DIY sub for Klipschorn based HT (and music) - Tuba HT - build done (except for finish)!

[Quiet_Hollow]

24" what?

[mustang guy]

For the THT's at 21" and wider, the best drivers are the DVC 385-88 and RSS390 HF-4. Both drivers are available at parts express

[psg]

Hi all,


So it's been nearly three years already with the Tuba HT, and I am
thinking of moving it and adding SPUDs to use as a second row riser.


I dug up an old SketchUp I had made initially to decide between the two
subs, and just added annotation to show you all what I am considering.

So the Tuba HT is currently at the base of the arrow. I am considering
moving it into an adjacent closet and have the opening shooting into the
HT room. I would lose corner loading, but the current location has
never been ideal acoustically anyway. I don't think the sound from the
THT will spill into that adjacent room. It it very stiff and does not
vibrate. I suppose the wall that the THT will be up against may carry
more LFE to the rest of the house. If that happens, I'll just use the
THT when it's not a nuisance (and just use the SPUDs).


Then I would build a pair of Spuds (are these still popular three years
later?) to use as a second row riser as indicated. I have yet to test
out an 11-inch step, which seems high to me.


Any thoughts? I recall people saying not to mix the SPUD and THT together.

[CECAA850]

They MAY have different horn lengths and need some sort of time alignment. Why not leave your THT where it is and build another for the new proposed location?

[psg]

Primary reason is that I need a riser anyway. Plus it might be nice to have the open space in the room. The THT is a much more complicated build as well, so building another weights heavier on me than the simple SPUD.

If I were to build another, I could still move the first in the proposed location and place the second similarly in the room adjacent to the back wall. So two hidden THTs. But seems a waste to build a riser and not use the volume as a sub. []

[psg]

I tried placing the THT up front, sideways, to mimick the response I might get from moving it up front. Not good. The blue line is
back-of-room placement (with EQ removed) and the green line is
front-of-room. (XO on receiver set to 200 Hz; main speakers unplugged)


Would room treatment fix the huge loss from 30 to 50 Hz? What kind?


I am about to (finally) put in my suspended ceiling, so I'll need to try
this again when it's done. But the ceiling is already filled with 6
inches of Roxul so i don't expect much change.

[CECAA850]

The dip looks like a cancellation. The only way to stop that would be bass traps in the corners that I'm aware of. Unplugging your mains as you have has eliminated phase as a concern.

[psg]

Looks like cancellation to me as well.Has to be, the sub itself hasn't changed.

So a large panel on the back wall won't do anything for bass, right? Too thin?

Thick pieces such as wedges are required for bass? Thinkthey would work that much?

[CECAA850]

They help quite a bit. Bass traps have to be large and thick. They work best in corners. There's a bunch of DIY's on them. I went the lazy route and ordered mine from GIK.

[ZombieWoof]

OK read the whole thread finally had skimmed it a few times in the last couple of years

BUT now that I'm gonna build 2 THT Low Profile come this spring I thought it best to read it all ,

what great work from all the different builds , Peter what a great thread & a Great build

the Stanley's are just too pricey for me & the L P THT will work for the living room better in my case

I love my SVS cylinders but I want a bass horn

can you say more about how that miniDSP works ?

[CECAA850]

can you say more about how that miniDSP works ?

Good info HERE . Click the first time user button.

In simplistic form, a minidsp is an adjustable inline eq. Adjustments are made on your computer and programed into the minidsp. It's then put in the signal path between your receiver and sub amp.

[RRFL]

I tried placing the THT up front, sideways, to mimick the response I might get from moving it up front. Not good. The blue line is

back-of-room placement (with EQ removed) and the green line is

front-of-room. (XO on receiver set to 200 Hz; main speakers unplugged)

Would room treatment fix the huge loss from 30 to 50 Hz? What kind?

I am about to (finally) put in my suspended ceiling, so I'll need to try

this again when it's done. But the ceiling is already filled with 6

inches of Roxul so i don't expect much change.

From my understanding this issue will be related to the location of the mouth in the room relative to the distance from reflective surfaces that cause certain wavelengths to cancel at certain positions in the room and only stopping the occurrence of the reflection can resolve this.

Or move the mouth.

[mustang guy]

Hi all,

So it's been nearly three years already with the Tuba HT, and I am

thinking of moving it and adding SPUDs to use as a second row riser.

I dug up an old SketchUp I had made initially to decide between the two

subs, and just added annotation to show you all what I am considering.

So the Tuba HT is currently at the base of the arrow. I am considering

moving it into an adjacent closet and have the opening shooting into the

HT room. I would lose corner loading, but the current location has

never been ideal acoustically anyway. I don't think the sound from the

THT will spill into that adjacent room. It it very stiff and does not

vibrate. I suppose the wall that the THT will be up against may carry

more LFE to the rest of the house. If that happens, I'll just use the

THT when it's not a nuisance (and just use the SPUDs).

Then I would build a pair of Spuds (are these still popular three years

later?) to use as a second row riser as indicated. I have yet to test

out an 11-inch step, which seems high to me.

Any thoughts? I recall people saying not to mix the SPUD and THT together.

Placement in the top-right corner should be the best. Here are placement instructions for the THT:

"Placement

Boundary loading should be used whenever its practical to do so. Having subs next to a wall gets you 6dB of additional sensitivity below about 80Hz, and putting them in a corner an extra 12dB. In most cases youll have best results with the cabinet mouth on the floor against one wall, about 18 inches from the adjacent wall. If the cabinet mouth is a quarter-wavelength from a boundary there will be up to a 24dB deep cancellation at that frequency. Within the nominal bandwidth of the THT a quarter-wavelength ranges from 19 feet at 15 Hz to 2.8 feet at 100 Hz, so middle of room placement usually wont work well."

By looking at your sketchup, the THT is shoved back into the corner, probably with the mouth facing away from the wall. If you turn it 90 degrees and face the mouth toward the top wall with the mouth 18" back from that wall, you should get some decent response with the least amount of standing waves.

[RRFL]

OK read the whole thread finally had skimmed it a few times in the last couple of years

BUT now that I'm gonna build 2 THT Low Profile come this spring I thought it best to read it all ,

what great work from all the different builds , Peter what a great thread & a Great build

the Stanley's are just too pricey for me & the L P THT will work for the living room better in my case

I love my SVS cylinders but I want a bass horn

can you say more about how that miniDSP works ?

Personally, I prefer the Dayton RSS390HF-4 15" aluminium cone driver. It's cleaner than the other recommended driver DVC385-88. The Rss390HF-4 was reproducing Cymbals rather well when I played music through it during breakin. I did not expect anything much above 800hz. The DVC385-88 is more sensitive but not as clean. The THT LP were all built in 24" wide 1/2 the width of a sheet of plywood except for a pair I built in 16" wide 1/3 the width of a sheet of plywood. For these 16" wide I used the RSS315HF-4 12" aluminum Cone Driver and they are also very clean.

In 15", I have built a single a set of three and a set of two so as to experiment with the combined mouth sizes. The 7th & 8th were the pair of 12". The 12" pair are 16"x18" mouths, so you can add them together to create a combined 32"x18" mouth or a 16"x36" mouth. Currently they are set up as 16"x36" mouth and pointing at the ceiling with one wall on the 16" edge. When listening from the 16" edge performance is not wonderful. When listening from the 36" edge performance is fantastic. They are matched with my LaScala and I very much like the result. They have the LaScala clarity that goes out below you hearing when there is low bass in the recording. They don't invent there own bass like many other sub woofers that just woof woof woof. The THT LP are not boring they become essential. I like the shape 6' long as it's easy to place and point into a corner from any direction.

I have finished my experimenting now and at the moment I intend for my Jubilee LFE to build a pair of 24"x18" with the RSS390HF-4 15" drivers and stack the along the back wall into the back left corner under the stair case 36"x24" mouth shape. The stairs are to be altered to be minimal and remove the risers having only the treads and stringers with two triangular treads in the corner then three treads to the floor.

I trust this experience is useful in assisting with your choice.

[ZombieWoof]

OK read the whole thread finally had skimmed it a few times in the last couple of years

BUT now that I'm gonna build 2 THT Low Profile come this spring I thought it best to read it all ,

what great work from all the different builds , Peter what a great thread & a Great build

the Stanley's are just too pricey for me & the L P THT will work for the living room better in my case

I love my SVS cylinders but I want a bass horn

can you say more about how that miniDSP works ?

Personally, I prefer the Dayton RSS390HF-4 15" aluminium cone driver. It's cleaner than the other recommended driver DVC385-88. The Rss390HF-4 was reproducing Cymbals rather well when I played music through it during breakin. I did not expect anything much above 800hz. The DVC385-88 is more sensitive but not as clean. The THT LP were all built in 24" wide 1/2 the width of a sheet of plywood except for a pair I built in 16" wide 1/3 the width of a sheet of plywood. For these 16" wide I used the RSS315HF-4 12" aluminum Cone Driver and they are also very clean.

In 15", I have built a single a set of three and a set of two so as to experiment with the combined mouth sizes. The 7th & 8th were the pair of 12". The 12" pair are 16"x18" mouths, so you can add them together to create a combined 32"x18" mouth or a 16"x36" mouth. Currently they are set up as 16"x36" mouth and pointing at the ceiling with one wall on the 16" edge. When listening from the 16" edge performance is not wonderful. When listening from the 36" edge performance is fantastic. They are matched with my LaScala and I very much like the result. They have the LaScala clarity that goes out below you hearing when there is low bass in the recording. They don't invent there own bass like many other sub woofers that just woof woof woof. The THT LP are not boring they become essential. I like the shape 6' long as it's easy to place and point into a corner from any direction.

I have finished my experimenting now and at the moment I intend for my Jubilee LFE to build a pair of 24"x18" with the RSS390HF-4 15" drivers and stack the along the back wall into the back left corner under the stair case 36"x24" mouth shape. The stairs are to be altered to be minimal and remove the risers having only the treads and stringers with two triangular treads in the corner then three treads to the floor.

I trust this experience is useful in assisting with your choice.

YES ,

this help immensely, that Dayton RSS390HF-4 is what I was looking at as a driver due to the rubber surround & AL cone , to actually have someone comment on how it works in THT LP is priceless to me . Bill's site the guys really just say follow the plans & not much else .

that 24" x 18" size makes the best of a sheet of birch plywood , I have a local source for 4 x 8 sheets of 1/2" Russian birch .

I hope to place them on the floor with the opening aimed at the front & then the rear corners

[psg]

Hi all,


So it's been nearly three years already with the Tuba HT, and I am
thinking of moving it and adding SPUDs to use as a second row riser.


I dug up an old SketchUp I had made initially to decide between the two
subs, and just added annotation to show you all what I am considering.

So the Tuba HT is currently at the base of the arrow. I am considering
moving it into an adjacent closet and have the opening shooting into the
HT room. I would lose corner loading, but the current location has
never been ideal acoustically anyway. I don't think the sound from the
THT will spill into that adjacent room. It it very stiff and does not
vibrate. I suppose the wall that the THT will be up against may carry
more LFE to the rest of the house. If that happens, I'll just use the
THT when it's not a nuisance (and just use the SPUDs).


Then I would build a pair of Spuds (are these still popular three years
later?) to use as a second row riser as indicated. I have yet to test
out an 11-inch step, which seems high to me.


Any thoughts? I recall people saying not to mix the SPUD and THT together.

Placement in the top-right corner should be the best. Here are placement instructions for the THT:

"Placement

Boundary loading should be used whenever it’s practical to do so. Having subs next to a wall gets you 6dB of additional sensitivity below about 80Hz, and putting them in a corner an extra 12dB. In most cases you’ll have best results with the cabinet mouth on the floor against one wall, about 18 inches from the adjacent wall. If the cabinet mouth is a quarter-wavelength from a boundary there will be up to a 24dB deep cancellation at that frequency. Within the nominal bandwidth of the THT a quarter-wavelength ranges from 19 feet at 15 Hz to 2.8 feet at 100 Hz, so middle of room placement usually won’t work well."

By looking at your sketchup, the THT is shoved back into the corner, probably with the mouth facing away from the wall. If you turn it 90 degrees and face the mouth toward the top wall with the mouth 18" back from that wall, you should get some decent response with the least amount of standing waves.

Yeah, that sketchup made drawn up before I bought the plans and then realised it had to be placed away from wall. The mouth faces a sidewall at an angle and the response wa a bit better than facing the corner.

Here's an old picture:

The reason to meove it to the front of the room is only to get the floor space back, as it would occupy space in a closet there.

[CECAA850]

Floorspace.

I know it's impractical in many applications, but that's one of the great things about an IB, No box in the room.

[mustang guy]

Yeah, that sketchup made drawn up before I bought the plans and then realised it had to be placed away from wall. The mouth faces a sidewall at an angle and the response wa a bit better than facing the corner.

Here's an old picture:

The reason to meove it to the front of the room is only to get the floor space back, as it would occupy space in a closet there.

You will get the most standing wave trouble in the middle of the room. That is your problem here. The sub should be touching the wall on the side, and 18" from the wall the mouth is facing. Under the DVD racks would be perfect. The side of the sub against the wall under the DVD's, and the mouth 18" from the right wall pictured.

[ZombieWoof]

Floorspace.

I know it's impractical in many applications, but that's one of the great things about an IB, No box in the room.

Yeah , you need a room with a extra room on the other side of the wall the wall space or ceiling & attic or a hole i the floor & a crawl space ,

I have all of the above in my house , but I gonna try the THT L P , that cutting holes in the house is not a wife [:@] friendly process .

I'm gonna look into my house & see if a IB would work , but I 'll build the pair of THT LP 1st . Good DIY subs sell very easy , My SVS Cylinders will sell fast when I build the THT L P

I have the skill set to build a set THT's that will be finished very nice , that's the best part of DIY if you build it real nice someone is always willing to fork over serious cash for your work

CECAA850, That Black high gloss sub of yours would sell in minutes if you offered it up for sale .

[CECAA850]

I have all of the above in my house , but I gonna try the THT L P , that cutting holes in the house is not a wife friendly process .

My wife was very understanding. When I told her we'd pull one huge box and one big black tube out of the living room, she was all over it. More room, less things to vacuum around. I was even going to make some nice grills for the openings but she said she liked the way the drivers looked!

CECAA850, That Black high gloss sub of yours would sell in minutes if you offered it up for sale .

Thanks but then what would I use with my Lascalas????[]