I don't think my wife would appreciate if I extended the room into the shower in the bathroom.
Of course, it might add a whole new dimension.. I could sing Opera while in the shower. 😉
I'm finding them used.... hmmm..... thanks, I hadn't thought about it.
There's a direct flight from Denmark to LAX. With good traffic, it's about an hour from LAX to my house.
If you bring beer, you're welcome to listen.
OK... I ordered the Dayton Audio DSP-408 4x8 DSP and the corresponding wired remote: DSP-NRC
The woofers are shown as back ordered but some how they sent me an email saying that they had them in stock and they let me order and pay for them.
So I ordered two woofers, Dayton Audio MKSX4.
I think the price on the woofers did go up from three weeks ago... Tariffs? But it's less than 20%. They show them as backordered until 7/15.. hmmm, we'll see. They took my Paypal money so let's see if they ship them.
This should be a start... two woofers up front and two in the back.
The folks over at AVS Forums recommended the miniDSP as mor reliable but they are now charging an outright 30% tariff and on top of that the thing does too much. Meanwhile Parts Express is running a 15% off for Memorial Day... so we'll see what happens.
Now I got to clean up the clutter in the room.
The woofers are shown as back ordered but some how they sent me an email saying that they had them in stock and they let me order and pay for them.
So I ordered two woofers, Dayton Audio MKSX4.
I think the price on the woofers did go up from three weeks ago... Tariffs? But it's less than 20%. They show them as backordered until 7/15.. hmmm, we'll see. They took my Paypal money so let's see if they ship them.
This should be a start... two woofers up front and two in the back.
The folks over at AVS Forums recommended the miniDSP as mor reliable but they are now charging an outright 30% tariff and on top of that the thing does too much. Meanwhile Parts Express is running a 15% off for Memorial Day... so we'll see what happens.
Now I got to clean up the clutter in the room.
Sure enough, just got an email... woofers in backorder until mid July. Oh well.
Someone over at avsforum suggested different crossovers... they suggested 100 Hz but when I run the low pass that high I can hear directional clues from the woofers... that problem is likely created because I'm running the main speakers fully wideband. I suppose I could run the main speakers through the crossover, which I did, and then the bass merges better but then I hear some degradation in the midrange and treble.
Also, someone suggested REW software and a mike. I think that's an excellent idea. It will give me time to get used to how the room measures now so when I bring in the back woofers the measured difference will be obvious from the get go.
Do you know of any REW that runs off a Chromebook, or Android? The mike should be a USB?
You know what is really funny.... what if we waveformed up to 150 Hz? Can you imagine a small room supporting all the way down to 16Hz. Cut holes on two facing walls and mount eight 18 inch woofers... on each wall.
Someone over at avsforum suggested different crossovers... they suggested 100 Hz but when I run the low pass that high I can hear directional clues from the woofers... that problem is likely created because I'm running the main speakers fully wideband. I suppose I could run the main speakers through the crossover, which I did, and then the bass merges better but then I hear some degradation in the midrange and treble.
Also, someone suggested REW software and a mike. I think that's an excellent idea. It will give me time to get used to how the room measures now so when I bring in the back woofers the measured difference will be obvious from the get go.
Do you know of any REW that runs off a Chromebook, or Android? The mike should be a USB?
You know what is really funny.... what if we waveformed up to 150 Hz? Can you imagine a small room supporting all the way down to 16Hz. Cut holes on two facing walls and mount eight 18 inch woofers... on each wall.
If you want a plane wave up to 150 Hz, you'll need a sub every 1.15 m or 3.75 ft (vertically and horizontally) - remember that reflected sources are as far away from the wall as your actual source. So you need half that to the wall and then that distance to the next sub. What are the dimensions of your room? And you are talking about using 2 in front / 2 in back?
I'm gonna start with two front and two in the back
The room is long 12.5, wide 12, and height from 10 (where the speakers are) to 14 (back wall to the speakers). Speakers are along the "wide" wall.
There are shelves on both of the wide walls....
With front to back woofers about 12 feet away I figured that doing a 60Hz cut off it should be doable.
Depending on how things turn out, I plan on moving forward and get four more woofers. I could add those about 8 feet off the ground
Adding the woofers higher up will help setting up a rear surround with a Schiit Syn. Just mount a small pair of speakers up there with a derived surround track. I wonder if the out of phase woofers will affect the surround track?
Gotta try I guess.
My biggest concern is: What if the home office ends up sounding the best?
The room is long 12.5, wide 12, and height from 10 (where the speakers are) to 14 (back wall to the speakers). Speakers are along the "wide" wall.
There are shelves on both of the wide walls....
With front to back woofers about 12 feet away I figured that doing a 60Hz cut off it should be doable.
Depending on how things turn out, I plan on moving forward and get four more woofers. I could add those about 8 feet off the ground
Adding the woofers higher up will help setting up a rear surround with a Schiit Syn. Just mount a small pair of speakers up there with a derived surround track. I wonder if the out of phase woofers will affect the surround track?
Gotta try I guess.
My biggest concern is: What if the home office ends up sounding the best?
So 2 subs along the 12 ft wall(s) would give you a plane wave horizontally up to 94 Hz. But 1 sub in the vertical direction (10 ft) limits you to 56 Hz (if you locate it at half the vertical dimension! Unlikely...).
This is according to the math at https://en.wikipedia.org/wiki/Double_bass_array (I made a lil spreadsheet for it)
IDK what it would be like in the 56 - 94 Hz octave. I don't know what it would be like at all, I've never heard this kind of array...
2x2 and you're still at 94 horiz but now 112 vert so presumably working well up 94 at least?
3x3 (on both ends!) gets you 140 Hz plane wave operation horizontally and 168 vertically, and that's getting to be a lot of subs... I wonder how small of a sub would make sense, holding output down to 30 Hz? But prob don't have to go that far, who crosses to their sub at 140 Hz? Maybe it depends on when your room transitions from lumped to modal.
I guess you'd just have to come up with some awesome improvement for the main setup at that point! What a bummer to have to do! I know you'll soldier on bravely should that eventuality arise.
This is according to the math at https://en.wikipedia.org/wiki/Double_bass_array (I made a lil spreadsheet for it)
IDK what it would be like in the 56 - 94 Hz octave. I don't know what it would be like at all, I've never heard this kind of array...
2x2 and you're still at 94 horiz but now 112 vert so presumably working well up 94 at least?
3x3 (on both ends!) gets you 140 Hz plane wave operation horizontally and 168 vertically, and that's getting to be a lot of subs... I wonder how small of a sub would make sense, holding output down to 30 Hz? But prob don't have to go that far, who crosses to their sub at 140 Hz? Maybe it depends on when your room transitions from lumped to modal.
I guess you'd just have to come up with some awesome improvement for the main setup at that point! What a bummer to have to do! I know you'll soldier on bravely should that eventuality arise.
Do the woofers need to be at mirror locations on the front and back walls?
And yes, the front and back wall are different heights, nothing I can do about that. Can't reorient along the other two walls.
I suppose 60Hz is a good place as that's where the main speakers and woofers best match. A higher crossover and then I'll be throwing away part of the reason for getting those nice minis.
I guess if for some reason I can't guite get the waveforming working, I can always turn all of the woofers in phase, turn up the volume and blow the roof off.
;-)
Choices, choices. The main system... well, you haven't heard the upgrades to the Linn.... the op amps in the P3 yet and running it all balanced. ;-) All of that was done earlier this year. It did change the sound quite a bit... And I keep the volume down on the Maggies. I was a bit exhuberant when you heard them as I just had gotten the new amps.
In the meantime, we need to get some stools or chairs that we can take to Japan. The small Japanese style house we rented only has pillows and futons. I got no issues sleeping on a futon, but sitting on the floor, hmm... Unfortunately, we're only taking a small bluetooth stereo speaker and a Chromebook..
That's gonna be tough. 😉 😛
And yes, the front and back wall are different heights, nothing I can do about that. Can't reorient along the other two walls.
I suppose 60Hz is a good place as that's where the main speakers and woofers best match. A higher crossover and then I'll be throwing away part of the reason for getting those nice minis.
I guess if for some reason I can't guite get the waveforming working, I can always turn all of the woofers in phase, turn up the volume and blow the roof off.
;-)
Choices, choices. The main system... well, you haven't heard the upgrades to the Linn.... the op amps in the P3 yet and running it all balanced. ;-) All of that was done earlier this year. It did change the sound quite a bit... And I keep the volume down on the Maggies. I was a bit exhuberant when you heard them as I just had gotten the new amps.
In the meantime, we need to get some stools or chairs that we can take to Japan. The small Japanese style house we rented only has pillows and futons. I got no issues sleeping on a futon, but sitting on the floor, hmm... Unfortunately, we're only taking a small bluetooth stereo speaker and a Chromebook..
That's gonna be tough. 😉 😛
I have previously proposed a variation of the DBA. That is to use noise cancelling techniques to create bass absorbers on the back wall. This way they would not be connected to the main array in any way, they would just work, even if there were variations throughout the room.
Other than that, the array has been designed to produce a plane wave up to a certain frequency. If the mirrored array is different you may throw that off. If it happens to be better then at the least you'll have to scale it which could be an unnecessary pain to do.
If the room is not theoretically ideal, such as it has furniture or is not symmetrical, then you'll have a discrepancy on the delayed array. Who can say without measuring it.
Other than that, the array has been designed to produce a plane wave up to a certain frequency. If the mirrored array is different you may throw that off. If it happens to be better then at the least you'll have to scale it which could be an unnecessary pain to do.
(1) 60 Hz is where I'd like to do this, which is somewhat problematic as that an 18' wavelength.... Ideally I should be doing this at 100Hz with a wavelength of 11 feet, in a room with ~12x13x( 10->14 cathedral ceiling ). I guess I can play with it as I go along. Perhaps the smallest room that can support waveforming at 60Hz is 18'? We'll see. It might be a compromise between integration of the front speakers and the standing nodes in the room.
(2) I got two 3' x 1' cylindrical bass traps that I could put at the top of the back wall corners...
(3) I also got a quarter cylinder trap, 5' x 8" that I could put at the very top of the middle of the corner by the top of the back wall and the ceiling.
Those three bass traps should help to control the reflections from the top 4' of the back wall.
(4) I can mount the front and rear "top" woofers at 9' from the floor and make them symmetrical. The bottom woofers will be at floor level both for front and back. They will be symmetrical side to side as well.
I think that's the best I can do, unless I add two more woofers to the back wall ( for a total of six )... and turn the volume to match the acoustic power of four front woofers. I can also bring out a more power NAD 6 channel amp...
But, at some point I will have to figure out when enough is enough, huh?
Because, you see. I need to make sure that all of that is quake safe. If there's a quake and I'm sitting down with all of that stuff over my head...
The delay gizmo I got is for 8 output channels, I think it allows me to delay each channel separately, so I could play with that... but with so many channels, I'm gonna need to do some REW. Ideas?
(2) I got two 3' x 1' cylindrical bass traps that I could put at the top of the back wall corners...
(3) I also got a quarter cylinder trap, 5' x 8" that I could put at the very top of the middle of the corner by the top of the back wall and the ceiling.
Those three bass traps should help to control the reflections from the top 4' of the back wall.
(4) I can mount the front and rear "top" woofers at 9' from the floor and make them symmetrical. The bottom woofers will be at floor level both for front and back. They will be symmetrical side to side as well.
I think that's the best I can do, unless I add two more woofers to the back wall ( for a total of six )... and turn the volume to match the acoustic power of four front woofers. I can also bring out a more power NAD 6 channel amp...
But, at some point I will have to figure out when enough is enough, huh?
Because, you see. I need to make sure that all of that is quake safe. If there's a quake and I'm sitting down with all of that stuff over my head...
The delay gizmo I got is for 8 output channels, I think it allows me to delay each channel separately, so I could play with that... but with so many channels, I'm gonna need to do some REW. Ideas?
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We do what we can, and no more. Perfection doesn't exist, alas.
Match? That's what the DSP is for! With DSP you could go to 4th order (or higher...) lo / hi pass and drive the XO up if you wanna. Still using those Metronomes? The less bass those little FR's have to push they better they'll sound.
Almost like you needed a really nice little BT project!
I made, at one point, an active bass trap! Sub with a mic in front of it, mic input inverted and fed back to the sub, so that it drove itself toward zeroing output at the mic. Used opamp filters to hp + lp the mic feed, kept the sub sealed to reduce phase wackiness. The issue here is that it only worked at the mic location and was dependent on some significant amount of energy (rel to the room) appearing at the mic. I only made the one, so an array would probably have been more impactful (I was never able to measure an impact of it in-room). I think for a DBA, you could push the total energy from the absorbing array higher (to an extent), and depend on the room to smooth / approx the plane wave a bit, and thus get more impact from the absorbing array.
A related idea, however, is to use an active absorber on a speaker (on the back) to drive it to cardioid performance, I think that might be pretty cool. ANC design is non-trivial!
If we can make it work, the whole idea is that the room becomes infinitely long. Or rather, the back wall becomes a black hole. So you won't get any room gain - and sub output will be lower as a result - but it won't ring or resonate either. How well it works in reality is a question mark, of course. Bass traps sound like an interesting idea. I think in a world of perfect flexibility you'd maybe call the larger (taller) wall the emitter, and then the smaller wall the absorber and use the room as a horn to focus energy for easy (active) absorption. But whatever. Nothing is perfect. Give it a go if you're willing, I bet it will be interesting.
Egad! Yes, of course. I hadn't even considered that bit.
The subs on either end should work as a group. Perhaps you could make some gains by handling them individually, but I don't think that's how the concept works. You need 2 channels for your mains, and a single channel for the emitting sub array and a single channel for the absorbing array. If you are using passive subs (that Dayton? I haven't looked at the product spec) and need to find amp channels, you could probably run series / parallel to keep your amp requirements down.
Indeed, and congratulations.
Yes, I agree the need for an array remains in order to cover the wall up to a given frequency. Putting an extra absorber in here or there would be trivial, if there were a point to it, but it makes the other point of self correction and adaptability.
I've done that.... used to stack two pairs of AE1s, one on top of each other, in and out of phase, forward and backwards... biamped... ended up getting the Maggies.
It's not exactly what I'm looking for in here as the room is too small for a dipole.
On the rest... thinking about my reply.... ;-)
It's not exactly what I'm looking for in here as the room is too small for a dipole.
On the rest... thinking about my reply.... ;-)