Q: Hi there, I'm writing you from Venezuela and I have two very simple questions, but I haven't been able to get an answer yet. I own a 1998 Hyundai Sonata equipped with the following: Nakamichi CD45 head unit, Planet Audio PA1002 and PA4003 amps, Planet Audio PEQ-15 preamp/EQ, Planet Audio P4250X front speakers (dash), Kenwood Excelon KFC-X716 rear speakers and Jensen KS212 sub (connected in parallel).
I'm running the rear speakers with the PA1002 and I'd like to know if I could also run a set of Planet Audio P62CK components (located in the front doors) connected in parallel (resulting in a 2-ohm load I believe) off the same amp. The second question is regarding a power capacitor. The stock alternator in the Sonata is rated at 90 amps and I wonder if it would be possible to add a capacitor without having to replace the alternator.Thanks for your time and excuse my English.Jonathan
A: Connecting a second set of speakers to an amplifier is generally not a big problem. Most amplifiers built since the mid '90s can handle a 2-ohm load, since the demand on the amplifier isn't as large as it would be with a set of subs. The key is to make sure that your rear and front speakers are both somewhat similar. It's no big deal if you connect 6x9 speakers in the back and 6-inchers in the front, as long as they are all fullrange, rather than subs or midbass drivers. Another aspect to consider is the nominal impedance.
For instance, connecting a set of 8-ohm rear speakers with a set of 4-ohm front speakers would result in the front speakers drawing more power from the amplifier than the rears. This might cause a balance problem in what you hear, even though your combined load is over 2.6 ohms. The amp would like the higher impedance better, but the sonic imbalance would remain. The reverse is also worth considering: If you had rear speakers that are larger and had a lower impedance than the front speakers, the bigger rear speakers would draw more power and produce slightly more output which could improve front to back balance. This is a good way to naturally balance a four-speaker system using a single amplifier without fading capability.
As for the capacitor, the alternator isn't really a factor. The capacitor will only help your situation, since it will store energy that can be quickly accessed by your audio gear. This is especially true in less-expensive compact cars where the charging system is fairly lightweight. Other vehicle functions will also be able to access the additional power storage unless you're using an isolator to prevent the current from flowing back to the car's accessories.
The only reason why you'd want to upgrade to a different alternator is when your alternator cannot keep up to your audio system and you find that your battery either keeps going dead or the charge indicator is making you feel uncomfortable.
By the way, your English is great!
Q: I have two Rockford Fosgate 10's - an 8 ohm and a 4 ohm. I have one of the very first black Punch 40's pushing them. I have them hooked to the amp in parallel wiring. I already replaced the 4-ohm speaker before because it blew. Does this really matter that I have two speakers that are two different ohms, and should I just buy another 4-ohm speaker? I'd appreciate any information that you can give.Thanks!
A: You have one of the most classic amplifiers out there! I still remember the white Teflon power wire that the first Punch amplifiers used. And how you needed to install them with rubber grommets to keep the amplifier's chassis from contacting metal and causing noise. Oh, the memories
As I mentioned in Jonathan's question, using two different speaker loads will cause the power to divide unevenly. Since your speakers are from the same manufacturer and the same size, let's assume they're identical with just the different voice coil impedance. If that were true, the 4-ohm speaker would draw twice the power compared to the 8-ohm speaker. With your power now divided in a 21/43 to 11/43 ratio, the 4-ohm speaker would be trying to convert the extra power into around a 3dB increase in sound pressure (not counting the increase due to the doubled speaker cone area). This doesn't factor in the moments when first generation revolutionary amplifiers freak out and attack speakers (some refer to this as "the amp went DC.")
As a result, your 4-ohm sub will get hotter than the 8 ohm and will try to move farther in "excursion." You didn't mention if the speaker blew by frying the voice coil or shredding the piston components, but the result is the same. On an old Punch 40, I'd prefer to run a pair of 8-ohm speakers to keep the amplifier in its stable range.
That reminds me, I have an ancient red Orion HCCA that sounds sweet. While I was looking for photos of your amplifier on www.ampguts.realmofexcursion.com, I checked out my Orion. I was also able to see my old Blade VTH100 tube amplifier. I should put it into a legacy system for old times sake.