Time to go active.

[DejaWiz]

I'm doing it. Finally. Just bought a brand new Coustic XM6 crossover for my SPX-177R's.

My question is this: Does anyone have any knowledge of how low the ring radiator tweeters will respond down to? I'm thinking of crossing them over at about 2600 Hz and then running the mids band-pass 75 Hz to between 2500-3100 Hz.

Power is from an Infinity 7541a... 100W to each mid and 65W to each tweeter.

Anyone have any advice for a good starting point before I really tinker with the xover points?

[azbass]

hmm 2600 seems kinda high. well for me, i like my tweet tooplay way lower.

[DejaWiz]

Ya know, it's funny you mentioned that. The X's have all those jumpers in the passive xover's and the xover points can range anywhere from 2200-3800 Hz.

I figured I'd start with one of the median frequencies that can be set with the passives, but I'm open to any and all suggestions.

[genxx]

Depending on the tweeter but I think most are running tweeter between 2200 or 2400 for active. However some tweeter do not like to play this low. Is this a 2 way or 3 way set-up. If 3 way it would depend how high your midrange will play. If 2 way depends on if your mid woofer will play that high and still keeps its response intact. I will see if I can find some numbers to give you an idea of what other are doing and what seems to be the general rule of thumb. Problem we are running different set-ups. I do not personally know the Alpine and what is best for it, I wish I did and could help you out more.

[Latina33]

Deja, I went active a couple of weeks ago, and I totally dig it! I'm running 75X4 to my Crystal SSCS6's, and they sound awesome....actually clearer and more detailed than they seemed to when they were being run passive.

I was able to switch my Alpine 7998 to 3 way mode to be able control the crossover and time alignment settings from the HU, and so far, it's been GREAT!

Good luck with the tuning!

[DejaWiz]

Thanks for the vote of confidence in my decision, Latina33.

genxx - the SPX-177R is a 2 way component set. Mids are 6.5in and ring radiator tweets are 1in. Appreciate the initiative to help me out.

Here's what is listed in the SPX OM for the mids and tweets:

MIDS:
Power Handling (RMS) - 40W
Freq Resp (-10dB) - 25-8kHz

TWEETS:
Power Handling (RMS) - 25W
Freq Resp (-10dB) - 600-60kHz yeah I can hear that high


Does this help anyone out in giving me some advice or ideas?

Again, thanks.

[alphakenny1]

simply put, your mids won't play that low or high and same goes with the mids. my guess is somewhere between 80-3000 for mids and 2000-4000 and up for tweets. go out and experiment. usually with a 6.5 mid though 80hz @ 12db/oct is a good starting place.

[DejaWiz]

simply put, your mids won't play that low or high and same goes with the mids. my guess is somewhere between 80-3000 for mids and 2000-4000 and up for tweets. go out and experiment. usually with a 6.5 mid though 80hz @ 12db/oct is a good starting place.

Yeah, I know... crazy what a manufacturer will put on paper. Thank you for the advice.

I was thinking of starting with bandpassing the mids 75 to 3100 Hz and HP the tweets somewhere around 2200 to 2600Hz.

Sub will be LP'd at 80 Hz.

Hmmm, maybe I will set the BP for the mids to 75-3000 Hz and HP the tweets at 2000 Hz to start with then.

The XM6 has 18dB/Oct HP (channels 1-2) and BP (channels 3-4) as well as 36dB/Oct LP (channels 5-6). Since it's a little steeper roll-off than 12dB/Oct, I was thinking that a LP 80 Hz for the sub and a BP starting at 75 Hz for the mids might blend a bit better. Thoughts?

[krisfnbz]

Im Subscribed! I plan on going active later on in the future.

[helotaxi]

The lower you go on the x-over freq, the less power the tweet will be able to handle. It's not a thermal issue it's an excursion (or rather lack of excursion) issue. Also note that the freq ranges listed are the -10dB points. Hardly near usable output 10dB down.

Final thing the top of the midrange low-pass on the XM-6 is 3khz.

[DejaWiz]

The lower you go on the x-over freq, the less power the tweet will be able to handle. It's not a thermal issue it's an excursion (or rather lack of excursion) issue. Also note that the freq ranges listed are the -10dB points. Hardly near usable output 10dB down.

Final thing the top of the midrange low-pass on the XM-6 is 3khz.

Ah yeah, good point. So 3kHz it will be set at then.

[Tempe]

Yeah that's why I did NOT buy that crossover. 3khz is pushing it if you go with small format tweeters. Here are some reviews and crossover point suggestions for this tweeter:

http://www.diymobileaudio.com/forum/...ad.php?t=10458 (XT25)
http://www.diymobileaudio.com/forum/...ead.php?t=1484 (XT25 and XT19)
http://www.diymobileaudio.com/forum/...ead.php?t=7774 (XT19 boner thread)
http://www.diymobileaudio.com/forum/...ead.php?t=8053 (XT19)
http://www.diymobileaudio.com/forum/...ead.php?t=7256 (XT19 - extensive review halfway down page 1)

T

[helotaxi]

You can go a lot higher (8kHz) on the tweet HPF, just not on the mid LPF.

[Tempe]

But what's the point of stopping at 3khz on the mid if the tweet can be crossed over as high as 8khz??? To me I see that as an idiotic design. The mid HPF should match the sub LPF range, and the tweet HPF should match the mid LPF range IMHO

Usually you leave a gap or sometimes overlap, but the points should be relatively close to each other!

T

[genxx]

Dejawiz-With the the 2 way you are going to have some gaps in freq response. Try to get as much of the freq. range covered as you can and them still sound really good, the way you like them. Unless you have an RTA to know exactly where the gap is or have a great ear(some people do) it will be hard to know exactly where the gap is to fix it. With a good 3 way up front it opens up many more options. You can add mid later, so just get it sounding good the way you like it.

If I was guessing I would say alphakenny1 is pretty **** close in his numbers and might have nailed it for you. Don't know what to tell you about the x-over looks like you stuck kinda on that one with what you got available.