Jump to content

DO HST-11 Build Thread with measurements


Electrodynamic

Recommended Posts

First off thanks to Paul for sending me the link to this forum. Honestly I didn't even know Data-bass had a forum. Oops. :) 

 

Second, and most imporantly, I decided to build a subwoofer to move a LOT air and work in a VERY small enclosure while still being able to play VERY low. Yes I am aware that there are words in capital letters that usually don't go together but with power being very affordable these days one can sacrifice sensitivity for LFE especially if the enclosure is going to be super small. I have a small house with small rooms and the one extra room that I had available to use measures 11' by 11' with an 8' tall celing. Enclosure size and space had to be as small as possible and I still wanted to have exceptional LFE along with enough output to put a smile on my face, which is not easy to do having been in the car audio SPL industry and owning a 150+ dB car before. :) 

 

So I decided to build a unique driver which became the HST-11. Yes it is an 11 inch woofer. The OD of the basket measures 11.25" so it's not a 10. The only frame that would support the travel I need is the newer, heavy, Sundown Audio frames used on their X and Z series drivers. The 11" frame allows for a total of 4.25" of peak-to-peak travel and utilizes an 8 3/8" spider landing. An 8 3/8" spider with a 3" coil ID offers a lot of cone travel - more than the basket can support. So I designed my own spider and moving assembly and used it along with the same motor I use on the HS-24" and HST-18" woofers to deliver the HST-11. 

 

Using two woofers in a dual opposed configuration will keep enclosure vibrations to a minimum and also have the smallest footprint for two drivers. The HST-11's are a sealed only woofer. They can not be ported. WinISD will tell you otherwise but even if you put one HST-11 into a 1 ft^3 box tuned to 19 Hz the 6" round port needed to cope with the amount of displacement the woofer is capable of ends up being over 25 FEET long. Sealed only guys. :) 

 

I had a local high-end cabinet and furniture maker in Troutman, NC build the enclosure for me. The enclosure has triple baffles on each end with double baffles on the four sides. I wanted the enclosure to have a natural look to it and to look like it was made by a person and not look super smooth in piano gloss black. I have a 2.5 year old son and the enclosure is in his "play room" (my media room) so piano gloss black would not last long, haha. 

 

Now for the pictures:

 

Enclosure being built - 

HST-11_Beg.jpg
DOHST11_box2.jpg
DOHST11_box3.jpg
Link to comment
Share on other sites

  • Replies 106
  • Created
  • Last Reply
I then picked up the enclosure from the builder. Very cool guy who is also moderately into speakers. I'm sure we are going to swap out work for product later. I requested the enclosure be finished as natural as possible while being black in color. We used two layer 3/4" arauco plywood. Not only were the panels doubled up but he took the extra mile to vacuum the panels together with wood glue between them for the highest strength. Anyway, I absolutely love the way the enclosure turned out. Is it 1000% perfect? No, but I like it that way. You can see that it was made by a person and the quality shows. Being an old-school wood worker most of the seams are dado joints (the inside brace between the drivers motors), etc. 

 

So, on with the build:

 

First time lugging the enclosure up the stairs to the media room:

DOHST11_Home.jpg

 

DOHST11_Home2.jpg

 

And then I began the extremely tedious task of installing the woofers. I do not like a non-treated enclosure and I have found through testing that with extremely small internal volumes that loose fiberglass insulation works the best to smooth out the FR while adding a touch of output on the bottom end. By small enclosures I am talking about these drivers. After the drivers displacement is accounted for there is about 0.4 ft^3 per woofer. Very small. 

 

DOHST11_AfterInsulation_andBeer.jpg

 

I managed to get the first woofer installed after finding out that zip ties were not going to work as the two zip ties I used to install the first woofer snapped and left the zip ties under the frame so the woofer rocked back and forth. I had to tip the enclosure over, remove the zip ties, and then use a rather unorthox method to mount the woofer. I used the smallest allen bit I had and placed it through the mouting hole of the driver and then mated it up with an open screw hole. It was my only chance of aligning the pre-drilled holes with the screw holes of the frame. Thankfully it worked out pretty good. 

DOHST11_ZipTiesNoWorky.jpg

 

Here is a look at how we used the PE dual screw terminals in the double 3/4" enclosure walls:

DOHST11_InsideTerminals.jpg

 

Picture of the twin HST-11's on the floor:

DOHST11_RawWoofers.jpg

 

How close the motors are to each other:

DOHST11_MotorsClose.jpg

 

Here is my before EQ and after EQ responses late at night. Keep in mind I took these measurements with my 2.5 year old son asleep in the next room. 

 

Absolutely zero EQ and low volume:

DOHST11noEQacFanOff.jpg

 

After first EQ adjustment:

DOHST11noEQacFanOff_AfterEQ_LowVolume.jp

 

Oops, I forgot I could lower the FR of the Omimic:

DOHST11noEQacFanOff_AfterEQ_ModVolume_la

Link to comment
Share on other sites

Here are two completed pictures:
 
DOHST11_Finished.jpg
 
DOHST11_FinishedWdvd.jpg
 
The OD of the enclosure measures 14"x14"x22".
 
And a FR of the OmniMic spec'd to read down to 5 Hz with higher resolution:
DOHST11noACthreeBandsEQ_21hz_26Hz53HzAt9

 

 

You can see the raw speaker wire in the picture and it is/was there on purpose. I "played" around with room placement and my suggestions over the past few years to customers proved correct again - best placement was in the middle of the front wall. I then ran my speaker wire inside the wall and down close to the floor behind the subwoofer cabinet so neither the wire nor the single gang opening can be seen with the woofer installed. 

Link to comment
Share on other sites

Today I got the opportunity to crank it up and measure at least one track. Using a UMM-6 mic and SpecLab software with BossoBass's configuration file I was able to grab this measurement while using the track "Bass I Love You". 

 

DOHST11BassILoveYouUMM6micNoClipping.jpg

 

FWIW: Earlier I had the OmniMic complete setup running and had to stop using it because I was hitting the peak dB limit too often. Every time it would get decently loud and go over 115 dB the big letters OVERDRIVE would flash across the screen and the measurement would temporarily stop. Haha.

Link to comment
Share on other sites

NICK!

 

Great to see you here and what a cool build!! I LOVE the 11" surround-with-dust cap drivers and the micro box DO design. A-w-e-s-o-m-e.

 

What are you driving the sub with? Can you run a close mic with just the sub and a 200 Hz crossover (or post the WinISD model FR if it's close to actual)?

 

Yeah, I love small. It makes multiples doable without looking stupid and, more importantly, it gets the job done. The SpecLab cap tells the story. Looking at the 9 Hz hit and seeing zero harmonic distortion at 2HD and 3HD is superb performance from a 2-1/2 ft^3 outside dim. box.

 

And, you're only running the sub 30dB hot.  :P:lol::o:blink:  I can stop breakin' Adam's balls now and concentrate on you. :D

 

I built a DO using 10s about 12 years back. The net interior volume was just under one cube. The exterior volume was smaller than yours because I used a 1/2" thick PVC cylinder for the enclosure. Of course, the drivers couldn't pump like the 11" top fuel dragster HSTs, but they kicked up some dust. The experts hate small and loved to throw Hoffman at me and all sorts of other cliches but the bottom line is always performance. In those days, there was no one even approaching flat-to-3 Hz cleanly at reference level, in-room. And, there still aren't many doing it today, relatively speaking.

 

Well done, my friend, and, glad to see ya here.

Link to comment
Share on other sites

Cool build Nick. What's that little sucker weigh 140?

 

Welcome to the forum.

 

The two drivers alone weigh 70 lbs each or 140 lbs together. The box probably weighs 25. So close to 170 lbs total. All I know is I'm not picking it up without help. :D I scoot it around a few inches here or there when I need to get to the wiring on the back side. Thankfully it scoots pretty good on carpet, haha. 

Link to comment
Share on other sites

NICK!

 

Great to see you here and what a cool build!! I LOVE the 11" surround-with-dust cap drivers and the micro box DO design. A-w-e-s-o-m-e.

 

What are you driving the sub with? Can you run a close mic with just the sub and a 200 Hz crossover (or post the WinISD model FR if it's close to actual)?

 

Yeah, I love small. It makes multiples doable without looking stupid and, more importantly, it gets the job done. The SpecLab cap tells the story. Looking at the 9 Hz hit and seeing zero harmonic distortion at 2HD and 3HD is superb performance from a 2-1/2 ft^3 outside dim. box.

 

And, you're only running the sub 30dB hot.  :P:lol::o:blink:  I can stop breakin' Adam's balls now and concentrate on you. :D

 

I built a DO using 10s about 12 years back. The net interior volume was just under one cube. The exterior volume was smaller than yours because I used a 1/2" thick PVC cylinder for the enclosure. Of course, the drivers couldn't pump like the 11" top fuel dragster HSTs, but they kicked up some dust. The experts hate small and loved to throw Hoffman at me and all sorts of other cliches but the bottom line is always performance. In those days, there was no one even approaching flat-to-3 Hz cleanly at reference level, in-room. And, there still aren't many doing it today, relatively speaking.

 

Well done, my friend, and, glad to see ya here.

 

Thanks Dave.  :D

 

I'm pretty happy to have been informed about this forum. All of the threads are informative and friendly. Not common these days on most forums.  :P

 

I'll take a close up measurement with the LP set to 200 Hz. I don't know when I can do it though - I'll have to have another "Nick Hour" to test the subwoofer system, which means my fiance' and son will need to be out running errands. 

 

Yeah yeah, the subs were VERY hot in that measurement.  :P  I need to do some room treatment to help my in-wall speakers sound better and I'd prefer to not rip my head off right now so I ran the subs very hot for that measurement. 

 

It's refreshing to hear you post about some people throwing Hoffman's Iron Law at you, haha. I got the same slack. But the cool thing is that these days you can grab cheap power for cheap. Not the best power out there but it is sufficient for most people, especially most DIY guys. So if you have a lot of power available you're not editing Hoffman's Law but you can say screw it to that weird looking pie chart with one massive section for power and use a massive amount of power with the proper drivers. These HST-11's are very well behaved unless I'm REALLY cranking on it with information that includes sub sonic. The only time I have heard any back talk from the drivers was when I was viewing the initial War Of The Worlds scene with the subs still at 30 dB hot. That's the only time so far. Either that, or it was something in the room falling like it was when the sun shade fell down while listening to Ghosts 'N Stuff.  :blink:

 

You and Paul need to come up here and hear these things. Most people are not aware but you live in the next city from me. Literally. Paul has my number - send me a text when you two are available for a few hours one weekend and we will spend some time in the media room cranking on the "little" guys. 

 

For power I am using an iNuke6000DSP. I know, I know.  :mellow:  But for this house I did not want to use anything decent and solid due to me having a 2.5 year old tazmanian devil of a son. I wouldn't put it past him to see what things he can stick inside the fan opening of the amplifier as he gets older and more curious. I'd rather him ruin this amplifier than ruin one of your beasts. 

Link to comment
Share on other sites

I put in Finding Nemo to see what all the buzz was about regarding the scene where Darla hits the fish tank as a reference of "see what your subs can do" to find a little surprise that my DO HST-11's were actually moving enough for me to feel them move on my fingertips. Keep in mind the time I measured this is 11:45 PM and I have a 2.5 year old asleep in a nearby room so the volume level was pretty low but the measurement is still there. Pretty surprising results but I know these HST-11's are not going to break a sweat playing that same scene even at full tilt. Having over 4" of cone travel on your subwoofers that have a natural in-room F3 of 26 Hz has its advantages.  :D

 

NemoDarlaFishTankDOHST11s.jpg

Link to comment
Share on other sites

Finally! Someone else who is running hot as hell posting Speclabs. :lol:

 

Hey Nick that looks like you still had it pretty loud even with a sleeping child haha. Out of pure curiosity how much do you think those little beasts had left in them? Also will you make another just for symmetries sake...or any reason you wanna choose. ;)

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.


×
×
  • Create New...