Can I start by saying I am not an electronic engineer, I'm a musician? I have managed in the last 20 years to put together various PA systems and instrument amps and cabinets without blowing myself up, due to my rudimentary knowledge of Watts and Ohms. I can also spot a black, frazzled resistor when I see one, and solder in a new one. That's about as far as my knowledge goes, hence my question.
I am building a new speaker cabinet for my double bass. So far I have two 10" 200W 8Ω cones, and I want to wire them up in parallel to give me a 400W 4Ω cabinet. My amplifier puts out 350W at 4Ω, but the performance is frankly a bit rubbish with an 8Ω cabinet. So I want to keep my cabinet as close to 4Ω as possible.
I would quite like to add some sort of tweeter to the system. The performance of the cones rolls off quite sharply at 2kHz, and I would like to make the sound just a little bit more lively than that. I looked at high-impedance peizo horn tweeters, which do not require a crossover, but I have been told they can be problematic in a high-powered rig like this, and they don't really kick in until 4-5kHz, so there would be a big hole in the middle of the sound.
So I started looking at low impedance compression drivers instead. I found a couple that had a good range, they kick in at about 1.7-2kHz, they are 8Ω (so I could use two to give me a 4Ω load if necessary). I heard good reports of their performance, but I would need a passive 2-way crossover. Now, here's where my ignorance of electronics kicks in.
Almost all of the crossovers I have looked at are quoted at 8Ω nominal impedance, but I want a 4Ω cabinet. So my questions are:
I would appreciate your comments on my electronic naïveté. Once you have finished laughing, of course. Thank you.
I am building a new speaker cabinet for my double bass. So far I have two 10" 200W 8Ω cones, and I want to wire them up in parallel to give me a 400W 4Ω cabinet. My amplifier puts out 350W at 4Ω, but the performance is frankly a bit rubbish with an 8Ω cabinet. So I want to keep my cabinet as close to 4Ω as possible.
I would quite like to add some sort of tweeter to the system. The performance of the cones rolls off quite sharply at 2kHz, and I would like to make the sound just a little bit more lively than that. I looked at high-impedance peizo horn tweeters, which do not require a crossover, but I have been told they can be problematic in a high-powered rig like this, and they don't really kick in until 4-5kHz, so there would be a big hole in the middle of the sound.
So I started looking at low impedance compression drivers instead. I found a couple that had a good range, they kick in at about 1.7-2kHz, they are 8Ω (so I could use two to give me a 4Ω load if necessary). I heard good reports of their performance, but I would need a passive 2-way crossover. Now, here's where my ignorance of electronics kicks in.
Almost all of the crossovers I have looked at are quoted at 8Ω nominal impedance, but I want a 4Ω cabinet. So my questions are:
If I put a 4Ω low frequency load and a 4Ω high frequency load onto a crossover, do I get a 4Ω system, or is the crossover itself going to give me an 8Ω load?
My schoolboy physics suggests to me that if I want to run a 400W @ 4Ω load through a crossover which has been quoted at twice that impedance, I need to get a crossover with double that power rating: for 400W @ 4Ω I need an 800W @ 8Ω crossover. Is this anywhere near correct?
Does all this messing around with impedances change the characteristics of the crossover in any way, like the crossover frequencies, or the degree of roll-off?
I would appreciate your comments on my electronic naïveté. Once you have finished laughing, of course. Thank you.