[keelay]

Having just finished a set of Parts Express Triunes for a friend, I was hooked. I had been reading about the Natalie P and many positive reviews so I thought I'd give them a try. The main issue is that I had just finished building our entertainment center using a set of Ikea (Billy) bookcase. I had to heavily modify them to get this far ... AND.. my wife really liked it. The only thing she didn't like was the speakers sitting on the shelves.

So here is the before shot: Family room / Home Theater room (It's a small house)

The design thread that I used to build these speakers: On/In Wall Natalie P cross over variation Design thread

For Reference here is the Original Natalie P design thread which has baffle step compensation in the crossover

 

[keelay]

So then here is the plan. I wanted to place the new main speakers vertically, still use the existing bookcase design for the most part, and place the new speakers roughly splitting the room into 1/3's. That makes an ideal placement for mains. I also wanted the speakers to integrate into the existing book case design, which I had to heavily modify to make them look like this in the first place.

So here was my plan:

Split the book case and add a thin book case with a speaker built into the bookshelf.
Here's my original autocad drawing:

So Here is the original Natalie P thread that sold me on the reference design.
And Here is the Natalie P crossover for in/on wall crossover without Baffle Step Compensation. This is the design I implemented.

 

[keelay]

So here are a bunch of shots of the bookshelf. This was a standard 15 3/4" Billy bookcase from Ikea. I modified the shelves to make the bookcase more narrow. It's actually only 8 3/4" wide now. I added an 3/4" MDF back, and added 3/4" MDF top and bottoms. The front baffle is 1.5" MDF making only the sides particle board (Billy bookcase material). But once I'm finished there will be 1.5" of particle board on each side.

You can see I added lots of bracing. Side to side and front to back

 

[keelay]

So here
I added a couple front to back braces. These braces will sit against the baffle once it goes in and reduce baffle resonance. These I went ahead and drilled holes in to reduce reflections from these internal braces.

 

[keelay]

So here the enclosures are complete with Crossovers installed. I have also provided sound damping in the form of carpet pad for the side walls. and around 2" fiberglass insulation everywhere else.

 

[keelay]

So here is the baffle construction shots. The baffle is made from sandwiching two 3/4" pieces of MDF. The port tube is integrated onto the front baffle. The Speakers were recessed to be flush mounted.

 

[keelay]

So here are the boxes put together. I was just finishing painting and installing the drivers. The Port is configured on top since this was the only free space to place it. A little unconvensional. Once I build My Dayton 15" HF subwoofer I plan on sealing the port. Port is tuned to 39 Hz. Internal Volume is 1.4 Cubic Feet.

 

[Anthony]

Nice build. Keep the pics coming. :T

 

[keelay]

I have the speakers installed now I just need to take some pictures of them. I don't have the grills completed yet, my wife can't wait till that happens . I will likely have some time this weekend to take a picture of them installed.

- Kyle

 

[filtor1]

That looks amazing!

 

[fbov]

In another thread, you linked to the main NatP build thread on HTGuide. I remember your situation and I like the approach you've taken, but, as I may have mentioned, you may not be happy with the results using the stand-alone NatP XO for an in-wall application. You really want this one.
http://www.htguide.com/forum/showthread.php4?t=22626

I made my NatP's as an LCR set with the infamous toppled MTM in the center channel. Understanding the issues that represented, I bought parts for two NatPs and 2.5-way XO, and tried both in the CC. I found that neither design sounded good in the CC, both for the same reason - BSC, baffle step compensation. Like you, I had integrated the CC into the TV stand, effectively making it an in-wall implementation. I switched to this in-wall XO design and it finally sounded right. Apparently, correct levels of BSC was more important to me than the lobing issues of a horizontal MTM.

So if you used the standalone XO design and find your NatP's a bit boomy, consider using the in-wall XO design. I liked it much better.

Have fun,
Frank

 

[keelay]

Thanks for the very thoughtful input. I actually did use the In/On Wall Natalie P Crossover design. I have a link on the first post to both the Original Natalie P site and the On/In Wall crossover variation, but it may not be obvious which one I used. I will fix that. I have everything installed and the In/On Wall Crossover sounds very balanced across the frequency spectrum. There is no boominess. I'm very happy with the choice even though this cost around $50 more in parts than the no BSG Natalie P Xover. I'm thinking of getting some measurement equipment to test these out, but that might take me a while to get.

Thanks,

Kyle

 

[Owen Bartley]

Very cool project Kyle, great idea. I'm really looking forward to seeing the finished product. Are you still using the CC from your original post, located on top? Any plans for a NatP CC or camouflaging the existing one?

 

[keelay]

I am still using the same CC from the original post. It is an Infinity Reference that I picked up on craigslist for $20. It isn't quite as good as the Natalie P's but it's decent. I plan to replace the HT in a box surrounds, then the sub and then the Center Channel.

For the Sub I'm going to build a LLT with a Dayton HF 15" sub and a 500W BASH amp from oaudio.
For the surrounds I'm trying out the RB kit from madisound. Just ordered a pair.
I'm still looking for the "perfect" center channel reference design. You know how it goes.

 

[fbov]

May I then suggest the Modula MTM CC.
http://htguide.com/forum/showthread.php4?t=11475

Same RS180Ss and designer as the NatPs, but with a $200 Scanspeak tweeter that's so small you can bring the drivers to a 9" spacing on a 9" wide baffle. I can't justify it sonically; I'm still trying to hear the lobing defect, even though I can measure it. But it's the one to make when the time comes.

Have fun,
Frank

 

[keelay]

So I took some pictures tonight and am posting them. I haven't started the grills yet. The black circles in each corner of the baffle are carriage bolts that I ground flat. I intend to use magnets on the grills and use these spots as magnetic anchors.

After:

Before: (I thought I'd show them together for comparison)

The sound is better than anything I've heard before. I have relatively untrained ears, but that is changing fast. I spend hours listening to these. I hear new things in tracks that I've never heard before. The same songs have more impact. They really show the difference between a good recording and a mediocre one. You can hear nuances, bit rate differences, in the recording. The imaging a soundstage are impressive. The only bad thing is they really detail points in songs where audio compression has been used. You get so used to the dynamics of the drivers on uncompressed songs and movies that when a compressed song shifts to the chorus and the lead goes from just singing to belting, It sounds a little odd. Almost like someone turned down the volume (exactly what happened in the recording).... mostly because you expected it to be louder.

 

[keelay]

I have been planning to add a Dayton 15" RSS390HF-4 in a LLT configuration. I originally planned to make the natalie P's sealed. knowing that the Subwoofer will fill the low end better and more accurately than the porting would. I built the ported version knowing that I can seal it. The Q would be less than .7 but not much and I have some volume consuming ideas when I go to seal the ports. I just really wanted to hear how low the ported version can go. It really can go low. You could actually live without a sub for most music. HT you'd want the sub. The Natalie P's can go low and deap.

My cabinets are 1.4 Cubic Feet with the port tuned to 39 Hz. The port on top is because I wanted it as far away from the speakers as possible. The driver placement was intended to place the tweeter as close to ear level as possible while remaining in the space allocated in the bookcase. The tweeter is 42" off the floor.

 

[keelay]

Here is a little closer up:

Here is a single speaker closeup.

 

[Owen Bartley]

Kyle, they look awesome, and I'm glad they sound as good as they look. Just a thought... why not leave them ported, especially when you're planning to build a LLT sub, which will play very low, and the speakers should blend nicely around their tuning frequency? Unless you were planning to set them to 'small' and have the sub handle all of the low bass duty. then I guess there's not much point.

 

[fbov]

First off, my apologies for not remembering (or reading back to see) you'd stated early on that you'd use the in-wall XO design. My comments can only have supported that decision.

Second, I know what you mean about good low end; my sub's been off for 2 months and I can feel things I can't hear with a 2.5 cu ft (70l) box and 33Hz tuning. Same with transients - they deliver a lot of punch when the input asks for it. If I decide to seal them, long term, it'll be by an internal baffle down to 50l. With an F3 point of 40 Hz, and a somewhat larger room than I, you'll integrate with a sub nicely. I have a primary room mode at 40Hz (15' dimension) that really needs bass management to address it properly.

Nicely done!
Frank