New build - NeoPro 5i + PHL1120 + TD15M

This summer I came across a classified ad I couldn't refuse over at TechTalk making my dream of this exact speaker a reality. A pair of NeoPro 5i, pair of PHL1120, and four TD15M's for a VERY reasonable price. I'm not sure what it is but I don't have much motivation for speaker building during the warmer months, these guys sat in boxes all summer and fall. Just like last year though around January I started getting the itch t build something. For some reason I have the misfortune of getting the itch right around the time temps are bottoming out here in northern MN

Honestly though the real reason involved visiting a local audiophile's setup that was very very good (TLS Guy over at audioholics forum) plus hearing my good friend Dave's Magnepan MMG's in my room A/B'ing against my waveguides (and sounding better than them EVEN at high SPL AND being pushed by a lowly Onkyo TX-SR304 ). It took me a long time to admit it to myself but there was always something "off" with my waveguide build (http://www.avsforum.com/avs-vb/showthread.php?t=1220016). I'm pretty certain someone that knew what they were doing could have gotten them straightened out but I just lack the knowledge and motivation at this point to fix them. Something in the crossover.

So once again I find myself out in the garage cutting wood in full MN winter gear: long underwear, snowpants, winter boots, hooded sweatshirt, winter coat, hat, gloves; the whole bit. I finally got some use out of my table saw (that I had been too intimidated by to use before) though so the cutting went very smooth. I overbuilt the boxes a bit - I've been trying to do something more elaborate with each build. They have a double baffle and include window bracing that is glued together in the middle (check the pics below). I used the 1 1/4" roundover on the baffle and went over the rest with a 3/4" roundover. I still want to attempt to flush mount the drivers but neither will be all that easy. I need to get a bushing set for my router then maybe I'll give it a shot.

Currently I'm using the TD15M still in the old speaker with the new mid+tweet enclosure set on top. The crossover is a passive network that Curt Campbell was kind enough to share with me. Unfortunately it's not one of his published designs and it is not mine to share (please don't ask, I have a lot of respect for Curt and he was nice enough to share it with me - I'm not going to break his trust). It's the crossover he designed for exojam's JCW 3-way (http://www.avsforum.com/avs-vb/showthread.php?t=1061558) minus the woofer network. I had a pair of black anodized double binding post plates so I wired them up for biamping with the tweeter and woofer networks completely separate (why not right ). The woofer - mid crossover is active using DCX2496. I haven't messed with this XO very much (for some reason I don't think it will have a significant effect on the sound), I just set it for LR24 at 350hz arbitrarily.

Listening impressions have been very, very positive. The new speakers do not exhibit any of the crossover issues I had with the waveguide. Also measuring them in-room with REW shows a very nice FR curve - even with room interaction? The clean output capability exceeds that of the waveguide build with the faulty XO. I actually had a new experience with these last night. I was playing Nine Inch Nails Downward Spiral SACD - the 2nd disc has some random tracks on it including one named "A Violent Fluid". It's just an instrumental but has some crazy high frequency dynamics. I had to back off the volume as the HF was giving me a mini headache with each pulse. With the waveguides I could definitely play it loud enough that my ears hurt but this was different, my ears weren't complaining but my head was!? Unfortunately I let my 1 year old play with my SPL meter a couple days ago and haven't seen it since so I have no clue how loud it was... if I had to guess I'd say at least 105dB peaks probably closer to 110.

I'm hoping someone can give me suggestions on what to do for the woofer enclosure. I'm trying to figure out if I can cut down the current enclosures and re-use them somehow or if I should do it right and build new ones. The bummer is the current enclosures would go to waste If I do build one I want to do a tapered enclosure similar to dlneubec's BaSSlines (http://www.avsforum.com/avs-vb/showthread.php?t=1064857) with them tapering to the width of the mid+tweet enclosure. The tweeters are way too high right now, I've got them pointing down a bit (propped the backs up on some DVD's) but it's still not quite right and doesn't work for listening in other rooms very well...

Pics:
Note, my wife LOVES when I glue up speakers on the kitchen counter!

Hi James,

The enclosure is ported but it's not at all ideal for the TD15M. It was designed for the TD15X and I switched them out this summer. I cut the port down after making the change to move the tuning frequency to something more appropriate for the M but the enclosure is still way oversized for what's necessary. I think it's currently 150l and tuned to 45hz. When I rebuild I'm looking at more like 80l tuned to 40hz or just sealed.

I noticed today that the XO on yours is a shallower cross at 500hz. Curt mentioned 350hz in one of the emails so that's where I started. I do plan on trying something closer to 500 but probably not until I get the enclosure for the TD15M figured out... Right now the C-C spacing is too large between TD15M and PHL1120.

Thanks for the tip, I'll try it closer to 500hz and see how it goes. I've already beat on them pretty hard crossed at 350 though


So the inevitable finally happened to me. I was showing this thread to one of the guys at work - the guy that knows everything about everything, ya you know the guy. He commented how good they look then mentioned how good his old Bose speakers from the 80's still sound... He went on to say how it's just unbelievable the awesome sound they produce and from just a little 4" cube! I literally laughed in his face then told him I was laughing at him He insisted that they sound great though and "without distortion" at high playback levels. These are the old good 1980's Bose speakers not the crap that they make now he said. I told him I'd have to bring my measurement rig over some time and we'll see how much distortion they're putting out at "high playback levels" lol He didn't budge though, told me how he bought them when he worked at a stereo store in a mall and they cranked them up so loud in the store their pants were flapping standing by the "sub". It was classic! This is the guy that doesn't generally say something unless he's pretty sure he's right too, made it oh so sweet

Thanks man, if he only knew... he'd be SO embarrassed having made that comparison

I made some awesome progress on the bottom section today. I started working up a cutsheet for a simple new enclosure for the TD15M last night and realized it was going to take 2 sheets of MDF Inspired by that realization I decided to try cutting down the current enclosures. It actually went very smooth, much easier than I was thinking it would be. I measured and cut the fronts/backs using a circular saw with a straight edge clamped down and the blade set pretty deep - about 2" or so. Then I cut the sides by sliding the blade of the circular saw into the grooves left from the front/back cut and clamping the straightedge down using that as a reference. I ended up with a very nice edge all the way around to glue to. In all I got them disassembled, cut the top off, cut the bottom off, cut new top/bottom, glued together, hit them with 3/4" roundover, and hit the baffle with 1 1/4" baffle. How did muster the drive to get this all done in one day???? The inlaws were visiting and... well, that's pretty much it, the inlaws were visiting I still want to add some more bracing and I need to do bondo the recess from the horn - but that's going to have to wait for spring when I can leave them in the garage to set. I tried to bondo that tonight but the smell was just too much to do in the house.

Started the day with this:


Now they're 1/4" shorter... and there are some lines across them


What's this!?


Got them glued up by 2pm

I got the additional bracing put in today, a 2x4 across the top and an angled piece (I had 1x12 and one scrap of MDF that's about 8") behind the woofer. When measuring my old speakers I had a blip around 500hz. Someone thought it could be a front-back resonance. This angled piece should fix it if so and will add some much needed bracing regardless.

I've got a bit of a problem now though... They look goofy! I tried flipping them around so the woofer's right by the floor and it didn't help much. I have a couple ideas but for now I'm just going to leave it. One idea is to build a triangular stand and put it between the woofer enclosure and mid/tweet to make the difference in cabinet width less glaringly obvious. Another idea is to put some wood dowels in between raising raise the mid/tweet enclosure up a couple inches. I'll probably try the wood dowels first and see how it turns out.

Unfortunately there's no place to move the rack to... it's not as close as in that pic through, not ideal but not as bad as that. Also the two amps on top aren't permanent they're just sitting up there for now (they need to go in for repairs).

I couldn't find the mach 15 but the mach 17 looks like what I've got in mind but only tapered on the sides, the mid/tweet enclosure is the same depth as the woofer enclosure. In my head the wood dowels look nicer but just the top enclosure weighs 45 lbs so whatever I do it has to be stable with 4 kids running around the house... I'd have to really fasten the dowels down and I'm not so sure I want to commit to that. It would be really cool if I could figure out an adjustable height solution actually. They sound fantastic sitting down but standing up and walking around you're too off axis vertically for the ribbon tweeters. Raising them up will help a bit to split the difference between sitting/standing but adjustable would be neat - not sure when I'd actually want to use it though now that I think about it.

Thanks for all the ideas, I'll have to look over them tomorrow Just taking a quick glance the Funky Waves one is what I had in mind with the wooden dowel suggestion, I'm not sure now though as I remembered it weighs 45lbs I'll have to check out that sock one too, I have to do something for a grill as I'm afraid the 1 or 2 year old will poke the PHL! One of them already stuck a metal ball fro their magnetix to the NeoPro... the magnet's so strong it bent the screen just from sitting on there for however long it was before I found it

Hmm, hadn't considered it. Thoughts on this? I don't want to go too much taller (maybe 6" at the moste) as then I move out of the sweet spot for the ribbons.

I've got to do something though, since I got home from work today I've fixed 3 dust caps that got poked... How could I have fixed 3 when I've only got 2 you ask? I came home to find one poked, fixed it and went in the other room. Came back 5 mins later to find them both poked The 2 year old got in big trouble for that... She also almost pushed one of the top enclosures onto the floor. I don't think she'll be doing that again (I sure hope not anyway!). I guess there were a couple nice things about having 100lb speakers For an initial something I'm going to look into the "sock" idea as it looks pretty simple and it will keep their eyes off the dust cap. Those things just scream "poke me" lol.

There's some information about them on the first page of the thread below but nothing very indepth. We used a web page to calculate the lengths of each piece and it gave us the layout to use:
http://web.archive.org/web/200704292...alculator.html

http://www.avsforum.com/avs-vb/showthread.php?t=1312919

The avs thread has more/better information though. They were mostly a test project for my buddy's HT that he's building. I did hang them in my living room and noted that things sounded "different". I'm not sure if it was better/worse but different. I tried to measure a difference but didn't see much other than a slight FR change around 3k (if memory serves). The wife said "no way" to leaving them up though and I didn't argue too hard, they were within reach for our 4 kids and wouldn't have lasted very long lol That reminds me I have to send those home with him the next time he's up.