Crossover question

[Bruce Weldy]

Bill, in checking the plans of the DR280 to get some other info, I noticed that the 2k crossover option for the CD is a 4th order filter. But, the 1.2k option is a 3rd order filter at a slope of 18db/octave.

Wouldn't a 4th order filter give better protection, especially with the NSD2005 being replaced by the F151? Or, is the type of filter different creating a different slope? I don't know enough about it to do anything other than ask.

[Bill Fitzmaurice]

I went 4th order with the 2kHz because the driver quality wasn't as high.

[Bruce Weldy]

With the F151 looking a little less robust than the NSD2005, would it be worth going 4th order when using it? Or, is it tough enough to stick with the old crossover?

[Bill Fitzmaurice]

I haven't had any reports of failure. Also note that the F151M has higher sensitivity than the ASD 1001, so it doesn't need as much power, another reason why it can get away with a 3rd order high pass.

[Bruce Weldy]

I haven't had any reports of failure. Also note that the F151M has higher sensitivity than the ASD 1001, so it doesn't need as much power, another reason why it can get away with a 3rd order high pass.

My only concern was the published crossover suggestion by Eminence. I know they are supposing a 12db slope, so your crossover will go lower safely, but the NSD had a lower usable frequency than the F151.

Hey, if it's working, it's working. Just something that has stuck in my mind ever since the NSD went away. I still have a couple of the NSDs and some diaphragms in stock.....so, it won't be something I'll have to deal with for a while. ......maybe I need to build something else....

hmmm.... I've considered an SLA sans piezos with an NSD in a plastic horn on top - using the OT12 crossover network....Or, just use one of the Dayton amps like I have in my other SLA to handle the crossover duties.

What the heck am I thinking......I already have more speakers than I use.....there's just something about making sawdust.

[Bill Fitzmaurice]

The low frequency limit is determined by the Fs. At 1kHz Fs the F151 is OK at 1.2kHz. I could have gone lower with the NSD but didn't for two reasons. One was to allow more driver choices, the other being none of the speakers needed lower than 1.2kHz.

[Bruce Weldy]

The low frequency limit is determined by the Fs. At 1kHz Fs the F151 is OK at 1.2kHz. I could have gone lower with the NSD but didn't for two reasons. One was to allow more driver choices, the other being none of the speakers needed lower than 1.2kHz.

Thanks for the explanation.....

[Keryn O'Shea]

......maybe I need to build something else....What the heck am I thinking......I already have more speakers than I use.....there's just something about making sawdust.

It's a relief that you have these conversations with yourself also Bruce

[Bruce Weldy]

......maybe I need to build something else....What the heck am I thinking......I already have more speakers than I use.....there's just something about making sawdust.

It's a relief that you have these conversations with yourself also Bruce

I have found that I'm a good listener.......to me.