HF crossover below driver specs.

[Jidis]

Hi,

I've been fighting with crossover frequency/type decisions on a small pair of two-ways I built. I've been testing different virtual configs in software and feeding the hi/low drivers separately.

Problem is, the tweeter's frequency specs cut off relatively higher (3k) than many of the settings I seem to like. It's looking like I may end up with some 2nd-order variant there, but filters in the 1k-2.5k range seem to sound the least "scooped" and I'd like a slightly "pronounced" midrange.

Am I endangering my tweeters much more by running below cutoff like that, or is the spec more of a guideline saying their response is just going to be weak below 3k?

-Thanks!

George

PS (FWIW)- They're Pioneer soft poly dome tweeters:
* 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

[Iain McNeill]

You mean the tweeter resonance is at 3KHz, they roll off below that?

Two problems with running tweeters low:
1: have to watch the power level, as you include more of the music spectrum, the tweeter has to do a bigger percentage of the work and can therefore be overloaded (i.e. burn out)
2: distortion rises very fast below resonance. This'll add some grunge/rasp to music peaks.

You really ought to XO above resonance by 0.5 octave for 2nd order but hey, try it. Might get some of that warm tube sound

[Jidis]

Hey Iain,

Yeah, I'm not sure what they really roll off at. I'm just going by the manufacturer's specs of the range they're supposed to handle.

Originally Posted by Iain McNeill

2: distortion rises very fast below resonance. This'll add some grunge/rasp to music peaks.

You really ought to XO above resonance by 0.5 octave for 2nd order but hey, try it. Might get some of that warm tube sound

That's the sort of info I was afraid to hear. I'm already unhappy with my choice on these HF drivers. I think I picked them by recommendation from MCM long ago. Indeed, they do have a somewhat buzzy harshness in that area. The cabinets are already routed out to fit these tweeters, but I planned to do a second pair later and may switch to something else.

They do sound nice and smooth with crossovers up higher, but they also have a bit of that "smiley face" consumer EQ sound to them, and I was trying to tune them for use as reference monitors on a small audio rig here. Slight harshness may not be all that bad for that if the overall response is accurate. I'll also see if there's anything I can do on the woofers to get a boost in that crossover region. That might enable me to get the tweeter up higher without losing so much. The woofers are supposed to make it up to 10k, but they don't sound like it. Maybe the impedance could be flattened some.

BTW- These won't be something I'll be pushing really hard (very close range, and only 4.5" woofers).

Much thanks for the advice!

George