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New three-way monkey coffins
For some time now my brother has been wanting a three way system that has modern performance but styled as yesteryears designs - the design we colloquially refer to as 'Monkey Coffins'. I like the idea and its certainly back in fashion with plenty of manufacturers jumping back onto this format again.
Broad criteria:
Mid 30's to 20K response, as compact as possible
Paper and textile woofers and tweeter
Good power handling and a reasonably large woofer
Driver costs not an issue
Ok to compromise as follows:
Size over bass depth
Sonic quality over razor flat response
Old school look/design over diffraction concerns
My brother really likes the ATC Classic line of speakers and so we set out to design something similar.
Now credit where credit is due - in researching a design like this you'd be a fool not to look at the work of Troels Gravesen. As so it was that one of his SBA designs was a close match for this criteria. So the eagle eyed observers here - yes this design takes a sizeable amount of inspiration from Troels in terms of format - but beyond form factor is not a replica.
Landing on the same drivers, the SB Acoustics WO24P-8, MR13P-8 and TW29 tweeter. I've worked with the woofer and tweeter plenty before so I was leaning this way anyway and honestly the addition of the MR13P to round out this combo is simply a no brainer.
So here's the basic cabinet design:
Offset mid range and tweeter (my signature move lol) keeps our diffraction issues to a minimum with a square, zero round over baffle!
Aiming to keep to around 38-40L net for the woofer with a 28-30Hz tuning (to be tweaked once it all comes together). This gives us a magnitude response as follows:
Magnitude response:
Cone excursion + power:
Tuning allows for a full 70Watts of power within the music spectrum. This tuning for this woofer forces the region where the cone unloads to below 25Hz...which is certainly well outside the normal music listening range and gives us mechanical power handing close to but within the thermal rating of the woofer. I like it!
It also gives a nice gradual roll off in the lower octaves that yields an [email protected], [email protected]!! and [email protected] (nuts). We'll see how close to this we get once it all comes together and after woofer break-in.
Should be good for 106db (less baffle step PLUS room gain).
Broad criteria:
Mid 30's to 20K response, as compact as possible
Paper and textile woofers and tweeter
Good power handling and a reasonably large woofer
Driver costs not an issue
Ok to compromise as follows:
Size over bass depth
Sonic quality over razor flat response
Old school look/design over diffraction concerns
My brother really likes the ATC Classic line of speakers and so we set out to design something similar.
Now credit where credit is due - in researching a design like this you'd be a fool not to look at the work of Troels Gravesen. As so it was that one of his SBA designs was a close match for this criteria. So the eagle eyed observers here - yes this design takes a sizeable amount of inspiration from Troels in terms of format - but beyond form factor is not a replica.
Landing on the same drivers, the SB Acoustics WO24P-8, MR13P-8 and TW29 tweeter. I've worked with the woofer and tweeter plenty before so I was leaning this way anyway and honestly the addition of the MR13P to round out this combo is simply a no brainer.
So here's the basic cabinet design:
Offset mid range and tweeter (my signature move lol) keeps our diffraction issues to a minimum with a square, zero round over baffle!
Aiming to keep to around 38-40L net for the woofer with a 28-30Hz tuning (to be tweaked once it all comes together). This gives us a magnitude response as follows:
Magnitude response:
Cone excursion + power:
Tuning allows for a full 70Watts of power within the music spectrum. This tuning for this woofer forces the region where the cone unloads to below 25Hz...which is certainly well outside the normal music listening range and gives us mechanical power handing close to but within the thermal rating of the woofer. I like it!
It also gives a nice gradual roll off in the lower octaves that yields an [email protected], [email protected]!! and [email protected] (nuts). We'll see how close to this we get once it all comes together and after woofer break-in.
Should be good for 106db (less baffle step PLUS room gain).
This measurement is essentially un-gated (500ms) and has no smoothing applied!
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