First Speaker, trying to figure out a contour filter

[SState13]

So I've been thinking about building a set of speakers for a while, and I'm thinking that using full range drivers would be a good place to start. After looking around partsexpress and madisound, I'm thinking that the Tang Band W4-1052SD 4" Driver would be a good candidate due to its low end extension, decent sensitivity and low price ($27 per driver).

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=264-828

Specs: Power Handling: 20 watts RMS/40 watts max *VCdia: 1" *Znom: 4 ohms *Re: 3.80 ohms *Frequency range: 60-15,000 Hz *Fs: 63 Hz *SPL: 87 dB 1W/1m *Vas: .26 cu. ft. *Qms: 4.21 *Qes: .54 *Qts: .48 *Xmax: 4 mm

I wanted to use 2 drivers per side, so it would match up to my amplifier output of 40 Watts at 8 ohms and would give me more SPL. The enclosures would either be sealed or vented and tuned low. They would be crossed over to my subwoofer @ around 80Hz with an active crossover.

What I'm having a problem with is finding out how to design a contour filter to attenuate the higher frequencies and to remove a peak at 8kHz. Any help with the filter or driver choice (ideally $40-60 per side) would be great.

 

[mikejennens]

I've been toying with the idea of putting a filter on a full range I have. It would be my first too. Anyway, I don't know if this will help, but I'll share it just the same.

http://www.diyaudioandvideo.com/Calculator/SeriesNotch/Help.aspx

Keep us posted.
Mike

 

[SState13]

Thanks for the link, i will check that out.

Another idea i just thought of was to do sort of a 1.5 way design, leaving one driver full range and putting a high pass (probably 6db/octave) at maybe 4kHz or something, to boost the low end and midrange so it matches better with the increased output in the high end

 

[SState13]

Or i guess even a TL, I recently built a TL subwoofer with great results, but I guess I'm worried about peakiness in the octaves above tuning

 

[ltmon]

I have put my 1052-SD in a MLTL (the TABAQ to be precise, the design of which can be found by searching this forum).

Sound is good, with excellent bass extension for a 4" driver. I previously put them in a mocked up (i.e. thin crappy wood and gaffer tape) bass reflex and then the same in sealed and TABAQ before building the final enclosure. I found the TABAQ much better than the other two.

I don't have measuring equipment, so I can't tell you empirically, but the top end seemed more controlled in the TL rather than less. Not perfect, but better than the other options to my ear.

I have adjusted the filter on the TABAQ a few times and found the one I like the most is simply a textbook baffle step compensation circuit.

 

[SState13]

I will look that up. how much power are you able to run in that enclosure?

 

[ltmon]

I'm just running from a 20Wpc (into 4ohm) chip amp. They are certainly loud enough for me, but I'm not a very loud listener.

The drivers on their own won't take any more than 40W I think.

 

[SState13]

The manufacturer says that 40 watts (music power) is the max, but looking in WinISD, it looks like they wont take much power before exceeding xmax. I was just trying to get a real world idea of how much abuse they can take, since I have 80 watts @ 4 ohms to play with.

the room these are going in won't be all that big, but i would like to be able to reach fairly high volume. I guess I'm a little wary of counting on 1 4" driver to do this, but worst case i could always go back to my old yamaha bookshelves if i need more volume (they were sufficiently loud in a dorm room, but got harsh quickly and never really sounded that good)