Folded Horns
Well, I must be stupid because I'm really struggling with this program!
Thought I'd try simulating a classic front loaded single folded horn, the old EV Eliminator 1 & 2. I have the Thiele Small parameters for the later used 15B driver, not sure why I would need the length of the sealed rear enclosure for instance? I know the horn was exponential and tuned to 55Hz according to old EV specs but at a complete loss how to go about simulating this in Horn Response!
Reason for the enquiry is to see how this old design would perform with drivers with considerably more Xmax and power handling, but I fail to see where the programme takes account of any of these specs?
Is there and absolute idiots guide to working with this programme??
Well, I must be stupid because I'm really struggling with this program!
Thought I'd try simulating a classic front loaded single folded horn, the old EV Eliminator 1 & 2. I have the Thiele Small parameters for the later used 15B driver, not sure why I would need the length of the sealed rear enclosure for instance? I know the horn was exponential and tuned to 55Hz according to old EV specs but at a complete loss how to go about simulating this in Horn Response!
Reason for the enquiry is to see how this old design would perform with drivers with considerably more Xmax and power handling, but I fail to see where the programme takes account of any of these specs?
Is there and absolute idiots guide to working with this programme??
Welcome to the club! 
IIRC it was probably a decade after I first DL'd it before I tried fiddling with it again.
Anyway, post the critical dims.......note that if folded you must unfold it to input in HR or if you know its frequency and flare factor or at least its axial length, then with throat, mouth area, HR can calculate the various expansions.
The reason for the sealed chamber depth is HR calculates basic standing waves [eigenmodes] for when the cab has a high aspect ratio, which can be useful in other types of designs, so for a typical compression chamber just always make it ~1.5x the driver's installed depth.
There's places to do it all and a whole lot more thanks to the tremendous number of upgrades done in recent years, many that he said would NEVER happen, more than I've had time to 'assimilate' in my dotage.
GM
IIRC it was probably a decade after I first DL'd it before I tried fiddling with it again.Anyway, post the critical dims.......note that if folded you must unfold it to input in HR or if you know its frequency and flare factor or at least its axial length, then with throat, mouth area, HR can calculate the various expansions.
The reason for the sealed chamber depth is HR calculates basic standing waves [eigenmodes] for when the cab has a high aspect ratio, which can be useful in other types of designs, so for a typical compression chamber just always make it ~1.5x the driver's installed depth.
There's places to do it all and a whole lot more thanks to the tremendous number of upgrades done in recent years, many that he said would NEVER happen, more than I've had time to 'assimilate' in my dotage.
GM
If you are not interested in seeing the chamber resonances, simply put any value you like for Lrc and use the "resonances masked" option.
Hi and thank you both for responses and particularly David for helping out here.
I noticed a spreadsheet programme "The Subwoofer DIY Page", horn folding spreadsheets which exports to Hornresp which could be a useful tool?
Must admit though, the more I look at the various designs, the same old arguements return for me. Horns are large boxes usually created out of 15mm or 19mm BFP for lightness, large panels which need a lot of bracing, steep roll off's and limited bandwidth, all in the name of efficiency?
And I keep coming back to small rigid Linkwitz Transform trapezoid cabinets, 15" drivers and in one design case a cabinet of only 45 litres. Tuned to a very low frequency for reduced cone excursion..(or sealed if you like) it is possible to extend the base to -6 at 35Hz with identical responses/very low group delay and a roll off of 15dB/octave in both reflex and sealed versions created with slightly different EQ's for each variant. One particular Beyma driver will handle 750 watts still remaining within it's Xmax (250watts if sealed) but with a massive margin with an Xlimit of 65mm.
If you block 4 together you have a baffle area of around 10 sq ft, power handling of 3000watts and an spl (still remaining within linear cone excursion), of 135dB "continuous" with more on programme with the driver coil capable handling 1600 watts. I am guessing with mutual coupling you have dropped the F3 to around -6dB at 28Hz as well..
So tricky to decide!! Always compromises!
I noticed a spreadsheet programme "The Subwoofer DIY Page", horn folding spreadsheets which exports to Hornresp which could be a useful tool?
Must admit though, the more I look at the various designs, the same old arguements return for me. Horns are large boxes usually created out of 15mm or 19mm BFP for lightness, large panels which need a lot of bracing, steep roll off's and limited bandwidth, all in the name of efficiency?
And I keep coming back to small rigid Linkwitz Transform trapezoid cabinets, 15" drivers and in one design case a cabinet of only 45 litres. Tuned to a very low frequency for reduced cone excursion..(or sealed if you like) it is possible to extend the base to -6 at 35Hz with identical responses/very low group delay and a roll off of 15dB/octave in both reflex and sealed versions created with slightly different EQ's for each variant. One particular Beyma driver will handle 750 watts still remaining within it's Xmax (250watts if sealed) but with a massive margin with an Xlimit of 65mm.
If you block 4 together you have a baffle area of around 10 sq ft, power handling of 3000watts and an spl (still remaining within linear cone excursion), of 135dB "continuous" with more on programme with the driver coil capable handling 1600 watts. I am guessing with mutual coupling you have dropped the F3 to around -6dB at 28Hz as well..
So tricky to decide!! Always compromises!
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