TC-1000, RS150, RS52 and D26 SWWMT

[Paul Ebert]

I'm almost ready to purchase these drivers (actually, I have the D26NC55s already) to design a SWWMT. Why the RS150? Well, I'd like the WWMT part to fit in the 1.0 cu. ft. PE MTM cabinet and it appears to me that a pair of RS180s will not fit.

My plan is to put the TC-1000 (12") in a cabinet I build onto which the PE cabinet will rest. The sub cabinet would be about 1.0 cu. ft. and I'd use an LT to equalize the lowest octave. Both cabinets would be sealed.

Crossovers points would be ~85, 600 - 700 and ~3000. The subs would be crossed over actively and powered by UCD modules.

Any thoughts, concerns, red flags?

[JonMarsh]

Won't fit? As in doesn't hit the Fb/response you want, or physically won't fit with the mid and tweeter? (depends I think on how you arrange them).

Sounds like an interesting project, Paul, I'm building my so called center channel as a full set of surrounds using the RS52 and D26CN55s, though I'm going to step out on "convention" around here and use HiVI D6.8 (an old love of mind- there will also be a crossover for the RS180).

I may build RS270 bass cabs to go with these, which would also work as stands for the MTM's. Hmmmm, do you have a worm installed in my Mac sending my Curio and EazyDraw files to you?

[Paul Ebert]

Won't fit? As in doesn't hit the Fb/response you want, or physically won't fit with the mid and tweeter? (depends I think on how you arrange them).

I mean they will not fit physically. They should work as a center channel, but with the drivers in a vertical line, it doesn't work.

Sounds like an interesting project, Paul, I'm building my so called center channel as a full set of surrounds using the RS52 and D26CN55s, though I'm going to step out on "convention" around here and use HiVI D6.8 (an old love of mind- there will also be a crossover for the RS180).

I may build RS270 bass cabs to go with these, which would also work as stands for the MTM's. Hmmmm, do you have a worm installed in my Mac sending my Curio and EazyDraw files to you?

Nope. But I have been carefully following the 'Help me Obi Wan' thread and got most of these notions from there. I'm still not decided about the RS150s. It might be better to use an existing crossover design and build the box. At least I have a bit of experience with the woodworking.

I wish I could do a dipole, but I just don't have the space.

[joecarrow]

Have you done any diffraction simulations? It is often advantageous to offset the tweeter. The TC-1000 is a proper sub, and it would probably help you to have some flexibility about how low the midwoofers can play- thus it would be nice to have the RS180s.

On the other hand, that tweeter doesn't cross quite as low as the usual suspects when working with the RS180. The higher crossover available with the RS150 will help you out a lot.

I guess that since you have the tweeters, the mids follow naturally- it might be good to double check the high frequency of the TC-1000 sub. I'm not familiar with its strengths, although I know it's quite good. Can it play up around 200 hz comfortably?

[Paul Ebert]

I have not done any diffraction simulations, and I need to for BSC if for no other reason. Perhaps I can squeeze everything in if I angle the tweeter. I'll look into that.

The RS52 is 'between' the midwoofer and the D26, so the upper crossover for the midwoofer shouldn't be an issue for either one.

Being built on the TC2 motor, I assume the TC-1000 should do fine. I'm not sure I'd use it to 200 hz, but, then, I'm not planning to go that high.

[joecarrow]

Hey, I forgot about that RS52! You're really fitting a lot of drivers in this cabinet!

You're good for your chosen crossover between that mid and a woofer; you could use a single RS225 instead of the two RS150, and probably do all right. The RS225 has been used far higher than 600 hz, and it should have superior low end since it has comparable radiating area and greater Xmax.

Of course, I forget if 1 cu ft is too small for one of those woofers... OK- I admit, I haven't had my coffee yet. I may not say the configuration that's best, but hopefully I'll at least help you think about it from multiple sides.

[JoshK]

Although it wouldn't fit, if the RS180 doesn't fit, the Usher 8945a looks like it would be interesting in this mix. Note the thread on klippel measurements, the 10mm xmax might come in handy crossing over lower to the 12" sub. That and it apparently measures really well.

[JoshK]

P.S. if you need a slightly larger box for a less compromised design but didn't want to build them yourself, Jon Bateman (diybox.net) did a really good job on my Modula MTM cabinets and his price was in the ballpark of the PE cabinets. This and he used wood for the roundovers and custom did the finishing.

[Paul Ebert]

Does anyone know if I could use the RSS315 HO driver instead of the TC-1000? I would save some $$ and it has a black cone (which I like), but I'm not sure the xmax would be sufficient for use with a LT.

Thoughts?

Oh, and I'll check out diybox.

[joecarrow]

According to Xmax and driver area, my estimate is that the RS315 will give you about 95 db max SPL at 20 hz, where the TC-1000 will barely touch 100 db. Room gain, speaker placement, left/right correlation, etc, could give an honest 3-6 db of boost to either woofer choice.

Based on my listening habits, such bass would be more than enough for music, but not quite sufficient for movies. I normally listen to music somewhere in the mid 60 to low 70 db range, maybe touching 80 if I'm really in a party kind of mood and I don't think the neighboring apartments don't mind. I've measured peaks in movies of right around 90 db with just my Modula MTs and no sub. If I had total freedom to crank it up, I'd go just a touch louder.

So, is it just music, or some home theater as well?