Canned Crossover Design - What Next?

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Are these two resistors an L PAD?

Am I getting warmer :D
 

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Tried the xo in last post - okay, thought I lost some bass with the 16g series woofer coil. I switched it out with a 14g and used 14g feed wires, quite the improvement (bass).

I thought the tweeter sounded a little hot on some songs, so swapped the 1st tweeter resistor; 2.2ohm with a 3.3ohm ....They sounds nice, they pound, kick, slam and have nice high end.

(ordered some steel lam inductors - will try that next)

Visions of the DQ10 are coming back ... :D
 
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I saw that "cut-out" on here somewhere, it seems to enhance the imagining.

Going to experiment with the tweeter LPad, make sure I'm not missing out something good. Not sure why it is in there:
SF 8" is 93.7db
ScanSpeak Tweeter 91.4db

[soon will try the ScanSpeak with smaller 6.5"]
 

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Still going here, made a 3rd 8" box. It is a little smaller and tuned a just a bit lower. Also added damping wool to both, 8.5 oz.

[also used better grade wood]

Results, more bass and better middle, the tweeters are starting to shine a bit. I had to move the speakers out from the wall, was starting to pick up some boom.

**
Still really happy with the 6.5" and vifa, that's a good little speaker; too bad the cost of copper is so high now (that runs up the price on a set).
 

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Pic of # 3 8" SF woofer/Discover tweeter.
Still not as much deep bass as the 6.5" (although its not a wimp either).
Going to start #4 today, not sure what to try next, maybe reducing box size another 50 square inches.

[but it all works together, e.g. box depth/height control vent sizes]
 

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Pic of #4, this one has more of a "biff" than a "boom" so maybe this is the ticket. [there are a few small improvements]

*** Would like to try a 6.5" MTM (2nd pic), in a 24 - 25 liter "tower", again xo is a roadblock.

I'm guessing 2 - 4ohm or 2 - 8ohm woofer combinations is typical; next question would be would there be two inductors - or just one :confused:
 

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Using 2 8ohm drivers in parallel will result in a much more efficient, 4ohm speaker; If you arranged them in a 2.5way configuration then you could just use a single inductor on the bottom woofer to roll it off at baffle step. But I think the crossover would have to be redesigned, at least to the extent that different values would be needed to compensate for the lower impedance of the two woofers.
 
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The second pic isn't an MTM ;) more a TMMT and I'm not sure how that would work out... most likely would have interference problems..

Generally in an MTM both mids run with the same crossover. In a 2.5 way the configuration is more likely to be TMM (with tweeter on the top) and one of the woofers (probably the bottom one) only covers the lower bass whereas the other one covers bass and midrange. The one covering only the bass augments the bass at frequencies where baffle step is reducing the output.

Tony.
 
Wintermute,

Thanks, simple enough (guessing a 2.5 is more expensive).

Pic - Flipped speaker(s) and use both sets of xo's (4) for this 2.5 test run (top tweeter is not connected).

Sounds powerful, great bass, clear, good imaging. Need to think how to pull this together into one box.

[4ohm hookup now]
 

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That's ******* awesome! Speaker legos! :D

Making a 2.5 way has some benefits: if you have a BSC filter on the woofers, that can be removed in favor of a single inductor on the bottom woofer to roll it off at the baffle step frequency. Assuming you're running the drivers in parallel, you'll get higher efficiency so you also need less padding on the tweeter. Good luck!
 
Doug, it's very bad to leave a tweeter filter unterminated but connected. Very resonant to the amp. Be careful.

The series wired D'Appolito has a very simple connection. You wire the two basses and two bass filters in series, along with a single tweeter and filter. The levels work out, leaving the elegant conclusion that converting a standard two-way to a series wired D'Appolito is almost trivial. Bass impedance doubles, of course. :D

Simplifying the resulting bass filter is then a simple exercise of halving and doubling the component values. IIRC, you halve capacitance and double inductance and resistance.

The parallel wired 4 ohm D'Appolito is altogether more complex to design. :scratch1:
 
Thanks Steve - for saving my neck - disconnected high side.

Presto Changeo
Only listened to the test boxes for a few hours before going crazy; cut off tops and gluing them top to bottom. There is substantial bass now; and I like the smooth roll-off :cool:
 

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The mid bass xo has other filters, so changing the series coil is worrisome.
(the xo at bottom is the mid/woofer components only)

I was curious if I could just change the bottom speakers' xo with say a 6.0hm lam. sub-woofer coil? [and/or add second amp]

How do these sounds as is? Not bad, better than I thought they as far as a Hifi sound. I was worried about the mid range, which is not bad and easy to listen to, but probably could use a little tweaking.

Crazy Bold Bass :eek:
 

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Not to belabor this idea, but these are turning out to be 2 foot tall monsters. The double 6.5s just pound away - effortlessly.

Been listening to a mix of sources/cds; I did think the cymbals in a Dire Straits song sounded a bit exaggerated, but still very natural sounding. Also a few action movies, all very impressive.

Could think about a new tweeter, but I think the xo point moved up; a new xo design would needed to save on copper coils.

Going to mount tweeter in middle here, hopping that doesn't mess with imaging :(
 

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