Thiele-Small Parameter
Measured the Thiele-Small Parameters today (after ca. 2 months of use) using Dayton Dats:
Quite close to what is listed on Reckhorn's web site:
Thiele-Small Parameter: Re = 3,6 Ohm, Le = 1,195 mH, FS = 28 Hz, Qms = 5,69, Qes = 0,32, Qts = 0,30, Sd = 132 qcm, Vas = 17 l, Mms = 43 g, BL = 9,38 N/A. Wirkungsgrad: 83 dB 1 W / 1 m
Measured the Thiele-Small Parameters today (after ca. 2 months of use) using Dayton Dats:
Quite close to what is listed on Reckhorn's web site:
Thiele-Small Parameter: Re = 3,6 Ohm, Le = 1,195 mH, FS = 28 Hz, Qms = 5,69, Qes = 0,32, Qts = 0,30, Sd = 132 qcm, Vas = 17 l, Mms = 43 g, BL = 9,38 N/A. Wirkungsgrad: 83 dB 1 W / 1 m
Attachments
Finished
Sub is finished
Plateamp made with my own class d design running with +-40Vdc Connex Electronic SMPS, delivering some 200 W in the 4 ohm driver.
Learnings:
Rechorn D-165 is a mighty good driver.
It performs as specified, which is not a small feat only costing 30 Euro.
Highly recomended.
The passive drivers are not really up to the task. If you wanted to tune to 40 Hz, I think it would be ok, but not for going down to 25Hz. Not really recommended.
Sealing the plateamp to take the huge preassure in the small box is not at all easy. I still get some wisteling at high volume, so next time it will be with a separate compartment for the amp, to make totally sure the box is properly sealed.
The small preamp works really well. Can be recomended.
Had made room to a small cooling plate to connect the two regulator transistors to the back plate. But at the voltage her +-40V and using an NE5532 it was not necessary.
A fun project, with a really good result, despite the small hickups.
Next:
I think I will buy a D-165 more and make a vented version as shown in post #14, but using 2 drivers and reusing the plateamp.
Sub is finished
Plateamp made with my own class d design running with +-40Vdc Connex Electronic SMPS, delivering some 200 W in the 4 ohm driver.
Learnings:
Rechorn D-165 is a mighty good driver.
It performs as specified, which is not a small feat only costing 30 Euro.
Highly recomended.
The passive drivers are not really up to the task. If you wanted to tune to 40 Hz, I think it would be ok, but not for going down to 25Hz. Not really recommended.
Sealing the plateamp to take the huge preassure in the small box is not at all easy. I still get some wisteling at high volume, so next time it will be with a separate compartment for the amp, to make totally sure the box is properly sealed.
The small preamp works really well. Can be recomended.
Had made room to a small cooling plate to connect the two regulator transistors to the back plate. But at the voltage her +-40V and using an NE5532 it was not necessary.
A fun project, with a really good result, despite the small hickups.
Next:
I think I will buy a D-165 more and make a vented version as shown in post #14, but using 2 drivers and reusing the plateamp.
Attachments
Last edited:
Very nice project. Based on your recommendation on the D-165 I ordered 8 of them and will build a double bass array out of them. 2 drivers in 120cm long 20cm diameter cardboard tube wired in series, one in both ends. 2 of these tubes in the front, 2 at back with delay and reverse polarity.
Do you know if I can find the Hobby HiFi test and measurements of the drivers anywhere?
Do you know if I can find the Hobby HiFi test and measurements of the drivers anywhere?
Hi Mayuri
120 cm x Ø20 cm is 37 l ..... vented and tuned to 25 Hz?
Should be ok.
8 pcs more or less same as 2 x 12". Should be fine for a home theather, and for sure for music.
Maybe you should try to put them more asymetric. If place in each corner, you might as well put them al in one corner .....
Don't really know if you'll need the delay or the inverted polarity ... but of course good to have the posibibility
Please write with your results when finished.
120 cm x Ø20 cm is 37 l ..... vented and tuned to 25 Hz?
Should be ok.
8 pcs more or less same as 2 x 12". Should be fine for a home theather, and for sure for music.
Maybe you should try to put them more asymetric. If place in each corner, you might as well put them al in one corner .....
Don't really know if you'll need the delay or the inverted polarity ... but of course good to have the posibibility
Please write with your results when finished.
Not vented, sealed. I am running these out of miniDSP so I'll just boost the low end a bit.
The double bass array works on "pitcher-catcher" principle, where the front part of the array sets in motion a wavefront of bass, and the rear part cancels it. It is active dampening. More here:
Double Bass Array (DBA) - The modern bass concept! - AVS Forum | Home Theater Discussions And Reviews
First I was also interested in the prospect of multiple distributed subwoofers, Geddes-style, but the more I researched into double bass array, the more sense it made. But with 4 identical tubes and the MiniDSP 2x4 HD, I can try all of these configurations
The double bass array works on "pitcher-catcher" principle, where the front part of the array sets in motion a wavefront of bass, and the rear part cancels it. It is active dampening. More here:
Double Bass Array (DBA) - The modern bass concept! - AVS Forum | Home Theater Discussions And Reviews
First I was also interested in the prospect of multiple distributed subwoofers, Geddes-style, but the more I researched into double bass array, the more sense it made. But with 4 identical tubes and the MiniDSP 2x4 HD, I can try all of these configurations
Not sure if this is still of interest: I have the HobbyHifi 4/16 featuring the "ReSub" using this chassis.
The Sub is designed for desktop use and uses one D-165 as active chassis and one D-165 as a passive driver in 18l. To the passive D-165 20g extra weight was added. Powered by a Mivoc AM80 plate-amp which provides (fixed) +3db at 35Hz. In this set-up the sub reaches 28Hz at -3db.
In a second set-up with 80g extra mass and equailised by a mini-DSP the sub goes down to 20Hz (-3db).
Distortion at 90db is quite high but for desktop (80db) use it is OK.
Without extra weight the frequency response it flat to slightly below 40Hz.
The Sub is designed for desktop use and uses one D-165 as active chassis and one D-165 as a passive driver in 18l. To the passive D-165 20g extra weight was added. Powered by a Mivoc AM80 plate-amp which provides (fixed) +3db at 35Hz. In this set-up the sub reaches 28Hz at -3db.
In a second set-up with 80g extra mass and equailised by a mini-DSP the sub goes down to 20Hz (-3db).
Distortion at 90db is quite high but for desktop (80db) use it is OK.
Without extra weight the frequency response it flat to slightly below 40Hz.
Hi All,
FYI:
b
FYI:
b
Attachments
-
3_Alpair-7-gen3_Reckhorn D-165 in Sealed~6.5 liter-Box - Stereo Setup+Sub 1- 2-3 and 4.JPG -
2_Alpair-7-gen3_Reckhorn D-165_ in Sealed~6.5 liter-Box - Stereo Setup+Sub 1 and 2.JPG -
1_Alpair-7-gen3_Reckhorn D-165_ in Sealed~6.5 liter-Box-Stereo Setup.JPG -
c_Alpair7_Gen.3_BW2-70Hz_Reckhorn D-165_HOLMImpulse-sum.JPG -
b_Reckhorn D-165_~6.5-liter-SealedBox.JPG -
a_Alpair-7-gen3_Reckhorn.JPG -
Baldin_Reckhorn_D-165_Consistency-Chk_vs_Measured.JPG -
Reckhorn_D-165_#1.JPG
Hi Mayuri
Did you finish your array?
I'm thinking on upgrading my main speakers, or that is build some new ones.
I'm considering 6 x D-156 per side + 6.5" - 7.5" cardioid mid and a waveguided dome. Aiming for 110 db from 25Hz and up.
Like the drivers a lot, and they are just so cheap
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