New DIY MTM Towers designed by Dennis Murphy and Paul Kittinger

Now here's where the fun begins. I had a gallon of high gloss, oil based polyurethane laying around and thought I'd experiment. I originally wanted to spray it on using the HVLP gun but after I shot a test piece, there's no way I'd want to do that again. It got on EVERYTHING and surface wasn't that smooth. The paint was a little messy and somethings got overspray on them. With poly, everything gets nasty. My arm hair was forever frozen in the overspray of polyurethane.

So out with the HVLP gun and in with the cheap, foam brushes. I did the test on the top surface of my speaker stands that have the same paint. I applied probably 6 coats at 2 coats a day. Of course applying poly with brushes leaves pretty extreme brush marks but because I built it up so much, I could wet sand it smooth pretty easily without sanding through the poly. By the way, it's advised to let the final coat of poly cure for at least a week.

Here are some pictures of my progress.


Here, I've done some wet sanding to smooth out the brush strokes with 600 grit.



1000 grit.


2000 grit.




After sanding, I used some Maguiars Cutting Compound followed by a random non abrasive polish I had laying around. I have to stress that these products applied the way I applied them is not ideal, it's simply what I had laying around.





Here's what 10 minutes of work looks like.




And here's what about 20 minutes of work looks like. Again, if I had better products, I probably would not have needed to spend so much time on them.




Here's a picture of a somewhat finished surface showing a reflection of my
TV. The result is an almost mirror like finish that feels like glass. I really like the end result. It's a lot of work but it's very rewarding. When I return from Utah, I will start on the enclosures!

So you covered up the cool wood grain on your front baffle?!?!?



I thought you were going to stain it to bring out the grain? That would have looked very cool, wood grain baffle with black top and sides.

Sean - I'm really impressed with your high-gloss black finish . I can't wait to see more photos!

darien87 said:

So you covered up the cool wood grain on your front baffle?!?!?

I thought you were going to stain it to bring out the grain? That would have looked very cool, wood grain baffle with black top and sides.

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Funny story about that. My wife was trying real hard to convince me that we need this new kitchen table that had a black top with stained wood legs, same with the chairs. I opposed the idea greatly as I didn't like the combo of black and brown so if I had finished my enclosures like that, she would have built me dog house with black walls and brown shutters.

Alex2507 said:

You should be able to find a forum with tips about using a gravity feed HVLP sprayer. About all I know about spraying is that you don't want the spray hitting the speaker at an angle. So point the sprayer directly at the work and don't angle it up, down, left or right. I think I would lay the speaker on it's side to paint the top and bottom and stand it up to paint the sides. Figure something out to separate the wet bottom from the work table when you stand it back up like standing it up on a few screws or something. Use a milk crate elevate the speaker. You need that to keep from having to point the sprayer down to spray the bottom. Make sure you have the right size nozzle for the finish you're applying.

When I first started refinishing furniture I wanted every piece to be the brightest piece in the room. As my tastes evolved I came to understand that there was an understated elegance to low luster finishes. I am still happy with my high gloss brighter than the sun sheens but ...

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Thanks for the advise. I got to see first hand what you were talking about. Getting the distance from the work piece just right, not pointing it at an angle, tip size etc. Also, when spraying, I overlapped the paint about 60-70%. This resulted in a nice, solid looking color with no spray lines.

You should post some pictures of some of the piece's you've done. I'd like to see them.

Alex2507 said:

Sean, the latex won't sand out. Think of sanding latex gloves. I think that oil base Kilz will sand out but alcohol base Bin Primer is for sure sandable. With a shellac finish you don't have to sand in between coats. You may need to skim out the rough primer if it is like orange peel but if you have a dry spray condition sanding may be enough to get you an acceptable result. Holding the gun too far away causes under atomization (dry spray) and holding it too close causes under atomization (orange peel). My friend Eddie says he has gotten excellent results spraying latex on cabinets. He says holding the gun 6" away works best for him with a turbine.

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The latex was somewhat difficult to sand. It gummed up the sandpaper quite easily. I would not choose to sand latex again. I think next time I will use the alcohol based primer. It seems like it will spray nicely too.

Swerd said:

Sean - I'm really impressed with your high-gloss black finish . I can't wait to see more photos!

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Thanks! This is turning out to be a very nice low budget finish. So far, I think the only thing I've purchased is the Macquiars Compound.

skyline_123 said:

Now here's where the fun begins. I had a gallon of high gloss, oil based polyurethane laying around and thought I'd experiment. I originally wanted to spray it on using the HVLP gun but after I shot a test piece, there's no way I'd want to do that again. It got on EVERYTHING and surface wasn't that smooth. The paint was a little messy and somethings got overspray on them. With poly, everything gets nasty. My arm hair was forever frozen in the overspray of polyurethane.

So out with the HVLP gun and in with the cheap, foam brushes. I did the test on the top surface of my speaker stands that have the same paint. I applied probably 6 coats at 2 coats a day. Of course applying poly with brushes leaves pretty extreme brush marks but because I built it up so much, I could wet sand it smooth pretty easily without sanding through the poly. By the way, it's advised to let the final coat of poly cure for at least a week.

Here are some pictures of my progress.

After sanding, I used some Maguiars Cutting Compound followed by a random non abrasive polish I had laying around. I have to stress that these products applied the way I applied them is not ideal, it's simply what I had laying around.

Here's what 10 minutes of work looks like.

And here's what about 20 minutes of work looks like. Again, if I had better products, I probably would not have needed to spend so much time on them.

Here's a picture of a somewhat finished surface showing a reflection of my
TV. The result is an almost mirror like finish that feels like glass. I really like the end result. It's a lot of work but it's very rewarding. When I return from Utah, I will start on the enclosures!

Click to expand...

Did you thin the poly before spraying it? It needs to be thinned about 50%. I used naptha when I shot my kitchen cabinets and the overspray was very low, but I also played with the gun to minimize the amount of material going out and kept the pressure as low as possible. Thinned with naptha, any overspray was almost dry by the time it landed on anything and that made cleanup very easy.

highfigh said:

Did you thin the poly before spraying it? It needs to be thinned about 50%. I used naptha when I shot my kitchen cabinets and the overspray was very low, but I also played with the gun to minimize the amount of material going out and kept the pressure as low as possible. Thinned with naptha, any overspray was almost dry by the time it landed on anything and that made cleanup very easy.

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No, unfortunately, I didn't thin it. What I thought was unusual was that the poly that I have was thin enough that it sprayed very nicely as it was so I didn't think it needed thinning. I'm assuming thinning it with Naptha isn't exactly to 'thin' the liquid so as to shoot it better.

skyline_123 said:

You should post some pictures of some of the piece's you've done. I'd like to see them.

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I just ran around real quick and snapped some pic's. I was in my wood phase when I did this stuff so paint and press wood were sins. I did allow one piece of veneered ply for the top in this table that I threw together. The wood came from various junk piles in Boston. This is brushed on polyurethane.



This was a uniformly fugly brown stain sitting beside a dumpster when I found it. Brushed on finish.



This also had a fugly brown stain and was sitting curbside waiting for the garbage truck. It is fake Mahogany (Sapele) veneer on lumber core. Once again with the brushed on finish ... like 2000 coats. It really looked sharp when the brass hardware was polished.



Now we step into the high dollar arena. It's oak. Two bucks at a flea market got me this but it was painted then. Once again with the brush.



Now this was 25 bucks but it was falling apart which sort of helped because I took it apart completely to love it up and strip it like everything else. It's old and it's maple. I left the dark stain in the beads to accentuate the work. It was at this point that my tastes evolved from turned legs to tapered legs. I came to view the turned ones as bulbous but saw the thinner tapered legs as elegant. Whoa ... I think I just sprouted a vagina.

I had my friend Eddie spray this with his HVLP.



Last but not least the coffee table. It too was a fugly brown. It is now natural maple with a sprayed on floor grade polyurethane that is bullet proof. There's a little orange peel in this finish but you have to know that it's a flaw to notice it. All anybody ever says is that it's nice. This was forty bucks! I sh!t you not.



You just can't imagine the man hours spent stripping, sanding and coating. Oh yeah, I had to redo the top of Cheryl's hope chest because I put a cigarette burn in it when I was drunk. That went over big.

skyline_123 said:

I'm assuming thinning it with Naptha isn't exactly to 'thin' the liquid so as to shoot it better.

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Yeah, it is for that and so it skins over faster, leaving a smoother finish without catching as much dust. It still dries fast but the surface isn't tacky for as long and that made a big difference compared with any poly I have brushed on without thinning- I always had to deal with the dust specs. I got that tip from a painter on a high-dollar home where I was doing some of the low voltage work. Those painters did some of the best work I have seen.

My word you have a lot of furniture. Those pieces look great! I especially like the first picture where you can see the reflection of the candle holders. I don't even want to know how much time you have in all of those put together (or even just one piece). I take it you worked on them at your friend's shop?

skyline_123 said:

My word you have a lot of furniture.

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Yeah, I'm all done with that now. I still like good pieces and can see potential in lots of stuff but I'm out of space. In that Sound Panels thread there is a pic of a killer armoire I have over at Eddies that has book matched veneered doors and a round top but I'm out of space and don't have the furniture lust. It's funny that now that I actually know stuff and have some practical experience I am not so interested.

I especially like the first picture where you can see the reflection of the candle holders.

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That's an odd piece that I built to go in a tight spot to hold a scanner or maybe a printer. At first I kind of thought it was ridiculous because of the three mismatched species and referred to it as my clown table but it has consistently drawn compliments.

I take it you worked on them at your friend's shop?

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Those were done at his old shop (he lived closer then) and at another friend's garage.

I'm looking forward to pic's of your set up completed. I think you might need your own copy of Brothers in Arms now. Oh yeah, in case you missed it there is a killer deal on a Yammie 3900 in the Deals Forum from the AH Store. Just sayin ...

This has probably been covered but I was wondering about the efficiency and impedance/phase curve of those speakers. I'll look around for it. Oh yeah, that book I linked on wood finishing has a section called Finishing the Finish which is what you're playing around with. I haven't ventured into that as I was okay with what I was able to get out of a brush (foam and/or bristle) and even better from Eddie doing my spraying but that gloss black does look pretty soogin'.

Lastly, wear long sleeves when operating a spray gun.

Alex2507 said:

This has probably been covered but I was wondering about the efficiency and impedance/phase curve of those speakers. I'll look around for it.

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Predicted system impedance (solid red line) is no lower than 4 ohms.



I would expect these speakers to have a sensitivity of roughly 88 dB, similar to the sensitivity of the Salk HT2-TL. They can be easily driven by 100 wpc AVRs.

The gloss finish looks amazing.

Whats the process for wet sanding? Did you use water or something else?

Did you sand by hand or use a power sander?

I think I might give it a try on my next project.

Skyline, that looks like a fantastic design and the workmanship is second to none! Great job! If I decide to build my own, I think it'll be that design.

Skyline, I've read this thread through twice and I want to know how the build is progressing. If you've finished, you owe all of the thread readers your opinion on how excellent these speakers sound. I'm planning to build them myself next spring/summer. Please continue with the thread!
I know these are going to be great speakers!
Thanks, Tom

If you've finished, you owe all of the thread readers your opinion on how excellent these speakers sound.

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Correct you are. I was hoping to have the finish completed so I could post pictures as well but things keep getting in the way. I'll post a couple of pictures at the end even though they're not done.

Here's my opinion on the ER18's. Bear in mind, I'm no audio snob so my I don't have a lot of negative things to say.



The short version:

In one sentence, I would describe these speakers as sounding very warm, rich and accurate with a very detailed and full bodied sound that plays low with real impact and authority.



The long version:

The first thing I noticed about the ER18’s was how well they imaged and how spacious and lifelike the instruments sounded. For example, I’ll use Michael Buble’s “The More I See You”. This song, much like all his songs, has many instruments, all fighting for attention. There are strings, horns, drums and upright bass and all have their places in the soundstage. If I close my eyes, I can hear exactly where each instrument is playing and how far back they’re set. After the intro, the vocals and bass appear to come from the center of room with such sharp precision, the speakers truly disappear, and I mean disappear! They trick my eyes into seeing things that aren’t there. They do take a while to get the distances and angles just right but it’s worth it. I usually listen to music late at night with the lights mostly out and the first time I heard this song, my eyes shot open in a panic because I could not believe what I was hearing. I immediately and involuntarily grinned this ‘kid in his first candy store’ smile because my ears had tricked my eyes! How could I be starring at a speaker that wasn’t making noise yet music was pouring out the center of my dresser? Crazy!

The ER18’s really shine when it comes to vocals. I’m a visual person and a lousy musician so when I hear music being played and sang I always visualize it. The ER18’s give me far more detail than I’ve ever heard before and I can picture exactly how the artist’s mouth is moving and if the lips are wet or not. It’s as if I can hear the mood and attitude of the singer when they were performing the piece. In general, the vocals are very realistic and really make the music really come to life.

The bass is something I still can’t get over. It’s very tactile, smooth and effortless with an incredible ability to play even the lowest notes of a bass. These four 6” drivers are simply amazing and surprise me every time I listen to them. People who have heard these question whether or not the subwoofers are turned on, especially when they’re set up in my bedroom. The bass is tight, accurate and seemingly bottomless yet very civil and smooth. I love listening to music with an upright bass to compare the sound to some small, private concerts I’ve attended. In these concerts, I pay attention to the upright and how loud it is compared to all the other instruments. Sure enough, the ER18’s play that upright just as effortlessly as the musician in the concert.

For all you die hard movie fans who purchase movies just because you've heard it'll compromise the structural integrity of your house (guilty), these may lack a little impact in the explosions department. It's easy to forgive as they're just cute little towers.


Another great feature worth mentioning is that they’re not power hungry. I currently drive them with my Yamaha RX-V665. They make quite a bit of noise before any distortion occures but at those SPL’s, being in the same room is not very comfortable. The enclosures are very simple to build and the design is very easy on the eyes. For the price, I’m not sure anyone is going to get a better, near full range experience quite like these that don’t require serious electronics to run. I’m so impressed with the ER18’s, I just want someone to buy these from me so I can do it all over again. Thanks so much to Dennis Murphy and Paul Kittinger for designing such an amazing speaker. Bang for the buck has a whole new meaning.

Well done. Top notch workmanship. From your description it seems you have really speakers.

Good speakers should not appear to have anything to do with what you are hearing. It sounds to me that you have a good 3D sound stage.

have you had time to compare the tritrix?

Sean - very well done!

lucasamiller said:

The gloss finish looks amazing.

Whats the process for wet sanding? Did you use water or something else?

Did you sand by hand or use a power sander?

I think I might give it a try on my next project.

Click to expand...

The sanding process is quite simple. Regardless of your paint process (obviously a sprayer would be preferred to get everything as smooth as possible), all you really need is to build up the poly thick enough so you're able to sand it flat. I started wet sanding with a 400 grit and got everything perfectly flat. Once it's flat, then it's time to remove the fine sanding scratches using 1000 grit, then 2000 grit. The trick is to make sure with each increment that you remove the previous sanding scratches.

Once it's perfectly smooth and ALL sanding scratches have been removed with the 2000, it's time to polish. This was the biggest challenge for me as I didn't have proper technique/equipment. You can do this by hand but I chose life. I used a product by Maguiar's called M105 with a white, Lake Country polishing pad followed by M205 with a black, LC finishing pad. These were applied with a Flex 3401 buffer (see above link). The results are nothing short of amazing (the picture below is of a test spot, I hadn't even used the polishing compound yet).

camrsz said:

have you had time to compare the tritrix?

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I did have a little time to compare the ER18's with the TriTrix. I will start off by saying that Curt Cambell did an excellent job at designing this budget friendly speaker. The TriTrix is a pleasure to listen to, especially considering the cost. They are PERFECT for a first time speaker builder. If you so choose, you can build the cabinets from scratch or buy them pre cut. The crossovers are very simple to put together. I believe there are 5 or 6 components to each crossover. And the best part is that if you find yourself way over your head during construction and you quit, you're not out very much money. And if you do go through with it, you have a wonderful set of speakers you can be proud to say you built.

As for comparing the ER18's and the TrixTrix, it's a hands down decision on which I'd rather listen to. The TriTrix images surprising well and has a very spacious sound with surprising bass considering the 5" woofers. Curt claims F3 to be around 50-55 hz. I wouldn't hesitate to suggest this build to others. With that said, in my opinion, the ER18's have a much higher quality sound overall. The bass reaches lower and sounds much cleaner. Instruments sound much more natural and the vocals more realistic. I will admit, this is a very vague description, maybe if anyone has a specific question, I may be able to answer with better information. When I was comparing the two, switching back and forth at the press of a button, every category I was trying to compare was dominated by the ER18's, the bass, mid range, highs, vocals, imaging, etc. I believe in this instance, you really do pay for what you get. The ER18's are bigger in every sense. They're physically larger, the drivers are larger, they cost more and the sound is that much more pleasant. Because of the cost difference though, it's almost unfair to compare the two.

I have to make a correction about the F3 of the TriTrix TL version. On Curt's website, he describes the TL version as being similar to his Triunes. He says that in his listening room, the TL Triunes will play in the sub 40hz region relatively well.