Will there be compatibility issues??

[Elfenstar]

Here's the fun bit. I bought a toyota Sera which comes with the SLSS (super live surround sound) system. This means i have 2 pairs of OEM components, 1 OEM sub and 1 OEM front centre speaker. sound is controled through a dsp/small amp behind the dash and the rear components are in a "sausage" enclosure that can tilt at a button to change the angle the sound bounces off the glass.

 

As the car is a 1990 model i was thinking of refurbishing all the speakers. Due to the unique nature of the rear speakers i have to get them professionally done. I have also sorted out the front components.

 

My problem lies in the sub and centre speaker. Due to space constraints i am left with 1 speaker. its a 20w RMS with a 40w max power. I will be running a VDO Dayton HU that cranks out MOSFET 4x55w. Do you think i will be blowing the speakers or will i just have distortion if i turn the volume up to high?

[Bobcatsysop]

Hi Bro,

<

 

Generally, your HU with 4x55w MOSFET is delivering only about 30w RMS per channel as 55w is their peak power. So, your 20w RMS with a 40w max power is a little small if you accidentally turn up the volume to max. Like what happened to one bro I knew, his speaker(s) burst right way. General rule of thumb, a MOSSFET 50w x 4 is actually delivering about 25w-27w RMS per channel.

Edited June 3, 2006 by Bobcatsysop

[Elfenstar]

This would mean i either get a new HU or will resistors attached to the speaker wires coming out of the HU (to reduce the power output). Which would be a better idea?

[Bobcatsysop]

Hi Bro,

You have your front component speakers, your sub. If properly tuned and TA, you need not have the fill-in depth as this center speakers may interfere with a little inferior sound quality to your Front Stage and your rear passengers are treated to inferior sound quality. Thus, IMO, I would prefer to do away with your center speakers.

 

That's my 2 cents worth. Let the other bros comment on your question.

[Elfenstar]

Its the one front centre speaker (theres no rear centre) and the sub which have the same problem, due to the space under the dash and the factory sub box size i am stuck with this 20w RMS speaker for both of these units.

 

4 inch speaker-

http://www.jaycar.com.au/productView.asp?I...x=&SUBCATID=383

 

I might be able to fit a 5 inch speaker (which i think are better in regards to the power issue) to replace these but i will have to measure all the dimensions.

 

5 inch speaker-

http://www.jaycar.com.au/productView.asp?I...x=&SUBCATID=383

 

Click on the links for the specs.

 

Alternatively I have a 100w RMS 4 inch speaker (from another manufacturer)which i could use as well, but its not as suited for the sub as its freq range starts at 550Hz). These would be severly underpowered without an amp but i figure i could use line drivers to boost it. Would that work?

 

Not using the factory sub is last on my agenda, but i could do without the sub as i already have a sub an amp from my previous car. However as the problem is still the same as the centre speaker i figured i might as well try and get them both to work.

 

Edit: btw whats TA??

Edited June 3, 2006 by Elfenstar

[Bobcatsysop]

Due to my limited knowledge, I could not advise further. Perhaps other bros here can help you out.

[Elfenstar]

No worries. will wait for them then. Thanks though... now looking at alternative methods of getting the system running like OEM

[Elfenstar]

In case anyone needs this info.

 

1 ignition 12v wire, 1 wire to the parker lights, 1 ground wire, 1 pair of wires for the front speakers and 1 pair to the rear speakers run to the DSP/amp from the back of the factory HU.

 

All the speakers run directly off this unit (with a passive crossover for the components) except for the sub which has the wire from the DSP/amp run to a small amp then to the sub.

 

Nobody seems to know if its just a DSP or a DSP/amp combined unit. There is also no sign of any wattage marks on the speakers or HU.

[Headshok]

yo elfen,

 

ur HU power is 4x55watts MAX, thus it will prob be pushin out abt 22watts rms. thus prob just nice for ur spkr.

 

no worries abt blowin the spkr.

[Headshok]

This would mean i either get a new HU or will resistors attached to the speaker wires coming out of the HU (to reduce the power output). Which would be a better idea?

 

yoyo,

 

i tink the 'resistor' coming out of the HU is actually a small capacitor, to filter out the proper frequencies.

 

the best idea would to just get an amp, all ur power issued will be solved man.

[Elfenstar]

yo elfen,

 

ur HU power is 4x55watts MAX, thus it will prob be pushin out abt 22watts rms. thus prob just nice for ur spkr.

 

no worries abt blowin the spkr.

 

thats good then just need a couple more confirmations just to play safe.

 

yoyo,

 

i tink the 'resistor' coming out of the HU is actually a small capacitor, to filter out the proper frequencies.

 

the best idea would to just get an amp, all ur power issued will be solved man.

 

i meant i was going to solder resistors myself on each of the speaker wires before the speaker to keep the power down. I don't think an amp is gonna be of any use in my case as I think the HU might be too powerful for my speakers.

 

Btw, while we're at it can someone explain what the difference between 8 and 4ohm is with regards to speakers.

[Headshok]

hi elfen,

 

i tink there's no need to soldier resistors to kepe the power down, at most just change to better spkrs, y limit urself rite?

 

aniway, for the 8ohm 4ohm thing, home audio usually comes in 8 ohm while car audio is usually 4 ohms.

 

thus it depends on the amp u are using. if for example, ur home audio amp can only take an 8 ohm load, and u use a car sprk which is 4 ohms, ur gonna blow ur amp as at a lower resistance, it will result in the amp drawin more current. it if cannto handle it, it will blow,

 

its like puttin TOOO BIG a turbo into ur car.

 

so imagine the different ohms are are like different ratings for the turbos. some cars can take BIG MASSIVE turbos while some, if u change to a big turbo, ur gonna blow the engine.

 

BUT if u drive an 8 ohm spkr with an amp which is rated at 4ohms, ur gonna get less power pushed to the spkrs as less current will be drawn.just like imagine u got a Massive engine, but u shrink ur exhaust pipes and everything. so though ur engine is powerful, becos u gotta small pipe, thus ur gonna lose power

 

 

 

 

hope my explanation helps!

Edited June 3, 2006 by Headshok

[Elfenstar]

perfect. you just gave me all the info i needed to know!!! May not be correct according to ICE circles, but it will work for me

[Elfenstar]

Actually, sorry. One last question for now.

 

All other things being equal, would there be a difference in quality if you run say a 40w RMS, 4ohm headunit with a 20w RMS, 8 ohm speaker vs a 40w RMS, 4 ohm speaker?

[Headshok]

at 8ohms, ur amp will push less power to the spkr, thus u wont get the full potential of the spkr

 

have fun man