Pass SLOB Build Discussion

I won’t be able to make it to California for speaker camp, but maybe I will have my own. I just need to finish the bases under the slot, and mount the woofers and the speakers will be complete. I have a MiniDSP for initial testing and the LX mini/full range EQ to set up right after. I still need to work out all the values and make a digikey order. I will also need to re-arrange my listening space, and find a home in my home for my current speakers. I am running out of space.

IMG_8683.jpeg
 
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I was finally able to find the time to get my SLOBs up and running. I am using the Lii fast8 for the full range, SB bianco 150B350 woofer for the slot. I am using a MiniDSP 2x4 HD to handle crossover and eq for the time being. The fast 8s are being driven by ACAs, and the Bianco by a Emotiva A-150 75w amp. Below is the initial measurement with no eq. The UMIK was at ear height, 1 meter from the baffle.
SLOB xover no eq.jpeg

Crossover set at 80 hz low pass, 160hz high pass. Not too shabby right out of the gate, but that peak around 8k was noticeable. I pulled down the peak at 8800k and pushed up a little at 700hz and got pretty flat. I also boosted at 20hz a little because well, why not.
SLOB eq and 1st.jpeg

Here is the final curve versus the original. Made for a great listing session. I am really surprised at how good these sound with minimal correction. I will probably play with the eq a little, but for now I am really happy. A big thanks to Nelson for this project! This really beats my other speakers, and at a fraction of the cost.
SLOB 1st and final.jpeg

The next step to this project will be the LXmini/full rang eq.
 
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Founder of XSA-Labs
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Max upper bandwidth is controlled by depth of slot chamber and 1/4-wave cancellation. For example, an 8in dia driver would need a circa 9in deep slot to accommodate the driver bezel and baffle thickness. That’s a 0.229m deep slot and speed of sound is 342m/sec. 342m/sec / 0.229m /4 = 374Hz

A 15in dia driver and 16in deep slot depth on the other hand, will be about 210Hz upper bandwidth.

On my SLOB, I use 6.5in drivers and can achieve about 470Hz upper bandwidth. I use this natural falloff coupled with an electrical low pass at the same frequency to get a 4th order slope for 2nd order electrical filter in complexity.
 
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Founder of XSA-Labs
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The XSD uses inexpensive drivers with 75Hz fs and achieves -6dB of about 44Hz (nominal sensitivity of 93dB at 2.83v and 1m).

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More info here: https://www.diyaudio.com/community/threads/the-xsd-speaker.385717/

If you pick a more premium driver with a lower Fs, you can do a lot better. But since it uses 8 drivers per speaker (same Sd as two 12in drivers), the cost can add up fast.
 
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