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Master "deals" (massdrop, ebay, Amazon, etc.) Thread on Audio Product Sales

JohnBooty

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I believe that the RB42's woofers are the same ones found in the Dayton MK402, with a modified frame. Their excursion and bass output considering their tiny size is unreal.

PE sells a bizarro (but very cool) compact passive slimline subwoofer based on four (lol) of those drivers in an unusual arrangement: https://www.parts-express.com/dayto...driver-low-profile-passive-subwoofer--300-495

I'd love to see a compact 3-way speaker design using slightly higher-end drivers for mid/treble that essentially incorporates those woofers as subwoofers handling 80hz and below. If I had the chops, tools, or time I'd love to build something like that. I've been thinking about cobbling together a poor man's version of that using a MiniDSP as active crossover and 4 channels of amplification. Sort of like this (scroll 1/2 way down) but with Dayton MK402s or Micca RB42s on the bottom.
 

JohnBooty

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Oh snap, that's a great deal. I have one and I like it. Might have to get another at that price. I got it from Proaudiostar as well. They have a sketchy rep, but I had no problems with my order.

Great if you have studio monitors or other pro gear that wants a +4dbu level signal. You can toggle between that and -10dbv for consumer level stuff. Solid feel to the unit, definitely a pro or prosumer level feel.

I'm using it strictly for volume control and input switching. Have not tried the USB DAC feature.

You can have multiple inputs (and outputs) active at once which may be a useful feature for some. However, there's no independent volume controls for the inputs so that feature is somewhat limited.
 

amirm

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JohnBooty

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That is a good deal. I have no use for it but couldn't pass up on the bargain. :) Will review when it gets here.
Awesome! I have a small request - I wonder if you would be able to measure distortion on the analog inputs as well as the digital? I suspect I'm not the only one who will use this device without touching the USB input.
 

amirm

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Awesome! I have a small request - I wonder if you would be able to measure distortion on the analog inputs as well as the digital? I suspect I'm not the only one who will use this device without touching the USB input.
I can but am confused. Do you mean the ADC? If so, capture over what interface if not USB?
 

HammerSandwich

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I believe that the RB42's woofers are the same ones found in the Dayton MK402, with a modified frame.
That's probably right. Tymphany has a few that look similar, but they all take 6 mounting screws. Sure are a lot of driver OEMs, though...

I'd love to see a compact 3-way speaker design using slightly higher-end drivers for mid/treble that essentially incorporates those woofers as subwoofers handling 80hz and below.
That would work, but it sounds like a "because I can" project. Quad TCP115s give 80cc of Vd, which isn't much of a subwoofer. This can be matched by a number of 6.5-8" woofers, even with similar box volumes & driver cost. I'm pretty confident Dayton alone has several options here, and there's always the TB 1138.

All that said, the Dayton sub you mentioned is pretty interesting. A couple of those would be easy to hide in a multi-sub setup, though I'd still want 1 (much) bigger sub for the bottom octave or so.
 

JohnBooty

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I can but am confused. Do you mean the ADC? If so, capture over what interface if not USB?
I could be wrong, but my understanding is that there's no ADC. I think the analog inputs follow an analog path thru to the analog outputs.

What I'm curious about is if anything is sacrificed by running analog inputs through this thing - is there an increase in distortion, etc. Would also be curious if the gain settings affected measurements.

I suppose this would be tested by...

(A known-good DAC) --> (Analyzer)

and then

(The same known-good DAC) --> (JBL M-Patch) --> (Analyzer)

and then comparing the distortion/etc. numbers. Or maybe this request of mine makes no sense. I'm relatively new to this. =)
 

amirm

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I think it also has an ADC but yes, I understand what you want tested. I don't need to use a DAC though. I will be testing it just like a pre-amp, analog in and analog out.
 

JohnBooty

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That would work, but it sounds like a "because I can" project
It would only really have use for space-constrained situations. Desktop audio and so forth. But, those are pretty significant situations. Big bookshelves with 6.5" - 8" woofers are too big to be practical in a lot of setups.

I'm pretty confident Dayton alone has several options here
Speaking of Dayton...

I did some quick and dirty in-room measurements of the RB42 vs. Classix II (Dayton Audio DC160-8 6-1/2") vs. Pioneer BS22. These are indoor measurements, so room issues galore. I also didn't volume match. Just wanted to see how the bass rolled off and what kind of extension they might give "in the real world." The RB42 was pretty competitive with the Classix II in that department, though the Classix II is much more enjoyable overall.

https://www.dropbox.com/s/069oqlq7pcu33c9/measurements-indoor.png?dl=0

All that said, the Dayton sub you mentioned is pretty interesting. A couple of those would be easy to hide in a multi-sub setup, though I'd still want 1 (much) bigger sub for the bottom octave or so.
Yeah I'd mainly see that sub being useful for micro systems where there's no room for bass-capable main speakers. Two tiny main speakers and one of those subs tucked behind the desk or whatever.
 
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I think it also has an ADC but yes, I understand what you want tested. I don't need to use a DAC though. I will be testing it just like a pre-amp, analog in and analog out.
I've got a DX3 Pro coming, which I am planning to use as a preamp connected directly to my amp, and I'm thinking of putting this in line between the DAC and my 250wpc Krell as a permanent max level limiter...to keep from vaporizing my speakers, ears, plants, and probably my cats if the DX3 was to be accidentally set to line out... would there be a better way to do that? Basically, a manually set in-line attenuation?
 

JohnBooty

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I've got a DX3 Pro coming, which I am planning to use as a preamp connected directly to my amp, and I'm thinking of putting this in line between the DAC and my 250wpc Krell as a permanent max level limiter...to keep from vaporizing my speakers, ears, plants, and probably my cats if the DX3 was to be accidentally set to line out... would there be a better way to do that? Basically, a manually set in-line attenuation?
It would certainly work for that, but there are much simpler ways to do it if you don't need all of the input switching and multiple outputs. There are passive units like this (search for "passive volume control") as cheap as $7 or so.

https://www.amazon.com/Nobsound-Precision-Passive-Controller-Preamplifier/dp/B07GRMM9XT?th=1

https://www.amazon.com/Schiit-Audio...ontroller&qid=1562250615&s=electronics&sr=1-8

https://www.amazon.com/Schiit-Audio...ontroller&qid=1562250615&s=electronics&sr=1-8

Also FWIW the JBL is a powered unit. Not sure which bits of it (if any) function when the power's off. Most inline volume controls, including the ones I linked to, are fully passive.
 
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It would certainly work for that, but there are much simpler ways to do it if you don't need all of the input switching and multiple outputs. There are passive units like this (search for "passive volume control") as cheap as $7 or so.

https://www.amazon.com/Nobsound-Precision-Passive-Controller-Preamplifier/dp/B07GRMM9XT?th=1

https://www.amazon.com/Schiit-Audio...ontroller&qid=1562250615&s=electronics&sr=1-8

https://www.amazon.com/Schiit-Audio...ontroller&qid=1562250615&s=electronics&sr=1-8

Also FWIW the JBL is a powered unit. Not sure which bits of it (if any) function when the power's off. Most inline volume controls, including the ones I linked to, are fully passive.
I have one if these (Mackie Big Knob Passive) which I use for ABX testing (well, AB unless someone pushes the button and I close my eyes.)
It works very well and has pretty good stats, and its passive! Yay!
 

HammerSandwich

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It would only really have use for space-constrained situations. Desktop audio and so forth. But, those are pretty significant situations. Big bookshelves with 6.5" - 8" woofers are too big to be practical in a lot of setups.
Understood, and I absolutely agree with the 1st part. OTOH, I still believe a ~10L net box for 1x 6.5" can be smaller than 10L for 4x 4".

I did some quick and dirty in-room measurements...
Nice, thank you! No complaints about the extension, only SPL capability. It certainly smokes the Pioneer, though, and at a very good price.
 

JohnBooty

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Nice, thank you! No complaints about the extension, only SPL capability.
With regards to overall SPL output (if you don't mind more totally sloppy informal measurements) in my 200sqft den, they were able to put out a comfortable 80-85dB average (according to my cheap-o $12 SPL meter) on actual music, with decent room left over for dynamic peaks.

The was with my Emotiva A-100 (50W into 8ohms, 80W into 4ohms) with the volume knob at around 75% IIRC.

I didn't try to push them too much further than that as I rarely listen that loud... that was more than loud enough for me already. I would guess they had a few more dB to give but probably not too much more.

It certainly smokes the Pioneer, though, and at a very good price.
In terms of bass, absolutely. The Pioneers are nice, especially crossed over to subs. And they can be crossed over at 60hz instead of 80hz in my experience, which is nice. But without subs, the Pioneer's bass output turns into a flabby fart machine at higher SPLs. All flabby midbass hump, no deep extension. Nice at lower SPL though.
 

JJB70

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I noticed in the San Francisco Microsoft store last night that their Surface headphones are now $249, at that price they're well worth a punt if anybody wants a good wireless NC headphone. The Surface headphones were a remarkably strong first headphone from MS with excellent NC technology and possibly the best control interface of any product in its class but at the original price I thought that the Sony 1000XM2/XM3 models and the Bose QC35 II were ahead on sound, slightly better on NC (although I suspect that in the real world the difference in NC is not significant) and with better battery life hence better choices. However, at $249 the Surface Pro looks like a cracking headphone if you do a lot of travelling and want active NC.
 
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