I was connecting some speakers at a gig last weekend which consisted of an 8 Ohm passive sub and then a cable from there to a 4 Ohm 'wide-range' speaker which sits on top (same both sides).
Can somebody confirm that the in/out connections on the speakers are just in parallel and that I've actually given the power amp a load of somewhere under 3 Ohms? I've assumed that there is not usually a cross-over and that this function is just a result of the relative speaker characteristics. Is this right?
The regular guys in the band are very much 'if the plug fits it's fine' so I didn't like to ask!
Comments
A sub only reproduces the lowest frequencies and some kind of filter is required. A passive crossover at low frequencies requires a lot of copper windings and will be heavy if it's mounted inside the cabinet. If not you fed full range to both boxes and would have got mush out of it in a very inefficient manner.
If I was running this rig I would use an active crossover (or DSP) before the amp and have one half of the stereo power amp driving both top cabs in parallel and the other half driving one sub on it's own giving a 4 Ohm load or both of them in series to give an 8 Ohm load to the amp.
That way the amp would be way more efficient and the cabs would also not be producing wasted effort trying to reproduce frequencies they cant.
It would be interesting to know the make/model of the gear you are using.
You should be able to test it without taking it apart - if you plug the amp into the 'output' jack, if there is a crossover you will get no (or very little) sound from the speaker, because it would have to be going first through the high-pass filter (backwards, but it makes no difference) and then through the low-pass filter to reach the speaker.
If you get a good strong sound then the input and output are in parallel, even if there's still a low-pass filter before the driver.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
Could be in parallel though and could be less than 3 Ohms or so .... as low as that is some amps are happy down to 2.5 Ohms. I've seen an old H&H 500D amp drive four bins and 2 tops without complaint for 200 gigs or so
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein