So my living room is 11x18 or so. I’ll measure proper when I get home. Listening position is facing a fireplace centered on one of the narrow walls. About 3 feet from that wall on the left is a 3-1/2 to 4 foot opening to another room, which used to be about 8 feet, but has built in bookshelves/cabinets either side. To the right is a large window spanning 2/3 of the wall. Behind is a wall with an opening about 3 feet wide, and behind that a hallway. Ceiling is 8’ tall.
I’ve been planning for some time to build a line array set a-la Roger russel to go at the front of the room. Corner array isn’t going to work, given there isn’t really a free corner due to a window in the corner of the end wall. I know these won’t go low enough for movies, regardless of what I do, so I’ve been thinking the last week or three about subwoofers. I’ve read many things, about three being better than one, etc, etc.
What I’m wondering is how low of these really need to go, what kind of SPL? I don’t want my house to rattle, but I do want to get a little more immersive for films and occasional TV watching. Normal listening level for me is 85-90db max. When things are loud. That’s measured with an iPhone app from middle of the room, but hopefully gives a decent idea of how loud I get the mains. I have plebty of amp to drive anything reasonable, and can acquire another 2-400W in stereo for $100 or so.
I’ve found drivers I can build into 1cu ft cabinets that would be $50 or so, and get me up around 100db for one. With f3 of about 30 hz or a little lower. Getting more than 103-105 at that level, and it seems I’d be smarter just to buy something for $200 like those Klipsch units at circuit city for $200. seems hard to push the sound levels at low frequency much past 105 or so without getting big cabinets or pricey drivers.
So I’m wondering how much i really need as sound reinforcement, not so much as teeth rattlers.
I’ve been planning for some time to build a line array set a-la Roger russel to go at the front of the room. Corner array isn’t going to work, given there isn’t really a free corner due to a window in the corner of the end wall. I know these won’t go low enough for movies, regardless of what I do, so I’ve been thinking the last week or three about subwoofers. I’ve read many things, about three being better than one, etc, etc.
What I’m wondering is how low of these really need to go, what kind of SPL? I don’t want my house to rattle, but I do want to get a little more immersive for films and occasional TV watching. Normal listening level for me is 85-90db max. When things are loud. That’s measured with an iPhone app from middle of the room, but hopefully gives a decent idea of how loud I get the mains. I have plebty of amp to drive anything reasonable, and can acquire another 2-400W in stereo for $100 or so.
I’ve found drivers I can build into 1cu ft cabinets that would be $50 or so, and get me up around 100db for one. With f3 of about 30 hz or a little lower. Getting more than 103-105 at that level, and it seems I’d be smarter just to buy something for $200 like those Klipsch units at circuit city for $200. seems hard to push the sound levels at low frequency much past 105 or so without getting big cabinets or pricey drivers.
So I’m wondering how much i really need as sound reinforcement, not so much as teeth rattlers.
~1128.6/2/18 = ~31.35 Hz before any room gain and will be lossy if a real fireplace, so assume only room boundary gain available.
Re how low, powerful, browse this for the movies you have/want to see if they have any significant <20 Hz output @ 'x' dB as a reference: The Ultimate List of BASS in Movies w/ Frequency Charts | AVS Forum
GM
Re how low, powerful, browse this for the movies you have/want to see if they have any significant <20 Hz output @ 'x' dB as a reference: The Ultimate List of BASS in Movies w/ Frequency Charts | AVS Forum
GM
I've had luck with ported at f3 of 27hz, subsonic below that.
But still wanting to try f3 of 31hz sealed qtc .707 (2 x 15") .
But still wanting to try f3 of 31hz sealed qtc .707 (2 x 15") .
Enough! 😀
Whatever you need or want, mix in a bit of economy and a dash of space restrictions. Sprinkle with DSP and suitable amplifier, enjoy!
You probably need less power than you think. I started out running my two subs from amps in the 200 to 400 wpc range, but for reasons I don't remember (tired of fan noise? needed the amp for a party?), I hooked the subs to a modest amp of less than 40 watts/channel. And that was more than enough to make bass I could feel. The subs in question were one NHT1259 in a sealed box of about 2.9 cubic feet, one Servodrive Contrabass (DIY). Note that I set my sub levels correctly using a sound level meter; when I'd set levels by ear, it was tempting to run them at least 10 dB too loud, which demanded 10 times the amp power. So, my advice is to get the best driver(s) you can afford, put them in sealed boxes (because sealed means better transient response, slower rolloff, less sensitivity to driver variations, easier construction) and use whatever amplifier you can lay your hands on (at least to start with). Enjoy the much improved bass, but keep an eye out for a good deal on a used pro or "mid fi" power amp with a few hundred watts/channel. Which you may not actually need, but could be fun to have for those times you show the system off to visitors by playing a few demo clips and need the air to shake.
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I recently snagged a pair of crown ct-410 amps for a song, so should have plenty of power. I Was planning to use one for my main speakers, and one for the sub(s) when I bought them. They get loud a lot cleaner than my poor old marantz receiver did with its 20wpc.
I read somewhere today that 95db is plenty to make the house start shaking. I figure at this point that one that goes up to 100db at close enough to the frequency where room response kicks in and I’ll be in good shape for now. Thinking about two smaller boxes to go with the main speakers, and one more eventually to flesh out the room.
I read somewhere today that 95db is plenty to make the house start shaking. I figure at this point that one that goes up to 100db at close enough to the frequency where room response kicks in and I’ll be in good shape for now. Thinking about two smaller boxes to go with the main speakers, and one more eventually to flesh out the room.
Attached is an approximate floor plan. the room is bigger than I thought. how does this work with the room gain? 2x the longest distance is the frequency where it starts? so if we're just counting this room at 20', I'm looking at room gain from about 28Hz? but if we count the room to the left, it's 24' x 2, and 23Hz, but to the back I have the other big opening and hallway that extends about 15' from the center of the opening until it's end, so 35' x 2 for 16 hz?
I'm listening to some music playing in the living room at moderate volume from a room at the end of the hallway, and it's kind of amazing how much the lowest frequencies are bumped up at this location compared to where I normally sit in the living room.
Given all of this messy floor plan, I'm probably going to get best sound in room from some kind of DSP, but to get closer to where I need to be, what would be a good lowest frequency for me to make the sub roughly flat to? I'm planning for the first one to be a 4th order band pass box, since it seems easy to keep the drivers safe from over-excursion by limiting input power, and designing for enough diver/box to get the dB that I need.
I'm considering the fireplace as location, or two near the main speakers. Also considering building a chair/sofa with sub inside/underneath, so I can get a bigger cabinet without taking up space needlessly. "coffee table" sub box is another option, but using furniture, it seems like I'd have less good options to place things. Another option, since I own the place, would be to put some boxes in the ceiling, but the attic gets mighty hot in the summer, and again, a pain to move things, if the location doesn't work out sound-wise.
I'm listening to some music playing in the living room at moderate volume from a room at the end of the hallway, and it's kind of amazing how much the lowest frequencies are bumped up at this location compared to where I normally sit in the living room.
Given all of this messy floor plan, I'm probably going to get best sound in room from some kind of DSP, but to get closer to where I need to be, what would be a good lowest frequency for me to make the sub roughly flat to? I'm planning for the first one to be a 4th order band pass box, since it seems easy to keep the drivers safe from over-excursion by limiting input power, and designing for enough diver/box to get the dB that I need.
I'm considering the fireplace as location, or two near the main speakers. Also considering building a chair/sofa with sub inside/underneath, so I can get a bigger cabinet without taking up space needlessly. "coffee table" sub box is another option, but using furniture, it seems like I'd have less good options to place things. Another option, since I own the place, would be to put some boxes in the ceiling, but the attic gets mighty hot in the summer, and again, a pain to move things, if the location doesn't work out sound-wise.
Attachments
So I’m currently thinking I need to design for between 23-28 for the F3, and let the room handle the stuff below that, or do I need to go deeper if I want to reach down to hear the bottom at 20Hz? Looking for clean, but full sound more than boom and rattling.
And if I want clean, how much headroom between x-max on most speakers before distortion gets ugly? Say I have a speaker in a box that makes power to 109db before it hits x-max at f3 of 26hz, I’m guessing that I really only get maybe 105 dB of “clean”, low distortion sound from the speaker? Or is X-Max usually quoted as the maximum excursion before undesirable distortion levels set in?
Decent subs will have 10% (or less) distortion at X-max, and would be judged by most as "clean" at that level.
With your normal listening level of 85-90db max, a pair of the 1cu ft cabinets you suggested in the OP will probably be enough.
I did some consulting for a recording studio with a similar floor plan and speaker location as yours, the clients sitting about where your LP is complained of lack of kick and bass, which was easily verified with a quick test.
The 11' wide room to the left of your speakers may cause a null at the LP, be prepared to move subs to a different location than the fireplace or close that room off. In the recording studio, we rolled a gobo in front of the opening, partially closing the secondary room smoothed out the main room considerably, and made a huge difference at the "client couch".
With your normal listening level of 85-90db max, a pair of the 1cu ft cabinets you suggested in the OP will probably be enough.
I did some consulting for a recording studio with a similar floor plan and speaker location as yours, the clients sitting about where your LP is complained of lack of kick and bass, which was easily verified with a quick test.
The 11' wide room to the left of your speakers may cause a null at the LP, be prepared to move subs to a different location than the fireplace or close that room off. In the recording studio, we rolled a gobo in front of the opening, partially closing the secondary room smoothed out the main room considerably, and made a huge difference at the "client couch".
Somewhere there are doors for that room, but they’re sad hollow core doors. Either side of the opening it is built in shelves maybe 1/2” or 1/4” ply between them? I haven’t investigated deep enough to see. And above is about a 1’ opening to that room, so even with doors, it’s not really closed.
Would I do better to put a sub at the listening position instead of two up front? I know the old adage is that you can never have too many subwoofers, but I’ve got to start somewhere 😉
Is the hallway behind the room going to present problems? I can work out doors for that space much easier than trying to close the space to the left.
Also wondering how low they need to go to capture the deepest notes without overkill room boost. I suppose one way to find out is to build a closed box and boost the low end with eq, but hoping someone has more experience guestimating such things than I do. Not looking for perfection to start, though it wouldn’t hurt, but I’d like to start with more informed guessing than to rely on pure luck.
Would I do better to put a sub at the listening position instead of two up front? I know the old adage is that you can never have too many subwoofers, but I’ve got to start somewhere 😉
Is the hallway behind the room going to present problems? I can work out doors for that space much easier than trying to close the space to the left.
Also wondering how low they need to go to capture the deepest notes without overkill room boost. I suppose one way to find out is to build a closed box and boost the low end with eq, but hoping someone has more experience guestimating such things than I do. Not looking for perfection to start, though it wouldn’t hurt, but I’d like to start with more informed guessing than to rely on pure luck.
You can answer all your questions by testing the response of your present speakers in various positions. Subs will give you more output, but the room modal distribution won't change.
The answer to your question lies in your expectations. Being a lopsided space, if you get the listening position response to keep up with the highs at 25 to 30 hz, you'll be rattling things not so nearby. Bass travels MUCH further than voices. Be careful what you wish for.
This situation gets worse, not better, if you put subs right next to you. Experiment around the space with a test sub with decent response, then figure out how much more volume you need with the sub in that spot.
This situation gets worse, not better, if you put subs right next to you. Experiment around the space with a test sub with decent response, then figure out how much more volume you need with the sub in that spot.
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So subs nearby the listening position make higher spl elsewhere in the room than they do at the listening position?
Depends on the space. In many spaces, with the subwoofer close to the listening position, listeners feel the sound better than they hear it. With the bass source further away, the surround sound blends in with the low frequency content more seamlessly.
Another easy test to do is to place a test speaker at the listening position and then crawl around the room while playing test tones to find areas where the spl tops out. Placing the speaker in a peak zone will induce the same peak behavior at the listening position.
Another easy test to do is to place a test speaker at the listening position and then crawl around the room while playing test tones to find areas where the spl tops out. Placing the speaker in a peak zone will induce the same peak behavior at the listening position.
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