RS180 + SEAS Prestige 27TFFNC/G in a Horizontal LCR?

[ratten46]

I'm looking to do a home theater build, I have a pair of SEAS 27TFFNC/G, and 3 RS180's to work with. My biggest constraint/concern is that all three front speakers will need to be horizontal, and the LR speakers will have a size constraint on the front baffle. I don't have the exact measurements on me at this time, but the LR sizes will have a max of around 8"x18" for the front baffle, and that will be arranged horizontally (with 18" dimension as the width). The height can be changed within 1 or 2 inches, but the width cannot. The three speakers do not need to be identical, but I'm only working on the LR speakers right now. I think my depth is also close to 18".

I'm new to home audio DIY, I've done a quite a bit of car audio in the last 15-20 years though, so please forgive my questions if they're ignorant/noob. I know there are issues, specifically with comb filtering on a horizontal arrangement, but this is why I want to design with my limitations in mind. These speakers I have blend nicely, but I wonder if I might be better off creating a 3-way, putting the tweeter above a small 3 or 4" mid, with the RS180 pulling woofer duty to the side? Any ideas or suggestions from existing designs would be appreciated. If I do need to make a 3 way...what mid would blend with these? (Also....the components I have are all 4 ohm....).

Thanks!
Ryan

[johnnyrichards]

Re: RS180 + SEAS Prestige 27TFFNC/G in a Horizontal LCR?

Get your tweeter as close as possible to the woofer and cross it over as low as you can and you shouldn't have any problems with lobing. If you look at some well-designed 2-way speakers, you will notice that the vertical off-axis is usually pretty good and that is an indicator of how it would perform as a "toppled" speaker.

It sounds like you are building them into some existing shelving or something like that? If so, do some research on "baffle step correction" so that you don't over do it on the bass extension. When in doubt, just run them sealed and use a subwoofer.

I wouldn't worry about doing a 3-way, I doubt you would find an acceptable midrange driver that will keep you under the 8" +/-1" limitation on your baffle height. 3-ways are usually better, though.

[ratten46]

Re: RS180 + SEAS Prestige 27TFFNC/G in a Horizontal LCR?

Thanks for the input. I will definitely need to factor in some BSC, as I am building the speakers to fit in shelves in a built-in entertainment center. I've already had to make a flat screen LCD fit into a space made for a "tube" television, so this is just another compromise of compromises for that existing space. My current subwoofer bit the dust, so I was hoping to go without for a while. (I already have...and the lack of lowend on these mini speakers is driving me insane).

Back to my question....I've seen the plan for the Modula MT, and that seems to fit my needs almost perfectly, except that my RS180's are the 4 ohm version, which has a completely different set of specs. Is there a 2 way project that uses these 4 ohm woofers (as a reference) or has someone done the Modula MT with the 4 ohm RS180s to use as a guide? My other alternative is to find someone to sell or trade with to get the 8 ohm version. Since the 4 ohm ones are on backorder until December, I imagine someone would be interested in helping me get the 8 ohm ones....