3.5 way towers

[secretsquirrel]

So, I have never build speakers before and was hoping someone could double check my idea.

I am trying to build a set of four tower speakers for listening to music, TV and movies through an Onkyo receiver. Later on down the road, I plan on making a center channel to match and a separate subwoofer.

I am thinking about using these drivers:

http://www.parts-express.com/pe/pshowdetl.cfm?&DID=7&Partnumber=290-088&ctab=1#Tabs
Pioneer W25GR31-51F 10" Butyl Surround Woofer
Ported

(70Hz - 600Hz)

Power handling: 90 watts RMS/130 watts max
Voice coil diameter: 2"
Impedance: 8 ohms
Frequency response: 26-6,000 Hz
Magnet weight: 30 oz..
SPL: 90 dB 1W/1m
Vas: 4.77 cu. ft.
Xmax: 3.0mm
Qms: 4.17
Qes: .36
Qts: .34
Fs: 26 Hz
Net weight: 7 lbs.
Manufacturer model number: W25GR31-51F
Dimensions: Overall Diameter: 10-1/8", Cutout Diameter: 9-1/4", Mounting Depth: 4-1/2", Magnet Diameter: 5-3/4", Magnet Height: 1-1/2".

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http://www.parts-express.com/pe/showdetl.cfm?Partnumber=280-020
Pioneer B11EC80-02F 5-1/4" Cup Midrange

(600Hz - 5000Hz)

Power handling: 50 watts RMS/75 watts max
Voice coil diameter: 1"
Impedance: 8 ohms
Frequency response: 320-6,000 Hz
Magnet weight: 9.3 oz.
SPL: 94 dB 1W/1m
Net weight: 2 lbs.
Manufacturer model number: B11EC80-02F
Dimensions: Overall Diameter: 5-1/4", Cutout Diameter: 4-1/8", Mounting Depth: 3-3/4", Magnet Diameter: 3-1/2", Magnet Height: 3".

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http://www.parts-express.com/pe/showdetl.cfm?Partnumber=270-035
Pioneer FBDE75-52F 1" Soft Dome Tweeter

(5000Hz - 20,000Hz)

Power handling: 50 watts RMS/75 watts max
Voice coil diameter: 1"
Impedance: 8 ohms
Frequency response: 3,000-20,000 Hz
Magnet weight: 6.3 oz.
SPL: 92 dB 1W/1m
Net weight: 1-1/4 lbs.
Manufacturer model number: FBDE75-52F
Dimensions: Overall Diameter: 3-7/8" x 3-7/8", Cutout Diameter: 3-1/2", Mounting Depth: 1", Magnet Diameter: 3", Magnet Height: 3/4".

Current plan is one tweeter, two midrange, one woofer - crossovers at 600Hz and 5000 Hz. Do these drivers seem like they would work well together? Also, am I correct in reading that these midranges and tweeters (sealed) would work without lan enclosure?

As far as the woofer, I was thinking a ported enclosure that measured (internal) 15" wide x 24" tall x 9.25" deep with a flared port (something around 3" diameter, 8.33" long, with a 90 degree bend to make it fit).

As far as actual design, I sketched this out (very rough)

Does anyone see any obvious flaws?

 

[adason]

I do not see any flaws. Except with one woofer it will be 3 way, not 3.5 way. (Does not matter how many midranges you have, depens on crossover design)

You would need two woofers, one crossed lower than the other to make it 3.5 way. Read Zaph site.

Although the tweeter and midrange do not need enclosure, it would be pitty to use that midrange with its cup. You can get much better midrange quality making it open baffle. Read about NaO and other open baffle speakers (Orion, Phoenix).

good luck
ed

 

[MJL21193]

Hi,
Agree fully with adason about not getting the advantage of OB mids.
Also, that woofer will be running out of excursion (xmax) at fairly low power. You might want to look at a different woofer.

 

[secretsquirrel]

Thanks for your input.

adason - I was thinking of using a 12" wide x 1" thick board (of some kind of hardwood) to mount the speakers (like the NaO). I would flush mount them, the woofer inside the ported enclosure at the base and the mids and tweeter mounted above the enclosure without side walls. Isn't this an open baffle setup, or would I need walls on the side for this to be effective? How deep should the walls go and how do I determine this? Also, if I removed the cups from the mids, wouldn't they need an enclosure then?

MJL - That woofer has a power handling of 90 watts RMS and 90 db SPL, any idea why the xmax is so low? Any recommendations for another 10" woofer?

 

[MJL21193]

Also, if I removed the cups from the mids, wouldn't they need an enclosure then?

MJL - That woofer has a power handling of 90 watts RMS and 90 db SPL, any idea why the xmax is so low? Any recommendations for another 10" woofer?

Hi,
The mids are conveniently cupped like that to use in a box with a woofer - you would not need to build a sub-enclosure inside the box to house the midrange. You would pick an open back mid to use OB (output from the rear of the driver too). Understand?

The woofer can have a power handling of 1,000,000 watts and still run out of excursion. Power handling has nothing to do with Xmax.
Download and learn Unibox, it will do very accurate modeling for vented boxes.
As for another driver - you can look for one with similar specs, but with a higher xmax.

 

[adason]

the base and the mids and tweeter mounted above the enclosure without side walls. Isn't this an open baffle setup, or would I need walls on the side for this to be effective? How deep should the walls go and how do I determine this? Also, if I removed the cups from the mids, wouldn't they need an enclosure then?

the midrange has a cup in back, so its closed back midrange by the design, it does not matter if you put it in the box or on open baffle, it still has closed back and behaves the same....
in order to make it open baffle, you have to remove the cup

no, it does not need the enclosure, that is the point of open baffle, please read linkwitz site, you will find all the unswers to you questions
http://www.linkwitzlab.com/index.html

 

[adason]

when it comes to the woofer, it depends how loud you want to run them, it actualy might be ok for normal domestic use, especially when you want to ad subwoofer later

 

[Moondog55]

This is just my $0.02 but if using those drivers, and considering that this is a first project, please consider using a sealed box and just one mid.
And make one pair to start with or change to 4 small 2-ways.
Consider it a learning project, if you are happy with the end result then OK, but if not then the money and time spent is less and they will probably make good garage speakers.

For a first time OB midrange look up AndyG's "Blackwoods" or the "Aethers"
Note that when time permits I am going to be working on a project very similar to both, at the moment stuck on an OB full range project and moving homes.
Best of luck and welcome to a very addictive hobby
Ted

 

[MJL21193]

As far as the woofer, I was thinking a ported enclosure that measured (internal) 15" wide x 24" tall x 9.25" deep with a flared port (something around 3" diameter, 8.33" long, with a 90 degree bend to make it fit).

Your box is ~36 litres when you subtract the driver and port volume. This is a good size for this woofer in a sealed box, but it should be twice that for a vented - 60-70 litres.

Here's what i mean about running out of excursion:

 

[MJL21193]

Here's a better woof for a vented 36 litre box:
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-110

This is how it looks. It will handle 100 watts before running out of excursion.

 

[secretsquirrel]

That Dayton woofer seems like a perfect fit, thanks!

As far as a box for that driver, Bass Box Pro 6 says I should use a 1.5 - 1.6 cu. ft. vented (I like the deeper bass response) box - 23" x 14" x 8.75" with a 3" x 8.75" - 9" port tube. This seem right?

And Moondog - I was planning on rough-building one tower first to get the kinks out of the design before building the whole set.

Speaking of tweaking designs - what kind of testing equipment do you guys use? Not looking for the whole 9 yards, just something economical.

 

[Moondog55]

I use one set of very old and tired ears and the opinion of my partner

 

[MJL21193]

As far as a box for that driver, Bass Box Pro 6 says I should use a 1.5 - 1.6 cu. ft. vented (I like the deeper bass response) box - 23" x 14" x 8.75" with a 3" x 8.75" - 9" port tube. This seem right?

The Dayton is a bit more expensive but better fits your plan.

If you want to with a bigger box (1.5 cu. ft. = 42 litres) you will get slightly lower extension.
A 3" port for this driver in that volume is too small. A 3.5" minimum (8.75cm inside dia.) will keep port noise down.

Here's what I get from Unibox in a 42 litre box (your dimensions above are for the inside of the box, right? That gives 44 litres - allowing 2 litres for driver volume and the port).
Highlighted in blue is the box volume, port diameter and port length.

 

[MJL21193]

Here's what the cone excursion looks like with 100 watts. This is very good.

 

[adason]

secretsquirrel, if you are going with Dayton woofer, which is definitely a better choice, you might as well consider Dayton midrange. I used this one and was very happy with it:
http://www.parts-express.com/pe/psh...-010&FTR=295-010&CFID=192849&CFTOKEN=95552386

 

[PeteMcK]

what kind of testing equipment:

http://www.fesb.hr/~mateljan/arta/index.htm

http://libinst.com/SynRTA.htm