RS150 MTM's or Nat P's, input pawease...

[Blazin_Jason]

I've been reading up for quite some time on various diy projects. Please understand I am completely new to this home stuff. I can build the cabinets and wire crossovers as long as there are clear diagrams and plans to follow. That's not really a concern for me, it's just deciding what to do. Here is where I'm at right now as my plans have changed from the original. I have not purchased any equipment yet but I want to start ordering parts and building. We will be moving into our (first) house in just over a month and would like to have this ready. I'm pretty set on the onkyo 706 receiver, and a crown xti 2000 amp for subs. The subs I will be using for now will be 2 jl 12w6v2s that I already have. I don't want to buy any subs right now and these should do me fine for now. This will probably be 50/50 ht/audio. My original plan was: Nat P's, no sub, no rears, no center at first then add as I go. I would then add the RS150 center, unknown rears, and sub. Now I'm thinking to build the RS150's for the mains and center. I don't know what version of them yet at this time. I don't know if I should do another pair of cjd's 150s or just some sort of MT for the rears. At this time I will not be building rears until we move in and I know what type I need (wallmount or w/e). So seeing how I am now going to be running a sub setup can I get by and be happy with the rs150's, and which versions would be recommended? This would save me some money and also build at least 3 of the same xo's. Any input is appreciated. Thanks

Jason

[ThomasW]

The choice would be dependent on the size of the room, distance from the speakers to the listening position and how loud you want them to play.

[Blazin_Jason]

The room is 13x17 and the position would be somewhere in that range (probably 9-10' I would think). I don't know the particulars at this time. I just have the time/tools to start building now. I'm not a huge audio quality critic so it doesn't need to be perfect.

[ThomasW]

It's really not a function of 'audio quality', it's a function of how loud RS150's can play compared to RS180's

[Blazin_Jason]

Right now I am only planning on using the receiver power which is rated around 100wpc. I don't plan on playing it loud very often but if I needed to I would like to have that option. Would you think 5 rs150 (if that's what I do) would be able to handle it? Or would the mains being the 180s make a noticeable difference?

[Jonasz]

I would build the NatP as mains just bc a little extra headroom can't hurt. I believe the NatP also have better sensitivity wich would "save" some juice for the center- and surroundchannels... :B

[cjd]

NatP has less sensitivity for two reasons: It has more baffle step, and the RS180 is slightly less sensitive than the RS150.

That said, the RS180 has a significant power handling advantage.

If you're crossing to a sub at 80Hz, the RS150's in a sealed setup probably do about as well as the NatP. If you want to run them without the sub, you get a little extra reach and probably double the power handling in the NatP.

[Jonasz]

NatP has less sensitivity for two reasons: It has more baffle step, and the RS180 is slightly less sensitive than the RS150.

Oooops... my bad! ops:

Sorry

I would probably go for the NatP's as mains anyway just for the added surface area wich should make them better if you ever wanna crank'em up. 8) I haven't heard the RS150 MTM but I'm sure they also are very, very capable speakers.

[ThomasW]

Or would the mains being the 180s make a noticeable difference?

It's all about how much air is moved. The RS180s will move significantly more air than the RS150s. This means they'll play louder and do so with less distortion.

You can always start off building with the RS150s and move them to surround duty if you end up needing the added output of the RS180s

[Blazin_Jason]

I think I have decided to do the nat p's, and cjd's rs150 center for now. I can get all the xo parts for the center from PE as well right?

[geno742]

I think I have decided to do the nat p's, and cjd's rs150 center for now. I can get all the xo parts for the center from PE as well right?

That is exactly what I've been running for over an year now and the ONLY reason I'm contemplating upscaling to the statements is for bragging rights. (and of course, the fun of building them).

I bought all the parts from P.E.

I might add that I can't hear anything quieter that a jet but I like to see my guests jaws drop when they hear this setup.

I backed up the Nat P.'s with a 24"x 56" ported sonosub with a 15" dayton dvc driver.

I am running them in a 18" x 28' room with no problems at all.

I'm powering the whole thing with the Emotiva LMC-1/LPA-1 combo.
I use three channels for lcr and two channels for the sub. Not so much wattage, but the dynamics are excellent.
the two secondary LPA channels power the rear surrounds.

I am a happy camper.

[Blazin_Jason]

Couple of quick questions re: parts for the 150's. I can't find any 35uF caps. I think I remember reading somewhere you can add 2 caps in parallel and it's basically adding. So I could get a 25+10? Or would a 33uF cap be ok? Also which inductor 1.2mH, 15 or 18g? What would be the differences? I think that's all I was wondering. Hopefully placing an order within the next couple days. Thanks

Jason

[fbov]

Jason,
Caps in parallel add, so get the 35uf combo with the cheapest values you can. In general you can assume there a 5% tolerance on part values, so 33uf might be as close as the sum of 5% of each when adding caps. For inductors, see what resistance is listed for that XO component. (They're usually shown with a note to ignore.) The 15g will be lower resistance than 18g, but also more expensive. No point unless the design calls for it.
Have fun,
Frank

[Blazin_Jason]

BOM calls for either 15 or 18. Thanks for the help.

[Blazin_Jason]

PE order showed up today with what looks like all the parts I need for 1 rs150 center and a pair of nat p's. Now to stop being lazy and hopefully get them done before moving day.

[fbov]

Jason,
I recently finished a NatP LCR set (with the dreaded horizontal center), documented here. Page 1 is a lot of discussion; things get built on page 2. Note that I also used 3 different XO designs in the center...:

https://www.htguide.com/forum/showthread.php?t=30536

If you follow the dates, you'll see it took 3 days to get the center done, and 7 months to get the mains. Build at your own pace, but beware of creaping elegance if you're working against a deadline. Basic MDF boxes are a cinch in a month, but the works of art you see here take months for people with day jobs. You can't rush wood finishing, but you can listen unfinished as long as you need to.

However, whatever you build, add internal bracing in all 3 dimensions and you'll hear something quite close to what the designer intended. My initial, close-mic'ed measurements of one of my NatP towers s came out +/-2.5dB from 200-20KHz, with bass extension to 30Hz. I'm happy.

HAve fun,
Frank

[Blazin_Jason]

Thanks for the advice. This is just an mdf and paint build. It's just the look I am after right now Weather hasn't been that great and I was only just able to start bucking up some wood yesterday.

I have a question about adding a terminal strip to my crossovers. Can I place it where I have it in the pic? Are there any areas of a crossover to avoid having signal wires near or anything?

[ThomasW]

Realistically there's no place on that board for the strip. Had you moved the caps in the upper right hand corner closer together and closer toward the inductor on their left, the strip could have gone there.

How about attaching a narrow piece of wood to the board where you have the strip in the pic?

[Blazin_Jason]

Ok I might look into that. Would there be any problem mounting it on the backside then?

[JonP]

I have a question about adding a terminal strip to my crossovers. Can I place it where I have it in the pic? Are there any areas of a crossover to avoid having signal wires near or anything?

You probably should avoid placing the strip near any inductors. The screws inside could have a value changing effect, since they're likely ferrous (magnetic) metal.

Keeping them an inch or two away from the inductors would reduce their effect to next to nothing. Wires are not so critical, though you also want to not run them right next to (never thru!) an inductor.

[Blazin_Jason]

Thanks for that info Jon! I have an idea on how I will be mounting the xo's, so I should have extra room to place the terminals there. I haven't spent any time working on these lately. Just waiting on a parts order to come in to continue ahead. Next step is to figure out how I am going to do the port. Should get the cc xo built today.

[Blazin_Jason]

Any problem with lining the cabinets with as much foam as I had planned? It seems like it might be too much. Or maybe I should just stick with the back wall? It's the 1" wedge foam. Was going to do the same on the nat p's.

[fbov]

Jason,
I lined mine with ~1", all but the baffle and very bottom of the box. You want the box to support port resonance, below ~60 Hz, and absorb anything above that. Sub-60Hz frequency means 20+' wavelengths and nothing absorbs frequencies that low at a 1" thickness.
Frank

[Blazin_Jason]

Tested out one speaker, it plays music and it read 4.1Ω on my meter. Girlfriend said it sounded crappy. We'll see what she says once the speakers are 100% built, get a cleaner signal than the static radio, and have both up and running. So tomorrow I glue the back on these things! Then this weekend I hope to get to painting these (2 subs, nat p's and the cjd center).

[Blazin_Jason]

Spent a lot of time (way more than I planned or wanted to) priming and sanding these. Used a gallon of slicksand high build primer, then sanded them all smooth. I've got some flat black paint on them right now. It's too flat for what I wanted it to look like. So I will be finding something else to do them with, probably a satin black.

[fbov]

Jason, in wood working, and many other things, slow and steady give far better results. You've got a lot of time invested in the enclosures you've pictured, and you'll have a great-sounding set up when you're done. Just remind yourself that, not unlike your new house, construction is temporary while enjoyment is long-lasting.

I think satin black will look great!

[Blazin_Jason]

Just need to give the natalie p's a listen now. Then some more sanding and painting on the other speakers.

[wkhanna]

Nice job Jason.

That was a big project, and it looks like you took the time and had the patience to get it done right.

Now tell us what they sound like!

[Blazin_Jason]

Thanks! Just got them playing and the onkyo half setup. So far they put the tv speakers to shame. Can't wait to play around some more.

edit: As I suspected I think one of the drivers needs to be replaced. It makes a scratchy type sound at higher volumes. I noticed the problem when I first took it out of the box. Playing it confirmed its not right. Almost like the coil is rubbing almost or something.

[Blazin_Jason]

I did a short demo for a buddy and he wondered where the sub was =) They do sound good so far. I want to start building the surrounds now. I was originally thinking of just doing the cjd's for the rears. Would there be any reason not to build those, or other things I should take into consideration? Doing another set of natalie's for the rear would probably not really be using them to their full potential I'm thinking.

[ThomasW]

The choice of what surround speakers to build depends on how loud you want them to play.

Another option for smaller speakers would be the Modula MTs

[cjd]

Depending on your timing and intended install locations, I'm cooking up an alternative surround-specific TM with the RS180-4 as well. ModulaTM and the 150 based MTM's net out to about the same max SPL (excursion limited), but the MTM is more sensitive so takes less power to get them there.

[Blazin_Jason]

I think I want to do the MTMs for the rears. Keep with the look Now I get to build/design a rack/stand for this mess of stuff. I think I will make the center mount above the TV and keep the TV lower. Not too sure yet.

[fbov]

Conventional wisdom recommends CC at the same level as the mains, but then it also never recommends a toppled MTM... Please your eyes and ears; no one else will know the difference.
frank

[Blazin_Jason]

Finished my stand a week ago so now the 3.1 is complete. Will build rear speakers when I can get the time/money to do so. I'm more than pleased with it though! Thanks for all the help everyone.

[---k---]

Looks very nice. :T