SB Acoustics SB20FRPC30-8 (8" Fullrange Cheap Monster II)

Nice to hear. You are driving both drivers from one amp? which amp, just curious?
thanks for posting your project progress. 👀
Thanks! Yes, one amp, the M2x. The simulated sensitivity of the speaker is about 93 dB or so, so 25w seems to be okay.

Looks great. Do you mind me asking what the specs are for your crossover please?

I see you use IKEA chopping boards too! I bought a job lot earlier this year - well worth the money!
Thank you! As I wrote, the xo (and the whole speaker) is not ready, so the values are subject of change. At the moment, for the woofer I use a 4.7mH toroidal inductor only. For the FR a 60uF cap, in series with a 5.1 ohms resistor, followed by an RL complex (inductor with 5mH, R with 2.2 ohms). That's it. And again, it's a trial at this stage.
Tomorrow I will short the RL in order to check how it behaves when the treble is unregulated, and as a second trial I will decrease the seriell R.
btw those components look like some serious sh*t esp the turntable 😵
oh, now I see in your other OB thread. Yeah expensive looking stuff and brands I never heard of before.
:cheers: I'm sure you know Marantz and Project stuff. The other things... diy 😀
 
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Picture of @nandappe SB 8" speakers. Looks good.
 

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I got the speakers reassembled after the modifications, which are:
1) Assembling a frame on the back which acts as bracing - I used 25 x 25 mm pine.
2) The central panel (darker bit) is 18mm MDF with 6mm closed-cell foam between it and the pine baffle - this has really reduced the baffle resonance.
3) 6mm open cell foam strips applied to the inside of the frame around the driver.
4) Platforms to raise the front to help tilt backwards.

My father came around today and we had a listening session - he was impressed. Compared with previously the sound it cleaner and clearer. We listened to a range of music but also a CD he recorded with him playing piano accompaniment to a soloist - this included songs by Strauss and Greig - he said it sounded 'magnificent' so I'm happy with that 🙂.

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I got the speakers reassembled after the modifications, which are:
1) Assembling a frame on the back which acts as bracing - I used 25 x 25 mm pine.
2) The central panel (darker bit) is 18mm MDF with 6mm closed-cell foam between it and the pine baffle - this has really reduced the baffle resonance.
3) 6mm open cell foam strips applied to the inside of the frame around the driver.
4) Platforms to raise the front to help tilt backwards.

My father came around today and we had a listening session - he was impressed. Compared with previously the sound it cleaner and clearer. We listened to a range of music but also a CD he recorded with him playing piano accompaniment to a soloist - this included songs by Strauss and Greig - he said it sounded 'magnificent' so I'm happy with that 🙂.

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Nice mods. Did you ever lay them on their sides to see the affect if any on the bass response?
I still think you'd get better sound overall if you made them a lot shorter, leaning back more, to get the drivers much closer to the floor.
 
I got the speakers reassembled after the modifications, which are:
1) Assembling a frame on the back which acts as bracing - I used 25 x 25 mm pine.
2) The central panel (darker bit) is 18mm MDF with 6mm closed-cell foam between it and the pine baffle - this has really reduced the baffle resonance.
3) 6mm open cell foam strips applied to the inside of the frame around the driver.
4) Platforms to raise the front to help tilt backwards.

My father came around today and we had a listening session - he was impressed. Compared with previously the sound it cleaner and clearer. We listened to a range of music but also a CD he recorded with him playing piano accompaniment to a soloist - this included songs by Strauss and Greig - he said it sounded 'magnificent' so I'm happy with that 🙂.

View attachment 1111262View attachment 1111263View attachment 1111265View attachment 1111266
I like it! Regarding bass, you could also turn the whole speaker upside down, just mount the support around the speaker, I think it would be an easy task.
 
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Some tweaks... First I removed the wings, but it led to a very thin bass - but to more clear mids, more liveliness; sure, my woofer are mounted at about 70 cm, so no floor effect. Next I shorted the wings as shown in the picture and the bass came back, but I still missed some liveliness. So I reduced the serial resistor (level adjustment for the FR) from 5,1 ohms to 3,6 ohms. Now it sounds better than at the beginning. Small steps 🙂
I think I will make a measurement soon. But it means, I measure my ears, in fact :rofl:

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Nice mods. Did you ever lay them on their sides to see the affect if any on the bass response?
I still think you'd get better sound overall if you made them a lot shorter, leaning back more, to get the drivers much closer to the floor.
Not yet I’m afraid. I will do at some point. The room they are in at the moment does not have space for them to lay side-ways but our lounge does so I will have a try.
 
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