View Full Version : Adding third speaker w/DX3065's
08-25-2001, 06:32 AM
I power my DX3065's with slightly more horsepower then thy can safely handle. So, I am thinking about adding a third speaker to use as a subwoofer of sorts. I would like to know if hooking it up before each crossover for the 3065's (+) of amps left channel to third speaker (+) and third speakers (-) to amps right channel (-) will work. The amplifiers manual gives this way of using it as an example. However, it shows it with a capacitor inline after each of the left and speakers and a coil on the middle speaker (third speaker) to work as a 6dB crossover. The only downside I can see for this type of setup is that I won't be able to protect the DX's mid/woofers (the main idea) using the either the amps HPF since this would also block the lows intended for the middle speaker or using the headunit's Frnt ch. HPF crossover freq. options. The fact that their would now be 3 drivers per channel (third driver shared by each channel) has me somewhat confused. Is there a more appropriate method avialable to me as far as adding a third speaker across both channels. I want to protect the DX's. However, I don't want to have to sacrifice the systems lower bass to do so. I have tried to lower the gain thru the headunits HPF crossover options but I am weak and cannot resist the pull of the amps raw power and excellent dynamic headroom and always find myself setting it back to 0dB. I have already had one of the 6510's stop working for me and Polk was gracious enough to replace it without hesitation. Thank You Polk. I do not want to risk damaging either of it's new replacements as I doubt the kind people (thanks Kim) over at Polk would be as understanding the second time around.
08-25-2001, 02:28 PM
So let me get this straight, you have a cross over in your deck, a cross over in your amp, and yet another BEFORE the speakers...I think it would be fair for me to guess that all these crossovers are high pass. Well, take the one in your deck, turn it off. The crossover on your amp, turn it to full pass. Where are you at now?the components have a cross over, so they are fine. Now, add your sub-woofer. You could always turn the gain down on your amp also.....
08-27-2001, 01:08 AM
Sorry for my post not being that easy to comprehend.
Let me try this again. My headunit offers HPF and LPF for both front and rear speakers as well as one to controll the HPF and/or LPF for the subwoofer. All of which offer +12dB or -12dB adjustments for gain. The amp has 2 channels and can be run in high current mode stable to 1 ohm. or in high voltage mode stable to 2 ohms. Also has built-in options of being used as a low pass 200hz to 50hz and a boost option of upto +10dB gain at 40hz. Or as a high pass 50hz to 200hz or in full pass mode. And so, bla bla bla. Anyhow, the in-line crossovers that the DX-3065's come with do not allow the user to block the lower freqs. sent to the woofer. So, in order to prevent me from possibly overpowering the woofers and damaging them it was recommended that I not only listen at lower volume levels but to block the low freqs. sent to the woofers around 90hz to 110hz. Well, that would be cutting out much of the musics ambience. My amp has tremendous dynamic headroom, so damage by overpowering them remains a concern of mine. Because the amp has only two channels, by adding speaker inbetween the left and right speakers it would be dividing the power amongst three speakers instead of the two. I am unsure if by adding a 500uF capacitor inbetween each of the mid/woofers and the amp would cause the impedance of the speakers to change. Or if using another crossover setup such as an active crossover would be better. Suggestions welcome.
08-27-2001, 01:51 AM
turn the cross over off in your deck. if you can't, buy one that you can. turn the cross over to full range on the amp, if you can't, buy a new one. buy 2 bass blockers for your speakers. get your sub woofer and your low pass flter. They will not change your inpendnce. they will match. Now, throw this stuff together and wala. subwoofer choke 30$, bass blockers 10$ a pair. have your sub cut off at 80hz for 10 and 12's and 50hz for anything bigger. use the bass blockers to pick up were your subs left off. There. If ya can't get it working that way, goto your local mobile electronics center and have them do it. What is with the amp that has high current mode and high voltage mode?? What amp is it??
08-27-2001, 02:06 PM
That is the information that I needed to have explained to me. As far as what high current mode and high voltage mode is, it is away to supply a specific type of electrical output that may be better suited for a specific type of speaker setup. Such as if running the amp to power large 15" subs which typically can have a much higher demand for current then smaller speakers. They claim (Sony) "produces a very powerful sound". In high voltage mode the amp will send higher voltages to the speakers instead of the ability to produce higher current (amps). Sony claims that it allows the amp to produce more dynamic headroom. The amp in question is Sony's HX1002. And in high voltage mode it does have excellent dynamic headroom. 3.6dB if I've done my math right. Here's it's specs. as reported from Sony.
Imepedance 1-8 ohms (stereo)
2-8 ohms (when used as a bridging amp)
Max. outputs (HIGH CURRENT/HIGH VOLTAGE)
120/230 W x 2 (@ 4 ohms)
380/580 W (monaural) @ 4 ohms
Rated output (HIGH CURRENT/HIGH VOLTAGE)
@ 14.4 v. 50/100 W x 2 (20hz-20khz) @ 4 ohms
70/140 W x 2 (20hz-20khz) @ 2 ohms
140/280 W (monaural) 20hz-20kh @4 ohms
Current drain at rated output (HIGH VOLTAGE @4ohms) 26 amps
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