Powerful 3 Way System - Help needed

[voodooless]

If you tune the B&C to low, for instance to 22Hz@100L your maxSPL is 110dB @20Hz (single driver). You'll need some boosting to get the response flat, but it can probably handle that. If you take room gain into account, you might not need a lot of boost anyway. Put them in corners to get some extra output

 

[LineSource]

"I get by with a little help from my friends"

You might set up an email dialog with diysoundgroup.com to discuss purchasing their HTM-12 econowave kit ($300), along with their precut 1"->12"->18" Magnus-18 CNC 1" thick baffle, plus CNC cut 12" midrange sealed chamber. This baffle is cut for an 18" B&C woofer ( B&C 18TBW100). Explain your plan to Bi-Amp, and that you would only require the HTM-12 passive crossover tuned for the sealed Maximus-18 12" chamber.

HT-12 DIY Sound Group
(you can also compare to their Fusion-12 kit)

Maximus-18 DIY Sound Group

 

[hollowboy]

Hey man, thanks a lot for your help.

I will definitely work with Hornsrep and figure these numbers out. Heres a question: so the B&C woofer reaches its Xmax limits @ 40Hz 115 dB which works out to about RMS 500 right, would the Ultimax or HO (Dayton Audio RSS460HO-4 18" Reference HO Subwoofer 4 ohm) give me the same performance at a higher RMS but simillar sized box?

At some point you just have to decide for yourself. Give the simulations another go.

The dark line is a hundred watts into the B&C (175 litre ported box)
versus

The pale line is a thousand watts into the Ultimax (75 litre sealed box)

The Ultimax would be a very easy and compact build. It suits very low frequency use.

A pro 18" would suit a bigger box, and be a slightly more complex in build and setup. It would need a lot less power and would play well to a higher frequency.

 

[Butaboy]

This baffle is cut for an 18" B&C woofer ( B&C 18TBW100). Explain your plan to Bi-Amp, and that you would only require the HTM-12 passive crossover tuned for the sealed Maximus-18 12" chamber.

Thanks for the advice.

If I mount the B&C 18RBX100 sub in their enclosure according to their Magnus 18 Baffle, will I get a good performance out of the sub?

 

[LineSource]

Published suggested diysoundgroup Maximus-18 Box Measurements: 23" wide" x 48" tall x 16.75" deep, should net over 7.5cuft for the 18RBX100 woofer which models -F3 ~34Hz.

Google review a few EconoWave speaker combination options so you will feel comfortable with your selection before purchase.

 

[LineSource]

For a ~$100/speaker more....

If you do email diysoundgroup.com, ask about purchasing just the TM portion of the Maximus-18 design, and explain how you will use Hi+Lo active crossovers and two amplifiers with B&C 18RBX100 woofer.
--The $142 Denovo FL-450 compression driver used in the Maximus-18 design has a copper shorting ring, aluminum phase plug, and neo magnet, producing superior high frequency measurements to the DE-250.
--The B&C documentation shows the same mounting outer rim diameter and drill hole ring diameter for both the 18TBW100 and 18RBX100. Should fit.

--Discuss purchasing at least the advertised CNC front baffle and midbass enclosure, and discuss the option to purchase the complete CNC cabinet flat pack.
--After midbass box and cross supports, the internal woofer volume is slightly larger than 7cuft

"I'm going to try with a little help from my friends"

 

[Butaboy]

For a ~$100/speaker more....

If you do email diysoundgroup.com, ask about purchasing just the TM portion of the Maximus-18 design, and explain how you will use Hi+Lo active crossovers and two amplifiers with B&C 18RBX100 woofer.
--The $142 Denovo FL-450 compression driver used in the Maximus-18 design has a copper shorting ring, aluminum phase plug, and neo magnet, producing superior high frequency measurements to the DE-250.
--The B&C documentation shows the same mounting outer rim diameter and drill hole ring diameter for both the 18TBW100 and 18RBX100. Should fit

Hey man thanks for all the advice, I have decided I will go the route you recommended. Will contact diysoundgroup.

Thanks for all the advice.

 

[hollowboy]

--The $142 Denovo FL-450 compression driver used in the Maximus-18 design has a copper shorting ring, aluminum phase plug, and neo magnet, producing superior high frequency measurements to the DE-250.

It looks like that particular driver and kit are no longer available, but there are heaps of equivalents. I'm sure the OP will end up with something good.

I wish there was an equivalent in Australia - we don't have any large flat packs like these, and what we can get is several times the price.

Will contact diysoundgroup.

I'm curious to see how this turns out, please update when you buy + build your kit.