Microbe SE BOM

[bjmmy]

Since there isn't a published BOM (or a build thread here that I can find) for the Microbe SE, can anyone verify that this BOM I put together based on Roman's site is correct? My total comes out higher than others I have seen on this forum, but I'm not sure why. The 1.8 mH inductor seems awfully pricey, but seems to be what Roman is calling for in the wiring diagram if I'm not mistaken...

QTY PE PN Description Unit $ Ext $
2 295-360 RS125S-8 21.85 $43.70
2 Seas 22TAF/G 27.45 $54.90
2 027-418 3 uF capacitor $1.67 $3.34
2 027-422 4.7 uF capacitor $1.89 $3.78
2 027-425 5.6 uF capacitor $2.10 $4.20
2 255-028 20ga 0.3 mH inductor $3.24 $6.48
2 255-428 15ga 0.42 ohm 1.8 mH inductor $19.26 $38.52
2 255-200 18ga 0.05 mH inductor $2.26 $4.52
2 004-6 6 ohm resistor $1.38 $2.76
2 004-7 7 ohm resistor $1.38 $2.76
Subtotal $164.96

Thanks in advance! These, along with the RS150 MTM center and Modula MT R/Ls will be my first crossovers built from scratch and I want to make sure I order the correct parts.

[PoorboyMike]

The BOM looks good.

Don't forget a couple of ports, speaker cups/binding posts, and some cabinet dampening material.

[bjmmy]

The BOM looks good.

Don't forget a couple of ports, speaker cups/binding posts, and some cabinet dampening material.

Thanks for the quick response! Yeah, I still need to include some parts beyond the crossover and drivers. Have you built these? If so, did you use that same 1.8 mh inductor? That's the one that I really question - especially since I saw some posts where people said parts would cost $68/speaker. Size is still a big concern to me, but it makes me think twice about these for $82/ea when I can build another 2 Modula MTs for $110/ea...

[Landroval]

1.8mH 0.42Ohm inductor looks good to me. That's what it should be.

[PoorboyMike]

Thanks for the quick response! Yeah, I still need to include some parts beyond the crossover and drivers. Have you built these? If so, did you use that same 1.8 mh inductor? That's the one that I really question - especially since I saw some posts where people said parts would cost $68/speaker. Size is still a big concern to me, but it makes me think twice about these for $82/ea when I can build another 2 Modula MTs for $110/ea...

I haven't built these. You might want to give Madisound a call and find out the DCR on their 15AWG inductors. It's not listed on their site, but if it's close, it would save you $7-8 per side.

[PoorboyMike]

I've read a few posts at PE that said Jeff B.'s RS150/Seas27XXXX sound good and the parts cost would be lower than the microbes.

Images not available

[bjmmy]

I've read a few posts at PE that said Jeff B.'s RS150/Seas27XXXX sound good and the parts cost would be lower than the microbes.

Images not available

Interesting... I hadn't seen those before. That certainly is a simple looking crossover (not sure if that's so good...), but the thing that seems potentially good is that all 5 of my speakers would have the same tweeter with that design. That might be worth looking into. It's a good thing I haven't started cutting the MDF for my surround enclosures yet!

[JonP]

Thanks for the quick response! Yeah, I still need to include some parts beyond the crossover and drivers. Have you built these? If so, did you use that same 1.8 mh inductor? That's the one that I really question - especially since I saw some posts where people said parts would cost $68/speaker. Size is still a big concern to me, but it makes me think twice about these for $82/ea when I can build another 2 Modula MTs for $110/ea...

Might be the lower costs were back before copper went up in price. Past couple of years inductors have gone up 30% or more....

$220 for a pair of ModulaMT's? Just built a pair, and either you went for the iron core on that big one, and lowballed some of the other parts, or that's the pre Cu=precious metal pricing...

[Jed]

I'm pretty sure Roman uses an iron core inductor for the 1.8mh, but an air core with low DCR is better- just takes up more room in the cabinet.

[JonP]

I'm pretty sure Roman uses an iron core inductor for the 1.8mh, but an air core with low DCR is better- just takes up more room in the cabinet.

Yes, Roman did... but you know Jon... he's liable to show up any minute wagging his finger at iron core users.... :twisted:

[bjmmy]

Might be the lower costs were back before copper went up in price. Past couple of years inductors have gone up 30% or more....

$220 for a pair of ModulaMT's? Just built a pair, and either you went for the iron core on that big one, and lowballed some of the other parts, or that's the pre Cu=precious metal pricing...

Hmmm… Those costs came out of the BOM in the build thread. I looked at the prices for some of the parts and they were dead on with that BOM. I guess I should look up each and every part before I go shooting my mouth off!

[Jed]

Yes, Roman did... but you know Jon... he's liable to show up any minute wagging his finger at iron core users.... :twisted:

:nono: Just say no to iron core. Where's Jon? :B

[bjmmy]

Might be the lower costs were back before copper went up in price. Past couple of years inductors have gone up 30% or more....

$220 for a pair of ModulaMT's? Just built a pair, and either you went for the iron core on that big one, and lowballed some of the other parts, or that's the pre Cu=precious metal pricing...

Off topic, but I just updated the unit prices for this BOM and it comes out to $233.70 for a pair.

[bjmmy]

Ok, I'm confident that my BOM has the correct components thanks to your help, but now I am wondering about the Dreydel speaker vs. the Microbe SE. I can't find any information on the Dreydel other than that from its creator, but I like the fact that if I built these for surrounds, I'd have the same tweeter in all 5 of my speakers. Should I be so hung up on that? Has anybody heard this speaker? The Microbe SE seems like a safe bet because a lot of people have built them and like them, but I really like the idea of matching tweeters...