks for your help.
 
also coupling chamber size.

V = (CxSd)/((2pie x Fh)x(1000 / m3))

following ^that^ i cant seem to get (even using the example in the literature) the same chamber volume.

V =...............(342x0.05309)
......____________________________
.......(2pie x 100) x (1000 / 1.837 cubed)

when i do that i get a number close to 0 which i'd assume is not correct?

without a coupling chamber with the driver firing directly into the flare i get this (right) with a guestimated coupling chamber i get this (left)

they look closer to the output detailed in MJK's paper? i'm still working out how to define this horn using the mathcad sheets so i can't post any of the comparisons to infinite baffle etc yet.

An externally hosted image should be here but it was not working when we last tested it.
 
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