Enginerding with Weeb Labs

[jtwrace]

Exactly. Similar in function to that board but much smaller and with TDM support.

And in stock.

I'm sure the diyaudio forum guys will buy 'em up

 

[Weeb Labs]

First board assembled!

Time for testing.

 

[JayGilb]

First board assembled!

View attachment 159183

Time for testing.

The SRC4192 really is a self contained solution. Not much support hardware required, looks like a few SMT passive components, an oscillator and one transistor and a dip selector.

How was this assembled ? After watching a few of your vids, I'm guessing you designed/assembled a pick-n-place robot and a soldering oven.

 

[Weeb Labs]

The SRC4192 really is a self contained solution. Not much support hardware required, looks like a few SMT passive components, an oscillator and one transistor and a dip selector.

How was this assembled ? After watching a few of your vids, I'm guessing you designed/assembled a pick-n-place robot and a soldering oven.

For these initial boards, I'm using the SRC4190. With a unit price of EUR 6, it's a significant savings over the EUR 12 SRC4192 and is essentially identical (pin compatible).

I assembled this one by hand, which is something that I enjoy doing when time isn't in limited supply. For the larger runs, I will either avail of JLCPCB's assembly service or order stencils.

 

[JayGilb]

For these initial boards, I'm using the SRC4190. With a unit price of EUR 6, it's a significant savings over the EUR 12 SRC4192 and is essentially identical (pin compatible).

I assembled this one by hand, which is something that I enjoy doing when time isn't in limited supply. For the larger runs, I will either avail of JLCPCB's assembly service or order stencils.

Very nice work on the layout and assembly. The pcb is really small.

 

[Godataloss]

After discussing this with a friend, we arrived at the possibility that the perceived sync issue might actually be an illusion resulting from the apparent mismatch between my appearance and voice, together with the close micing.

Regarding the AVRs, volume might be an issue depending upon one's use case. If the unit in question is an ancient AVR being used solely as a DSP, volume control will be handled by the source and this won't be a problem. For multichannel applications, there are several solutions with one of them being a couple of QuadVol board. I actually use a couple of these already, as they are a convenient means of automating volume control in conjunction with an ESP32.

For situations wherein a PC is the multichannel source, this is also not really a problem.

If you are particularly adventurous, you could even sniff the SPI data destined for the onboard volume controllers and route it to an external QuadVol.

Your voice is so over-damped it doesn't match the appearance of the environment you are in. Sync is fine for me, but you sound like you are trapped in a couch cushion. I think a touch of reverb would give you greater verisimilitude. Excellent video though.

 

[Weeb Labs]

New video this Friday at 18:00 (GMT). My allergies are going berserk at the moment, so I'll be slightly hoarse and thin (speaking of audio) but I've been meaning to complete this one for a few weeks. My schedule will most likely be every second Friday.

 

[Weeb Labs]

The video is live! Now commencing work on the next ones.

 

[Weeb Labs]

More projector shenanigans, today. I'm experimenting with lamp irises for my JVC X500 and X5500 projectors. These have the effect of almost doubling the already excellent 40,000:1 native (on/off) contrast ratio with minimal light loss.

These are the first two variants, with 29mm and 33mm apertures.

The LCOS-facing side has been blackened using a heat resistant spray paint and then inserted into the optical block, in front of the lamp assembly.

Next, I need to take several measurements in order to determine the effect of each iris.

 

[Weeb Labs]

Purchased a pair of Mackie MR524s. They're rather pretty and I will be posting detailed quasi-anechoic measurements soon.

With the possible exception of cabinet or facia resonances, I expect these to be quite well behaved.

 

[Madjalapeno]

For the programming, I took the brute force route rather than attempting to make use of an existing motion control library. The code will probably end up on Github soon.

For anything to do with steppers I can't recommend these boards highly enough - https://www.duet3d.com/DuetEthernet



So simple, even someone like me can program them with simple G-code.

 

[Weeb Labs]

Component measurements are complete. Now working on the nearfied/gating composite for farfied response and directivity. Having completed all of the horizontal measurements, I can tell you that directivity on that axis is very smooth. There appears to be a small mismatch at the crossover but it is extremely narrow and not an audible concern.

According to Mackie, the crossover point for these monitors should be 2KHz but as you can see below, it appears to be 1.2KHz.

White: Port
Red: Midbass
Yellow: Tweeter

The midbass seems to be quite happy at the crossover and the tweeter isn't going berserk either. Looks good, thus far. That port spike at 1KHz may or may not be a resonance. I suspect that it may simply be midbass leakage but we shall see when the waterfall is generated.

Once all measurements are complete, they will have their own thread in the speaker review subforum. If you are interested in subjective impressions, then my initial thoughts are that they sound mostly correct out of the box but that bump at 10KHz is immediately audible. It was apparent before I performed any measurements at all. Once that has been corrected with PEQ, they sound wonderful.

 

[Weeb Labs]

First on-axis result. This should be quite accurate but I'm going to experiment a little bit before generating the final exports.

 

[Weeb Labs]

This evening, I picked up a single M-Audio BX5 D3.

This will be the subject of my next spinorama and I have rather high hopes for it at the moment. It is smaller than the 524s but denser and the front baffle is far more inert.

The tweeter waveguide diameter relative to midbass is sane, which leads me to expect very uniform horizontal directivity. I performed a quick driver component measurement, which looks very encouraging. This measurement includes my subwoofer crossover below 100Hz, so that band can be disregarded.

Crossover point is at 2KHz, which aligns with the manufacturer's specification and both drivers appear to be quite happy.

This is an ungated, in-room measurement at my desk.

Subjective impressions were very positive. They exhibited a loud bump around 200Hz, which may be either a room mode or inadequate baffle step compensation. With a couple of filters, it was easily corrected and the result was a surprisingly lovely response with the correct tilt.

I ran a full ARC measurement and that produced ever nicer results.

I will be capturing the full spinorama this evening and expect to see a rather well behaved speaker. This speaker cost me only EUR 60 and typically retails for around EUR 75, which represents exceptional value for money.

Regarding amplifier noise floor (tweeter hiss), they are very quiet. The MR524s are slightly quieter but both are inaudible beyond approximately 25cm.

 

[Weeb Labs]

Spin is now complete and I am rather pleasantly surprised. I incorporated ground plane measurements into this one, which means that low frequency resolution is excellent. Stand by for the thread in speaker reviews!

 

[Tks]

The video is live! Now commencing work on the next ones.

Man this thing is gorgeous

 

[Vincentponcet]

As it turns out, there is nothing wrong with the AVR or the SPDIF output. The XDA-1 simply didn't like the 8804's output.

How do you explain this ?
The 8804 output is not SPDIF compliant or the input of the XDA-1 is not ?

 

[Weeb Labs]

Sharing an announcement from my channel community. You will have to excuse the mildly clickbaity form but I have rather high hopes for this content.

My objective is to produce the most comprehensive video on the platform that discusses room correction and loudspeaker design fundamentals. Everybody in possession of speakers should be able to benefit immediately from the contents of this video, even if they don't own a microphone of any kind.

 

[Weeb Labs]

Another speaker review in progress! This time, it's the M-Audio BX4 D3. They retail for €110 per pair and the design is sane.

 

[Weeb Labs]

Prospective buyers beware; the BX4 D3s do not have a crossover.

The tweeter likely has a singular capacitor within the waveguide chamber but the midbass driver is simply left to enter breakup and rolloff naturally.