Question about sub and rear speakers

hardtop_66 · 02-07-2006, 10:54 AM

OK you guys I have

ed, without results, so maybe the question is so stupid that no one even considered it...

Is it possible to connect BOTH the rear speakers AND the sub (bridged) to the rear speaker terminals on a Sony Xplod amp, or is that a sure way of getting into trouble?

Regards,
hardtop_66

Current vehicles Renault Laguna -02 and Golf Cabrio -94

RedGTiVR6 · 02-07-2006, 10:55 AM

you wouldn't want to do that. Your rear speakers and your subs both reproduce different frequencies....or at least they should. Sure, they should have SOME overlapping, but not much. Are you considering this to try and save money?

there are numerous reason why this isn't ideal.

hardtop_66 · 02-07-2006, 11:06 AM

For different reasons I would like to keep (and relocate) my headunit and connect my carputer thruogh the aux connection on the HU. Maybe a better suggestion is to let the frontspeakers and sub pass through the amp, and let the rear speakers be fed from the HU?

The ansver to your question is yes and no. The budget for the project has already reached classified_from_wife_ status. Secondly the car is the family car, and whenever we go somewhere it is jam-packed. I have room for the PC and one amp, but I need all the space I have and can not afford a major reconstruction of the luggage compartment... (in short...)

Geeeeee I miss my ol '66....

Will Albers · 02-07-2006, 11:14 AM

if the sony xplod amp is tri-way capable, then yes. You would have to look up the specs of the amp and locate a tri-way passive crossover. I personally like this type of design

hardtop_66 · 02-07-2006, 11:16 AM

Quote: Originally Posted by Will Albers

if the sony xplod amp is tri-way capable, then yes. You would have to look up the specs of the amp and locate a tri-way passive crossover. I personally like this type of design

Thanks but if I don't speak greek - what am I looking for?

Tri what?

3onDubs · 02-07-2006, 11:45 AM

Quote: Originally Posted by hardtop_66

Thanks but if I don't speak greek - what am I looking for?

Tri what?

He is saying that you will need to use a special crossover that will divide the frequencies that come out of that shared channel. This specific type of crossover is called a tri-way crossover because it can split the signal into 3 different frequencies.....the extreme highs (tweeters), the regular highs (midranges), and the lows (subs). If you have a crossover like this, than you can take the speaker wire that comes out of the channel that you want to share on your amp, and plug that wire into the crossover's input terminal. You then run your "midrange out" from your crossover into your rear deck speakers and you run your "subwoofer out" from your crossover into your subs.

The reason you need the crossover is because the subs expect to see really low frequencies, and normally you would use the amp to cut off all frequencies above a certain level (in order to prevent distortion). But since you want to use that same channel on your rear speakers, you can't cut out those frequencies because those rear speakers are going to need them. Instead, you will have to cut out those frequencies with an external device, namely, a triway crossover.

hardtop_66 · 02-07-2006, 11:54 AM

Ok and that is always built into the amp, or is it available as a ad-on like a filter? My Amp has switches for low and high pass filter but I guess it's not the same...? I'm having a little problem getting the terms right - after all technical english is not my mother tounge... :-)
Btw the amp is a http://caraudiosecurity.com/shop/pro...s_id/4019.html

3onDubs · 02-07-2006, 12:21 PM

The triway crossover is not built into the amp. It is an external component that you will have to purchase seperately. You might try searching on ebay for a "triway crossover" and see what comes up. Your amp's HPF and LPF will only help you tune that channel for one specific frequency range.

The subs and rear speakers need different frequency ranges.....let's use 60HZ as an example crossover point. You want your subs to play all the music from 0-60HZ and you want your rear speakers to play everything from 60HZ and up.

Using your amp's HPF and LPF features will only allow you to select one of those ranges, but not both. The triway crossover, on the other hand, will allow yout to take the entire frequeny range and divide it into those specific freuencies that your subs and rear speakers need....i know its kind of wordy, but did that make any sense?

hardtop_66 · 02-07-2006, 12:24 PM

thanks mate! The coin fell down, and I even think I know what it's called in my own language! ;-)

To make sure I got it all right : I'll be needing 2 3-way x-overs - one for each channel. The high and midrange tones will be led to the rear spaekers, wheras the low frequencies will be bridged from the x-overs to the sub?

Will Albers · 02-07-2006, 01:33 PM

Quote: Originally Posted by hardtop_66

thanks mate! The coin fell down, and I even think I know what it's called in my own language! ;-)

To make sure I got it all right : I'll be needing 2 3-way x-overs - one for each channel. The high and midrange tones will be led to the rear spaekers, wheras the low frequencies will be bridged from the x-overs to the sub?

eeeeks, nope! This is an easily understandable miscommunication. a Tri-way is a completely different monster than a 3-way. I guess its marketing. Give me a few and i will try to find examples....

tri-way from crutchfiled: http://www.crutchfield.com/S-H6WBrhS...asp?i=127TM100

The PAC TM-100 Tri-Way crossover allows you to power a pair of stereo speakers and a subwoofer simultaneously from a Tri-Way compatible 2-channel amp. It's a cost-effective way to drive a subwoofer.

The TM-100 has input and output wires that you connect to your amp's speaker outputs and to the wires leading to your speakers. A 12 dB/octave low-pass filter sends frequencies below 100 Hz to your subwoofer. A 6 dB/octave high-pass filter sends frequencies above 100 Hz to your main speakers. Handles 250 watts RMS per channel. 4-3/4"W x 2-1/16"H x 3-13/16"D. 1-year warranty.

Important Note: A Tri-Mode or Tri-Way compatible amplifier is required.

3 way crossover are what Dubbs explained. in this case, it takes one signal (side) and divides the frequencies into 3 ranges. on for tweet, one for mid, and one for woofer. You would need 2 of these and a total of 6 speakers to do correctly. Most home speakers (tower spakers) have them built in.

I'm recommending something like the first. However, I'm not very keen on the specs of that one. The x-over points and slope arent the best. I will do some searching. ohh, btw. it looks like the xplod amps are tri-way capable so this will work.

edit-- Damn hard to find any tri-way but the PAC. It would work if you cant find a different model and its pretty inexpensive. If you were looking for better specs, I would just build one. You will be fine with the PAC and the system/amp you have

hardtop_66 · 02-07-2006, 01:46 PM

So the budget sollution to my problem would be something like this?

Quote: Originally Posted by hardtop_66

Maybe a better suggestion is to let the frontspeakers and sub pass through the amp, and let the rear speakers be fed from the HU?

While I'm at it - can I use a simple input selection device to switch between carputer and HU as input to the amp if I don't want to feed my carputer signal throug my HU?

Will Albers · 02-07-2006, 01:52 PM

Well, yup, that would work. it would give you more control on the sub but less power.

The switches work, but tend to pop when you switch. Its messy. An Aux in on the HU is a better bet.

No aux on the HU? hmm, i wonder if you could feed the HU output into a hi-lo adapter and thn feed it into the line-in on the sound card. The carputer would be the sole controller them. Just as, if not uglier

3onDubs · 02-07-2006, 01:52 PM

Quote: Originally Posted by hardtop_66

thanks mate! The coin fell down, and I even think I know what it's called in my own language! ;-)

To make sure I got it all right : I'll be needing 2 3-way x-overs - one for each channel. The high and midrange tones will be led to the rear spaekers, wheras the low frequencies will be bridged from the x-overs to the sub?

I'm trying to understand your setup. Since you have a 4 channel amp, why don't you run your amp in bridged two channel mode and then use your subs on one channel and your rear speakers on the other? This would allow you to tune each channel seperately and eliminate the need for an external crossover.

For example, you can run the 4 channel amp in bridged two channel mode (so that you can get double the power). On the first bridged channel, run both rear speakers. On the other bridged channel, run the subs.

In order to accomplish the above example, you would not need any external crossovers. You would be able to set the frequency range on the first bridged channel directly from the amp. You would set that channel to HPF and set the frequency on the HPF to about 80 HZ. On the second bridged channel (subs), you would set that channel to LPF and set the frequency on the LPF to about 70 HZ. These are just rough estimates, you might play around with these numbers until you feel that your speakers sound just right.

This is just one option, another option would be to run your amp in 3 channel mode and use two for your rear speakers, and the last one on your subs.

Will Albers · 02-07-2006, 01:56 PM

your first example dubs would put the bridged line to the rear speakers at a MONO, 2 ohm load. It would over heat the amp. You could wire the speakers in series, then you would have the same exact power as if they were run in stereo, but using a mono signal.

Your second example is a better example. Many of us would rather send more power to the front speakers than the rear. I do not run rear speakers at all. Only a 6.5 component set and 10" woofer. All speakers are in front of me

3onDubs · 02-07-2006, 02:04 PM

True....I am running a similar setup as well. I removed my rears, so now I'm just running two 6.5" components and a pair of subs in the trunk. The sound is much cleaner and it isn't comming from all over the place.

I'm really bad with calculating ohm loads...lol...but now that I think about it, that first example wouldn't work.

@hardtop_66: What subs are you trying to run? What is their RMS wattage? You might want to give them more power if you want them to sound better. I would suggest running a 4 channel amp for your inside speakers and running a two channel or mono amp on your subs.