[SteveEvans]

I've just got my Match PP 82DSP installed and an initial tune done using guessed crossover frequencies, and I have to say I'm very impressed, but I'm wondering what the "correct" approach is to setting up the crossover frequencies.

I'm using a fully active setup, with no passive crossovers, so everything is adjustable. Subs, mids (front and rear) and tweeters are all driven directly from the amp.

One option is to mute all speakers bar the woofers, set their low-pass crossover to a higher frequency than anticipated, and measure the response using the ATF tool's spectrum analyser. Then repeat with all but the midrange muted, and with their high-pass cross over set to a lower frequency. If I do this I'd expect to see some overlap in the speaker responses that would allow me to pick crossover frequencies that are optimal. The above could then be repeated for the mid/tweeter crossover.

Whilst the above seems like an obvious approach it assumes that just because a speaker works at a given frequency, it's a good idea to use it for that frequency. Am I correct in my understanding that speakers may have resonant frequencies near their operating range which must be avoided?

I'm keen to avoid a setup which appears to work, but which is harming any drivers.

Thanks,

Steve

[ctuna]

14 part ytube series on how to set up your helix dsp its a
lot of work.
This is basicly the same method as Helix suggest on there site.

[SteveEvans]

Thanks

Steve

[ctuna]

Also Helix has several revisions of setup software on there site
some of the newer ones are more complete with setup features
than the one displayed in the videos.

If you can find a user group they might share some settings with
you. But most people that buy the plug and play kits don't do active.

Also since this is a long process you may want to do something
to ensure you don't drain your battery flat . Like a charger or battery
tender attached.

[kaigoss69]

Don't use the measured frequency response, use the published resonance frequencies of the drivers as a guide.

For tweeters, if Fs is x, then cross over at 2x or higher.
For midranges, if Fs is x, then cross over x or higher.
For subwoofers, Fs is more or less irrelevant.
The slopes will have an impact on how low the drivers will play, and the lower the slopes, the farther away from Fs you should move the x-over points.

There are more considerations than this, but its a rough rule of thumb. Often the manufacturer will publish recommended crossover points, and slopes.

[SteveEvans]

Originally Posted by ctuna

Also Helix has several revisions of setup software on there site
some of the newer ones are more complete with setup features
than the one displayed in the videos.

I'm using the latest, and the principle of where to stick the crossover is much the same.

If you can find a user group they might share some settings with
you. But most people that buy the plug and play kits don't do active.

I figured the amp was capable of so much more than it's plug and play configuration. So far I'm very impressed and I've yet to upgrade the speakers.

Also since this is a long process you may want to do something
to ensure you don't drain your battery flat . Like a charger or battery
tender attached.

Yup, attached a charger and turned off the DRLs.

Steve

[SteveEvans]

Originally Posted by kaigoss69

Don't use the measured frequency response, use the published resonance frequencies of the drivers as a guide.

For tweeters, if Fs is x, then cross over at 2x or higher.
For midranges, if Fs is x, then cross over x or higher.
For subwoofers, Fs is more or less irrelevant.
The slopes will have an impact on how low the drivers will play, and the lower the slopes, the farther away from Fs you should move the x-over points.

There are more considerations than this, but its a rough rule of thumb. Often the manufacturer will publish recommended crossover points, and slopes.

I plan installing Focal ES100Ks in the doors and IFBMW-SUBs for which such numbers are published. This was more a question of how to handle the existing base speakers.

Steve