Dicking around this morning, and discovered that you can cross the 4 ohm at 3400 if you want:
Takes some creativity, and probably not worth the components - mostly because the cabinets are tiny. I don't want to sausage stuff these lol. Still, I did find some 100V MKP capacitors out in the wild and I have those weird small form factor 2mH laminate core I bought on buyout years ago - could do this XO with minimal footprint. Hmmm...
This was with the Beast Mode since I now have five of them, something about a sale price.
Purely prototype right now, based on single axis, single channel measurements. However, it is proof of concept that higher crossover points are achievable with these drivers.
I'll throw an 8 ohm in there, maybe later. See how the day goes. I'm feeling fairly lazy today.
The 8 ohm is definitely the better of the two. Both have the cliff noted above, the 8 ohm is less noticeable. Nothing I am going to sweat, though.
Spent a good chunk of yesterday evening and this evening playing with the 4 ohm model of the TM.
Not going to go in to too much detail, but some things are just not worth the headache - like eliminating the phase interference above 10K in this design.
Anyways, the four ohm model is quasi second order somewhere around 2.8K
Simple crossover, probably do away with the little parallel capacitor if a fella wanted.
Impedance because:
Anyways, will post about the 8 ohm TM.
I will eventually do a 4 and 8 ohm MTM. The 2.5 way TMM for obvious reasons will only be available as a 4 ohm design.
So that XO was shits and giggles. Was not correct. Here are the details for the 4 ohm model:
Crossover. Kept it as simple as I could. One compromise not inherent to the drivers, and that is the phase issues up in the "too old to hear it anyways" area.
On axis and reverse null showing the asymmetric slopes:
Impedance over frequency:
And again, surprisingly low distortion. Part of that is Beast Mode, but I am starting to believe that shallower slopes are just lower distortion.
Anyways, thats enough 4 ohm shit. The 8 ohm driver is more linear in-box, and I will work on that tonight some, if I stay out of the beers.
Will not be doing the 8 ohm - but have something not shitty using the 4 ohm.
All of the above plus the final XO:
Results in this FR/Impedance:
And this distortion 1/2M@90db. That is all she could take, captain.
So...My verdict on these little SB is that they are worth the money if you are willing to make a few concessions. One of them is the peak at 1K might be objectionable. Another is the top end is wonky - it absolutely extends too high for the response shape. The spikey part at the top of its range is a pain in the ass so I just let it ride and have phase issues above 7k as a result. I don't care about that. I could and I should, but I just can't.
Subjectively nice bass and overall a balanced presentation. Would make a very nice upgrade from typical small form factor commercial speakers.
Comments
Cool idea and stackable.
I just knew you didn't have that many more arms than the rest of us . . .
TM flat packs cut and ready for glue up.
...and glued up sans baffle.
I'll route everything tomorrow.
The little ones are ending 0.23 net, with baffle dimensions similar to the Denovo knockdown. Close enough to work.
John H gifted me a pair of cabinets which will be perfect for the MTM/CC part of this project. Thank you, John.
Dicking around this morning, and discovered that you can cross the 4 ohm at 3400 if you want:
Takes some creativity, and probably not worth the components - mostly because the cabinets are tiny. I don't want to sausage stuff these lol. Still, I did find some 100V MKP capacitors out in the wild and I have those weird small form factor 2mH laminate core I bought on buyout years ago - could do this XO with minimal footprint. Hmmm...
This was with the Beast Mode since I now have five of them, something about a sale price.
Purely prototype right now, based on single axis, single channel measurements. However, it is proof of concept that higher crossover points are achievable with these drivers.
I'll throw an 8 ohm in there, maybe later. See how the day goes. I'm feeling fairly lazy today.
The 8 ohm is definitely the better of the two. Both have the cliff noted above, the 8 ohm is less noticeable. Nothing I am going to sweat, though.
Spent a good chunk of yesterday evening and this evening playing with the 4 ohm model of the TM.
Not going to go in to too much detail, but some things are just not worth the headache - like eliminating the phase interference above 10K in this design.
Anyways, the four ohm model is quasi second order somewhere around 2.8K
Simple crossover, probably do away with the little parallel capacitor if a fella wanted.
Impedance because:
Anyways, will post about the 8 ohm TM.
I will eventually do a 4 and 8 ohm MTM. The 2.5 way TMM for obvious reasons will only be available as a 4 ohm design.
When I remember to do so, I will do the 8 ohm version. It is complete, just forgot to save measurements.
Here is the XO for shits and giggles:
OH, and important - these are both with the double magnet XT25. It's nicer than the regular XT25 and I love that tweeter.
Wow - that's a hell of a valley on the 4 ohm woofers. Are those OEMs notably different from the regular versions?
So that XO was shits and giggles. Was not correct. Here are the details for the 4 ohm model:
Crossover. Kept it as simple as I could. One compromise not inherent to the drivers, and that is the phase issues up in the "too old to hear it anyways" area.
On axis and reverse null showing the asymmetric slopes:
Impedance over frequency:
And again, surprisingly low distortion. Part of that is Beast Mode, but I am starting to believe that shallower slopes are just lower distortion.
Anyways, thats enough 4 ohm shit. The 8 ohm driver is more linear in-box, and I will work on that tonight some, if I stay out of the beers.
Also, these little SB have excellent bass, subjectively speaking.
I would like to hear them if you still have them in the enclosure and will be around this weekend sir
Tore apart working on 8 ohm version.
Will not be doing the 8 ohm - but have something not shitty using the 4 ohm.
All of the above plus the final XO:
Results in this FR/Impedance:
And this distortion 1/2M@90db. That is all she could take, captain.
So...My verdict on these little SB is that they are worth the money if you are willing to make a few concessions. One of them is the peak at 1K might be objectionable. Another is the top end is wonky - it absolutely extends too high for the response shape. The spikey part at the top of its range is a pain in the ass so I just let it ride and have phase issues above 7k as a result. I don't care about that. I could and I should, but I just can't.
Subjectively nice bass and overall a balanced presentation. Would make a very nice upgrade from typical small form factor commercial speakers.
Oh, and this is Beast Mode tweeter.
Baby crossovers. The board is 1/2 of a PE small crossover board.
nice. what gauge wires are you using ?
16
I purposely designed these to match the desk/bench in my utility room lol. Not really, but it looks like it.
Yes, that is XO running on that PC. I still might move all of my measurement/design software to it but mostly it exists purely for nostalgic purposes.