Crossover for Dayton Audio B652 speakers

Dayton Audio B652 are hugely popular speakers.
I'd purchase a pair for evaluation, but I don't have space for any new projects.
Nevertheless I designed crossover for these speakers. It is based on measurements
provided by other people. I traced graphs from Zaphaudio site. He has the most helpful set of measurements.
Here is my crossover and parts list:

 

6.2uF capacitor (2)
http://www.parts-express.com/pe/showdetl.cfm?partnumber=027-427
22uF capacitor (2)
http://www.parts-express.com/pe/showdetl.cfm?partnumber=027-348
3Ohm resistor (2)
http://www.parts-express.com/pe/showdetl.cfm?partnumber=016-3
1.2mH inductor (2)
http://www.parts-express.com/pe/showdetl.cfm?partnumber=255-050

It is important to flip tweeter's polarity, otherwise you'll get this FR (yellow line)

White lines represent unfiltered response of the drivers.
The biggest expense in this upgrade are inductors. You could save some money by using piece of
foam to filter out woofer's high frequencies. But it would require you to have a sound measurement setup.
This version of crossover should provide nice laid-back sound.

How to improve sound of speakers you already have

I'd like to share with everyone how I set up my speakers for improved sound-stage, imaging and overall spaciousness of sound. Firstly and very importantly, speakers must be equalized to flat or slightly downward frequency response. Most commercially available speakers have very bright sound (too much treble ) It is easily remedied by turning down treble control on your amplifier. But, if you use a receiver which does not support treble adjustment (sometimes there are presets without individual controls), you can attach pieces of foam in front of your speakers. One way to do it would be by increasing length of grill's legs.

Now, when speakers don't have that annoying boosted treble, we need to place them for a best possible sound reproduction. Usually people adjust their speakers for their listening position "sweet spot". But then they can't share their music enjoyment with anyone else. Person sitting next to a person in a "sweet spot" won't have the same listening experience.

The solution for this narrow "sweet spot" problem is to physically separate both speakers.Another problem is how to make it aesthetically acceptable. I think, placing big piece of thick glass between speakers is a good idea, if one can afford such a large piece of glass. Another solution would be a piece of big furniture between speakers.

For computer speakers best placement would be on sides of the table, provided that table has enclosed sides. I personally used this setup for a long time, it creates very three dimensional sound on some recordings.

If you have fancy designer's table with open sides, speakers can be left on a table, separated by a piece of board.

That's it. Key to a great spacious sound is normalization of treble and physical separation of stereo channels. Of course, speakers themselves also matter. 2in computer multimedia speakers probably won't sound good no matter what you do. Something with larger radiating surface is needed.
And you will need multiple sub-woofers. It's very difficult to achieve good bass with only one subwoofer.
I know that many people will object to my proposed layout. But, I have tried it and it works for me an it costs almost nothing, except if you decide to use that fancy piece of glass.

4 way speakers

I was working on this project during last summer. It was an experiment, where I tried to make a speaker with very simple crossover. Lower frequencies were filtered out with capacitors and higher frequencies were filtered with foam of varied thickness. The benefits of this design are low cost(no expensive inductors) and flat impedance (easy load for an amplifier).
This speaker still needs a separate powered subwoofer, because lower woofer is in bandpass enclosure and it's frequency response drops sharply at around 100hz.
I don't have photos of finished speakers yet.

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Car Audio

I've been playing with different car audio setups for a few years. Here is where I am at now.
For tweeters I use modified  Aurasound NSW2 drivers (cone is slit and coated with damping spray and rear chamber is staffed with foam)  attached to small horns. they cover ~1khz-15khz
For midbass I use modified Dayton Audio PA165-8.
Subwoofer is 15in driver from diycable.com (very nice sub)

Foam acts as lowpass filter and provides smooth high frequencies roll off.

I use a single inductor for woofer's crossover. if you use metal drivers, notch filter has to be implemented, foam won't filter out metallic resonances.

This is frequency response(red) at driver's sitting position. It looks like high frequencies are recessed too much, in reality tonal balance is just right.

nearfield measurements of woofer and tweeter (system is playing pink noise)

frequency response on tweeter axis, mic is 8in away

So, my conclusion is that car system needs to be calibrated on tweeter axis, no matter where tweeter is installed. If I tried to achieve flat frequency response at drivers position, sound would be very bright and unnatural.

Of course there are still some problems in my install, particularly that hump at ~300hz

boombox, ghetto blaster

Here is my new project with drivers mentioned in previous post.
I used amp6 for woofers and t-amp for tweeters. Crossovers are passive (I didn't have time to design and build active ones). Crossover point is at around 1khz. Woofers' 7khz resonance is about 30db down, which is apparently not low enough, because at high volume sound becomes "crisp" It should be tested with higher power amp, because that sound could be caused by clipping amplifier. Anyway, it plays loud and sounds quite good for a boombox.
For power supply I use 10 rechargeable AA batteries.

Sunflower is not part of the boombox, it's just sitting behind.
Back of the boombox looks exactly the same as front(tweeter and two woofers)
Calculated frequency response.

Update, August 2013
I've tried to listen to this speaker through my UCD180 amplifier for a few days.
And I came to conclusion that notch filter must be used with metal woofers.
That spike you see around 7khz, 35db down is a big problem. It is not immediately apparent, but over time it develops into an unpleasant listening experience. If you are building speakers with metal drivers based on someone else's designs, I suggest you choose only those crossovers  that use notch filters.

aluminum woofers' cone treatment experiment

These modifications were done a few years ago. I'm just reusing these dayton DA175-8 woofers for a new boombox project. Cones were slit an covered with automotive damping spray. Small copper caps are glued on top of pole pieces.

Blue line in the graph below shows modified woofer's FR, measured on axis(in box).

Yellow line is FR measured with thick foam placed in front of the woofer.

Manufacturers' supplied FR

I was doing these modifications to reduce resonance above 5khz. As you can see resonance is still there. Unfortunately aluminum cones do not benefit from this kind of modifications.

Neo8 planar transducer in a waveguide

I just found photos of my unfinished project. Neo8 in a waveguide.
Animated  .gif picture illustrates effect of an acoustic filter (foam).
I don't remember FR's measuring distance.



At this time I don't have facilities to construct any real loudspeakers, so I'm just sketching some designs.

It's a fun party loudspeaker, with cupholders ), built-in amp, horns, 6.5" mids and 15" sub on the bottom.
"Party buddy"

Big 2 way DIY loudspeakers with waveguide

This project went from simple testing of vifa xt25 tweeter in 12in parts-express waveguide to finished loudspeaker.
I think most pictures here are self explanatory. One thing to note, this peerless SLS 830669 in it's stock form will not sound good with this crossover. It's cone starts to resonate around 700hz, and it is very audible. Cone treatments that I've applied, significantly reduced this resonance and it's audibility.

Dust caps are removed, top layer (polypropylene?) peeled from cones. Then cones are slit and coated with damping spray. Copper ring (from home depot plumbing supply) glued onto pole piece.

Red impedance curve is before and green curve is after cone treatments.

Preliminary crossover

Speaker is converted from open baffle to sealed. 12in cardboard tube ( for concrete) was glued to the baffle.

Final crossover.

I use these speakers for home theater. They can play loud with great speech intelligibility.

Until recently my main home speakers were ones with scanspeak drivers,

documented below. In process of moving I packed scanspeaks and carried out 

of the basement these speakers and placed them in place of scanspeaks.

Connected them to my favorite HarmanKardon amplifier and was surprised with much

improved dynamics over scanspeaks. Unfortunately I have to part with these speakers due to their size. In terms of sound quality, these may be the best speakers I've built, although I have not compared them directly to my 3 ways.

 

3 way loudspeakers

These are my first 3way speakers. They went through several crossover iterations, the chosen crossover sounds best, obviously :)
Parts used:
0.75 parts-express cabinet (sealed),
tweeter - Usher 9930-20
mid - CSS FR125(early model)
woofer - seas H511







Rear chamber for mid driver is made out several layers of duct tape.











Final crossover, and calculated frequency response.