Here an update that was long due. As many of you know my dad passed away a few weeks ago. But as they say: life goes on. So I’m picking up life again were I left it.
Some time ago I noticed that my 20 year old ready-made speakers show audible signs of aging. The units themselves look fine and it is probably something like capacitors in the x-over filter that have aged. The whole sound can be described as muffled in the mid-tones.
With the positive outcome of my first (but not yet 100% finished) DIY speaker project I started to think about replacing my main speakers with another pair of DIY speakers. The main goal is that they should sound at least as good as the old ones once did.
I’ve choosen to make it a 3-way system. Whishlist: fairly deep bass extension. Smaller than the speakers they replace, high quality drivers.
I’m not sure I met the size requirement 
. The f3 will be around 32 to 34Hz. By using SEAS Excel drivers I’ll have top notch drivers that should not fail with high distortion, compression etc etc.
The cabinet design follows the current trend of small baffles and deep cabinets. I’ve choosen for 1 10# woofer instead of multiple smaller one’s. The baffle needs to be relatively wide to accommodate the woofer. But with sloping side panels and facets I think I managed to keep the whole looks of the speaker as sleek as possible.
After creating above impression from the construction drawings I’ve changed one thing: the bass-reflex port has been moved off the baffle. It’s now located under the cabinet into the stand. It gives a more clean design.
With an internal height of almost 1mtr the first standing wave will occur round and about the 350hz. All other higher order/frequency standing waves do not influence the woofer as they are above the cut off frequency. But the 350hz is just on the edge of the planned x-over frequency. So I integrated a helmholtz resonator into the cabinet to dampen the expected standing wave.
