how to proceed

[arlis_1957@yahoo.com]

i kinda like the way the fr is heading but, the impedence is pretty scary. the mid is the rs150-4. perhaps i should get the 8ohm version.
what say you?

[mzisserson]

For most things solid state, it should be fine. The phase is well behaved. Though looks like it hovers around 3 ohms quite a bit. May want to try the 8...

[rpb]

How much are you padding the mid? Are you using a resistor in series, and one in parallel? Maybe you can delete or increase the one in parallel, and increase the size of the one in series by about 4 ohms.

[arlis_1957@yahoo.com]

it took so much to pad them both, that i had to pad the woofer as well. this weekend, i'll try wiring the woofers in series and remeasure. buying the 8ohm version is an option though.

[Sidi]

You really shouldn't attempt to attenuate the woofers... ever...

just my opinion though.

[arlis_1957@yahoo.com]

i agree. hence the reason for my post. i am far from being an expert and thought there my be some circuit that might help here.
by the way, for the intention of exporting for crossover design, how much smoothing should/can be applied to the fr measuremints?

[johnnyrichards]

i agree. hence the reason for my post. i am far from being an expert and thought there my be some circuit that might help here.
by the way, for the intention of exporting for crossover design, how much smoothing should/can be applied to the fr measuremints?

I export 1/24th for modeling, they are still kind of smooth with gating. I show off in 1/6th octave

Other than maybe doing a 3.5 way or something, that may help I dunno. Steeper slopes, maybe?

[mdocod]

Hello arlis,

Post a schematic of the x-over components/values, and your individual driver responses and driver data if possible. Padding the woofer sounds to me like a band-aid to some other issue going on. 4ohm mids and tweeters can often be implemented to produce an effective "8ohm" style load after BSC...

Regards,
Eric

[rpb]

it took so much to pad them both, that i had to pad the woofer as well. this weekend, i'll try wiring the woofers in series and remeasure. buying the 8ohm version is an option though.

There's no reason to pad the woofer. The mid is louder. The woofer probably needs a coil of about 4 mH or more, and a cap to ground. Maybe 30 uf or so. That should reduce it's midrange. A 4 ohm resistor in series with the mid will reduce its output some, but probably not enough. Maybe 6 ohms, with a 12 ohm to ground. Just guessing really.

[arlis_1957@yahoo.com]

took the speaker across the hall to the quiet room and remeasured. i think this is looking much better. here is a shot of my raw fr as well.

this is with 14 parts btw.

[JasonP]

Impedance looks a LOT better, good job! How do they sound like that? I'd think that looking at the response they might sound distant or removed, with the big room gain at the bottom and the rising top end, but I dunno. Though regardless this is a major step forward. Also, it must be nice to use the 150 so low that you don't need to worry about its breakup modes much... I keep pushing that little punk higher and higher lately but its a challenge.

[arlis_1957@yahoo.com]

this where i am now with pcd. i twisted and clipped together the crossovers this morning and im getting there. waiting to measure the next iteration.

[arlis_1957@yahoo.com]

well, here we are.






thats the good news.

heres the bad.



how to proceed?

[ryanbouma]

Maybe smaller caps and bigger inductors on the M/T. Especially the tweeter

[JasonP]

I wouldn't worry too much about the 100-200 dip in impedance, I have that in my Bento design and my 4 ohm capable amp seems perfectly fine with that (meaning the drop just below 3 ohms). However that dip between the RS150 and RS28A is fugly.

What blows my mind is that you have a series resister on both and its still so low. I'd look to see if 4th order electrical will be better, since I'd wager that 33 uf cap and .12 mh coil (OH MY GOD MAN) on the RS28 is a killer.

[cjd]

Egads. The Khanspire uses a pair of 8ohm RS150's wired in series and still needed padding...

That said, I think that the mid-tweet integration can be more benign on the impedance side and still get the breakup way out of range. Keep at it.

C

[arlis_1957@yahoo.com]

i will keep trying.

[arlis_1957@yahoo.com]

this is looking nice but.............with 9ohms on the mid i think i'll pick up a couple of 8ohm to replace the rs150-4. the 5ohm before the crossover got very hot! can you say 'fire in the hole'?
crossovers are around 400 and 1500. is this distortion proof that i have the breakup taken care of? it was done at 80dbspl

[JasonP]

Right, I assume you are talking about on the mid, and that will handle some power. I was just thinking about that since I needed a 3 ohm padding resistor on the mid for my Wavefront. I decided on two 25W erse 6 ohm resistors in parallel, figure 50W of handling should work nicely.

[ryanbouma]

What woofer is this. Surprised you need that much padding.