Canned Crossover Design - What Next?

[ODougbo]

Mike,

Will Box Port II switch over to rectangle ports? - WinISD didn't like all the manipulation, but this what I came up with.

I'd like to keep the box about a 1" less deep than the TB, i.e 9".

(the extra white line is exaggerated)

 

[ODougbo]

A few revelations:

Both woofers TB W5 - SF W7 are about the same size (OD), so the TB box is a good example (e.g. don't want to get close to edge at front)

Using same footprint as the TB box, cut about the 1" off the back, that will make the ID height 11" (for a 13 liter box).

(the TB W5 box is 14-1/2" ID)

Going to use scrap wood and build one test box, make sure there is minimal port noise.

[W5- W7 - W BOX - How'd that happen?]

 

[Michael Chua]

Mike,
Will Box Port II switch over to rectangle ports?

Box Port II doesn't have rectangular ports.

I think my Bass Box 6 can do that. I will check it out for you later. Haven't use Bass Box for a while.

 

[wintermute]

If you really want to get your teeth into something, you could try akabak

Tony.

 

[ODougbo]

Akabak? Oh Boy.

Speakers are in, nice to look at, pretty good sized magnets.

Working on test box now.

 

[Michael Chua]

If you really want to get your teeth into something, you could try akabak Tony.

Hi Tony
Thanks for the recommendation. I heard that akabak is very powerful. Trouble is I don't have the time for steep learning curve. Too much work already.

Hi ODougbo
I simulated the W17RC with Bass Box. The 2" diameter port length is almost the same, which means both are accurate.

For a rectangle port:
Height = 0.5"
Width = 6"
Length = 6.9"

A 1 inch height is not practical. Length is more than 12".

 

[ODougbo]

What am I tuning to? Might be good to put it in writing.

(stopped by HD picked up 12/ MDF for vent pieces)

 

[Michael Chua]

Box Tuning (Fb) = 49Hz

 

[ODougbo]

So going as planed. Used square vent strips just in case this is a flop (port noise).

Tuned at 43hz now and sounds fine; will cut flares in ports (vent strips) - to move tuning up to 49hz.

 

[Michael Chua]

Looking great. Are you able to check on the vent tuning?

 

[wintermute]

Hi Mike, I've had enough of a play with akabak to know that I'd like to become proficient in using it, but like you I really haven't had the time to do so. There is actually a good dummy's guide here on diyAudio which is enough to get going with simple projects.

Perhaps when I start to think about new cabinets for my Vifa M26WR-09-08's I may get a bit more into it. I'd like to model a double chamber reflex.

Tony.

 

[ODougbo]

Yes, didn't take long to get to 49-50hz (rounded vent strips)

I though the way it went together was good/fast. I cut a dado around the top and bottom plates and then nailed the back/sides on - then clamped vertically while the glue dried.

The goal is to make the dado just deep enough for the side panel and vent strip (mdf) thickness.

 

[ODougbo]

Thought it best to make template for the vents (the 1st set were beltsanded).

This is pretty simple, just attached to work piece and flush with router.

Going to play one all day here - then check tuning (-; (-;

 

[ODougbo]

New Pic:

Sounds good - using same xo as before; had to use 10ohm R for balance.

No damping material - not sure any is needed.

 

[Michael Chua]

I admire your woodworking skills. I have no experience with the vents you did but they do look great.

I suggest you try my crossover. It should sound quite different.

Also, line the inside with fiberglass wool or some other suitable material. Without it, the mids will sound harsh.

 

[Michael Chua]

Perhaps when I start to think about new cabinets for my Vifa M26WR-09-08's I may get a bit more into it. I'd like to model a double chamber reflex. Tony.

Hi Tony

Double Chamber Reflex are not very popular but they have their attributes. The main advantage of a DCR is in the Mid-Bass. It is actually a combination of a BandPass and a Bass Reflex.

I manually calculate the DCR with the help of Claudio Negro website. When I did a FR sweep with LMS, it's quite accurate.

 

[ODougbo]

yes - have some cork pieces, will also add some light damping material.

The wool cone has a very nice sound (I thought it might), not really having any mid problems as is.

 

[ODougbo]

Mike,

Can order parts Monday, what gauge wire should I purchase for the inductors?

Also the large resistor with the (BSC I guess); picked up 50ohm the other day (not expensive) will that work?

 

[Michael Chua]

I standardize all my inductors with 18 AWG air core types.

50 ohms is fine. I usually use 10W for testing. Once final, I switch to 20W.

If the 0.95mH is unavailable, you can use 1.0mH.

This network is a Bass Shelving Filter, not really a BSC. I like to hear mid-bass in my music. If the lower bass (like 40Hz) is a bit lacking, I can always add a Sub later.

 

[ODougbo]

Okay Mike,

Found 16G coils for woofer(s), the $36 meter that I just bought came in handy!
Going to make a temp wood strip and set inside box - I can use the tweeter xo from the other xo while waiting for tweeter parts.