Decoding the Signal Path of My 2-Channel Stereo

Posted on April 21, 2018 by Dan

Last week I changed around my stereo a little bit just for fun and wanted to share a few of the things I learned in doing so. I didn’t do anything too crazy, just removed the Schiit SYS passive pre-amp and replaced it with a Denon AVR-1801 receiver. The receiver has been part of my garage theater which is currently undergoing some modifications. So I thought this would be a good opportunity to add it to my 2-channel stereo setup so I’d have an actual active pre-amp in the mix. Or rather, an active 5.1 receiver that happens to have a pair or RCA pre-outs (not something every receiver has these days I’ve come to find out) that should double nicely as a dedicated pre-amp. Acting as a pre-amp only the Denon holds its own quite well. A plethora of inputs, optical, coaxial, analog, even a phono input. Right now I’ve got two modest sources, an Apple Airport Express and a Sony DVP-S300 DVD/CD player. It’s worth mentioning that I bought the Sony unit from Goodwill for $6, the Airport Express from a guy on Craigslist for $20 and the Denon unit from a different guy on Craigslist for $50. Total investment at this point – $75. I do audio on the cheap, I know. But good gear doesn’t have to cost a fortune either. And good used stuff is even better.

Now back to the setup. Since the Denon has both analog and digital inputs, I was left with two connectivity options for each source: connect the CD player and Airport Express to the analog CD/DVD inputs using a couple pairs of RCA cables, or connect the S/PDIF or Toslink output from the CD player/Airport to the S/PDIF and/or Toslink inputs on the receiver. Either way you get sound coming out the other end. What difference would either option make? Was there not an obvious better way to connect up this equipment? If so, what was it? And was there a way to know which option would be better without actually listening to them?

So my first instinct was to connect everything up using only the digital interfaces. I figured the Denon probably has a better digital-to-analog path in it and therefore would sound better. This means the conversion to analog is bypassed on both the Apple Airport and Sony units to allow the Denon unit to do all the work. I have nothing against running analog in’s and out’s between stereo gear, but if you can keep things in the digital domain longer, and not flip flop between them too often, then it just seems like that should be better. Especially if you have reason to believe one of the two potential DACs and subsequent analog parts in your signal path is significantly better in one piece of gear than in the other. Imagine having two pairs of speakers connected to your amp via an A/B selector switch and selecting the crappier speakers all the time without even realizing it. Little did you know that just by switching to “speakers B”, you could have been listening to a much better pair of “speakers”, you just had to pick the better pair and put those in your signal path. Just about every stereo setup anyone owns probably has an unused DAC in there somewhere. Missed opportunity perhaps?

After connecting the CD player to the Denon via the S/PDIF port, I popped in some CDs and had a listen. Up until this point my setup was such that I was using the DAC in the CD player to convert the digital 1’s and 0’s to analog, but now I was feeding those same 1’s and 0’s to the Denon unit and allowing it to decode and convert those bits into analog sound. So what did I think? Did it sound better? Actually, my first impression was that it did sound better. Inexplicably better, not definitive, but somehow just better. Maybe I was just hearing things? Probably, but could I prove that one setup was superior to the other? Sure, why not? So I decided to do a little deep dive into the physical signal path differences between these two setups and compare them. What is actually different? Which configuration looks better on paper? What DAC chips are actually in these units? Were there other obvious defining differences? Read on to learn what I found out.

For now this is just going to be a paper analysis. I’m not going to actually measure anything. So if you’re hoping for FR and phase plots, THD and FFT plots, sorry to disappoint. But this is an easy analysis just about anyone can do with their own stereo, though your mileage may vary depending on which gear you’ve got, brand and how old (or new) it is. The internet is a huge resource, but even then, some old parts are just not going to turn up. And some of the newer and boutique audio shops just aren’t going to publish that kind of info. No sense revealing the Colonel’s secret 11 herbs and spices.

You can download a pdf of the information I put together for this chain analysis here which includes excerpts of schematics and block diagrams for both units. Datasheets for all of the components can be found by clicking the hyperlinks within this post.

I started out by searching for service manuals for both the Sony DVD/CD player and the Denon AVR. Service manuals are great for digging into this kind of thing and I found a ton of super useful information on both units. Such as schematics, part numbers, troubleshooting tips, you name it, these service manuals had it. That’s when the fun began! I traced out the digital and analog signal paths for each unit starting at the optical transport and finishing at the pre-out of the receiver. The one thing I was interested in initially was what DAC was in each of these units (but I actually learned quite a bit more). I was hoping from there I could then find out some specifications that might indicate which one should be better. My search didn’t stop at just the DAC though. But I’ll jump right into that part, since it’s the most relateable component. And if you don’t end up reading this entire article, you will at least have learned that much.

The Sony DVP-S300 contains a Sony CXD8750N-T2 2-channel DAC. There is absolutely zero information about this DAC available online. It is most likely one of Sony’s proprietary designs so they aren’t inclined to publish anything on it which means there’s no info out there to get any sense of what the DAC can do. Searching the part number online reveals that it appears in units with model numbers M35/S300/S305/S315/S500D/S705D/S715. So it was a popular DAC in its day used in a wide variety of now discontinued models. Not much else go go on there.

So let’s move on to the DAC in the Denon receiver. This is where it got a lot more interesting. The DAC in a Denon AVR-1801 is an AKM AK4527 “High Performance Multi-channel Audio CODEC”. AKM have been making DACs for ages and have a wide portfolio of DAC and DAC-related products. The the most interesting thing noted in the datasheet for the AK4527 is they claim it supports multi-bit. The first paragraph in the data sheet states,

“The DAC introduces the new developed Advanced Multi-Bit architecture, and achieves wider dynamic range and lower outband noise.”

There is no other mention of multi-bit in the rest of the datasheet and in most cases there are references to sigma-delta processing if it does come up again. I have no idea if this DAC does in fact support multi-bit as it’s commonly referred to today or not. This data sheet is dated 1999. Other specs tout 128x oversampling, 96 kHz sampling rate, 24-bit 8x digital filter, 106 dB S/R and high jitter tolerance. EEtimes.com wrote a short article about this DAC when it was released back in 1999 and here’s a short excerpt from that article:

“The six D-to-A channels use a new multi-bit sigma-delta architecture with 128X over-sampling. The dynamic range in this direction is 106 dB. This part brings a new performance level to multi channel codecs,” said Ahmad Nowbakht, applications engineer at AKM Semiconductor, a subsidiary of Asahi Kasei Microsystems Co. of Tokyo. He suggested the AK4527 could be used with compressed audio applications such as AC-3, DTS or other multi-channel standards. “It could be used in DVD players, DVD-RAM drives, or home audio receivers along with many other multi channel audio systems,” he added. The AK4527 is packaged in a small 44-pin LQFP, 10-x-10-mm, package with the same pinout as AKM’s previous two-input/six-output codecs. Prototype quantities are available now, priced at $6.12 each for 5,000 pieces.

So there you go, what’s the real takeaway? That they use the term multi-bit and sigma-delta in the same sentence? Like, which is it? How about the fact that this is a $6 DAC? Either way, if I had to blindly pick a DAC in my setup, either the Sony unit or the AKM unit, based on the information available, I’d probably pick the AKM DAC over the Sony DAC just because it’s got some decent specs against a part that has, well, no specs. It offers good dynamic range with 24-bit/96 kHz processing whereas the Sony DAC probably only supports 16-bit/44.1 kHz audio, seeing as how it is designed for a regular CD player, ideally there’s no reason for anything higher. Besides the bit depth and sample rate, are there other less obvious sonic benefits to one DAC over the other? Perhaps other features built into each chip make a larger difference, like better digital filtering, better tolerance to jitter, better DC biasing (power supply and power supply filtering) and better analog filtering. Specs alone hardly tell the whole story. But it’s certainly a starting point.

Continue reading →

Posted in Audio/Video | Tagged , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , | Leave a comment

I Started a YouTube Channel – “How to Play” Songs on the Piano – Go Check it Out

Posted on April 1, 2018 by Dan

So a few weeks ago I pulled out my camera tripod, I set it up hovering over my keyboard and with my phone attached to the end, I hit record. I started playing a song, it was Piano Song by Erasure. A song I learned how to play some twenty-plus years ago. A song I taught myself how to play just by listening to the song over and over. A CD player on repeat with my parent’s old upright in the living room of my house growing up. This is something I’ve enjoyed doing ever since I was in grade school to this very day. As the phone recorded while I played through the oh so familiar chords I thought, what if I were to try and teach someone how to play this song? How would I do it? How long would it take to explain? How well do I know the names of all the chords in this song? Do I even play the song correctly? Would people care if it’s not note for note? Would people want to learn how to play this old song from so long ago? Should I post this on YouTube? Aren’t there already a million tutorials all over the Internet already? What difference would one more video really make?

After a couple of takes, hitting record and walking through a simple explanation of the chords for Piano Song, I finally ended up with a take that I thought was decent. Not perfect. But not garbage. I flubbed the chords only once or twice and I didn’t say something completely stupid on that take. I realized it is quite difficult to play piano and talk at the same time (totally different from playing and singing at the same time) especially when the talking breaks up the rhythm and timing of just playing the song beginning to end. And trying to play the piano and speak coherent sentences is no walk in the park either. The main reason it took me so many takes to get just one right. But I was really just playing around at this point. This song would be my “proof of concept” song. I would record it, edit it, add chord descriptions using some form of video editing software (Windows Movie Maker anyone?) and then post it to YouTube and see if I got any bites. This would be the first song, one of many I planned on doing depending if people liked it or not. If it was well received, then maybe I’d do another and another. What if made a video of every song I’ve ever learned how to play? Would people actually watch them? Would people like them? I asked myself all these questions, but ultimately knew there was only one way to find out. I’d have to post it and scariest of all…make it public.

I have to admit though, I am terrified of YouTube. And by that I mean YouTube as a platform for content creators not just for the casual viewer. YouTube is a melting pot for so many different types of people with complex varying interests from all over the world. They get billions of views per day and their market reach is near endless. And the worst part about YouTube is…the comments section. Here you can find the cream of the crop for some of the worst things ever said on the Internet. I just wasn’t interested in playing on that playground. Like the little grade-school boy inside me who liked to play piano instead of sports, the kids here are just too mean. Not to mention the fact that most of the stuff you can find on YouTube showcase people that have spent (what must be the better part of) their entire natural lifetime honing in on a skill that makes them seem almost super human. They have an unnatural ability to outflip, outrun, outplay, outperform, outdive, outrock, out-you-name-it, any talent you actually thought you had. I’m pretty sure there’s a 4-year-old kid that can wipe the floor with my sorry piano-playing skills. Not to mention that one kid who can pick out a Eb-add9-flat5-maj7-11th-over-C# just by hearing the one chord even without any other context (freaking amazing by the way). Makes you pretty much want to crawl back in bed and ask yourself, “What am I doing with my life”? Where comments like, “Kid can do this…I find a Cheeto stuck to my face” are not uncommon. Believe me, I’ve been there, I live there. Not necessarily with the whole Cheeto thing, but as someone who ditched Facebook a decade ago and don’t regret it one bit, I’m definitely not immune to the culture of social comparisons and mentally ranking where I fall in this vast world of talented individuals.

Which brings me back to the piano tutorials. I basically decided to throw caution to the wind and just go for it. I mean, why not? I’ve got about 100 songs in my back pocket that I’ve played for years that I could record today. And easily hundreds more I plan on figuring out just to grow the channel into hopefully something worthwhile. I don’t admit to being an awesome piano player. And I’m sure I will get comments where people tell me I suck or whatever. But ultimately I just decided, so what? I enjoy playing piano and I really enjoy playing all of the songs I’ve learned how to play. And if I can help even one person learn a great song, a song from a band that we both know and love, then it will be totally worth it to me. And as far as everyone else is concerned, well what can I say, haters gonna hate.

Anyway, the plan is to try and upload at least one video per week so that in one year from now I have 52 reasonably-produced instructional videos showing how to play different songs on the piano. For now my main interest will be to do songs that are originally played on the piano and/or are written for the piano. I don’t like adapting songs played on the guitar or other instruments and converting them into a piano arrangement. While I have done that for a handful of songs, I don’t typically enjoy doing them as much and am never quite happy with the way they turn out. So for now if it’s played on the piano and even better, it is primarily played only on the piano with very little other accompaniment, then that’s my jam. Especially because it’s usually easier for me to pick out subtle nuances in chords and chord variations (like inversions and augmented/diminished chords) if it’s just a solo piano playing without a lot of extra instruments backing it.

So without further adieu, I present the latest in YouTube greatness, Dan’s Piano Tutorials – An instructional video series teaching you how to play all your favorite tunes from the 80’s, 90’s and today. Take a minute to check out my channel which as of this writing has a whopping 5 songs including bands like Erasure, Morrissey, Matt Nathanson, Death Cab for Cutie and Coldplay. Click Subscribe to get updates on new videos and be sure to comment on which ones you like best! Also feel free to shoot me suggestions for songs you’d like to see me cover, they can be obscure titles, rare B-sides, deep cuts, or maybe just videos for songs no one has ever done before. I’m always open to a good “figure out this song” challenge. As always, thanks for supporting this blog and I look forward to seeing everyone over on YouTube!

https://www.youtube.com/user/danaktion/

Sample Playlist of my most recent songs from the Dan Marx Piano Tutorial Channel

Posted in Music | Leave a comment

Setting up a 3-Way Speaker with MiniDSP 2×4 using REW

Posted on August 5, 2017 by Dan

It’s been about a month since the completion of these speakers and it’s about time I do a write-up on how I set up and tuned these speakers. I’ve spent the last several weeks and many hours setting up and dialing in these speakers and overall I’d say I am very happy with the results of this setup. I doubt this will be my final tuning/crossover setup with the MiniDSP but for now I’m just enjoying the new speakers and how awesome they truly do sound. Because overall the speakers sound fantastic. Better than I could have hoped for. Of course, my opinion is somewhat/mostly biased. But they literally sound just how the response plots would indicate – flat and neutral. No frequency range sounds out of balance, neither too forward nor too timid. But before I get into the subjectivity that is describing hi-fi sound, let me share the setup.

The above block diagram details the setup for measuring and tuning the speakers. The setup starts with a pair of laptops, one running windows 7 with the MiniDSP 4-Way Advanced Crossover Plug-in while the other is running Lunix Mint Cinnamon and REW 5.19 Beta 4. The sound card is a Behringer UCA222 connected via USB. My measurement mic is a Behringer ECM8000 using the cal factors available from Behringer’s website. Home Theater Shack also has a popular cal table for the ECM8000 (newecm.cal) but I felt like it over-corrected above 10 kHz and wasn’t realistic of the actual response of my microphone. When I use it, it causes almost every speaker I own to have this rising tail at 20 kHz that I just don’t believe. Behringer’s correction factor is more subtle and even though I am sure it still does not perfectly represent my microphone, I feel like it’s close enough for casual home use. See my comparison plot below.

Also the Behringer cal table includes phase. I think the main reason people use the newecm.cal is because the correction factor goes all the way down to 5 Hz to satisfy all the bassheads need for insanely low frequency measurements. Since the mic needs 48V phantom power, I use a Behringer XENYX 1202FX mixing console (which is normally part of my home recording studio) between the mic and the UCA222. A Schiit Audio SCH-13 Sys Preamp allows simple volume adjustment of two different sources. For my modest setup at the moment, I have an old Sony DVD/CD player and an Apple Airport Express. Better sources are in the works, including a real pre-amp, but for now, this is what I’ve got. The Airport Express is more for just convenience of listening than any kind of critical listening. Check out this post here on my whole house audio system.

So I debated doing a really nice all-aluminum housing for the MiniDPs and in the end just installed everything into an old VCR enclosure. The big spring-loaded slot in the front makes for easy access to the USB cables that I keep tucked away in there when not in programming mode. It’s not super glamorous, but is functional and practical. Both MiniDPSs are mounted on standoffs along with four LM317 linear regulator kits I picked up for $2 a piece on Amazon. I had an old 15 Vdc wallwart that after tearing it apart realized it was complete garbage. It claims an output current of 1000 mA which is just about right for two MiniDSPs (they draw 150 mA each) while maintaining some overhead. But with only a single transformer, a full-wave bridge rectifier and one capacitor, this would not be my first choice in powering any audio gear. But it’s nothing we can’t clean up nicely with some decent linear regulators. The wallwart provides 15 Vdc and feeds the first LM317 which takes the voltage down to 10 Vdc. The second LM317 takes the voltage down to 5 Vdc and over to the MiniDSP. Each LM317 claims roughly 65 dB ripple rejection so long as Vin-Vout > 5 Vdc at 150 mA. So with two in series, we probably get around 100 dB rejection which should be enough for even the most demanding audio needs. Since the MiniDSP outputs feed the UPA-700 amp with a fixed 29 dB of gain, everything in the signal path and DC bias paths needs to be dead quiet in order to provide quiet, hum-free and hiss-free experience. I think I succeeded because even though there exists what I would call traditional background white noise in the setup, you only hear it from less than 1 foot away from the tweeter with your ear directly in front of the speakers. Once you back up a couple of feet, everything is dead quite. And this is with the original MiniDSP kit which only claim >98 dB SNR. It’s definitely plenty for me. And yes, the MiniDSP’s are on all the time. For curiosity sake, I plugged my little VCR/MiniDSP setup into a Killawatt meter and measured a measly 3 watts (or 0.003 kW/h) which if left on year-round amounts to only 26 kW/year (24*365*.003). I pay about $0.1/kWh at my house on average which amounts to a grand total of $2.60/year. So to leave on a pair of MiniDSP’s 24-7-365 costs less than a side of fries at Five Guys. In other words, it’s basically peanuts. Which oddly enough, you can also get at Five Guys.

I made six sets of speaker cables that are each 14 feet in length from a 100-foot spool of 12 gauge OFC speaker wire from Parts Express. I bought 12 sets of black/red screw-style banana plugs which dressed up the cables nicely and provide a clean transition from speaker cable to the binding posts at the back of the speakers. I wanted to do something fancier on each side, like bundle each set of cables into some nice black expanded cable sleeving but just ended up leaving the speaker cables exposed for now. It’s functional and does the job. No complaints here.

Here’s a quick shot of the back of the upper cabinet with the nice Dayton Audio Premium gold-plated binding post terminals and aluminum face plate from Parts Express. Normally I wouldn’t go all out and buy such fancy binding posts, but for this build I decided they would complement the high-end feel of the speakers overall. They are super nice and provide a robust quality and feel to the speakers. I definitely recommend them for that great premium look.

Here’s the basic microphone setup for doing near-field measurements of just the midrange driver. I moved the microphone around a lot during my measurements. I did near-field plots of each driver at 0.5″ distances and then 6″ and 12″ and 30″ and 1M distances (approximately) as well as in-room measurements. I haven’t done a lot of off-axis measurements yet. But I do plan to take more measurements as time permits. This mic orientation and distance do not represent all of the measurements taken/shown here.

So this is sort of how the setup looked. The old Dell Inspiron was used to connect to each MiniDSP and provide instantaneous crossover and PEQ changes while the HP Elitebook on the right was running REW for taking and recording all the measurements. I only played with one speaker at a time, so I could make all the adjustments to just one MiniDSP unit. Once I was satisfied with the settings, I saved a configuration file and then loaded the settings onto the second MiniDSP. I did some casual listening of various types of music with each setting. Then I would go back to making adjustments as needed and redo the process of tweaking one unit, taking a measurement, loading the second MiniDSP and then doing some listening. I basically did this for about a month. What I’ve really been doing with this whole experience is educating myself on not only the basics of crossover design but some of the more complex elements as well. I figured I have a really nice set of speakers built into a great enclosure, now is my opportunity to really understand the benefits of different slope rates or crossover types on a really nice set of speakers. I have at my disposal the ability to test multiple filter types and slopes and take tons of measurements to see just what makes one filter better than another.

Continue reading →

Posted in Audio/Video | Tagged , , , , , , , , , , , , , , , , , , , , , , , , | 2 Comments

DM-4 Reference Speaker Build Part V – Finally Complete!

Posted on April 14, 2017 by Dan

The speakers are done! I’m super excited to finally unveil the completion of the DM-4 Reference Loudspeaker. It’s been crazy though, the last few months have been such a roller coaster of different, unexpected projects, as is evidenced by my last few posts. It seemed like with each new project this speaker build kept getting put off more and more. At some point I said to myself, I just need to finish a couple of these other things on the to-do list and then hit the speaker project full-time and just get them done. This has probably been the longest time I’ve spent doing a single speaker build. From conception to completion this project taken almost 3 years. It got the point where in the middle somewhere I completely lost interest in the whole project and began designing a completely different set of speakers. But alas I persevered and now I can say that I am super happy I did because these speakers turned out amazing! Well, in looks at least. As of this post I haven’t hooked them up and actually listened to them yet aside from my initial tuning of lower enclosures which I did a few months ago. The method for creating the crossovers and doing the measurements will have to be saved for another post. For now I just wanted to get the rest of the build pics up and of course the final shots of them sitting in my living room just looking awesome.

It’s funny because as with so many DIY projects, at some point you just have to accept the little flaws in a project and recognize that this thing is made by the hand of an imperfect person. I know I get way too picky about the fit and finish of the final product that can’t enjoy it for what it is. Overall these speakers went together without too much fuss. I’ve been working with wood and MDF and building speakers for many years so I’ve come to understand what it takes to get the job done without making too many mistakes. But when it comes to the final paint and finish work, I’m a complete mess. For this project things were looking good all the way up until I added the Polycrylic clear coat. Staining the birch was a piece of cake, it went on like any stain, really cleanly and looked flawless once complete. I went out on a limb and did the black surfaces with just spray paint and to my surprise that also went on really well. I think I did 3 coats of gray primer and then 2 coats of flat black. I had masked off the birch while spray painting and when I lifted the masking for the first time I got a glimpse of what these speakers were going to look like and I was super excited.

The gray stain contrasting the black just made a killer combination that just looked different from the usual speaker. So I was excited and pumped to put on that first coat of clear coat to give it that clean, smooth, subtle shine to it. This is where it all fell apart. I seriously have to find a better method for clear-coating speakers. There has to be a better way. I won’t go into the details, but I ended up with 4 coats before I just gave up and said it’s as good as it’s going to get. After each coat I’d find a drip, or a spot where I’d brushed it again when I shouldn’t have, or a spot I missed completely. So I’d sand it down and put on another coat, only to miss another spot, over-brush a different spot and end up with a run somewhere else. After sanding down that coat and doing it again and again I just quit and said it is what it is. So that’s when I decided you know what, they’re not perfect and overall they look as good as I ever could have expected them to look so I’m just going to say that I’m happy with them for now. But if and when I learn how to do a proper clear coat, I’ll remove all the drivers, sand this top coat down once again and finish them proper. But that’s down the road, like, way down the road.

Well I should do a write-up on the final build of these speakers. They definitely deserve it, there are so many little details that went into every aspect of making this speaker. You can probably gleam how they were built from all the pics but a few words won’t hurt. I’ve already written quite a bit leading up to this point. A lot of finishing these speakers is just duplicating what I did to the lower cabs. I had just finished building the upper cabinet when I stopped late last year. So I will pick up this post with adding the 1/4″ MDF to the front/top/back/bottom and cutting the 45° chamfer around the edges. The 1/4″ MDF worked out great and gives a clean finish to work with as far as painting goes. Plus it allowed a perfect flush fit for the Dayton Audio drivers. I used Parts Express’s sweet Jasper Jig Model 240 to router perfect holes for the woofer and tweeter. This took a lot of trial and error though! I think I went through 5 different boards before I found a size that allowed the drivers to fit just right without the gap being too big or too small. I was shooting for a gap that was at least 0.005″ but no more than 0.015″. That’s basically a baffle diameter that is 1/32″ larger than the diameter of the driver basket. This allows for some growth from paint/clear coat but no so much that the driver can actually move around. The smaller the gap, the better the finished speaker looks, in my opinion. I did error on the smaller side for the tweeter and I had a tough time getting it fit after the 4 coats of clear coat that lined the inside edge. But since it is probably the only driver anyone is really going to look at, I wanted to make sure the transition from the tweeter’s faceplate to the baffle was absolutely seamless. Plus with the Jasper’s fairly course 1/16″ increments (or 0.062″) I didn’t have much choice with the tweeter as one size was spot on at 0.000″ and the next size bigger left a whopping 0.0315″ gap around the whole tweeter. That was more than double what I had already agreed was reasonable from an aesthetics perspective. So I cut it with no gap and then sanded it slightly to get the tweeter to fit. I then just tried to be careful with the paint and clear coat so as to not decrease that size too much. It worked out, because the tweeter fit by the skin of its teeth and the gap is nearly zero.

The next step was adding the acoustic insulation – I reiterate what I had stated about doing this insulation technique on the lower cabinets that it was an absolute pain and was super time consuming but I think in the end it is going to provide superior damping and absorptive properties than some of the traditional (and simpler) methods. I took a bunch of pictures of each layer going into the cabinet and then made a “sample coupon” on a separate piece of MDF just so show a cool cutaway view of the built-up layers of materials. In short each upper cabinet is covered with 2 layers of 1/2″ (6-lb.) standard carpet pad following by 4 layers of a 80/20 cotton/poly blend fabric/fill and then 4 layers of a 100% poly batting material. The total thickness ends up being almost 3″. Each layer is glued onto the previous layer with spray glue to create one cohesive material that won’t move around and hopefully provide consistent absorptive properties throughout the enclosure and in both enclosures. The upper cabinet is sealed and will have an approximate high-pass filter of around 200-400 Hz so for the most part I was shooting for a nearly-full enclosure, but still ended up with a solid pocket of just air with no fill in just the middle portion. So it’s probably like 75% filled if I had to guess? The lower cabinet only has the walls lined and is probably only 15% filled.

Alright so now the cabinets are done it’s time to start working on the finish. I picked up a can of Winwax “Classic Gray” and put 3 coats of stain the on birch sides for all four speakers. I didn’t bother masking the bare MDF since I was planning on painting it anyway. I should have stained those raw MDF edges better though because the spots I overbrushed with the stain actually sanded nicely and cleaned up that rough MDF edge look and then painted even better. But I did what I could to sand the bare MDF edge so it didn’t look like crap. In the end they are not perfect, I could have done some better edge prep, but they look fine overall and am not going to worry about it too much. After letting the stain dry I masked off the sides and began preparations to paint everything else. I picked up 3 cans of Painter’s Touch 2X gray primer and 3 cans of the flat black. Over the course of the next couple of months I went out to the garage and painted a coat of the primer, then sanded it, then did another coat and sanded it, until I had a really nice flat base finish. Then I moved on to the flat black paint. I also sanded between coats until I had a near-flawless black finish. This spray paint went on really well and I would definitely use this spray paint again. The flat black is extremely flat and I wouldn’t recommend it as a final top coat. It needs a satin or semi-gloss clear coat of some kind to finish it off.

Once the paint was all dry I brought the speakers in the house for the first time. I didn’t want to do the clear coat/top coat in the garage because seriously anything that sits in my garage for more than 5 minutes is immediately covered in a layer of dust/saw-dust/paint-dust/you-name-it-dust. It’s not like I’ve got a 10,000 clean room at my disposal so the house will have to be good enough. I masked off the floor and my coffee table and set up the speakers for their first coat of Minmwax Polycrylic Satin clear coat. I’ve used this stuff before on countless projects and usually praise the ease with which this product goes on. It’s usually forgiving of brush strokes, provides a really consistent sheen across its surface and it’s water based so clean-up is a breeze. But I realized that painting over a solid black surface is not as easy. Every blemish in the coat was readily visible. Any imperfection in the base finish showed through and any area in the top coat that wasn’t applied perfectly evenly was visible when the light shown off it at certain angles. Thus began the paint-sand-paint-sand-paint-sand-paint nightmare that lasted about a week. And yes, with the speakers sitting in my living room just like this pretty much the entire time. Anyway, I called it good enough after that last coat and accepted the fact that once again I’ve nearly ruined a perfectly good project with a shoddy top coat. I started looking at past speaker projects and realized that none of them are perfect and that surely after a while I’d soon forget all about it anyway. I can say that birch sides look great. The clear coat went on and after only the second coat looked great. So I will say that real wood, with a grain and some texture to it, is way more forgiving of the irregularities in the top coat. But that solid flat black was something else. Especially since the fronts have the holes for the drivers, brushing around the driver openings and trying to get it look seamless was just a pain. I’m doing a spray top coat next time. I’m sure that goes on easier.

Continue reading →

Posted in Audio/Video | Tagged , , , , , , , , , , , , , , , | 9 Comments

How I Built an Awesome Classic-Style Bookcase from Scratch with Mixed Lumber from The Home Depot

Posted on April 3, 2017 by Dan

So I’m trying something a little bit different. I’ve been blogging for a long while now and while I feel like it’s still a great venue for sharing DIY projects and what-not, the bigger and better trend these days is vlogging – the video version of blogging. YouTube is way bigger than Blogger ever was and for most people it’s the sharing platform of choice. Me, I honestly hate shooting video of my projects. It just takes extra time, it distracts me from the work I’m doing, and most of the time I just don’t know what to say on the video. But for this project I made a conscious decision from the very beginning, for good or bad, that I was going to turn this bookcase build into a video blog. Just to try it out, see what I could turn it into. So in addition to a very short write-up on my blog, I’ve created a 4-part video series of this entire project from beginning to end for your viewing enjoyment!

Honestly though this will probably be the last time I do this kind of thing. As much fun as it’s been working with one of the most useless and frustrating video editing tools known to man (Windows Movie Maker), I really don’t think that many people are going to sit down and watch this thing front to back. But I feel like if you are interested in building a project similar to this, then I hope there are some nuggets of useful information in the 30+ minutes of video I pieced together of this project. I will say that did have a lot of fun throwing in old songs I had written, some from as old as 20 years ago as well as some songs I wrote just last month, to back the videos and at least make it somewhat more watchable (though depending on your music tastes, that’s debatable). I’ve got hundreds of these old songs I’ve composed over the years that I never know what to do with, most are just synth beats with some melody and a bassline, reminiscent of synth pop music from the 80’s. My son enjoys listening to them, and so for some reason I keep writing them even if they are lame. Anyway, I hope you enjoy the soundtrack to the Benjamin Bookcase Project. I think I will leave it at that for now. I will do a more complete write-up here in the future. For now I’ll just post a few pictures as well as links to all 4 videos on YouTube.

As always, thanks for stopping by and I hope you enjoy the pictures and my first ever video blog of the Benjamin Bookcase Project – A classic DIY bookcase featuring victorian styles including crown and fluted mouldings mixed with old-fashioned farmhouse comfort with the shiplap backing and clean white features. This is an all-white, 6-shelf, classic-style bookcase measuring 12-1/2″ deep by 70″ wide by 100″ tall. This bookcase looks great in almost any home mixing a little bit of old with a little bit of new to make a unique center piece for any living or family room. More info about this project will be posted here. Pin it if you love it!

Benjamin Bookcase Video Part I

Benjamin Bookcase Video Part II

Benjamin Bookcase Video Part III

Benjamin Bookcase Video Part IV

Mega-Picture Gallery

Posted in Home DIY | Tagged , , , , , , , , , , , , , | 1 Comment

Just Jumped on the Painted Piano Bandwagon

Posted on February 16, 2017 by Dan

Last weekend I found some time to squeak in a quick little makeover project that my wife has been anxious for me to do for a while now. I’ll admit it, painting a beautifully-stained, vintage-style, classic Kohler & Campbell piano felt just a little bit wrong. How could anyone take something so original, so natural, probably hand-stained by some really old guy, and just slap a dull, ordinary coat of paint on it? I’m glad you asked, because I’m going to show you just how I did it!

First things first, Pinterest. There’s no shortage of painted pianos out there to get some ideas from. Everybody who’s painted a piano has a slightly different approach to it and it helps to see what’s out there. For purposes that suited me, I chose one of the simpler methods in terms of complexity. Though the results surpassed my expectations. Color options range from white, to off-white, teal, baby blue, green, gray and black and I even saw a few red pianos out there for the truly bold. In my case the color choice came down to the paint type I wanted to use. The wife wanted a classic gray and I agreed. So gray it was.

Now, if you’re willing to buy wall/house paint (such as the Behr brand from The Home Depot) you can pretty much pick the color of your choice. I’ve had decent success using Behr paint to paint furniture (and speakers). I’ve painted with brushes (tends to leaves brush strokes). I’ve painted with rollers (looks good but takes A LONG time). And I’ve painted with an HPLV sprayer (Wagner) though the finish has that “sprayed” look to it, it’s not as smooth as the other two options but is quick and the coverage is high considering the cost. This has just been my experience though and I am in no means an expert in painting techniques.

But there was always one paint type I avoided like the plague when painting furniture and that was good old fashioned spray paint. I always discounted spray paint as a legitimate painting medium because to me anything sprayed with spray paint looked just like that, like it was spray painted. Spray paint was reserved for those cheap projects, like a pinewood derby car, or a homemade set of roof racks for the car, or for people on HGTV who are trying to take junk from a flea market and sell it for 10 times what they paid to unsuspecting consumers looking for something “different”. So basically anything, almost anything but furniture is where spray paint was best suited. But until recently my opinion of spray paint has done a near 180 and when done right can truly look beautiful, yes, even on furniture. I’d venture to say that spray paint has come along way just in its engineering and chemistry alone in terms of quality, consistency and coverage since the last time I used it. Bare in mind however, not all spray paint is created equally and there is some pretty crappy spray paint out there that can be purchased for very cheap but I would recommend avoiding them or you may end up saying to yourself, yup looks like crappy ole’ spray paint.

The spray paint I used is Rust-oleum Painter’s Touch 2x Ultra Cover in a Satin Granite (gray). Each can of paint sells for about $3.89 at The Home Depot and for this piano makeover I used just about five cans. But before I get onto the painting details, let’s talk about prep work. Step one: If you’re going to spray paint your piano, you have to move it out of the house first. This alone is a deal breaker for most people who are looking to paint their old piano if they want to use spray paint. I don’t care how many square yards of 1 mil plastic you have, masking off half you’re living room to spray paint inside the house just seems like a bad idea all around. I had some friends stop by the house to help me move our piano out of the living room and onto the front patio. Took less than 5 minutes with their help. But it’s not a one-man job for sure.

Step two: Once out on the patio I began to disassemble nearly everything on the piano that had screws and could be removed. This is the second deal breaker for those looking to paint their piano. It’s just too much work and you risk either breaking something or losing some random piece of hardware or not being able to put everything back together just right. But if you feel inclined and up to the task, I recommend taking off as much hardware as possible and taking off as many pieces as possible and masking off everything else. This way each piece is fully painted on all sides so when it’s put back together, you don’t have any seams or cracks or small joints that still show through the original stained wood color. It also makes painting each piece much easier. You can see above all of the pieces I was able to remove and paint. I masked off the keys and the piano strings and hammers with some 1 mil plastic and blue painters tape. I also removed that long skinny piece of wood that sits right over the keys which has the strip of felt on it and painted it separately just so I could mask off the felt and get a good painted edge on the wood that sits right up against the keys.

Step three: repair and sanding. The main reason people don’t feel bad about painting an old piano, and the same reason why I caved as well, is because an old piano is just that, it’s old. The wood is usually damaged in multiple places, the finish has worn and it just doesn’t look as nice as it once did decades ago. This is where the repair part comes into play. My wife has had this piano in her family for a very long time. This was the same piano she played when she was 8 years old and it’s the same piano my kids play today. So with a little bit of wood putty I went around and filled all the cracks and broken wood parts and then sanded them smooth with 150 then 220 grit sandpaper. With my palm sander I sanded almost all of the piano with 220 grit sandpaper just to take off the very top layer of clear coat. I was not attempting to remove the clear coat or the stain and never intended on getting down to bare wood. I just went over each piece really quickly to take off the sheen and provide a somewhat roughed up surface for the spray paint to adhere to. This step you could probably skip, however. Depending on the existing finish of your piano. The parts I didn’t sand looked just as good in the end as the parts I did sand, so it probably wouldn’t have made much difference. The overall sheen was a little different in the sanded parts though, it ended up duller than the parts I didn’t sand. Perhaps another downside to the use of spray paint is that the finish ultimately is very dependent on the base finish. Since the paint goes on so thin, most of the underlying texture shows through. If the piano was really smooth and shiny to start with, then the paint will also go on and look and feel smooth and be shiny. But if it’s rough, the paint does nothing to make look smoother. Additionally the sheen is affected by the undercoat as well. Smoother wood looks shinier than rough wood, regardless of the sheen of paint you’re using. This satin Rust-oleum paint has just enough sheen to look nice without looking dull. But still varied based on quality/texture/ of the base finish. Test out a small section if you’re worried, like under the bench or under the piano top/lid.

I painted three light coats one after another all basically within the 1 hour timeframe allowed for re-coats. I started on one side and just worked my way around the entire piano and then to each disassembled piece and then started over back at the beginning. The trick, I think, is just not overdoing it in any one spot, allow the first coat to go on and not cover everything. The first coat won’t even look that good and you’ll be cursing yourself for even trying this whole project. But be patient. The second coat will fill the gaps once that first coat has had a chance to adhere and dry and by the third coat it will all just look like one seamless band of paint and you’ll be giddy with excitement. Okay so now I’m just describing how it all went down for me. It was panic and fear, then anxious relief and finally awe and bewilderment. Just take your time, don’t sand between coats, light and easy on the spray nozzle in quick short bursts from 8-12″ away at all times. If you do overdo it in a spot or two, let it dry a bit, sand it down lightly, and re-spray. That’s about it, take a step back and check out your wonderful work and don’t forget to snap a few pics for FB/IG.

Step four: let dry for 24 hours. I skipped this part and moved the piano back in the house the same day. I let everything dry for only about 4 hours but due to an impending storm I had to get that thing back inside before the rains came (which they did the very next morning). When moving the piano we tried not to handle the painted parts as much as possible, lifting from the back and undersides. But this job can be done in one day if you start early in the morning. I reassembled the piano once in the house and luckily managed to figure out where all the screws went. We set the piano up in its new location in the living room and sat back in amazement at the transformation. It looked fantastic. The best that piano has looked in all the years we’ve had it.

The last thing to do is to finish the fabric bench seat which for now is just a piece of fabric wrapped around the bench lid, but I will get it stapled down with a foam pad on it soon enough. The other thing that we didn’t get to do is put on a couple coats of Minwax Polycrylic satin clear coat. I bought a pint of this stuff expecting to use it but I was so impressed with the final finish of the spray paint that we decided to hold off for now. Now that the piano has been in the house for a few days I have noticed more inconsistencies in the sheen on the sides of the piano and the top. Basically a coat or two of the satin polycrylic will fix that right up. That step can be done anytime with a simple brush while in the house. So for another day we may get the final clear coat on this but even if that never happened, I would still be very happy with our new piano and hope to be able to enjoy it years to come.

Check out some of pics below of this little painted piano makeover project. Let me know what you think in the comments below and thanks for stopping by!

Obligatory Before and After Shot

Posted in Home DIY | Leave a comment