Hi everyone,
planning on building a large (ish) sub for HT / Music 50/50 mix.
I think I have settled on the Dayton HF15" driver in a 150 - 200 litre enclosure with a Dayton 15" passive radiator. want a low distortion driver to compliment my Kef LS50's. I have an anthem AVR with ARC room correction and will be powering the sub from most likely an Inuke DSP for added tweaking capability.
I have done some modelling in WIN ISD and obviously it tells me everything I need to know really. but the question is. how do I know if I'm going to be happy with the output? just because it says it will do 108DB at 20hz?
also, on the model it does drop off quickly after 20hz. xmax on both passive and driver is at 18hz. Do I need lower than that or not?
so i'm relying on you guys to help by giving you some information of what I have heard sub wise in my room. and how much of an improvement I'm likely to see.
room size = 5.5m x 5m
1st sub = ported mordaunt short 10 inch crappy thing
2nd sub = rel Q200E (great quality. sub 30 hz not great)
3rd sub = SVS SB12+ (bit better output, slightly less quality me thinks? not a worth it upgrade over the REL)
I have heard my mates arendal Sub1. that's got some kick. his room is the same as mine but mine is concrete floors and his is upstairs so wood. so you can feel it more.
so...will it be miles better than what I have. Will it be as good as a Sub 1 or even as good as a PB13 Ultra??
any help appreciated
planning on building a large (ish) sub for HT / Music 50/50 mix.
I think I have settled on the Dayton HF15" driver in a 150 - 200 litre enclosure with a Dayton 15" passive radiator. want a low distortion driver to compliment my Kef LS50's. I have an anthem AVR with ARC room correction and will be powering the sub from most likely an Inuke DSP for added tweaking capability.
I have done some modelling in WIN ISD and obviously it tells me everything I need to know really. but the question is. how do I know if I'm going to be happy with the output? just because it says it will do 108DB at 20hz?
also, on the model it does drop off quickly after 20hz. xmax on both passive and driver is at 18hz. Do I need lower than that or not?
so i'm relying on you guys to help by giving you some information of what I have heard sub wise in my room. and how much of an improvement I'm likely to see.
room size = 5.5m x 5m
1st sub = ported mordaunt short 10 inch crappy thing
2nd sub = rel Q200E (great quality. sub 30 hz not great)
3rd sub = SVS SB12+ (bit better output, slightly less quality me thinks? not a worth it upgrade over the REL)
I have heard my mates arendal Sub1. that's got some kick. his room is the same as mine but mine is concrete floors and his is upstairs so wood. so you can feel it more.
so...will it be miles better than what I have. Will it be as good as a Sub 1 or even as good as a PB13 Ultra??
any help appreciated
For one, you'll need dual [opposed] 15" PRs to go infrasonic without worrying about bottoming out.
HT nowadays ideally need a large, multi-driver IB since there's output down into the single digits on an increasing number of movies, so considering the PR's spike below tuning, a good idea to tune this driver down around 14 Hz for best overall performance and let room/boundary gain help it a bit, especially since high SQ is desired, though may not be up to REL or the sealed sub1's SQ:
The Low Frequency Content Thread (films, games, music, etc) - Bass Content - Data-Bass Forums
The Ultimate List of BASS in Movies w/ Frequency Charts - AVS Forum | Home Theater Discussions And Reviews
GM
HT nowadays ideally need a large, multi-driver IB since there's output down into the single digits on an increasing number of movies, so considering the PR's spike below tuning, a good idea to tune this driver down around 14 Hz for best overall performance and let room/boundary gain help it a bit, especially since high SQ is desired, though may not be up to REL or the sealed sub1's SQ:
The Low Frequency Content Thread (films, games, music, etc) - Bass Content - Data-Bass Forums
The Ultimate List of BASS in Movies w/ Frequency Charts - AVS Forum | Home Theater Discussions And Reviews
GM
Thanks for the reply. I can now see that If one wants the very best, 20hz isn't good enough. But what im trying to do is figure out what would be good enough for me. For instance. I know my sb12+ Doesn't have the output im after. I also know that I really like the sub1 but I can tell that it isn't the last word in output either. Although a lot better than mine.
Considering the sub1 has a single 13.8inch driver and a sealed enclosure. One could imagine a hf15 with a 15inch passive radiator should have substantially more output below 30hz.
The thing is, I dont actually know what 110db at 20hz and 106db at 16hz sounds like....i also know that the lower the frequency, the louder it has to be to hear it/feel it.
So I have no clue if 110db at 20hz is enough. And I didn't know until you posted that film went as low as they did. Since I can't have 2 in my room and don't want something the size of the earth. (Like I say 150 to 200 litres is about right) what is my best option.
I imagine you can't even here down past 15hz and to feel it one would require a seriously large / multiple subs.
How low do you need to go for it to be enough.?
Considering the sub1 has a single 13.8inch driver and a sealed enclosure. One could imagine a hf15 with a 15inch passive radiator should have substantially more output below 30hz.
The thing is, I dont actually know what 110db at 20hz and 106db at 16hz sounds like....i also know that the lower the frequency, the louder it has to be to hear it/feel it.
So I have no clue if 110db at 20hz is enough. And I didn't know until you posted that film went as low as they did. Since I can't have 2 in my room and don't want something the size of the earth. (Like I say 150 to 200 litres is about right) what is my best option.
I imagine you can't even here down past 15hz and to feel it one would require a seriously large / multiple subs.
How low do you need to go for it to be enough.?
THX cinema specs is 105 dB peak for each channel and 115 dB peak/20 Hz/listening position, so a bit louder at a typical 1 m spec. This also means that if speakers are set to 'small', then the sub system has to make up the difference and IIRC this puts it nearly 122 dB/listening position.
Of course few folks will tolerate this at home, so these numbers are typically dropped 10 dB, but still plenty loud, which led to yet another new reference for apts., etc., further dropping it, but don't remember it.
Regardless, if you can actually hear 16 Hz, then the rest will be at least as loud as an action feature at an IMAX, which is way too loud for most at home, so the usual goal is to let the < ~32 Hz BW be just rumbles, vibration that adds more 'fullness' to the soundtrack rather than actually hearing them.
I once had a loud enough system and the U571 movie's depth charges literally 'brought down the house', raining sheetrock ceiling and all the blown in insulation, storage boxes down on us and cracking apart one of the suspended floor's concrete block support pillars, causing one of the several hundred lbs, dual 15"/20 ft^3 subs to 'sink'.
Nearly a decade later it's still not all fixed, so be forewarned if you don't have a concrete slab floor, masonry walls, massive overhead joists, etc., and later decide to get serious about SOTA HT sub bass systems.
In short, the -10 dB reference will probably suffice, but if the budget allows, do reference, so everything is less stressed and/or if you want to do a bit of LF EQ to enhance some [typically older] movies that seem a bit lacking in mid-bass boom/punch.
GM
Of course few folks will tolerate this at home, so these numbers are typically dropped 10 dB, but still plenty loud, which led to yet another new reference for apts., etc., further dropping it, but don't remember it.
Regardless, if you can actually hear 16 Hz, then the rest will be at least as loud as an action feature at an IMAX, which is way too loud for most at home, so the usual goal is to let the < ~32 Hz BW be just rumbles, vibration that adds more 'fullness' to the soundtrack rather than actually hearing them.
I once had a loud enough system and the U571 movie's depth charges literally 'brought down the house', raining sheetrock ceiling and all the blown in insulation, storage boxes down on us and cracking apart one of the suspended floor's concrete block support pillars, causing one of the several hundred lbs, dual 15"/20 ft^3 subs to 'sink'.
Nearly a decade later it's still not all fixed, so be forewarned if you don't have a concrete slab floor, masonry walls, massive overhead joists, etc., and later decide to get serious about SOTA HT sub bass systems.
In short, the -10 dB reference will probably suffice, but if the budget allows, do reference, so everything is less stressed and/or if you want to do a bit of LF EQ to enhance some [typically older] movies that seem a bit lacking in mid-bass boom/punch.
GM
that is a big LOL. luckily for me, I live in an old house. concrete floors, brick walls. don't think I will be bringing the house down anyway with what i'm planning. its difficult to know if you are going to be satisfied or not. I actually want to feel the bass instead of just hearing it. but I only have around 150litre of box size to work with. sat around 3m away from sub I have thought about going with an 18" Ultimax Passive radiator design instead but didn't want to compromise SQ that the HF driver is known for. I have heard that the difference is minimal though SQ wise between the HF and the ultimax???
anyone have at opinions on that??
P.S thanks for the replys so far and sorry for the late reply. been working away
anyone have at opinions on that??
P.S thanks for the replys so far and sorry for the late reply. been working away
Hmm, assuming the sub will be XO'd at an HT's 80 Hz/4th order and the driver's Qts is = or < 0.5, then SQ will be about the cab alignment's acoustic blend with the room's acoustics, so considering that there's 'no replacement for displacement' when replicating WLs > ~13560"-sec/pi/80 Hz = ~54" dia. and still half this at the XO's -24 dB upper cutoff, BIB [bigger is better] rules!
You sure you're limited to only 150 L? I mean subs can be a very high aspect ratio to stand up in corners, lay down to create a mains/TV/whatever pedestal or listening position [LP] riser platform or flipped up to be between it and a wall, etc..
GM
You sure you're limited to only 150 L? I mean subs can be a very high aspect ratio to stand up in corners, lay down to create a mains/TV/whatever pedestal or listening position [LP] riser platform or flipped up to be between it and a wall, etc..
GM
Just a suggestion... Have you entertained a bandpass sub using a PR? You get the 12dB sealed lower rolloff, no port noise, a steeper topend rolloff, well controlled Xmax, and a fairly compact box. For example, an 8" Ultimax and a 12" PR in only 26 ltrs. I bet a 12" Ultimax and 15" PR would be monstrous. You get the tautness of a sealed box, output of an RS PR, and the heart of an Ultimax.
Wolf
Wolf
I haven't considered that at all. Thanks for the suggestion. Thus does sound what I'm after but I'm not sure how to design this. And build it. I will be e to do some reading on bandpass designs and how to implement a passive at the same time. How could you mod this in software?. I use winisd. But have access to whatever I want really.
Also. Would the sq be the same if it rolls off qui k in the high end say. Easy to get it blending with the mains? Which cross at 80 at the moment. Due to the massi e riom gain i have at 40 to 60hz.
Also. Would the sq be the same if it rolls off qui k in the high end say. Easy to get it blending with the mains? Which cross at 80 at the moment. Due to the massi e riom gain i have at 40 to 60hz.
Unibox (Unified Box Modeler, an Excel based sheet) can do it, but in a different process. You model the sealed box first. This gives you the basis for the sealed portion of the bandpass. Then model the bandpass. This gives you the response and the Xmax of the bandpass for linearity; use the PR diameter for port diameter for now. Then model the PR box of the same volume as the vented box from the bandpass with the specs of both the driver and PR to check Xmax and tuning mass required to achieve the tuning. This PR model is to check the PR Xmax. The active driver in the sealed box will not respond as pictured here.
Oh- and I went ahead and did this just for kicks...
UM12-22/RSS390PR combo in 75ltr/20ltr, and the PR tuned to 45Hz. I just make the vented/PR portion cross-section that of the cutout diameter. I did draw it up and everything fits, but I don't think I saved the drawing.
F3s are 32Hz/46Hz, and F10 low is 20Hz, and with 500W input, peak output is good to about 112dB. Xmax is not breached with either driver/PR at this output level.
I usually use an impedance measurement to verify the mass as modeled equates to the correct tuning, but I normally have to remove some of the mass to arrive at tuning.
Being the upper F3 is 46Hz and 24dB/octave slope without any filtering, you won't excite your room resonance more, and added electronic lowpass filtering only adds to the slope. You can easily get 6th/8th order if the LP is 2nd or 4th order.
Let me know if you want more info...
Wolf
Oh- and I went ahead and did this just for kicks...
UM12-22/RSS390PR combo in 75ltr/20ltr, and the PR tuned to 45Hz. I just make the vented/PR portion cross-section that of the cutout diameter. I did draw it up and everything fits, but I don't think I saved the drawing.
F3s are 32Hz/46Hz, and F10 low is 20Hz, and with 500W input, peak output is good to about 112dB. Xmax is not breached with either driver/PR at this output level.
I usually use an impedance measurement to verify the mass as modeled equates to the correct tuning, but I normally have to remove some of the mass to arrive at tuning.
Being the upper F3 is 46Hz and 24dB/octave slope without any filtering, you won't excite your room resonance more, and added electronic lowpass filtering only adds to the slope. You can easily get 6th/8th order if the LP is 2nd or 4th order.
Let me know if you want more info...
Wolf
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