TangBand W4-657SC Project

[Veke76]

I bought recently TangBand W4-657SC drivers and 3 pcs of 1000x200x18mm glued pine board and I'm starting to build my first DIY speakers. I was inspired to start this project after listening fullrange Gradient Preludes and my PC got Logitech Z-2200 speakers which are TangBand W3-series. Those sound great to me so why not start your own speaker project.

The speakers are planned to be used as a second stereo set in kitchen/terrace/sauna/bedroom. Music source is iPod touch and amplifier is Harman/Kardon HK 3370.

The box itself is planned to be sized (WxHxD) outside 150x240x236mm and inside 114x204x200mm. After sawing there should be 240x150mm 4pcs, 240x200mm 4pcs and 114x200mm 4pcs. Volume of box is planned 4,65 Litre (acoustic volume 4 Litre). The box will be bass reflex tuned to 70 Hz and will have 45mm reflex port at length of 200mm.

I have used WinISD Pro to verify my plans. Couple of points which i found out is that:
1. Low frequency extension will be -3dB @ 81Hz and -6dB @ 67Hz
2. Max listening power will be 15W which will produce 101dB@1 meter and 92dB@3 meter. The cone excursion will be out of limits if more power is used.
3. Frequencies below 60 Hz should be filtered out. So I planned to use a high pass filter.

[Veke76]

The plans for high pass filter is to use 3 or 4 pcs of Intertechnik Audyn-Cap ELKO glatt bipolar 100 MF/35 VAC 5%. 300MF or 400MF connected in series to plus in the speaker.

Filters will be 300MF(-3dB@66Hz) or 400MF(-3dB@50Hz) and 6dB per octave.

The low frequency extension of the speakers will be affected by the filters, but because of impedance rising to max 60 ohms it won't be so bad.

What troubles me is that capacitors are rated only 35 VAC. In theory short term voltage could rise over that when impedance is 60 ohms. I could have bought 400 VAC capacitors but the price would have been 6 times more!

[Godzilla]

>>> The box will be bass reflex tuned to 70 Hz...

That's probably just about right. I don't think you will need to use a hi pass filter because the speaker will drop off naturally. But if you need more volume i would recommend adding a powered subwoofer and (maybe) stuffing the port to make the speaker a sealed box. You can also run the speakers thru the powered sub which will 'filter out' the bass but i prefer to run them straight from the power amp because it sounds better to me. Also, you might want to consider a tweeter. I've added tweeters on the back so not to spoil the full range look.

TangBand W4-1320 4" Bamboo full range driver

My project uses the tb 4" bamboo driver but i would imagine there are similarities between these speakers especially regarding their bass tuning and limitations.

[Veke76]

Ok. One weekend wasn't enough to get the speakers finished. Status of the project is 75% ready.

Boxes are pretty much finished. Some sanding, stain&lacquer and installing components is needed.

[Veke76]

Originally Posted by Godzilla

>>> The box will be bass reflex tuned to 70 Hz...

That's probably just about right. I don't think you will need to use a hi pass filter because the speaker will drop off naturally. But if you need more volume i would recommend adding a powered subwoofer and (maybe) stuffing the port to make the speaker a sealed box. You can also run the speakers thru the powered sub which will 'filter out' the bass but i prefer to run them straight from the power amp because it sounds better to me. Also, you might want to consider a tweeter. I've added tweeters on the back so not to spoil the full range look.

TangBand W4-1320 4" Bamboo full range driver

My project uses the tb 4" bamboo driver but i would imagine there are similarities between these speakers especially regarding their bass tuning and limitations.

You got me intrested in tweeters! Allthough the speaker is not finished I have made plans to add TangBand 28-847S at top of box. Here is the "plan B" crossover circuit for it. DIYAudioAndVideo.com has great tutorial about crossover designing. I'll probably get my speakers finished next weekend so after that I'll see if "plan B" is set to go.

C1 = 7.95 uF (2500 Hz highpass 1st Order Butterworth)
L1 = 0.51 mH (2500 Hz lowpass 1st Order Butterworth)
R1 = 1.65 Ohms (LPad 2 dB)
R2 = 30.9 Ohms (LPad 2 dB)
C2 = 400 uF (50 Hz highpass 1st Order Butterworth)

[Veke76]

Two weekends spent building the speakers. Well maybe next weekend those will be ready.

I found a second option for tweeter TB 25-1719S. Good response all the way to 30kHz! Example of the crossover components can be seen on Standbox BPA CerAl 4.1

Maybe it's better select proven build of components than start building the crossover by yourself. Especially getting the right specs for components can be tricky.

I'm not sure wheter to go with 2-way system or stick with FR. Maybe I'll figure it out after carefull listening sessions with speakers.

[Veke76]

Here is couple of pictures of my TangBand W4-657SC Project. It's now finished!

[Veke76]

Short listening test revealed that everything works ok and sound is ok. I couldn't hear any problems in upper range and lower range works ok. There is actual bass coming from the speakers. Subwoofer with these would be nice Couple of pics from my test session

[Godzilla]

Cute and cost effective. Thanks for sharing the pictures.Great job! Now, what will your next project be? You can't just stop at one...

Zilla

[chrisb]

Originally Posted by Godzilla

Now, what will your next project be? You can't just stop at one...

Zilla

kinda like 'tater chips