Advice on setup

[BlackHatBrigade]

I have a feeling by the end of this post some of you might be cringing, but here is what I've come up with for a home theater DIY setup.

I purchased a Onkyo 805 and decided to try to build a home theater setup that is within a interesting budget. My current plan is to build two dipole cabinets with the RS150S-8 drivers, a center with two RS150S-8 drivers and two RS180S-8, two mains with two RS180-S, one RS150S-8 and one D26NC55 tweeter, and a sub cabinet with two 15" subs powered by a seperate amp.

I wanted to do all of them in sealed enclosures and built a test cabinet already with two RS180-S drivers that I have. I have been able to cut out enough of the high end with the equalizer / channel on the receiver and the active high pass to make the dipoles and center sound passable (I'm not getting any noticeable highs crashing, at least for anyone other than a audiophile).

If that didn't make you cringe, this will. I wanted to run the Mains with just a high pass on the tweeters and the 50Hz high pass on the receiver. I'll admit it's not an ideal setup, but I'm just lacking the budget to do the full 2-way passive crossover.

I'm sure this setup would sound better with some of the proven crossovers designed here and I'm fine with loosing a little bit of clarity that I might have gotten at the expense of a proper crossover setup, but my main concern is that the setup may sound completely horrible. My tests with the 7" Daytons using the builtin equalizer and high pass in the receiver has sounded surprisingly good to me. I guess the question is, would the Mains sound good with just the high pass on the tweeter and the mids left alone?

I know the strongly suggested path is to do one of the designs listed here, but I'm seriously not able to add the ~$250 / speaker in crossover parts for this setup, no matter how much I want to.

Thank you for your time and patience with a newbie

[ThomasW]

IMO RSS150's don't move enough air to be used in a dipole....that said, were someone to use them in a dipole and not have a proper crossover, they'd be destroyed by bottoming...

So....

Which is cheaper, using the 'right' driver and a correct crossover or buying more drivers after destroying the originals?

FYI, there's a reason for the saying "penny wise, pound foolish" .....

[---k---]

Yeah, you're not going to be controlling the metal cone breakup on the mids. Should sound pretty bad at decent levels.

You already have some of the drivers, so I' would say go forth and try it out. Hopefully, some day you'll have the cash to see how much better it can sound. Or, make it to DIY Iowa or such and hear for yourself.

If you didn't have the drivers, I would probably try and help you find a project that fits your budget.

[Dennis H]

Less drivers, more crossover parts, better sound, especially if you're crossing to a sub. Build 5 of the Modula MT or the SR71 and be happy. I guarandamntee you it will sound tons better than what you are proposing.

Edit: linkie for the SR71 kit. $165/speaker for everything including the assembled crossover.

http://www.madisound.com/catalog/product_info.php?cPath=35_40_402_408&products_id=8307&osCsid=0e3d24b0e04a423364840ef34df55e6a

[servicetech]

Doing a high pass only for the top end should be reserved for low budget (under $50) projects. You have too much invested in the drivers to not put a decent crossover on them.
I understand you don't want to spend $500 on crossovers, but at least put a filter on the mids. Perhaps somebody has or can design a "budget crossover" that gets much of the benefits of the $500 version but at a lower cost.

[---k---]

Thomas,
I think when he said dipole, he meant as in surround speaker with drivers pointed in opposite direction. Not the way we use dipole around here.

[BlackHatBrigade]

Ok, I must have said something to insinuate that I have the drivers already. I just have 2 RS180S-8's at the moment. I've been trying not to be hasty and take an intelligent approach to this project. If there is a reasonable alternative I'm more than open to the suggestion.

I've also been trying to get all the parts for a wallin jig to do some hands on learning. (Some parts are still in the mail, newark is pretty slow to ship things I've found).

Also, I don't believe low frequencies on the mids will be a problem because the receiver is able to use a limited high pass per channel. I don't know if that's what you meant by bottoming out or not. And yes, I'm talking about surround sound dipoles... there's another kind of dipole?

[BlackHatBrigade]

I have been looking at doing a Zobel network with 1st order butterworth on some of the speakers as I don't think that would run into too high $$-wise. But I haven't been able to price or design anything due to not having the correct tools (which I'm working on remedying).

[Dennis H]

Man, you're just not getting it. You might be able to get away with a simple crossover with a poly cone but no way with a metal cone. You have to deal with the cone breakup in a metal cone. Why do you insist on spending so much on drivers and so little on crossovers? It just doesn't make any sense if good sound is your goal. Spend less on the drivers and more on the crossovers.

[servicetech]

A simple 2 way 12db crossover shouldn't cost that much. If you don't want to use a zobel for the woofer be sure to buy the components based on the impedance at the crossover frequency you plan on using. The tweeter you are looking at has too high of an fs (1500hz) to work in a 2 way with your 7" woofer. You need a tweeter with an fs under 1000hz to do a two way with such a large woofer.

[Mazeroth]

How about you take the dual subs out of the equation and use that money to purchase proper crossover components.

"but I'm seriously not able to add the ~$250 / speaker in crossover parts for this setup, no matter how much I want to."

I don't know where you got $250/speaker in crossover parts. For instance, JonMarsh's Modula MTs are fantastic speakers that use RS180s and can be built for $218.70 for the PAIR, including drivers:

http://www.htguide.com/forum/showpost.php4?p=237591&postcount=238

Five of these would make for a great theater system as long as you crossed to a sub.

[BlackHatBrigade]

Well, first of all. I'd like to thank all of you for your feedback. I had one of those nagging feelings that I was approaching this wrong, but just wasn't sure. I now humbly accept my idea as flawed. I'm just grateful you guys are here to answer stupid peoples questions

I'm going to up my speaker budget and do it right. May take a little longer (Unless I can figure out where I put my money tree) but I tend to think the general consensus is that it's worth the wait.

I had seen the Modula MT setup but in ignorance didn't pay much attention to it. I actually had been looking at the Modula MTM setup. Which if I priced the parts out right, did toll in pretty pricey on the Crossover components. I've been a little picky about the surrounds as I was really hoping to do dipoles there, but I may go find a wall to smack my head against (soften it up a little) and go look at it again.

[BlackHatBrigade]

I do have a question though. I've learned that it will probably be a long time before I'm able to design a crossover (yeah, slight understatement), but I love woodworking and would love to do some custom stuff with the boxes. I'm not a huge fan of square speakers and would love to get creative with box design. I have read enough to know that these box designs are tuned to specific frequencies (at least, that's what I've been led to believe). I thought I could just get some software and start playing around with that, but I'm not sure which one would be best. Any suggestions?

Also, I'm quite sure all of the speakers I've seen are designed (more or less) in the regular square/rectangle shape for a reason. How possible is it for speakers to take on other shapes and still sound good? I would rather create speakers with an odd internal shape than make square speakers and then use a ton of material to embed it into my desired shape.

[ThomasW]

Speakers can be any shape you want. To do that you need to know how to design from scratch and must have measurement equipment.

If you use the forum's search function you'll find dozens of threads that addesss the issue of what's needed and how one does about designing a speaker.

Just so you know this process is SIGNIFICANTLY more complicated that it appears...You might want to start off by buying

"Speaker Building 201: A Comprehensive Course in Speaker Design" by Ray Alton

Read it before you buy anything...

[BlackHatBrigade]

"Speaker Building 201: A Comprehensive Course in Speaker Design" by Ray Alton

Read it before you buy anything...

Hopefully that doesn't include if I want to build something from the DIY completed projects on this site?

[servicetech]

I've build many speakers w/o having measurement equipment with mixed results. Low dollar commercial speakers aren't hard to beat. That being said for BEST results equipment is good thing. If you are spending over $200 on a project, measurement equipment is a wise investment unless you are building a proven design.

A frequency test CD, multimeter, and an SPL meter are a good way to start the equipment collection IMHO. Relatively low cost.

[Dennis H]

The budget version of the Modula MTM is the Natalie P. It has a cheaper crossover. However none of the MTMs are good as a center speaker. The MT is better at that position. I'd just build 5 of the Modula MT so all your speakers match (important for multichannel music) and save the money. They will go plenty loud if you cross them to a sub. But you could build MTs for the center and surrounds and build Natalie Ps for the R&L if you wanted to.

Dipole surrounds have more or less gone out of fashion with discrete 5.1 soundtracks and they really suck with music. Some people still like them for movies but they were really designed to make the old mono surround track sound more diffuse.

As far as changing the box, the important things are the size of the front baffle, the position of the speakers on the baffle, and the volume of the cabinet. The shape of the cabinet behind the baffle can change.

[BlackHatBrigade]

Well, this setup isn't for me. Box designing is something I want to play with for future stuff and I'll probably get that book that was mentioned to try and catch up on what I need to know. The setup I've decided to go with is the Lineup Maxx Tower (W5's on sale $18/ea and the Lineup center. Yes, I'm aware this is way above the price range I was originally talking, but I was able to squeeze a fairly large budget increase. That and I feel tons more comfortable doing a proven design, especially when the setup isn't for me.

I've decided to use the Modula MT's so I can pass the RS180's on. Might as well use them and from what I've heard they should do fine as surrounds.

Provided all of that sounds good? I'll then move on to the sub, which is more complicated that I was expecting, but I'm sure I'll be able to figure something out. I was a little concerned about mixing the Lineup setups with the Modula MT's. Anyone see any issues with that?

[Xander]

...But you could build MTs for the center and surrounds and build Natalie Ps for the R&L if you wanted to...

Just wondering, why would you build the lower budget speakers for the mains, and the more expensive for the surrounds, instead of matching the front 3?

[Dennis H]

The NatP and the Modula MT both have 'budget' (low parts count) crossovers. The original Modula MTM is the expensive one.