Efficient 2 way - HP-10W & KSN1165a - thoughts?

[natumbri]

Hi,

I'm in the process of building a set of speakers. The idea was that they should be loud, but not too large and not cost much.

I've settled on p.Audio HP-10Ws (http://www.cannononline.info/pdf/HP-10W.pdf) for the woofers and KSN1165a (http://www.piezosource.com/general/d..._datasheet.pdf) for the tweeters.

I'm thinking to attenuate the tweeters slightly and roll the woofers off at around 2200hz (or possibly lower). I've made a little spreadsheet to help me work with the speakers - attached. It is interesting to play around with the values (in the yellow boxes) and see the frequency response of the system change. I'd be interested to hear what people think would sound best...

I'm not sure if I've calculated the impedance of the tweeter correctly - the values seem a little crazy, but perhaps that is how they are supposed to be for piezo speakers? If there are any errors - typo or conceptual - in the spreadsheet, I'd be interested to hear about it!

At this stage, I'm thinking a ~26l sealed enclosure but have not settled on that. Smaller would suit me better, but I'm worried about the bass. Size is the reason I'm not (at this stage) thinking about a ported enclosure.

If I did use a sealed enclosure, I might investigate using a Linkwitz Transform (a la Linkwitz Transform Subwoofer Equaliser) to improve the bottom end - anyone have any thoughts/suggestions on that front? I'd be particularly interested in hearing how low to go...

Cheers,
Nik

[gfiandy]

Hi, I had a look at your spread sheet. Whilst this can give you a bit of a guide to what might happen. It cannot simulate the relative pahse of the two signals. If the phas is wrong they will cancel through the crossover region.

You may be able to get a better simulation if you use the FRD tools to simulate the effects of the box. Then transfer the modified responses into speaker workshop and run the simulation in that as it will take into account the phase response.

The tutorial here:-

FRD Consortium tools guide

describes how to do this.

Regards,
Andrew

[gfiandy]

On the use of a linkwitz transform. I think the effect on the rest of the frequency range of passing through this filter might be quite detrimental. However I only have agut feeling about this as I have only ever used them in sub woofers where they have worked well.

Regards,
Andrew