new version of this driver on PE, no specs yet:
https://www.parts-express.com/Dayto...C-Subwoofer-2-Ohm-Per-Coil-295-718?quantity=1
https://www.parts-express.com/Dayto...C-Subwoofer-2-Ohm-Per-Coil-295-718?quantity=1
This is what Dayton /PE writes about another woofer:
"Another common problem with many of today's budget subwoofer drivers is a lack of motor strength. This leads to drivers that are inefficient or are only capable of the "one note" bass that is the result of high Q drivers."
Seems to be in contrast what the PE forum moderator said.
"Another common problem with many of today's budget subwoofer drivers is a lack of motor strength. This leads to drivers that are inefficient or are only capable of the "one note" bass that is the result of high Q drivers."
Seems to be in contrast what the PE forum moderator said.
@neo004
4 cubic feet are about 113 litre. Even if that is the inside net volume, that is a very small enclosure for a 18" chassis. If the Dayton has the new data that are dicussed here, if I'm honest I would try to return it to the seller.
OK, with two of them in a "normal" room you can still get quite deep, but at 20Hz HT level it is not what you expect from 2x18" and 2x2000 Watt.
If Win ISD is right, I can get more dB at 20dB out of a "normal" 15" at 600W than from the 18" with 2000. Same cabinet.
4 cubic feet are about 113 litre. Even if that is the inside net volume, that is a very small enclosure for a 18" chassis. If the Dayton has the new data that are dicussed here, if I'm honest I would try to return it to the seller.
OK, with two of them in a "normal" room you can still get quite deep, but at 20Hz HT level it is not what you expect from 2x18" and 2x2000 Watt.
If Win ISD is right, I can get more dB at 20dB out of a "normal" 15" at 600W than from the 18" with 2000. Same cabinet.
Last edited:
I have to correct my last post.
The UM18-22 was simulated in a closed box, as it doesn't work for vented because of much too high Qts.
The simulation of another 18" was in a vented cabinet.
Anyway, if you have the same cabinet with two different chassis, it is usually not the principle (an additional port) that matters, but the end result. In home theater, you will not see advantages from a closed or vented system soundwise.
If you take the MX15 from Dayton, it is 200$ unstead of 300$ for the 18". If you take the same 4 cubic feet volume, the 15" vented will deliver a serious amount of 20 Hz level, compared to the 18". Like 4 times as much if winISD is right. 6dB are nothing to be ignored.
For me with music, 35 Hz are the low region to reach, but HT needs serious output in the 20Hz and even lower region.
There is another problem with the 18" Dayton. It has a 75mm or 3" voice coil. It will not diggest the rated 2000 Watt for more than a second. We can start a discussion about this, but the lower we get in frequency, the higher the input power we need, but at the same time it get's more problematic to get the heat away from it. Put a 2000 Watt heater in a wooden, closed 113 liter box and monitor the temperature over time. You will be quite surprised. The Nomex cone doesn't conduct heat very well, it is also used in flame resistant suits.
The good thing is, most amps Dayton sells are just as far away from the claimed output power, as their chassis from power handling. So sales lies somehow compensate them self. Don't try to run them with a serious, heavy transformer powered 2000 Watt PA amp from a "real" brand.
I write this, because as an excuse for a non linear sub construction is often mentioned "we take care of that with a DSP and powerfull amp". A killer argument? This may work for a few dB, but not endless. In the end there is no replacement for a well parameterized speaker in the right volume and cabinet principle. You can't DSP the sh#t out of any garbage.
The UM18-22 was simulated in a closed box, as it doesn't work for vented because of much too high Qts.
The simulation of another 18" was in a vented cabinet.
Anyway, if you have the same cabinet with two different chassis, it is usually not the principle (an additional port) that matters, but the end result. In home theater, you will not see advantages from a closed or vented system soundwise.
If you take the MX15 from Dayton, it is 200$ unstead of 300$ for the 18". If you take the same 4 cubic feet volume, the 15" vented will deliver a serious amount of 20 Hz level, compared to the 18". Like 4 times as much if winISD is right. 6dB are nothing to be ignored.
For me with music, 35 Hz are the low region to reach, but HT needs serious output in the 20Hz and even lower region.
There is another problem with the 18" Dayton. It has a 75mm or 3" voice coil. It will not diggest the rated 2000 Watt for more than a second. We can start a discussion about this, but the lower we get in frequency, the higher the input power we need, but at the same time it get's more problematic to get the heat away from it. Put a 2000 Watt heater in a wooden, closed 113 liter box and monitor the temperature over time. You will be quite surprised. The Nomex cone doesn't conduct heat very well, it is also used in flame resistant suits.
The good thing is, most amps Dayton sells are just as far away from the claimed output power, as their chassis from power handling. So sales lies somehow compensate them self. Don't try to run them with a serious, heavy transformer powered 2000 Watt PA amp from a "real" brand.
I write this, because as an excuse for a non linear sub construction is often mentioned "we take care of that with a DSP and powerfull amp". A killer argument? This may work for a few dB, but not endless. In the end there is no replacement for a well parameterized speaker in the right volume and cabinet principle. You can't DSP the sh#t out of any garbage.
Isnt the um18 famous for super low tuned vented home theatre apps where it can rumble and fart out deep explosions and earthquakes or tyrannosaurus foot steps?
the high qts allowing that stuff to resonate/ring/whstever?
the high qts allowing that stuff to resonate/ring/whstever?
The original designs i think were from a guy on the AVS forums. Which designed the whole series of marty subs.
GSG Audio then took those designs and made flat pack options and a whole website based on the designs
https://shop.gsgad.com/.
They do have lots of other options for which drivers they recommend, most I can't source in Australia or are crazy expensive with shipping.
That's why i ended up with the UM18-22.
I really don't know what to do now lol. I may have an option to return the UM18-22, but not sure what i would replace them with.
I would like two subs to help even out room modes etc. And I would be more than happy with 25-30hz +
I listen to more music than watch movies. So don't need to aim for 17hz.
What other ideas would you look at in this scenario?
GSG Audio then took those designs and made flat pack options and a whole website based on the designs
https://shop.gsgad.com/.
They do have lots of other options for which drivers they recommend, most I can't source in Australia or are crazy expensive with shipping.
That's why i ended up with the UM18-22.
I really don't know what to do now lol. I may have an option to return the UM18-22, but not sure what i would replace them with.
I would like two subs to help even out room modes etc. And I would be more than happy with 25-30hz +
I listen to more music than watch movies. So don't need to aim for 17hz.
What other ideas would you look at in this scenario?
What you build depends on what woofer you can get where you live and pay from your purse. Quite logical.
Can you get the MX15-22 form Dayton? It looks much better in simulations. Also the pictures I saw seem to make the the claimed data realistic.
They saved on the aluminum basket, but made drive and suspension right. The exact opposite of the UM18-22. The seller of the UM18 may be more happy if you buy another Dayton from him in exchange.
Two of the MX15-22 in your two 4 cubic foot cabinets should work very well for cinema and music. You even can close a port, part or fully, and store matching DSP settings for what you listen to. JBL, Altec and Elecro Voice did that in the days of great vintage HIFI.
This is my personal opinion, based on practice: Don't use any woofer with a Qts much higher than 0.5 until you have a very good cause to do so.
Do you use winISD? It is free. Look what driver you can get. Then go to https://loudspeakerdatabase.com/ and load the data to the driver directory of winISD. Start a new simulation with it. It will pick a reasonable simulation, then you can experiment with it. Do a closed and a vented and compare.
If the driver data are correct such a simulation is something you can bet on. If it gives no result you like, the driver is wrong for your task.
If you build a vented cabinet from such a simulation, try to keep the port lenght variable, so you can adjust to tollerances and room. It is easy with large woofer to make the port variable throught the chassis opening.
One thing to keep in mind, no vented simulation for driver with a Qts larger than 0.6 or results will not match reality.
If you can read the picture: These are the two chassis in the same volume, driven by 500 Watt each. MX15 ported, UM18 closed.
The difference is quite huge.
Can you get the MX15-22 form Dayton? It looks much better in simulations. Also the pictures I saw seem to make the the claimed data realistic.
They saved on the aluminum basket, but made drive and suspension right. The exact opposite of the UM18-22. The seller of the UM18 may be more happy if you buy another Dayton from him in exchange.
Two of the MX15-22 in your two 4 cubic foot cabinets should work very well for cinema and music. You even can close a port, part or fully, and store matching DSP settings for what you listen to. JBL, Altec and Elecro Voice did that in the days of great vintage HIFI.
This is my personal opinion, based on practice: Don't use any woofer with a Qts much higher than 0.5 until you have a very good cause to do so.
Do you use winISD? It is free. Look what driver you can get. Then go to https://loudspeakerdatabase.com/ and load the data to the driver directory of winISD. Start a new simulation with it. It will pick a reasonable simulation, then you can experiment with it. Do a closed and a vented and compare.
If the driver data are correct such a simulation is something you can bet on. If it gives no result you like, the driver is wrong for your task.
If you build a vented cabinet from such a simulation, try to keep the port lenght variable, so you can adjust to tollerances and room. It is easy with large woofer to make the port variable throught the chassis opening.
One thing to keep in mind, no vented simulation for driver with a Qts larger than 0.6 or results will not match reality.
If you can read the picture: These are the two chassis in the same volume, driven by 500 Watt each. MX15 ported, UM18 closed.
The difference is quite huge.
FWIW, high Qt drivers work well in large, narrow BW expanding pipe (horns), kind of a poor man's B0$3 wave cannon. 😱
So I did a little bit of testing, downloaded the winisd data and used that for the graphs.
Ive attached the graph of the UM18-22 (new specs) & the MX15, Transfer function, SPL, Cone excursion
UM18-22 Ported, 11 cubic feet, 17hz tune (to match full marty, green line) 1000W, F3 17hz
UM18-22 Sealed, 4 cubic feet (blue line) 1000W, F3 31hz
MX15-ported 4cf (red line) 800W, F3 24hz
The UM18-22 Ported uses a slot port, not sure if that stuffs up those graphs.
Based on those graphs, wouldn't you run with the UM18-22 Ported?
Or are we trying to say the UM18-22 with a Qts of 0.7, might look fine on paper, but isn't fit to task?
Ive attached the graph of the UM18-22 (new specs) & the MX15, Transfer function, SPL, Cone excursion
UM18-22 Ported, 11 cubic feet, 17hz tune (to match full marty, green line) 1000W, F3 17hz
UM18-22 Sealed, 4 cubic feet (blue line) 1000W, F3 31hz
MX15-ported 4cf (red line) 800W, F3 24hz
The UM18-22 Ported uses a slot port, not sure if that stuffs up those graphs.
Based on those graphs, wouldn't you run with the UM18-22 Ported?
Or are we trying to say the UM18-22 with a Qts of 0.7, might look fine on paper, but isn't fit to task?
Attachments
See, the problem with drivers that have a Qts higher than0.6 is that you can simulate them as vented constructions, but they will not work in practice as simulated. This is no joke or maybe thing, but you will end up with something sounding blurred and anoying. This is not oppinion, but the physics that makes speaker work.
The drive of the UM18-22 simply doesn't work for the stiff suspension ond heavy cone. What they changed in construction was an unsufficient try to compensate for some cost saving measures. Like making the cone lighter. It made a good chassis simply unuseable.
If you are objective, there is no construction you would pick the UM18-22 as a good candidat for. Not vented, closed, horn, open baffle or transmission line. They fu##ed up.
We can discuss until the holy uncorn resurrects, this is what it is. For a closed cabinet you want the resulting Qb (this is like Qts but in a box) to be 0.707, which is the point where impulse reaction, damping and response have a good value, free standing in a room. As Qb is allways higher than Qts, if you start with the UM12-22 you end up with something like 0.8 or 0.9 which is to high for a quality speaker.
Look at it this way: I you design a speaker and have just a little practice in that, after looking at the TSP of the UM18-22, you would not even load it inta a simulation. Just a "don't use it speaker". There is an endless number of such good looking, not working constructions out there. Mostly from Asia, where those that do decissions in most cases don't care for the result, if it looks good an some poor soul buys it. They often don't know and don't care about all the fuzz we make about development. That is why they buy all the Scandinavian speaker brands, by the way.
Now there are quite a lot in DIYS who don't know better and think they can beat physics and say, "Oh, lets use it, just for a try, maybe I'm more clever than the science around it:" If you like to waste time and money, you can do that. In the end you will not want to admit you build something sub par and live with it, saying "but I like it that way." Even as you realised the sound is nothing but loud noise, no good for a good home theater and anoying with music. These are the people you find in any forum, asking for help after building something stupid.
By the way, listening to someone who made money selling you junk, when he tells you "changes in TSP don't matter", is not wise. The guy simply doesn't want his useless chassis back.
The drive of the UM18-22 simply doesn't work for the stiff suspension ond heavy cone. What they changed in construction was an unsufficient try to compensate for some cost saving measures. Like making the cone lighter. It made a good chassis simply unuseable.
If you are objective, there is no construction you would pick the UM18-22 as a good candidat for. Not vented, closed, horn, open baffle or transmission line. They fu##ed up.
We can discuss until the holy uncorn resurrects, this is what it is. For a closed cabinet you want the resulting Qb (this is like Qts but in a box) to be 0.707, which is the point where impulse reaction, damping and response have a good value, free standing in a room. As Qb is allways higher than Qts, if you start with the UM12-22 you end up with something like 0.8 or 0.9 which is to high for a quality speaker.
Look at it this way: I you design a speaker and have just a little practice in that, after looking at the TSP of the UM18-22, you would not even load it inta a simulation. Just a "don't use it speaker". There is an endless number of such good looking, not working constructions out there. Mostly from Asia, where those that do decissions in most cases don't care for the result, if it looks good an some poor soul buys it. They often don't know and don't care about all the fuzz we make about development. That is why they buy all the Scandinavian speaker brands, by the way.
Now there are quite a lot in DIYS who don't know better and think they can beat physics and say, "Oh, lets use it, just for a try, maybe I'm more clever than the science around it:" If you like to waste time and money, you can do that. In the end you will not want to admit you build something sub par and live with it, saying "but I like it that way." Even as you realised the sound is nothing but loud noise, no good for a good home theater and anoying with music. These are the people you find in any forum, asking for help after building something stupid.
By the way, listening to someone who made money selling you junk, when he tells you "changes in TSP don't matter", is not wise. The guy simply doesn't want his useless chassis back.
Mine were made many decades ago using cardboard tubes, but can be simmed in HR when time permits.
I'm trying not to talk about other woofer's TSP in common, but only about this specific one. Keep the two letters OT in mind.
The thing that is so stupid about the UM18-22, is the heavy weight cone and the double suspension. There are speaker with high Qts you can use in some special cases, like an open baffle, but you don't need a one pound, reinforced membrane for it. Any horn needs a strong drive, so the energy transition from cone to horn end makes sense. Sorry, not with the UM18-22.
Let us do it the other way round: For what construction would anyone here pick exactly such an 18" driver?
I'm a science and practice guy. If I can get excelent results with well made, conventional constructions, I have no desire to try something that clearly predicted not to work. This curiosity I had as kid, was at some point mixed with solid science.
One life is too short to repeat all the mistakes others made before, until you sort out the working options. Read books and learn from those before you. Speaker science is very old and very far advanced. There are no wonders to be discovered any more, all improvements are the result of hard and smart, often expensive research work.
This chassis has a too weak magnet and a too wide gap, not driving the components right. Basta. Maybe if you make the cabinet 50 cubic feet large, but then still it would have the too high Fs for it's size. You can turn it in any direction, this is a chassis is no good.
The thing that is so stupid about the UM18-22, is the heavy weight cone and the double suspension. There are speaker with high Qts you can use in some special cases, like an open baffle, but you don't need a one pound, reinforced membrane for it. Any horn needs a strong drive, so the energy transition from cone to horn end makes sense. Sorry, not with the UM18-22.
Let us do it the other way round: For what construction would anyone here pick exactly such an 18" driver?
I'm a science and practice guy. If I can get excelent results with well made, conventional constructions, I have no desire to try something that clearly predicted not to work. This curiosity I had as kid, was at some point mixed with solid science.
One life is too short to repeat all the mistakes others made before, until you sort out the working options. Read books and learn from those before you. Speaker science is very old and very far advanced. There are no wonders to be discovered any more, all improvements are the result of hard and smart, often expensive research work.
This chassis has a too weak magnet and a too wide gap, not driving the components right. Basta. Maybe if you make the cabinet 50 cubic feet large, but then still it would have the too high Fs for it's size. You can turn it in any direction, this is a chassis is no good.
Ok I've done a little bit more reading. I'm definately thinking of switching out these drivers if there are better options to be had for similar money.
The drivers I can easily access, Anything else would get too expensive once you factor in overseas shipping.
21"
Dayton HTS545HE-4 ($1165)
LaVoce SAN214.50 ($1200)
18"
Dayton RSS460HO-4 ($795)
Dayton PA460-8 (pro audio) ($289)
15"
Dayton PA380-8 (pro audio) ($280)
Dayton RSS390HF-4 ($559)
Dayton MX15-22 ($489)
I definately want two subs, so i can help room modes.
Based on this list, which way do you think i should be going? Lets say mainly aiming for excellent music reproduction.
Home theatre is a bonus.
Thanks heaps
The drivers I can easily access, Anything else would get too expensive once you factor in overseas shipping.
21"
Dayton HTS545HE-4 ($1165)
LaVoce SAN214.50 ($1200)
18"
Dayton RSS460HO-4 ($795)
Dayton PA460-8 (pro audio) ($289)
15"
Dayton PA380-8 (pro audio) ($280)
Dayton RSS390HF-4 ($559)
Dayton MX15-22 ($489)
I definately want two subs, so i can help room modes.
Based on this list, which way do you think i should be going? Lets say mainly aiming for excellent music reproduction.
Home theatre is a bonus.
Thanks heaps
you have these drivers in hand. they are relatively inexpensive. just put them in the 4 cube sealed boxes, EQ and listen to the music. it's probably not going to be as disastrous of an experience as Turbowatch2 would have you believe (no disrespect to his high standards🙂 at least you can move them around the room by yourself. NX6000 is only gonna give you like 1200wpc actual power anyway.
just my .02
just my .02
Last edited:
In 4 cf sealed you get a Qtc of 1.07
This is usualy called a "one not bass" for a reason.
The NX6000 is a double NX3000 bridged internaly if I'm right. These amps have not that much power as you would expect. The NX6000 can only drive 4 Ohm or greater loads. I have a i-Nuke 3000D at home, which is the same amp in another case. You can easily drive that thing into hard, audible clipping on a 8 Ohm, 300 W rms rated EV 15" speaker, with CD based music.
Get me right, it is a fine amplifier, as I paid less than 195€ new for it. The DSP has very nice functions for PA and HT use, but it is no endless power amp. You got to stay with 4 Ohm per channel or the amp will release it's magic smoke. No 2 Qhm experiments. This is no heavy weight Crest Audio or QSC pro. 1200-1500 W /4 Ohm seems to be about right, with some headroom left. Behringer, after posting realistic numbers for some years, has returned to phantasy Watt, calling it "Peak". They even re-wrote their older manuals and erased rms values.
Anyway, much more power than you can use in a closed room and enough to do some serious response bending! Keep the thing cold and from time to time clean it from dust inside and it will last.
With the list of drivers, what size cabinet do you have on your mind? Just as a direction, the larger the volume, the deeper or louder the bass. Do you already have a cabinet?
What kind of music? What room size. You can not have an "do anything" sub, you have to narrow in a bit on the major use and see that it is suited for the secondary task's as well, maybe not 100%.
It doesn't help if you say "I want HT in the basement, but good music reproduction in a living room and do occasional open air PA for 250 of my best friends." You don't build such a thing or two of them every day. The time and effort you spent to plan it will decide how satisfied you are in the end. So excuse me asking all that intimate stuff.
With two cabinets and 15"-21" chassis it should be possible to get a HT capable music sub, but room size (volume) matters.
Why is the MX15-22 so expensive? It is 199 US$ on PE. A good candidate for such a very small 113 liter (4cf) cabinet.
Maybe start communication with the seller of the UM first. It makes negotiations simpler when you want something in exchange for the UM18, not your money back.
This is usualy called a "one not bass" for a reason.
The NX6000 is a double NX3000 bridged internaly if I'm right. These amps have not that much power as you would expect. The NX6000 can only drive 4 Ohm or greater loads. I have a i-Nuke 3000D at home, which is the same amp in another case. You can easily drive that thing into hard, audible clipping on a 8 Ohm, 300 W rms rated EV 15" speaker, with CD based music.
Get me right, it is a fine amplifier, as I paid less than 195€ new for it. The DSP has very nice functions for PA and HT use, but it is no endless power amp. You got to stay with 4 Ohm per channel or the amp will release it's magic smoke. No 2 Qhm experiments. This is no heavy weight Crest Audio or QSC pro. 1200-1500 W /4 Ohm seems to be about right, with some headroom left. Behringer, after posting realistic numbers for some years, has returned to phantasy Watt, calling it "Peak". They even re-wrote their older manuals and erased rms values.
Anyway, much more power than you can use in a closed room and enough to do some serious response bending! Keep the thing cold and from time to time clean it from dust inside and it will last.
With the list of drivers, what size cabinet do you have on your mind? Just as a direction, the larger the volume, the deeper or louder the bass. Do you already have a cabinet?
What kind of music? What room size. You can not have an "do anything" sub, you have to narrow in a bit on the major use and see that it is suited for the secondary task's as well, maybe not 100%.
It doesn't help if you say "I want HT in the basement, but good music reproduction in a living room and do occasional open air PA for 250 of my best friends." You don't build such a thing or two of them every day. The time and effort you spent to plan it will decide how satisfied you are in the end. So excuse me asking all that intimate stuff.
With two cabinets and 15"-21" chassis it should be possible to get a HT capable music sub, but room size (volume) matters.
Why is the MX15-22 so expensive? It is 199 US$ on PE. A good candidate for such a very small 113 liter (4cf) cabinet.
Maybe start communication with the seller of the UM first. It makes negotiations simpler when you want something in exchange for the UM18, not your money back.
Cabinet size can be flexible, I've got a bit of room. I can easily fit dual 4-6cf boxes. Or even duel Full martys which was where the original plan was heading.
So currently ive got one Full marty cabinet made, and one sealed 4cf which currently has one of the UM18-22 in for some testing.
I have half made another Full marty cabinet and the material is precut for another 4cf sealed box also.
As for music, i'm a top 40 kinda person, so it's a bit of everything. But no crazy metal or anything like that.
The room is fairly large 6.5m wide x 8m deep. 2.55m ceiling raking up to 3m in the centre of the room.
Its a combined kitchen/dining/living. Listening position is about 3.5m from the speakers currently.
Lets say 80% music, 20% home theatre.
Everything is expensive due to Australia Tax lol.
I'll touch base and see what their thoughts are but still curious to see what you would use, ignoring the UM18-22
Thanks
So currently ive got one Full marty cabinet made, and one sealed 4cf which currently has one of the UM18-22 in for some testing.
I have half made another Full marty cabinet and the material is precut for another 4cf sealed box also.
As for music, i'm a top 40 kinda person, so it's a bit of everything. But no crazy metal or anything like that.
The room is fairly large 6.5m wide x 8m deep. 2.55m ceiling raking up to 3m in the centre of the room.
Its a combined kitchen/dining/living. Listening position is about 3.5m from the speakers currently.
Lets say 80% music, 20% home theatre.
Everything is expensive due to Australia Tax lol.
I'll touch base and see what their thoughts are but still curious to see what you would use, ignoring the UM18-22
Thanks
A full Marty is a 420 litre or 15cf enclosure. That is a very different beast for a sub, compared to the 113 litre/ 4cf shoe box. Do you really want two full Marty in the room? Serious? From an acoustic standpoint, nice. The shoe boy is simpler to hide, but carefully said, a compromise. I have to read from the beginning again, I don't remeber your other speakers
Your room looks quite nice from paper and what I have experienced over the years. A ceiling not being flat but rising in an angle is a good thing for bass. Anything irregularity helps.
What I don't know is how solid floor, walls and roof are. This all comes into play when you leave the normal HIFI region. Even quite large floorstander don't deliver any real sub 35 Hz fequency in most cases.
Now let me say something very obvious: If you have a sub that doesn't deliver low frequency on it's own, you can DSP a bit out of it, even a lot depending on construction and amp. Too much and sound will suffer. Anyway, if you have a sub that goes too deep or has too much SPL, you can always DSP it down without any negative effect on sound. An example: In my listening room I have a drum set, which is played by my daughter. For listening to music at "nice" levels, I have to silence any felt and metal, or it will add a very special sound. In my living and TV room, I had to silenced glas windows in cupboards, screw down ceiling panels and rearrange quite some items. What I want to say, your room may develop all kinds of noises when you go through the frequency range on solid SPL.
Now I have two volumes and a hand full of drivers. Must have a look. I hope your prices are Aussi $ which would make Dayton prices similar to ours.
Your room looks quite nice from paper and what I have experienced over the years. A ceiling not being flat but rising in an angle is a good thing for bass. Anything irregularity helps.
What I don't know is how solid floor, walls and roof are. This all comes into play when you leave the normal HIFI region. Even quite large floorstander don't deliver any real sub 35 Hz fequency in most cases.
Now let me say something very obvious: If you have a sub that doesn't deliver low frequency on it's own, you can DSP a bit out of it, even a lot depending on construction and amp. Too much and sound will suffer. Anyway, if you have a sub that goes too deep or has too much SPL, you can always DSP it down without any negative effect on sound. An example: In my listening room I have a drum set, which is played by my daughter. For listening to music at "nice" levels, I have to silence any felt and metal, or it will add a very special sound. In my living and TV room, I had to silenced glas windows in cupboards, screw down ceiling panels and rearrange quite some items. What I want to say, your room may develop all kinds of noises when you go through the frequency range on solid SPL.
Now I have two volumes and a hand full of drivers. Must have a look. I hope your prices are Aussi $ which would make Dayton prices similar to ours.