Hi everyone.... in preperation for the arrival of my empeg Mark 2 I would like to get my del Sol set up for some real listening pleasure.

My plans involve installing a box with 2 12" subs in the trunk along with an amplifier in such a way that I can remove it all when I need the space. I already have the subs and box and amp (from my old car that was flipped). The interior of my car will also be getting some nice treatment in that I will be installing a 4 channel amp to drive the front and rear interior speakers. Here's where my dillema comes into play. The empeg has only 4 outputs and I need 6 (or 5???) so I am wondering whether or not I can just tap into the rear speaker outputs to drive both the 4 channel amps 2 rear channels and the amp for the subwoofers? In other words... can I split the signal from the 2 rear outputs to 4 rear outputs without any special gear, or will I have to add some sort of splitter to keep the voltage up there at 4v.

I have done a few stereo installs previously but nothing to this complexity, mainly replacing factory head units with aftermarket ones that have built in amps or something like my old car which was a simple matter of running the RCAs to the rear to power the subs while letting the internal amp power the regular car speakers.

Thanks, any help would be appreciated.

hmmm... this spell check isn't that good at all is it... I guess I shall call my empeg the emperor from now on ;)

P.S. The current amp I have is a Craig PowerPlay 250 (2 channel), how do I bridge it to drive just one Sub???

I'm running into the same issue - unless I find a better way to do it, I'm just going to use a standard Y-Cable on each of the rear outputs to split them (giving me 2 for the rears and 2 for the subs(which I'll use the amp to bridge)). The voltage will be the same on any of the split outputs, but the current will be split between them. I'm not sure what kind of an effect this will have - I don't believe it will cause any problems, but I'm gonna find someone 'in the know' to ask beforehand.

Hope this helps.

Don't worry, you don't need six channels of output. You can drive as many amps as you want from any RCA-cable-equipped head unit.

There are two ways you could go about it. The easiest way is to purchase amplifiers which have line-level RCA pass-through connections already built in. In that way, you could daisy-chain as many amps as you like. Or, if you didn't buy amps with pass-through connections, you could use RCA Y-adapter cables to split the channels to multiple amps.

In my installation (a 2000 Honda accord), I actually do a combination of both methods to drive multiple amplifiers. it works great.

Have fun with the installation, and good luck!

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Tony Fabris

I know there is lots of cool information at http://www.crutchfield.com. I'm not a persion "in-the-know", but I am fairly good at physics and energy.

I believe it was at crutchfield where it illustrated the effects of hooking up more than one speaker to a channel. Basically, if you hook up the speakers in parallel (which I think would happen using the Y splitters), your amp see's one 2-ohm speaker instead of a 4-ohm speaker. Less resistance means more power drain I guess, and if you have a crappy amp you could burn it out. A lot of amps have a rating that says they are 2-ohm safe. As far as I know, you shouldn't try this unless your amp is 2-ohm safe.

The other case is if you hook up the speakers in series, which would create one 8-ohm speaker instead of a 4-ohm speaker. More resistance would probably mean less power to you speakers (I suspect it would reduce the effectiveness of your amp in half on the channel). Your sound would have "less power" I'd think, and may be noticable as weak and flat sound if you have a wimpy amp.

Anyway, I got all that from crutchfield. I'm no expert on sound equipment really. I suspect someone else could explain this better.

Kureg

Basically, if you hook up the speakers in parallel (which I think would happen using the Y splitters), your amp see's one 2-ohm speaker instead of a 4-ohm speaker.

Although most of what you said is correct, keep in mind that when I refer to a Y splitter, I'm talking about in the RCA-cable line-level signal chain before the amplifiers. So the 2-ohm/4-ohm thing doesn't apply. The amount of load on the amplifier is only governed by the way the speakers are wired, not by the line-level inputs to the amplifiers. So you're perfectly safe with it and it works fine, provided you hook up the speakers to the amplifiers properly.

In other words, it's perfectly safe to do this:
Head unit---->Y-splitters---->multiple amps

Where you need to be careful is:
Single speaker output from your amp---->multiple speakers

As long as you only hook up one speaker to each of the speaker terminals on your amplifier, you're fine.



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Tony Fabris

Although I didn't fully understand that tidbit between amps before, I suspected as much. However, something in BillB's post somehow lead me to believe he was talking about speakers and not amps (although in the very first post ShadowMan's case was quite clear).

I went back and read BillB's post, and it seems a couple of possibilities exist in the interpretation. Either he wants to use the Y-splitters on the output from the head-unit, or how it appears to me, he wants to use the Y-splitter on the outputs of the amp for the rear channel to a set of rear speakers and another amp for the subs.


I can't imagine what this would do.
head unit --> amp --[rear channels]--[y-splitters]-->speakers AND amp-->sub woofers

Know what I mean? Is this a useable scenario? I can think of a few results of which most I think are probably not good.


Or maybe I just have my head up my butt .

Kureg

Sorry - didn't mean to be vague. Tony's right - I'm talking about coming out of the head unit, splitting the rear 2 channels into 4 using 2 Y cables, putting 2 of those channels into the rear 2 channels of my amp, and putting the other 2 channels into a bridged amp powering my sub. Pretty close to what Shadowman was talking about in his original post.

Hi Shadowman,

I'm new to this BBS, only recently got my registration number - I think ill be waiting a while.

I thought I should throw my thoughts re the connections of your sub woofers. Mark's info was a bit misleading. His connection suggestion would only be using one channel of the amp. If your amp has not got a bridge mode there is no simple answer. If you amp has a bridge mode the user manual should have the connection details.

Assuming your amp is not bridgeable there are a few thing you would need to do. One channel of the amp will need to be driven out of phase. Then the speaker would be connected using the two positive terminals (the negative of the speaker going to the positive terminal of the out of phase amp). Speaker impedance becomes important when connecting the amp in bridged mode. If you have a 4ohm sub your amp MUST be 2ohm friendly as the 4ohm speaker impedance is shared across the two channels. 2ohm on one channel plus 2ohm on the other channel equals 4ohm speaker. You mention that you have two subs, if they are 4ohm connect them in series to give 8ohm (the amp will then see 4ohm per channel and 2ohm friendly would not be needed). I think I'm being a bit long winded but you get the idea.

Also the sub should be fed with a mono signal (L+R) and low pass filtered. The mono signal would be fed directly to one channel and be inverted (out of phase) before being fed into the other channel.

So it's getting complicated. Perhaps you are better of just running a stereo signal into the amp and having a speaker on each channel. A low pass filter would still be a good idea.

Rod.

Or you could consider spilling a few more bucks for a decent crossover. I use a coustic XM-3 but due to ground loo problems and therefore whining caused by this poor old beaten unit I only use it as a Low Pass Filter for the sub.
I run the front and rear speakers off a Y RCA cable from the front and use the amp's gain to adjust the listening position (Front - rear balance)
The EQ on the Empeg is set to be a HPF on the front and a LPF on the rear. This LPF is duplicated somewhat in the crossover.

Works well for me

____________________________
Murray

.......orrrrrr...

Assuming you don't already have the amps, there are many which have built in crossovers AND daisy chain functions.

____________________________
Murray

If you're worried about splitting the 4v outs to multiple amps - don't worry! The empeg has good drive capability (100ohm) and as amps have high impedance inputs you shouldn't see any problems.

Hugo

Great, thanks for all the suggestions guys. Here's my take on things.

I currently have an amp to drive my 2 12 inch subs in the trunk. I will be either splitting the rear empeg output to the rear speakers and rear subs. Now if I do happen to find an amplifier with 4 channels with a front/rear adjustment I just might split front output to the front and rear speakers driving the subs only with the rear outputs.

I am glad to know the empeg is potent enough to split the outputs to multiple amps, great stuff guys!

About the bridging... well the current setup isn't going to be really efficient for my del Sol, so I may consider trading up to a single (RF, or something like that instead of Phoenix) sub and using my Craig amp to drive it. I asked about the bridging because it states on the amp that it is bridgeable but unfoutunately I bought the amp used (from a Car Stereo store, and theft isn't a big business here in Newfoundland, Canada) and it never came with a manual.
So now I can bridge her.

Again thanks for all the help folks!

(Now if only June 9th would hurry up and get here! )

WOW! With 2-12inch subs in the trunk what do you do with the Del Sol top when you take it off???

"I drank what?" - Socrates

Have you ever seen the trunk of a del Sol... it's huge, trust me, with the box I have there is enough room for the roof and probably 2 tote bags (say.. the size of a 24 each, but more bendy and squishy so they can fit around the box :), I have done a test fit to ensure this.

I will probably downgrade to a single sub in time though.