Seas 2.5 Way Graphite Kit - Delling

Hi Everyone,

It was getting to be that time of year when I encourage audiophiles to build at least one speaker pair in their lifetime as a matter of personal growth and education. The more builders we have in this hobby the less we rely on PR and reviewers alone to influence us, so this is something I feel has broad value to our hobby.

Anyway, I was checking out Madisound, and discovered that Seas has released a 2.5 way kit which looks very promising. 2.5 way speakers are, IMHO, some of the best designs for the average living room. Highly efficient, deep bass, small footprint so easy to live with overall.

At around $1,750 for the parts, including a crossover, this is not the cheapest possible kit, but certainly far cheaper than a commercial speaker would have to be.

Unfortunately I have not heard this pair myself, and I worry it may have a little extra presence, but that’s the beauty of DIY, you can tailor your sound directly in the crossover.


Well, as someone who just purchased the Joseph Audio Perspective speakers, that design looks somewhat familiar :-)
Can you clear something up for me please?  I see the claim of "deep bass" associated with those seas drivers.  How does this come about that a driver itself can be expected to put out "deep bass?"
If I understand correctly, it would be a combination of the driver motor which may be more "deep throw" - moving further back and forth to move more air, along with the driver material itself being able to withstand the greater force without breaking up, hence: a driver good for producing deeper bass.
Is that about right, or can you fix or elaborate on my understanding?
Hey Prof - 

Perhaps some of the most well understood aspects of mathematical modeling of speakers has to do with matching a cabinet volume, and port (if any) to a specific driver to achieve a particular low frequency response.  A free tool which does this which I have used is WinISD:

but you can also use commercial tools like BassBox Pro and even online calculators.  This is all thanks to the standard measurements given the Thiele/Small parameters of a driver:

The driver's diameter, resonant frequency, equivalent volume of air (Vas) and Qts are among the most important. 

Fortunately, vendors like Madisound or Parts Express will often recommend specific cabinets for you, either with exact dimensions, or give you internal volume and port sizes, with the projected -3 dB point.

In practice, Seas, FaitalPRO and Scanspeak make a number of 6.5" mid-woofers with remarkable bass output for the size, if you put them in the right cabinets.  I find the trick to this is good room acoustics. 


you don't learn much just by building a kit although it can be rewarding. You can learn a lot online without getting your hands dirty and for free. or get a dsp plate amp and then you can try multiple drivers whereas with a kit you only get to hear one design. Do not be duped into buying expensive kits. The whole point of DIY is to save money.  
I wouldn't call them that.

JA tunes his speakers differently and adds tube friendly circuitry.

for that kind of money audiophiles can build 2way or 3way horn type speakers  for the average living room. Highly efficient.Midrange to die for.3D soundstage.Bass,punch will depend on of  inner construction, ports placement,front ,rear..etc..
extravaganza please expand as I've been interested in horns for a while now for a second system.