I think in your case you're better of with a single 18" BR there are heaps of these type cabs appearing on Ebay that would be suitable. Would save you the work and probably be cheaper.
If you don't care about mid bass another option is a scoop bin. These are the ultimate for dub.
Speakerplans.com
Reminence, I'm afraid Col has a point. Non of the existing concepts are meeting your preferences and you can't break the law of physics. So somewhere down the line you have to accept some compromise.
When you design a TH with its Excursion dip below the 40Hz you can easily make up for the roll off. The make up will not cause extra excursion above its already highest point. With small band EQ you can get a flat response down to 35Hz within a small package and using the Ande LB15-1 driver. That is not possible with the same driver in a basreflex. The compromise is a lower sensitivity and lower max SPL.
Example: 94dB 1W/1m (2,83V - 96dB)
Edit: This example is probably too small to fit that driver...
When you design a TH with its Excursion dip below the 40Hz you can easily make up for the roll off. The make up will not cause extra excursion above its already highest point. With small band EQ you can get a flat response down to 35Hz within a small package and using the Ande LB15-1 driver. That is not possible with the same driver in a basreflex. The compromise is a lower sensitivity and lower max SPL.
Example: 94dB 1W/1m (2,83V - 96dB)
Edit: This example is probably too small to fit that driver...
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i might get it done when L4-5 is longer.
reminence,would you like me to design something for you from djims last example?
From the three designs simulated: If you want decent output below 40 Hz my choice would be the Martinson Tham 15. Both the Cubo 15 and SS15 do not have that 35 Hz extension the Tham 15 does.
Also + 1 on a 18" in a reflex.
This simulation of Cubo 15 Standard is pretty accurate: http://www.diyaudio.com/forums/subw...sound-tapped-horn-35-80hz-10.html#post2830678
Cubo 15 Extended was created, to take 1 dB from the peak before low roll off and add it to dip centered at 80 - 90 Hz. It does so by extending the horn path in exchange for chamber volume.
Best regards Johan
Also + 1 on a 18" in a reflex.
This simulation of Cubo 15 Standard is pretty accurate: http://www.diyaudio.com/forums/subw...sound-tapped-horn-35-80hz-10.html#post2830678
Cubo 15 Extended was created, to take 1 dB from the peak before low roll off and add it to dip centered at 80 - 90 Hz. It does so by extending the horn path in exchange for chamber volume.
I presume you have measurements (of both) to substantiate your claim?
Best regards Johan
Although I do think the THAM is a little underrated around here, for 'high power' PA use you should filter it below 37Hz.
I don't, why?
Impendance might be interesting in the future to minimize cabinet vibrations beyond human sensing.
Best regards Johan
Impendance might be interesting in the future to minimize cabinet vibrations beyond human sensing.
Best regards Johan
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Because both graphs can give valuable information and can't be corrected by 19" gear.
(Panel vibrations can be measured by industrial contact mics, love these things)
(Panel vibrations can be measured by industrial contact mics, love these things)
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I'd be interested to hear what kind of valuable information? Other then the plain obvious.
How much would a contact mic cost? And the aided software if necessarly.
Do you base the Tham 15 high pass settings on the frequency response or do you involve other information as well?
Best regards Johan
How much would a contact mic cost? And the aided software if necessarly.
Do you base the Tham 15 high pass settings on the frequency response or do you involve other information as well?
Best regards Johan
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Besides the usual interpretations you can also see the relation between the direct and indirect signals coming from a TH at different frequencies with different impulse responses. The impedance plot comes in handy to evaluate the software model for instance.
Normally I prefer to use reverse engineering, by using the actual drawings of a cab, to improve a HornResp model. If it is a ‘standard’ TH concept with no compression chambers/mouth you often can use the 1/4WL as cut off point. For the THAM we found the Fo exactly as predicted.
Industrial contact mics can be very expensive if they are certificated but occasionally they do show up in "Marktplaats" for reasonable prices. I have seen one selling (completely boxed) for 120 Euro’s a couple of month ago. But you also can use a homemade version with a piezo element for this kind of work.
Normally I prefer to use reverse engineering, by using the actual drawings of a cab, to improve a HornResp model. If it is a ‘standard’ TH concept with no compression chambers/mouth you often can use the 1/4WL as cut off point. For the THAM we found the Fo exactly as predicted.
Industrial contact mics can be very expensive if they are certificated but occasionally they do show up in "Marktplaats" for reasonable prices. I have seen one selling (completely boxed) for 120 Euro’s a couple of month ago. But you also can use a homemade version with a piezo element for this kind of work.
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Hi,
Piezo pickups: the old stand-by is DiMarzio's:DiMarzio Acoustic Model For Acoustic Guitar and Bass and more Guitar Pickups & Parts at GuitarCenter.com., and a cheap alternative is AXL's: http://www.amazon.com/AXL-Acoustic-Guitar-Transducer-Pickup/dp/B002C741B8
Regards,
Piezo pickups: the old stand-by is DiMarzio's:DiMarzio Acoustic Model For Acoustic Guitar and Bass and more Guitar Pickups & Parts at GuitarCenter.com., and a cheap alternative is AXL's: http://www.amazon.com/AXL-Acoustic-Guitar-Transducer-Pickup/dp/B002C741B8
Regards,
Nice find Oliver. Another tip, if you have access to a Canon 600D digital camera you can use its 60 frames per second filming capability to capture cone movement and resonances within the cone.
The plots I have seen are with the low cutoff dropping off at 45hz :S and if there is a design that does do 35hz at cutoff and is still under 30kg and a driver available in Australian that works then its a clear winner. If not then the search continues...
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Or i just build a home theater tapped horn for down to 20hz and build some much larger heavyer pro sound subs later when i have more transport space.
All loudspeaker "does 35Hz", whats interesting is at whitch amplitude.
Small horn that goes low does not play loud.
Use Hornresp to check how different TH adds up in multiples, and how the sensitivity relates to size.
Dag
I get that all speakers will do 35hz but flat to 35hz or having the rolloff point at 35hz is another thing.
I have come to the conclusion that the ss15 is the lowest I can go within my requirements and still be loud. Since I was hoping to use it as a home theater enclosure as well or in my studio the 40-45hz rolloff point makes it not very useful n that environment for me at all.
considering all this I have decided to separate the two and do each properly, ie a full size heavy PA tapped horn to 30hz (in the future) and a not so loud home theater studio tapped horn tuned as low as space permits (using aus ande drivers). I have started a thread for the latter here http://www.diyaudio.com/forums/subw...ped-horn-studio-ande-drivers.html#post2847682 as I will be tackling that first.
Thanks for all the help everyone,
If anything i look back at my proposal as being silly, trying to have a one speaker that fits all would mean way too many compromises than 2 dedicated designs.
I have come to the conclusion that the ss15 is the lowest I can go within my requirements and still be loud. Since I was hoping to use it as a home theater enclosure as well or in my studio the 40-45hz rolloff point makes it not very useful n that environment for me at all.
considering all this I have decided to separate the two and do each properly, ie a full size heavy PA tapped horn to 30hz (in the future) and a not so loud home theater studio tapped horn tuned as low as space permits (using aus ande drivers). I have started a thread for the latter here http://www.diyaudio.com/forums/subw...ped-horn-studio-ande-drivers.html#post2847682 as I will be tackling that first.
Thanks for all the help everyone,
If anything i look back at my proposal as being silly, trying to have a one speaker that fits all would mean way too many compromises than 2 dedicated designs.
good man. Right tool for the right job.
My friend lilmike's TH would be a good starting place, maybe see if there are some 8" or 10" ande drivers that sim well in hornresp.
Reed Exodus Anarchy 25hz Tapped Horn - AVS Forum
Those plans look awesome and smaller than I thought i needed, which is good. I cant get hold of hornresp atm (links down) but the smaller ande drivers are apparently not that great for TH. Though I am happy to build a 10" driver design.
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