My FR OB idea

[DougL]

At $10 a pop honestly could you complain?

It will sound fine. The issue is that the baffle roll-off is 6 db per octave starting at Fequal. If your baffle Fequal is 120 Hz, (just a WAG) you either are 6 db down, need twice the Xmax, or twice the area at 60 Hz. There are spreadsheets that calculate max spl. Run the numbers, but my intuition is that a 40 Hz base note could bottom the woofers at any reasonable volume. I had to keep the crossover point up (above 200 Hz) to avoid bottoming the mid-range.

If you try it, let us know. As you say, the price is right.

Doug

[Ppasco1018]

I shall. There will be pictures and all!

I want to sand and gloss black/red what ever gets built. So it will be while before they are done.

I think I am going to buy a pair of the little $10 3" and build a little MDF home for them to tinker around with in the bedroom to see how interesting the full range thing can be before I spend over $100 dolla!

Does anyone know how much mdf for my size will be.

I would say 30f by 20w FB / Small same height arms?

[chrisb]

Originally Posted by Ppasco1018

snip...

Is there a fostex driver thats good for OB?

Well, if you read the MJK project paper referenced earlier, you'll see he nominates a range of Fostex drivers for the mid/tweeter portion of his 2-way OB.

There are more than a few builders who've been very happy with the results. Probably most effusively - Jim Shearer and his FF85K - see his posts starting about here:

New MJK Baffle Article

Mind you, any of the suitable Fostex drivers will cost more than $10 each

[Godzilla]

Today i received the 5.5" jamo and the 8" jamo from PE... They look great in the pictures but not so great in person... plasticy and lightweight. Every single Fostex i have seen simply looks and feels better made. Every single TB i've seen looks and feels better made... I remember getting the titanium 3" TBs and couldn't wait to hook them up. Just looking at these jamo's i don't even want to hook them up. They look like they will break if i turn up the volume. Uhg... oh well, they only cost a few bucks.

Godzilla

[Ppasco1018]

I figure it would be a start though. I bought a pair of those insignia ns-b2111's today just to tide me over until I had the time to start building my OB's. Dear lord they sound fantastic at low levels (cost wise-paid $60) but once you crank up the levels the thin box really shows. I think I am going to do the rock hard mod to them and shove a 6.5 full range in them until I get the time to build the OB's. I think I am stuck on a 6.5 and a 8 or 10" for the OB.

I did a paint draw up of what I sort of want them to look like in the end.

Tell me what ya think!

[MisterTwister]

Ppasco1018, I think that you hear woofers' resonance, not the box.
stock crossover does nothing to attenuate that resonance.
here is proper crossover design for these speakers:
MurphyBlaster Productions

[Ppasco1018]

Cool. This box is real flimsy. Its only 5 dollars to add the rock hard and maybe two days of my time. I have the slightest clue how to do crossover stuff.

Is this a simple upgrade? Thanks for the tip, I can def afford $40 to make a better speaker. As when the OB's are done, the FR will be removed from this box and will need to be put back together with the original driver.

Does anyone know what kind of crossover I would have to widdle to use those drivers in my car until I put them back in later on? I would figure it would be a small filter??

Thanks guys, your nothing but help!