austi15
Super Member
The Backstory
About 4 years ago I was eager to get out of my parents house, but high rents in the area meant an apartment would be small in an unsavory place and saving money out of the question. I knew how to build a shed, had access to a very good electrician interested in tiny houses with great rates (Thanks Matt!) and I had about $7000 to work with for housing along with two possible places to put a small building for virtually no rent at all, both with access to nearby bathrooms to save on initial build costs. I figured if I built it to supercede code, left plumbing out and hired a great electrician to install quality wiring to code I at least wouldn't die. The number one objective was making a small space that supported multiple systems and wasn't a reflection nightmare.
The Space
I knew I wanted to design the building with acoustics in mind. The footprint was my only constraint, at 12x16, so I opted for an 8 foot ceiling on one 16 foot wall and a 10 foot on the other. The building needed to be sturdy enough to move later, so I used 16" OC 2x6 construction with tripled 2x6s in each corner as well as the middle of the 16 foot walls, with doubled 2x6s between them and asymmetric bracing between each studs to keep any common resonances of the cavities at bay. The floor is double 3/4" ply on 2x12s with asymmetric bracing and green glue company acoustic tape between the plywood and lumber, more for softer footfalls than acoustics but I like to think it helps a little. The ceiling is 24" OC 2x8s except for the middle joist over the central triple 2x6s, which is a beam made of 2 2x6s 3.5" apart with two 12 foot 2x4s between them, glued and riddled with long deck screws in case the building twists during transport. For moving this provides a mounting point for diagonal beams to keep the hardiepanel from cracking as the building weighs a great deal. The roof is 3/4" ply with 100% ice & water shield coverage under 30 year shingles. The exterior is hardiepanel cement board over 1/2" ply with tyvek vapor barrier and a pretty grey semigloss with a hint of violet that brings out all the seasons. The trim is 3/4" thick PVC glued and secured with stainless screws. All exterior hardware is stainless. Insulation is stone wool throughout, soon to be stone wool under mellotone grill cloth, when mellotone has a sale (or wants to offer distributor price for my obscene order in return for free advertising in an untapped market XD). The wall behind the speakers is closest to the nearest occupied dwelling, so I used two layers of 1/2" drywall with green glue in between to keep the wall from turning into a giant sd, low xmax passive radiator. That was my compromise vs no drywall at all. I realized that absent wall paneling the stone wool would do next to nothing for bass control, so I settled for sealing the building entirely to at least not port the thing. I bought a ton of silicone caulk. So much that my biggest regret in the entire project is not simply buying a 5 gallon bucket of the stuff. One day future people will be excavating the area and suspect a cult that worshipped silicone lived there. It's sealed inside, outside, along the paneling, EVERYWHERE. I got a bit crazy at one point with a headlamp, a ladder and no shirt applying caulk into the night. The door is a steel slab with CLD tiles with a touchscreen deadbolt and triple hinges. It presses against a 360 degree seal mounted on 3/4" thick 1x4" PVC trim in a 2x8 frame with extensive bracing and lateral buttressing. The 2x8 frame is adjusted via 24 1/2" diameter threaded stainless rods that pass through the buttressed double 2x6s around them into divots in the 2x8s with nuts to tilt it side to side if needed. Even if the building twists a little in transit, wide silicone seals and the adjustable doorframe make it more likely to survive without damage. The deadbolt passes through a 4x10" 1/4" thick stainless plate mortised in the 2x8 and attached with 4.5" GRK fasteners to the assembly. The seal was so good that with my initial AC unit, an indoor portable 7k btu LG which sucks air out of the room the door would resist 20-30lb of pressure to force open and emit a tundra-esque whistling howl as it finally broke seal.
Living in a sealed chamber is a bad idea, so a giant carbon filter kicks on 5 minutes an hour to pump clean fresh air into the room through 4 feet of wound tubing in an MDF box crammed with polyfill.
The thick stone wool helps compensate for the massive thermal bridging of so many additional 2x6s and unsealed stud cavities, Even in 100 degree weather a 14k btu ac unit only needs to run a few minutes every half hour to chill the room to low 70s and the amps/computer/me generate enough heat to only need the tiny space heater when it drops below 40 for long periods.
Two 40 amp buried lines feed the structure, each with a ground rod. Each line feeds one breaker box. One box feeds all the outlets and lights save for the wall behind the speaker. That wall is fed by the second box and has 3 4 outlet boxes loaded with 20a hospital outlets. One 20a breaker feeds each outlet box with wiring isolated 16" from each other in the wall. Left and right mid/high amps and dacs get their own outlet boxes and bass amps/DSP off the third. The computer is fed by the first breaker box and feeds only optical to the DSPs for the best isolation I could devise.
The System's origins
I had 3 JBL 2242Hs. Two in 4645B 8 cubic foot 25hz tuned enclosures I got through my friend vinyldavid from a great guy in st louis named Kresko who resells cinema gear for charity. Had a wonderful time road tripping there with my grandma (twice!) and meeting a few awesome people. Got to hear bozak concert grands owned by a really cool dude named Ken, I think he's on AK but I don't know his username. Glorious sound with a custom tube amp built by some brilliant navy tech.
I had a set of EV variplex B cinema speakers, also purchased in st louis. They sound glorious on their own, 105db 1w from 40hz to 1khz, two ported tight sounding 15s, a big double 8" midhorn running down to 330hz with a wide vertical pattern on the low end/a tight cutoff on top and a matching 1" CD. I tried running the 2242s up to 330/24db with a high pass around 40hz to better compare them to the double 15s and they sounded wonderful, so they went under the varimids. The varimids were pushed to 300hz, a hair below cutoff, but by running the upper mid drivers down to 300 the rising response of the 2242 matches beautifully in a notoriously difficult to cross region. The varimids got biamped with DSP in this period. I had fallen in love with the seos-12 and DNA-360 combo so I tried using them with the varimids. Mounted below them they sounded remarkably good in a narrow vertical channel, but the tight vertical pattern on the hf didn't match well to the mid, since the upper mid driver is the only one taken out to the 1450hz treble cross.
Being as I don't sit due to t-spine disc damage and cervical stenosis (the only chair in the tiny house is a folding wheelchair for guests lol) the tweeters worked better at head volume. I tried a series of mounting positions but a 7 degree downward tilt on the tweeters is perfect, I even get treble in bed. For amplification I had bought up a bunch of crown xls1500s when they discontinued them, 200 bucks apiece brand new! Two are bridged for the 18s, each midhorn gets one and each tweeter gets one channel off two DTA-120 t-amps.
Computer optical>minidsp nanodigi
output 1 goes to schiit bifrost uber for left upper mid and tweeter
output 2 goes to second bifrost for right upper mid and tweeter
output 3 goes to modi uber for lower mids (300-500hz)
output 4 passes through to minidsp DA8
DA8 feeds both subs and supplies 6 channels to the nearfield monitors.
I designed the nearfield monitors for lower level and late night stuff.
A carver AC-806x (really the amp boards of 6 of those little marantz monoblocks from the early 2000s/late 90s on two massive power transformers, 135w into 8 ohms x6 or 360w into 8 bridged 3 channels, sounds surprisingly good) feeds the three way monitors.
The bass section is a Dayton RS180 in .95 cubic feet tuned to 38hz with a 2" precision port. The rear mounted highly flared port allowed for a fairly high port velocity and the slightly small enclosure bumped up response under 100hz a hair in an effort to exploit everything the driver had to offer at lower volumes.
The mids are a pair of fountek fr58exs in tapered rear enclosures made from smaller and smaller holes each offset from the next for a spiraling taper. They are sealed with twisted pair ethernet internal wiring on the mids. If you don't need massive output and need something for the 600-6khz range the fr58exs are absolutely brilliant-double the SD of even larger 25mm domes with 3mm xmax.
In between them is presently a peerless dx25tg, but soon to be upgraded to css 22mm, morel cat308 or perhaps wavecor, idk yet. It sounds good, but it's clearly the weak point.
The cabinet sides are sheathed in 2" thick pine slabs cut from 2x6s, glued together and then torch burned. The base box is braced 3/4" MDF with an additional 3/4" birch ply rear baffle, while the front baffle mid/hi subbaffle is also 3/4" birch. The design inspiration was a pair of studio monitors I built for a friend with peerless ring radiator in between the same fountek mids with a ported B&C 8fg51, this traded the tiny size and tremendous midbass power for a half octave deeper performance.
The rs180s make quite a bit of bass on their own, but the dsp allows a rapid addition of the two jbl 18s at about 65hz. I may switch to anarchy woofers to double vd and reduce internal volume a bit since the crossover point to the mids is well within their passband, but multiple guests have commented that the tiny nearfield monitors at 3 feet sound nearly the same as the massive behemoths from 10 feet on lots of music.
The third sub was in use (in a similarly 8 cubic foot 25hz tuned enclosure, but of my own design with a top mounted 80lb cement port tube enclosure) to reduce nodes/modes to great effect until the new nearfield monitors came online and ate up the remaining DSP channels. Minidsp needs to make a non forced ASRC 16 channel DSP stat! A fourth sub is awaiting more DSP channels as well, a TC sounds TC-2000 sealed and mounted on the wall for a subsonic boost.
It goes to show that if you're crazy, poor, have the internet and few extraneous expenses you can make a room that sounds absolutely glorious for less than the cost of $400 in meh drivers crammed into a pretty box with a fancy name. Pics to be uploaded from phone in a few minutes.
About 4 years ago I was eager to get out of my parents house, but high rents in the area meant an apartment would be small in an unsavory place and saving money out of the question. I knew how to build a shed, had access to a very good electrician interested in tiny houses with great rates (Thanks Matt!) and I had about $7000 to work with for housing along with two possible places to put a small building for virtually no rent at all, both with access to nearby bathrooms to save on initial build costs. I figured if I built it to supercede code, left plumbing out and hired a great electrician to install quality wiring to code I at least wouldn't die. The number one objective was making a small space that supported multiple systems and wasn't a reflection nightmare.
The Space
I knew I wanted to design the building with acoustics in mind. The footprint was my only constraint, at 12x16, so I opted for an 8 foot ceiling on one 16 foot wall and a 10 foot on the other. The building needed to be sturdy enough to move later, so I used 16" OC 2x6 construction with tripled 2x6s in each corner as well as the middle of the 16 foot walls, with doubled 2x6s between them and asymmetric bracing between each studs to keep any common resonances of the cavities at bay. The floor is double 3/4" ply on 2x12s with asymmetric bracing and green glue company acoustic tape between the plywood and lumber, more for softer footfalls than acoustics but I like to think it helps a little. The ceiling is 24" OC 2x8s except for the middle joist over the central triple 2x6s, which is a beam made of 2 2x6s 3.5" apart with two 12 foot 2x4s between them, glued and riddled with long deck screws in case the building twists during transport. For moving this provides a mounting point for diagonal beams to keep the hardiepanel from cracking as the building weighs a great deal. The roof is 3/4" ply with 100% ice & water shield coverage under 30 year shingles. The exterior is hardiepanel cement board over 1/2" ply with tyvek vapor barrier and a pretty grey semigloss with a hint of violet that brings out all the seasons. The trim is 3/4" thick PVC glued and secured with stainless screws. All exterior hardware is stainless. Insulation is stone wool throughout, soon to be stone wool under mellotone grill cloth, when mellotone has a sale (or wants to offer distributor price for my obscene order in return for free advertising in an untapped market XD). The wall behind the speakers is closest to the nearest occupied dwelling, so I used two layers of 1/2" drywall with green glue in between to keep the wall from turning into a giant sd, low xmax passive radiator. That was my compromise vs no drywall at all. I realized that absent wall paneling the stone wool would do next to nothing for bass control, so I settled for sealing the building entirely to at least not port the thing. I bought a ton of silicone caulk. So much that my biggest regret in the entire project is not simply buying a 5 gallon bucket of the stuff. One day future people will be excavating the area and suspect a cult that worshipped silicone lived there. It's sealed inside, outside, along the paneling, EVERYWHERE. I got a bit crazy at one point with a headlamp, a ladder and no shirt applying caulk into the night. The door is a steel slab with CLD tiles with a touchscreen deadbolt and triple hinges. It presses against a 360 degree seal mounted on 3/4" thick 1x4" PVC trim in a 2x8 frame with extensive bracing and lateral buttressing. The 2x8 frame is adjusted via 24 1/2" diameter threaded stainless rods that pass through the buttressed double 2x6s around them into divots in the 2x8s with nuts to tilt it side to side if needed. Even if the building twists a little in transit, wide silicone seals and the adjustable doorframe make it more likely to survive without damage. The deadbolt passes through a 4x10" 1/4" thick stainless plate mortised in the 2x8 and attached with 4.5" GRK fasteners to the assembly. The seal was so good that with my initial AC unit, an indoor portable 7k btu LG which sucks air out of the room the door would resist 20-30lb of pressure to force open and emit a tundra-esque whistling howl as it finally broke seal.
Living in a sealed chamber is a bad idea, so a giant carbon filter kicks on 5 minutes an hour to pump clean fresh air into the room through 4 feet of wound tubing in an MDF box crammed with polyfill.
The thick stone wool helps compensate for the massive thermal bridging of so many additional 2x6s and unsealed stud cavities, Even in 100 degree weather a 14k btu ac unit only needs to run a few minutes every half hour to chill the room to low 70s and the amps/computer/me generate enough heat to only need the tiny space heater when it drops below 40 for long periods.
Two 40 amp buried lines feed the structure, each with a ground rod. Each line feeds one breaker box. One box feeds all the outlets and lights save for the wall behind the speaker. That wall is fed by the second box and has 3 4 outlet boxes loaded with 20a hospital outlets. One 20a breaker feeds each outlet box with wiring isolated 16" from each other in the wall. Left and right mid/high amps and dacs get their own outlet boxes and bass amps/DSP off the third. The computer is fed by the first breaker box and feeds only optical to the DSPs for the best isolation I could devise.
The System's origins
I had 3 JBL 2242Hs. Two in 4645B 8 cubic foot 25hz tuned enclosures I got through my friend vinyldavid from a great guy in st louis named Kresko who resells cinema gear for charity. Had a wonderful time road tripping there with my grandma (twice!) and meeting a few awesome people. Got to hear bozak concert grands owned by a really cool dude named Ken, I think he's on AK but I don't know his username. Glorious sound with a custom tube amp built by some brilliant navy tech.
I had a set of EV variplex B cinema speakers, also purchased in st louis. They sound glorious on their own, 105db 1w from 40hz to 1khz, two ported tight sounding 15s, a big double 8" midhorn running down to 330hz with a wide vertical pattern on the low end/a tight cutoff on top and a matching 1" CD. I tried running the 2242s up to 330/24db with a high pass around 40hz to better compare them to the double 15s and they sounded wonderful, so they went under the varimids. The varimids were pushed to 300hz, a hair below cutoff, but by running the upper mid drivers down to 300 the rising response of the 2242 matches beautifully in a notoriously difficult to cross region. The varimids got biamped with DSP in this period. I had fallen in love with the seos-12 and DNA-360 combo so I tried using them with the varimids. Mounted below them they sounded remarkably good in a narrow vertical channel, but the tight vertical pattern on the hf didn't match well to the mid, since the upper mid driver is the only one taken out to the 1450hz treble cross.
Being as I don't sit due to t-spine disc damage and cervical stenosis (the only chair in the tiny house is a folding wheelchair for guests lol) the tweeters worked better at head volume. I tried a series of mounting positions but a 7 degree downward tilt on the tweeters is perfect, I even get treble in bed. For amplification I had bought up a bunch of crown xls1500s when they discontinued them, 200 bucks apiece brand new! Two are bridged for the 18s, each midhorn gets one and each tweeter gets one channel off two DTA-120 t-amps.
Computer optical>minidsp nanodigi
output 1 goes to schiit bifrost uber for left upper mid and tweeter
output 2 goes to second bifrost for right upper mid and tweeter
output 3 goes to modi uber for lower mids (300-500hz)
output 4 passes through to minidsp DA8
DA8 feeds both subs and supplies 6 channels to the nearfield monitors.
I designed the nearfield monitors for lower level and late night stuff.
A carver AC-806x (really the amp boards of 6 of those little marantz monoblocks from the early 2000s/late 90s on two massive power transformers, 135w into 8 ohms x6 or 360w into 8 bridged 3 channels, sounds surprisingly good) feeds the three way monitors.
The bass section is a Dayton RS180 in .95 cubic feet tuned to 38hz with a 2" precision port. The rear mounted highly flared port allowed for a fairly high port velocity and the slightly small enclosure bumped up response under 100hz a hair in an effort to exploit everything the driver had to offer at lower volumes.
The mids are a pair of fountek fr58exs in tapered rear enclosures made from smaller and smaller holes each offset from the next for a spiraling taper. They are sealed with twisted pair ethernet internal wiring on the mids. If you don't need massive output and need something for the 600-6khz range the fr58exs are absolutely brilliant-double the SD of even larger 25mm domes with 3mm xmax.
In between them is presently a peerless dx25tg, but soon to be upgraded to css 22mm, morel cat308 or perhaps wavecor, idk yet. It sounds good, but it's clearly the weak point.
The cabinet sides are sheathed in 2" thick pine slabs cut from 2x6s, glued together and then torch burned. The base box is braced 3/4" MDF with an additional 3/4" birch ply rear baffle, while the front baffle mid/hi subbaffle is also 3/4" birch. The design inspiration was a pair of studio monitors I built for a friend with peerless ring radiator in between the same fountek mids with a ported B&C 8fg51, this traded the tiny size and tremendous midbass power for a half octave deeper performance.
The rs180s make quite a bit of bass on their own, but the dsp allows a rapid addition of the two jbl 18s at about 65hz. I may switch to anarchy woofers to double vd and reduce internal volume a bit since the crossover point to the mids is well within their passband, but multiple guests have commented that the tiny nearfield monitors at 3 feet sound nearly the same as the massive behemoths from 10 feet on lots of music.
The third sub was in use (in a similarly 8 cubic foot 25hz tuned enclosure, but of my own design with a top mounted 80lb cement port tube enclosure) to reduce nodes/modes to great effect until the new nearfield monitors came online and ate up the remaining DSP channels. Minidsp needs to make a non forced ASRC 16 channel DSP stat! A fourth sub is awaiting more DSP channels as well, a TC sounds TC-2000 sealed and mounted on the wall for a subsonic boost.
It goes to show that if you're crazy, poor, have the internet and few extraneous expenses you can make a room that sounds absolutely glorious for less than the cost of $400 in meh drivers crammed into a pretty box with a fancy name. Pics to be uploaded from phone in a few minutes.
