|
Bronze Member Username: ThrustPost Number: 72 Registered: Nov-04 | If you have a 6.5" compnent set and they are rated at 75w is it possible to determine how much wattage the tweeter and midbass speaker can handle individually for use with an electronic crossover? Thx '][' |
|
Gold Member Username: GlasswolfNorthWest, Michigan USA Post Number: 6172 Registered: Dec-03 | the electronic crossover will only be a line-level XO used to separate amplifiers. you'll still need the component passive crossovers for the midrange/tweeter sets. |
|
Bronze Member Username: ThrustPost Number: 74 Registered: Nov-04 | Thanks Glasswolf, you da man! Wait a minute! You're saying to use an electronic x-over AND a passive x-over?!? Not all X-overs are created equal, my RF Symmetry has RCA outs, not line-level, which goes to my PPI A204. I'm considering replacing the A204 with an A404, but I don't want to overpower and fry my components. By the name, the A404 would seem to be 40w x 4, but everything I see on the web states it's 50w x 4. With this setup I'd be pushin 40w or 50w to each tweeter and midbass driver. The component set is rated at 75w so I'm not too sure if the A404 would be too much amp for my PPI components. With all that cleared up, I'll ask again- is it possible to determine how much wattage the tweeter and midbass speaker can handle individually? As a side note, PPI has gone way downhill. Their tech support is by far the worst I've ever seen. The manual that came with my DCX 650S components is extremely sub-par and doesn't explain many of the features available with these models. "Tweak until your ears bleed!" |
|
Gold Member Username: GlasswolfNorthWest, Michigan USA Post Number: 6179 Registered: Dec-03 | RCAs are line level.. as opposed to speaker level (high level or powered) by line level I mean unamplified pre-out voltage level signals, like 4V RCA lines from the source. The electronic crossover is mainly used if your amplifiers don't have a crossover built into them, or you want finer control, or everything controlled from one device for XO settings. Generally most modern systems don't have need for a stand alone electronic crossover if the amps all have their own built in, unless your ehad unit doesn't have 3 sets of pre-outs or some other reason for needing a way to split up the source signal before the amplifiers. the crossover module for the component separates is usually designed specifically for that set of speakers, and matched ideally for them based on power, load, Q, and ideal XO points for those specific speakers. The only thing the crossover modules with your separates won't do is function as a HPF for the midrange if you want to cut the bass out of them so they won't bottom out, so the subs can handle all the low end stuff. PPI was a great company, back before PPI, Orion, a/d/s, and others were bought out by DEI. After that they went to crap, I agree. The old Art series amps were their best work by far, much in the same era as Orion's best products. As for the A404, you'd be ok using that to drive the components. as for power split, it's very hard to say since different companies use vastly different setups for both the crossover and their choices in tweeters. generally speaking for a ballpark figure, I'd say about 70/30 or 80/20 split for power between the mid and tweeter respectively in percentage. keep in mind that often the tweeter used in a compoennt set is 8 ohms, so it gets half the power of the midrange right off the bat. That's both to insure the tweeter doesn't get fried, and to keep the tweeter from being way too bright. |
|
Bronze Member Username: ThrustPost Number: 76 Registered: Nov-04 | How do components have a 4 ohm load when both midbass and tweeter are 4 ohms? I even checked with an ohm meter and both are very near 4 ohms. I guess the x-over must do something because it's impossible to series or parallel (2) 4 ohm speakers and end up with a 4 ohm load. PPI contacted me after I sent them a nasty e-mail! HEHE |
|
Gold Member Username: GlasswolfNorthWest, Michigan USA Post Number: 6214 Registered: Dec-03 | if both speakers are reading about 3.6 ohms DC resistance, then they are both 4 ohm speakers. I just said some use 8 ohm tweeters.. not all. remember though, using that crossover, the tweeter and midrange are producing different frequencies, and load only drops with speakers in parallel when the speakers are similar, and producing the same frequencies at the same time. In the case of separates, it's still just a 4 ohm load. What'd PPI say? |
|
Gold Member Username: Jonathan_fGA USA Post Number: 2707 Registered: May-04 | Active crossovers have their benefits, but you HAVE to consider the drivers you're using before you think about using an active crossover. They work best with drivers that have a very smooth impedance curve(most manufacturers won't even show you the impedance curve) and you have to choose your crossover points and slopes carefully. Passive crossovers are essentially the same as active crossovers as far as the actual crossover points and slopes go, it's all capacitors and inductors. But, a good passive crossover uses things such as Zobel impedance correction, sometimes resistors for certain drivers to balance out the sound, and tweeter protection and other options. As far as your question on power, when a component system says that it can handle 75W RMS, it means every driver and the crossover can thermally handle that much power. If you had a 4 ohm mid and a 4 ohm tweeter and powered it with a 75W RMS amp, both the mid and the tweeter would get 75W RMS because the crossover keeps the drivers pretty much independant of one another. If you had a 4 ohm mid and an 8 ohm tweeter, the amp would put 75 watts into the mid and roughly 37.5W into the tweeter (in reality it'll most likely be a little more). All the amp is seeing is a total impedance in the form of both the drivers and the crossover. Drivers are a reactive load, not resistive, meaning they have different impedances at different frequencies, and the impedance changes with temperature and other variables. In other words, the effect is that the amp sees a single driver that has different impedances based on frequency. It'll put out its rated power into any frequency, regardless of if it's a tweeter or a mid. The fact that you're limiting the amp to only certain frequency ranges will give it more headroom and essentially a little more power than it could normally provide, which is a benefit of active crossovers. In your situation, I'd put around 50-75W to each driver. It doesn't really hurt to have more power than you need as long as you're smart about it. |
|
Bronze Member Username: ThrustPost Number: 77 Registered: Nov-04 | Thanks guys preshadit! I've got all components in the car now, making sure it all works as it should and so far A.O.K. Got my Orion HCCA225 back and am wondering if I should use it instead of my Earthquake (520w x2 @ 2 ohms rms). What do you think? Think I'd be happy with 400w to subs running HCCA @ 1 ohm mono? Does competing affect that opinion? I'm definitely going to hook it up and listen to it myself this weekend. http://www.geocities.com/bigt_here/thrustsystem.jpg (I plan to take lots of pics to post to the site. Sound deadening this weekend!) Prelimenary testing so far seem like it's "too trebley". Is 4 tweeters too much? I already tried just hooking up 2 but I wasn't as happy with staging/imaging without all 4. Is running them @ 8 ohms bad? Just seems wrong to me but it would be less wattage? Or can I just EQ all the "bad" freq's out? Can't wait to start tweakin"! Funny you should ask about PPI Glasswolf, the "spec sheet" he sent me had all wrong data, was no help whatsoever, and only added to the confusion. My response back was kinda lengthy so I didn't include it in this post. From: ']['HRUS'][' Sent: Thursday, December 09, 2004 11:01 PM To: Audio Techs; John (last name removed) Subject: Thanks John Well I just got a confirmation for the e-mail I sent to Directed tech help yesterday. The confirmation I requested that was sent back to me said : "deleted without being read" and "Final-Recipient: RFC822; REMOVED@directed.com" A big ole middle finger goes out to John (last name removed). I don't know you but I don't think I like your idea of "tech help". Is that what you call it? And you get paid for this? To delete e-mails you've never read? I want your job! boo! '][' From: John (last name removed) To: ]['HRUS'][ Sent: Friday, December 10, 2004 10:12 AM Subject: RE: Thanks John Dear Sir, I would like to offer my apologies for the loss of your e-mail and the impression you were left with on the lack of support from myself and our department. I would like to let you know that yesterday our company was having difficulties with our internet service and most emails that were sent yesterday were sporadic at best, I know that this is no excuse but wanted you to know the facts first. I received your initial inquiry and your responding email at the same time. Here is the information that you requested. I can only hope that it might help answer some of your questions, and again I apologize for the technical issue that resulted in your frustration. Sincerely, John |
|
Gold Member Username: GlasswolfNorthWest, Michigan USA Post Number: 6243 Registered: Dec-03 | " What do you think? Think I'd be happy with 400w to subs running HCCA @ 1 ohm mono? Does competing affect that opinion? I'm definitely going to hook it up and listen to it myself this weekend." The 225HCCA is a great amp for subs, and in competition events, it keeps you in a lower power class, which is it's big benefit. It'll run very hot at 1 ohm, but it's designed to do that. Also for competing, remember the 225HCCA is a class AB amp, not class D. This is another advantage as long as you can handle the current supply demands. Class D amplifiers spike in distortion at or near their peak output, which is why so many competitors shred so many subs at SPL events. They push amps to their limits, and into distortion peaks. This destroys subs in a matter of moments. The class AB amp doesn't sufer this downfall, so the subs are going to survive SPL events much longer on the 225HCCA then they would on a class D mono amp. Is 4 tweeters too much? not at all, if it's done right. I ran 8 in my IASCA event car. 4 hard domes, 4 soft domes. I wasn't as happy with staging/imaging without all 4. Is running them @ 8 ohms bad? that's fine too. So would using L-Pads to trim or attenuate the signal so you can tweak their levels a bit if they're too bright. Another option is something like an Audiocontrol EQL or a pair of EQTs to adjust total curve. On my car with the 8 tweeters, I ran them at 16 ohms actually. 8 ohm soft domes, wired in series. They were all run on an Orion 2125SX, and 125wRMS per tweeter was just WAY too much for them.. even half that at 8 ohms was, too. 16 ohms gave tehm just the power I wanted, and I still ended up replacing the coils on those soft domes all the time because I'd toast them due to the amplifier's power or possibly just damage from weather etc, being mounted in the car's doors. Anyway, load doesn't matter at all. the resulting power is what matters, and how that amount of power works with the speakers. At least PPI/DEI responded to ya. I hope they offer something useful. |