S11 OB - Revisiting Desktop OB design using Seas 8" and Tang Band Full-Range

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Great work Gainphile!

Those were the inspiration of this design I did. I already have the woofers, except for the bass drivers. I have the passive crossover planned out but I still have to buy the stuff

B&G Neo3w dipole tweeter
Fostex FW168HR Midwoofer
Tang Band W5-1138SMF Subwoofer

The crossover points are 800Hz and 3000Hz, slopes are all 2nd order LR acoustically, but electrically the high pass on the Fostex driver is only a first order, that combines with the 6dB dipole rolloff.

The tweeters and woofers are open baffle, subwoofers are small (.12 ft3) sealed enclosures:

F3 70 Hz
F6 55 Hz
F10 41 Hz

I will likely add a dedicated subwoofer later, but it will probably not always be on. This should be fine for most music with a bit of eq. With room acoustics i should get some nice bass. I would have liked OB bass but the Fostex drivers only have 2.65mm of xmax, I figure sealed is the next best...

This is a budget build (except the woofer and tweeter, which I already had) because my computer died and I bought a new one. The cost of the crossover is about $116. I will run it with my gainclone.

This is what I plan to take to college, I need something really good or I will miss my home system. Compared to what I am used to, with a 12ft3 subwoofer and spawn double horns, this size desktop speaker is tiny!
 

Attachments

  • OB Hybrid Front.png
    OB Hybrid Front.png
    140.4 KB · Views: 1,062
  • OB Hybrid Back.png
    OB Hybrid Back.png
    88.8 KB · Views: 1,036
  • OB Hybrid Scale.png
    OB Hybrid Scale.png
    29.6 KB · Views: 1,008
Hi kctess5,

looks very nice :) . Concerning OB-Bass you might have a look at gainphile's S20z n-dipole-sub. I have a slightly modded one running with two Dayton SD270 drivers which are quite low priced for a 10" woofer (around $40 at PE).
Nearfield measures show a possible f3 at 30 Hz (f6 around 22 Hz) without EQ-help :D. I attached two pictures. One is the 3D-design the other one my test-mule ;).

picture.php


picture.php


Greets
Sven
 
Great work Gainphile!

Those were the inspiration of this design I did. I already have the woofers, except for the bass drivers. I have the passive crossover planned out but I still have to buy the stuff

B&G Neo3w dipole tweeter
Fostex FW168HR Midwoofer
Tang Band W5-1138SMF Subwoofer

The crossover points are 800Hz and 3000Hz, slopes are all 2nd order LR acoustically, but electrically the high pass on the Fostex driver is only a first order, that combines with the 6dB dipole rolloff.

The tweeters and woofers are open baffle, subwoofers are small (.12 ft3) sealed enclosures:

F3 70 Hz
F6 55 Hz
F10 41 Hz

I will likely add a dedicated subwoofer later, but it will probably not always be on. This should be fine for most music with a bit of eq. With room acoustics i should get some nice bass. I would have liked OB bass but the Fostex drivers only have 2.65mm of xmax, I figure sealed is the next best...

This is a budget build (except the woofer and tweeter, which I already had) because my computer died and I bought a new one. The cost of the crossover is about $116. I will run it with my gainclone.

This is what I plan to take to college, I need something really good or I will miss my home system. Compared to what I am used to, with a 12ft3 subwoofer and spawn double horns, this size desktop speaker is tiny!

Very interesting and well-thought design ! Let us know the build progress.

That W5 is very interesting isn't it. I wonder if one could do a w-frame styled "micro subs" with those. 9.5mm is surely an excellent excursion for the size. Price is even better !
 
That W5 is very interesting isn't it. I wonder if one could do a w-frame styled "micro subs" with those. 9.5mm is surely an excellent excursion for the size. Price is even better !

They look great, I've used Tang Band subs before and if they are of similar quality then I should be quite pleased. 9.5mm is astounding for that size, they should work nicely in sealed boxes. I think with two of them I may not even feel the need for a sub, especially with a bit of eq, the displacement is similar to my small 12" sub. They might be able to do open baffle but they will be quite close to the back wall, and I will have very limited eq options. Plus I need to keep size down, the dorm desks are quite small

Very interesting and well-thought design ! Let us know the build progress.

Thanks! When I finally get the budget to do it I will probably give it its own thread so I don't hijack yours. BTW great designs, I always like checking out your blog
 
Hi kctess5,

looks very nice :) . Concerning OB-Bass you might have a look at gainphile's S20z n-dipole-sub. I have a slightly modded one running with two Dayton SD270 drivers which are quite low priced for a 10" woofer (around $40 at PE).
Nearfield measures show a possible f3 at 30 Hz (f6 around 22 Hz) without EQ-help :D. I attached two pictures. One is the 3D-design the other one my test-mule ;).

Greets
Sven

Indeed great find with SD270. Thanks for sending me the nearfield .frd earlier!

Here is a comparison between SD270 with my Jaycar. Yellow graph is the eq needed for F3=20hz.

Dayton SD270

SD270.png




Jaycar CW2139

Jaycar.png



This dipole sub should work well if you have the space.
 
Plan or measurements?

do you have the plans or box measurements for the Sub?

Hi kctess5,

looks very nice :) . Concerning OB-Bass you might have a look at gainphile's S20z n-dipole-sub. I have a slightly modded one running with two Dayton SD270 drivers which are quite low priced for a 10" woofer (around $40 at PE).
Nearfield measures show a possible f3 at 30 Hz (f6 around 22 Hz) without EQ-help :D. I attached two pictures. One is the 3D-design the other one my test-mule ;).

picture.php


picture.php


Greets
Sven
 
Hi Gainphile,
I'm looking for a desktop ob speaker and have found your S11 OB projekt on your blogspot. It's exactly what I like to build; but I wanna do this in passive way. Would it be possible to create a crossover plan with the required parts ? I'm unfortunately not able to Develop a crossover by myself.
It would be great cause I really love the design of your speaker...

Sorry if my english is a little bit bumpy...
 
Well that was a quick project which turns out nice.

DSC_0236.jpg


The speakers are really small. I attached a pic with my notebook as scale. Very pleasing.

About the bass... the optimum compromise between distortion, listening level, and excursion is 40Hz. That's pretty deep, dipole or not. The woofers are working reaaaaallly hard. Some 30Hz can be felt but not respectable. Below 30Hz is just asking for trouble. These metal cone makes horrible sound when bottomed :D. It's simply just physics and there is no way I could get more, except putting again a pair of 15" on my desk.

The problem down low is also related to materials. LP rips have those pesky subsonic rumble which drives the cone to excursion to maximum a lot quicker than the program material. A 2nd order highpass at 17Hz fixes that effectively at the cost of group delay. I could not hear it.

Aside from that the speakers makes really great bass, but you already know what dipole bass is all about. I think it's like a good espresso. Small in quantity but what comes out is pure. I have a Yamaha sub below the desk and while it can provide the extension to last octave, it degrades the quality of the whole system. I turn it off and perhaps will use it to watch movies.

The distance to rear wall is about 35cm. I did could not hear any faults. Comparing to my living room dipoles (which is 1m from rear wall), maybe a bit less soundstage, but that's really nitpicking. Phantom image is very scary, almost like the speakers making no sound and the music comes out of the wall. Listening to some classical recording I got goosebumps. If there is one best thing that stands out from them, it's the midrange.

The TangBand as tweeter, well this is new to me. It actually makes great tweeter and I can't hear lack of high. Even better, I think the transition from w-t is smoother than normal dome tweeter that I have been using. This warrants another investigation, perhaps using the TangBand as my livingroom tweeters. But I listen nearfield with these (1m - 2m) so maybe that's why it's ok. I did not lower the xo point as my listening so far can't hear any faults with 1.5kHz.

Thanks all for reading/comments. Now I'm going to listen to some music. :cool:



Dear Gainphile, i am new here. As an enthusiast of open baffle speakers, i greatly appreciate what you have engineered here. S11 OB is intensely intriguing!

Due to being a lay-person, i have a natural question which i hope you will be considerate with in responding. :)

* May i know the amplifier wattage until which these Seas bass drivers remain well within its excursion limits.... both:

1. without &
2. with
....the 2nd order high-pass you have applied at 17 hz?

Thanks!
Sujat
 
Hello Gainphile,

I am working on a domestic hobby based 2-way speaker system for personal use, in a room L×W×H = 22 ft. X 16 ft. X 12.5 ft. Given this, i think i should need to feed it with up to 20 watts/channel and yet ensure that the 8" midbass remains well within its excursion limits of 3mm. I am aiming for a long term SPL of 99-100 dB at 1 metre, which i suppose is a reasonable expectation for personal use.

So my query is, is there a set of criteria (eg: Cms, etc.) that i should look for in an 87 dB/watt/metre sensitive 8" midbass driver to suit an open baffle (or probably a very lightly loaded.... Vb=Vas*4 sized sealed enclosure), ensuring that the 8" midbass remains well within its excursion (and distortion) limits of 3mm?

Even an approximate set of values should be of GREAT help to me in extrapolating a bit and eventually working my way to reach the desired target!

Thanks and regards,
Sujat
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.