Speaker question

Post by **FZ1** » Sat Oct 28, 2006 12:28 pm

I have the Logitech Z-5300 speaker system and I have some nice stereo speakers I'd like to hook to it instead of the ones that came with the system. Is it possible to put an RCA jack on regular speaker wire? Is it a PITA and will it kill the sound quality? I've never messed with it before.

Skippman · Post by **Skippman** » Sat Oct 28, 2006 12:45 pm

Do you know what the impediance of the speakers is?

Post by **FZ1** » Sat Oct 28, 2006 1:25 pm

8 Ohms/100W

Skippman · Post by **Skippman** » Sat Oct 28, 2006 2:11 pm

Ok, now do you know the ohm load on the amp inside the woofer you plan to connect this to? It should be listed on a FCC compliance plate. If not, check the doco that came with it.

What we're looking for here is that we don't "clip" the amp in the subwoofer enclosure as I doubt it had any sort of built in circuit breaker.

Razorbacx · Post by **Razorbacx** » Mon Oct 30, 2006 12:56 pm

Your Ohm load is important to watch here. If you overload your amp then you'll fry it. For instance if your amplifier is rated at 4 ohms and you drop it below that you'll eventually kill it. To figure out your ohm load take your speakers ohm impedance and divide it by the number of speakers that you are hooking up to the amplifier. For instance, if you are installing two 8 ohm speakers your ohm load would be 4 ohms.

Also, you need to look at your WMS rating, which is your true and constant watt output per channel. If your amplifier has a WMS rating of 20 watts per channel, but the speakers that you are installing require 5 watts minimum then you're overall sound quality will be poor due to lack of power. You'll get distortion if you push the volume and cause your amplifier to start clipping, which can kill your speakers. It's important not to look at the Total Output power as that is nothing more than a marketing gimmick, but rather the WMS rating.

Skippman · Post by **Skippman** » Tue Oct 31, 2006 11:52 am

Are you sure you intended to say WMS and not RMS rating? I've not heard of the WMS rating before.

Post by **FZ1** » Tue Oct 31, 2006 11:58 am

I haven't had time to mess with this since the weekend but the "new" speakers are rated nearly the same as the ones I'm replacing. The difference being that the old speakers are hard wired so I can’t adjust the wire length (without cutting into them) whereas the “new” ones I can make whatever length I want.

cadaveca · Post by **cadaveca** » Tue Oct 31, 2006 12:03 pm

Can you pull the speaker out of the cabinet? you could then replace the wires. the only real important thing to to make sure you connect you new speakers in-phase. This means making sure that the + and - match the original speakers, or you 3D positioning will be "muddy", to say the least. otherwise, it sounds as though you are good to go.

I'd even look at taking teh wires out of the Z-5300 speakers and transplanting them to your other speakers.

Razorbacx · Post by **Razorbacx** » Tue Oct 31, 2006 12:05 pm

Skippman wrote:Are you sure you intended to say WMS and not RMS rating? I've not heard of the WMS rating before.

You're right...I had my thoughts elsewhere. Good catch.

Post by **FZ1** » Tue Oct 31, 2006 12:53 pm

the speakers don't easily come apart and I don't really want to tear them up. Call me anal.

cadaveca · Post by **cadaveca** » Tue Oct 31, 2006 12:58 pm

Not anal...you paid for them...so quite understandable.

Skippman · Post by **Skippman** » Wed Nov 01, 2006 11:25 am

Ok, back to the whole phase thing since they appear to be of the same impedence (ohm rating). Cut the wires. Take a AA battery and apply voltage to the leads running from the speakers, not the amp. If the speaker extrudes (pops out) then you've got the polarity right. If it retracts (pops in) you've got the polarity reverse. Connect the wires in the correct polarity to the leads from the old speakers. Solder the connectors and heat shrink over them and you should be fine.