So I was playing around with these MCM 55-2421 trying to learn Horn Resp and because they always amused me and I was wondering how I could run an isobaric pair of subs in such a small horn. How to fold it? would you have to build a tube sticking into the mouth of the horn to essentially mount cone into the beginning of the horn, tube covers the motor side and allows mounting the second facing the same direction? Originally I was going to make it 4ft length in order to fit behind the seat of a single cab pickup. and still may, but any ideas are appreciated.
Attachments
isobaric really dislikes the large box size and rings/spikes at resonance only?? kindafunky? I could never find anything very good with isobaric
How do I make it in Isobaric mode permanently? Istg I went to that page and changed it 10 different times because it kept reverting. I go back to the drawing board a bit but honestly I don't mind a terribly high peak at 80ish hz if zi can get it to roll off at 6-8db per octave it would be perfect for a single cab pickup because of cabin gain. Thanks for pointing out my mistake. If I can keep my eyes open long enough I'll fix it now
S1 and S4 has to be big enough for both drivers to fit.
8.5" (room to fit driver width) x 5" (depth allows the vented voicecoil to breathe) x 2.54cm^2 = 274.193cm2.
274.193cm2 should be your starting point (S1) for a MCM 55-2421 8" isobaric TH.
8.5" (room to fit driver width) x 5" (depth allows the vented voicecoil to breathe) x 2.54cm^2 = 274.193cm2.
274.193cm2 should be your starting point (S1) for a MCM 55-2421 8" isobaric TH.
I wonder what is causing the exaggerated peaks in the isobaric model verses a pair of drivers in the same enclosure mounted separately?
is it the increased moving mass but lack of cone area? or the increased motorforce without the cone area?
simply increasing/decreasing ‘VAS‘ in any sisimulation has the same affect, but what’s actually happening to suspension stiffness here? Same issue with car audio drivers with the super crazy stiff spiders …. Yuck
@weltersys or @GM might be able to steer us in the right direction 🙏🏻
Last edited:
Look for the old Patrick Bateman thread on this forum about the MCM driver. I think he stated it takes a large enclosure to make it work, hence the high Qts.
If the two isobaric drivers are connected electrically in parallel, as is the case for the design being considered here, then Bl does not change.
If they are connected electrically in series, then Bl doubles.
The suspension stiffness is doubled, which means that the compliance Cms for the isobaric pair is half that of a single driver (assuming that the air trapped between the two diaphragms is acting as an incompressible acoustic mass).