Load from a crossover unit with 2 speakers?

[PaulKing]

Any amp/electronic experts able to answer me this?

I use a Markbass CMD121P combo. I just replaced the internal piezo-tweeter with a better mini-horn. Is there any risk to my amp from this? I don't understand how cross-overs affect the loading on the amp.

The original piezo tweeter was connected to a crossover unit in the combo.
The main combo speaker is 8ohms, meaning I could run an extension cab at another 8ohms, putting a combined load of 4ohms on the amp. The piezo tweeter running from the crossover didn't seem to affect the loading.

BUT, the new tweeter I have fitted (connected in the same way to the crossover) is a proper magnetic speaker, rated 8ohms.

How do I calculate the load on my amp now...? Do the two 8ohm speakers separated by a crossover combine to a load of 4ohms ... meaning I can't run my ext cab? Or does the crosover unit with two 8ohm speakers still represent just a single 8ohm load?

[Bill Fitzmaurice]

[quote name='PaulKing' timestamp='1370783106' post='2105436']
Any amp/electronic experts able to answer me this?

I use a Markbass CMD121P combo. I just replaced the internal piezo-tweeter with a better mini-horn. Is there any risk to my amp from this?
[/quote]There is, as piezos generally do not use crossovers, and when they do they do not have the same topology as those used by dynamic drivers. You can't just swap a dynamic tweeter for a piezo, and the crossover for a dynamic tweeter must be specifically configured for it. You're running the risk of blowing the tweeter and possibly the amp as well.

[PaulKing]

Thanks for that, right, treading carefully til I get some answers from Markbass on this.
Cheers