My Equipment: - Alpine CDA-9835HU - Focal Utopia 165W 2-Way Components in Front - PPI Ax400 to power Utopias - RE-XXX 6.5" Midbasses for rear doors - Orion HCCA 225G4 to power XXXs
The Problem: Now, my problem is this . . . how should I connect the RE-XXXs to the Orion HCCA 225G4? It is a cheater amp, so it likes to see a low impedance. The mids are 1.75ohms, so if I connect in stereo, the amp will only produce about 65W RMS, but the XXXs want to see 150W RMS. Is there a way to wire up the RE-XXXs in mono so that I get a larger output from the Orion, more suitable to the XXXs? The RE-XXXs are going to be the bass line of my car, because I will not be having any subs this time around. See the specs on the Orion and XXX below.
Here are the specs on the RE-XXX 6.5" Mids: RE: 1.75 Ohms Fs: 47.4 Hz Qms: 2.33 Qes: 0.59 Qts: 0.473 Mms: 15.04 g Cms: 7.505E-04 Vas: 21.49 ltr 1- way Xmax: 13mm linear Le: 0.14mH Bl: 3.636 t/m Power: 150wrms Spl: 87.75 dB 1W/1m
Here are the specs on the Orion HCCA 225G4: 4.0ohm stereo ~ 25W RMS 2.0ohm stereo ~ 50W RMS 1.0ohm stereo ~ 100W RMS 0.5ohm stereo ~ 200W RMS 4.0ohm mono ~ 100W RMS 2.0ohm mono ~ 200W RMS 1.0ohm mono ~ 400W RMS
Bryan, connect your 2 midbass drivers in parallel and then bridge the amp. That should give you max power. The G4's power numbers were rated at 12v. So in your car, you will get much more. Use the volume control with care.
By the way, I am only concerned about the front sound stage. The Focals shoudl provide enough midbass, so I want the XXXs to provide as low frequencies as possible. Could I treat them like a subwoofer and run them in mono, and tune thm to low frequencies?
Would the loss of stereo in the rear midbasses be a big deal? If I run them like they are subs, the left and right isn't really going to make a difference, is it?
The RE XXXs are 150W RMS, and if I bridge and run in mono, the Orion will be putting out about 400W RMS to both speakers (so about 200W RMS each?) If I adjust the gain properly, I should be OK?
It is very close. That is why I said use caution with the volume control. Set the gain/level to a tad lower. For example, if your HU is 4v, set it to 4.5v on the amp.
I think the XX's should be OK with the additional 50W RMS of power, as long as I use them within reason and hand have the gain adjusted accordingly so that the speakers do not distort.
Do you think that the HCCA 225G4 will be OK running at 0.85ohm in mono though? I am not going to be running at ridiculous sound levels, because this is a purely SQL setup.
I believe you are the person that originally recommended the HCCA to me. Every stereo shop I go to for an installation quote are impressed with the gear They said I "must have done my homework" to buy the HCCA and the PPI Ax400
Or is there a trick I can do with wiring up the factory rear Volkswagen tweeter with the RE-XXX's to get a lower overall impedance? I am going for a front sound stage though, and the rear tweeter might distract from the front . . .
There is nothing you can do to lower the ohms on the components cause they are SVC. The G4 should be able to handle .85ohms. G4 and PPI were 2 of the best amps in the past. You won't be able to find that kind of quality nowdays without paying 3x - 5x in price. For optimal operation, set the G4 in bandpass mode. The LPF should be 25Hz and HPF set to 2Khz - 3KHz.
It basically restricts the frequency to the desired range. For example, in your case, you just want midbass to the rears, so by turning on both the LPF and HPF, the amp's crossover will filter out anything that's outside of the determined range. It means your rears will be getting bass from 25Hz up to 3KHz (I'd set it to 2KHz to start). Not many amps can do that. They all either do LPF or HPF.
I did the bandpass as you recommended. The RE-XXXs sound really good, but when we measured the resistance on the Orion HCCA 225G4, it was 1.5ohms . . . with two 1.75ohm XXXs wired in parallel, shouldn't I have 0.875ohms resistance?? This really confuses me . . .
Not always. You see sometimes, the speakers themselves are not as stated. It may say 2ohms or 4ohms, but in reality, they are slightly off. As long as it's not off by couple of ohms, I wouldn't worry about it.
Yes. That is why you always measure with DMM before installing. Some speakers that were suppose to be 8ohms were actually 6 ohms. It is never 100% accurate.
I never knew that there was that much variance in the load of speakers. It makes it kind of difficult to properly match speakers to amps if that is the case.
They said I "must have done my homework" to buy the HCCA and the PPI Ax400