# Dayton RS1202K and Ultimax 18



## GregDunn (Oct 5, 2017)

I'm accumulating info on home subs to go with my main system. It's NOT a HT rig, it's going to be used for music only. The speakers (currently being refurbed by the factory) are a pair of Magneplanar Tympani 1C, which will be bi-amped. I'm in a relatively small room in terms of volume; it's 24x10x7, carpeted. I'm far more interested in bass extension than volume, but I do hope to reproduce both classical organ music and rock synthesizer at a usable (not concert hall) level.

The specs on Dayton's sub kits (RS1202K and Ultimax 18) look very good. Their tech support indicates that the differences between these models will probably be more influenced by the room positioning than by differences between the units themselves; their rated f10 is within a couple of Hz of each other and they seem to have adequate power to generate high SPL (again, if the specs are to be believed).

I'm curious whether anyone here has built either sub. They're priced well below some of the pre-built commercial subs that people seem to like - as they should be since they're kits. I have no concerns about assembling either one; I've been building speakers and electronics for a number of years and these kits seem quite manageable. They certainly have lots of useful built-in features for when I start working with room treatment and calibration of the system.

Thoughts?


----------



## theJman (Mar 3, 2012)

Given that you have Maggies the Ultimax is really the only one of those two you should be considering. Mark Seaton uses that driver in his F18, and if it's good enough for him there is likely no one it won't pass muster with. It's power hungry though, so it's a good thing PE uses a 1200 watt amp. The fact they include a DPS is a bonus as it should make fine tuning much easier, especially important for a 2 channel rig where room EQ like Audyseey is rarely used.


----------



## GregDunn (Oct 5, 2017)

Thanks - I've seen some comments online that indicate the amp is better placed in a separate enclosure even though they've designed it to mount in the enclosure itself, due to heating and of course the inevitable possibility of air leaks (I have no idea whether they've sealed the connectors, pot shafts, etc.). Is this a bogus concern?


----------



## theJman (Mar 3, 2012)

I wouldn't call the concerns bogus, perhaps overstated instead.

The amplifier is designed for the task at hand so things like heat and vibration are (or at least should be) accounted for. It's likely that only 1-2% of all subwoofers, commercial or hand made (DIY), are using an external amplifier so there's little worry about how internal amps can handle the environment. You will need to ensure an air-tight seal, but realistically that's not terribly difficult to do. You indicate being comfortable building things so I don't image this would be a challenge.


----------



## GregDunn (Oct 5, 2017)

Yeah, that's not a problem. I think that one has moved to the top of my list!


----------

