Answering my own question from a google it would appear that its an out of context plot from Martin Colloms book 'high performance loudspeakers'. Not read the book so have to take the internets word that its the average room gain for a std 11x14 room. As a rule of thumb that would work.
sure you have worked out that sealed boxes roll off at 12dB/octave and ported at 24...
sure you have worked out that sealed boxes roll off at 12dB/octave and ported at 24...
am i reading it correctly that the "rule of thumb"graph of room gain is aprox 2db/octave? (i don't understand that thing yet, just read that octave is half of frequency, 50-100hz is an octave, 25 -50hz is etc? if yes, for example Modding Project:Subwoofer by MetkuMods - Because you love your hardware! sealed doesn't seem to roll off 12db either from 100 to 50 or from 50 to 25)
it's close 20Hz=93 40Hz=103. Note the Q in the calculation (.638), which will reduce the slope, so to my eye it's believable.
It's a useful comparison for you before you start simulating.
I lived for a couple of years in chicago. Whilst there I borrowed a carver sunfire sub. crazy thing. SWMBO of the time banned the purchase as it rattled the fireplace on the floor above. Glass fronted fireplaces and deep bass do not go together!
It's a useful comparison for you before you start simulating.
I lived for a couple of years in chicago. Whilst there I borrowed a carver sunfire sub. crazy thing. SWMBO of the time banned the purchase as it rattled the fireplace on the floor above. Glass fronted fireplaces and deep bass do not go together!
i've been looking on putting for example ultimax 15 into 50l box. With linkwitz transform to 40hz and qts 0,8. it plays pretty simmilar from 20-30, but the main difference is 30-60 where most music bass is.
Is it a bad idea to put ultimax 15 (green) into 50l box, then equalize 30+hz -6db, to get effect simmilar to seas (grey), for movies, to get flatish with that "rule of thumb room gain" to 20ty, and turn equalization off, if i would like to take sub to an occasional miniparty and have higher spls at 30-50hz?
Maybe a different solution of putting larger driver to smaller box for this purpose?
Does it bring any other problems - putting larger sub in to much smaller box it is designed for?
How is linkwitz transform financially and skill wise to apply?
An externally hosted image should be here but it was not working when we last tested it.
Is it a bad idea to put ultimax 15 (green) into 50l box, then equalize 30+hz -6db, to get effect simmilar to seas (grey), for movies, to get flatish with that "rule of thumb room gain" to 20ty, and turn equalization off, if i would like to take sub to an occasional miniparty and have higher spls at 30-50hz?
Maybe a different solution of putting larger driver to smaller box for this purpose?
Does it bring any other problems - putting larger sub in to much smaller box it is designed for?
How is linkwitz transform financially and skill wise to apply?
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Am i doing something wrong? I get really similar results with stx and seas l26roy both at ~300w at cone excursion limits, both vented 22hz 50l box. Seas is 2x more expensive driver with almost 2x weight so i would expect greater difference. In this case i would consider stx even better, where is my fault?
Also if someone could reply to my previous post about ultimax15 in 50l cab, if it is fine with aplication i described, what problems it could bring? Box has qts over 1, linkwitz is set to final 0.7. I really dont understand linkwitz very much, how hard is it to implement technically and financially?
An externally hosted image should be here but it was not working when we last tested it.
Also if someone could reply to my previous post about ultimax15 in 50l cab, if it is fine with aplication i described, what problems it could bring? Box has qts over 1, linkwitz is set to final 0.7. I really dont understand linkwitz very much, how hard is it to implement technically and financially?
I believe that you would be much better off with at least 3 ft.^3 rather than the 1-3/4 ft.^3 box that you are proposing.
Maybe even 4 to 5 ft.^3.
IMO of course.
Dave
I know i would be better in much larger enclosure (but for now decided to go up to 50-60L) and that i don't get what i could from that driver, but from graph i posted i still can get ~same in 20-30hz range (compared to 10" driver), but more 30hz up. I am worried what other problem brings of putting larger woofer in small cab.
No fault : stx is 35mm voicecoil. L26Roy is 56mm voicecoil. So STX have a more easily "concentrated" magnet. That mean it take less volume, less weight. Maybe higher flux magnet. And moreover, the seas has a metal basket, whereas the STX is in aluminium...
Looking at photos, you can easily see the huge magnet of the SEAS. I suspect that SEAS to be more linear with excursion than the STX, but that's no sure.
I've not tested the STX yet into enclosure to verify if it (suspension) is noisy at low frequency. That can be a big problem. I've not yet finished it cab to review it.
Any comments on this?
also another question, is it possible to somehow power subwoofer from av receiver? I have yamaha rxv1900 whoch is 7x 190w, but i only ise 2 stereo channels, is it somehow possible to cheaply bridge and equalize properly other 190w amps to power a sub?
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