Large Scale Central

Speakers for the Crest revo system

Electronics Power and Sound
#1

Hi Folks

Hopefully my last question about this…Iv’e checked out numerous web sites and threads about sound on the crest-revo system and can`t find a specific answer to this one… I have two other locos using aristo speakers (8 ohm - 1 watt). I’d like to add a speaker to my LGB Forney.( no sound right now) What I have is a 6 ohm - 5 watt speaker that will fit. From my understanding, I can use a speaker less than 8ohm but I’m not sure. Also, is 5 watts output too much?

Any one running anything similar?

Thanks

Mike

#2

Ref’ George Schreyer’s pages;

http://girr.org/girr/tips/tips12/small_speaker_tips.html > electrical characteristics

The way I read his ‘notes’, with 5 watt rating you won’t blow the speaker. But on the impedance side of it, with a lower ohm (only 2 units lower though) you might have a problem.

doug c

#3

Thanks for the response Doug,

My overall confusion comes from the fact that I can’t find any specs on impedance from any of the Crest literature. The aristo speakers I have are 8 ohm and I thought 6 ohm would be OK. I’m no expert on the subject but I thought that the impedance of the speaker changed with frequency response anyway so 6 ohm would be close enough. It’s not like I’m throwing a 32 ohm speaker in it. :slight_smile:

Wondering if anyone has “blown up” the sound circuitry on one of these things and has a “sad tale” to tell - or a warning

Mike

#4

Many audio units have ratings for different speaker impedance ratings.

Zimo rates their audio large scale decoders for 10 watts in to a 4 ohm load, and only 5 watts for 8 ohms.

Trainli does have a 4 ohm FRS8 speaker available ( these fit nicely in 1/20.3 tenders). Rest are at least 8 ohms.

So one can have 2 8 ohm speakers in parallel to get max output.

The Zimo HO decoders are 3 watts.

#5

Unless the locomotive has an Aristo-Craft speaker installed, I use Phoenix Sound speakers. They are more robust than the Aristo-Craft speakers. I have never blown an Aristo-Craft speaker myself. But I did have a customer blow the one in his Dash 9 after I installed a Revolution receiver and Phoenix Sound P8.

#6

Thanks for the insights Paul.

My main concern was doing damage to the revolution Rx itself. Can’t seem to find any specs/ratings for speaker wattage/impedance so I was wondering what others have had success with. I have run 8 ohm speakers with no problems but I was wondering if a 6 ohm/5W speaker could damage the Crest sound system. It is a great little speaker with good sound but I don’t want to damage the board.

Mike

#7

If you are unsure, then to be on the safe side, stick with the standard 8 ohm speaker. Some other manufacturers units will work with a 4 ohm speaker, and some caution the user to not use a 4 ohm speaker because it will damage the unit. Since 6 ohms is 75% of 8 ohms, that is quite a significant variance, and if the unit isn’t built for that kind of variance, it could, possibly, cause damage.

Of course I defer to anyone who has better knowledge of the unit and can say yes or no with certainty.

#8

I used a visaton FRS5 speaker in my LGB forney, and are available in 8 ohm, round or square plus can handle a peak 10 watt/4 watt average.

14.95 at Trainli.

#9

What David said, especially in light you cannot get replacement units.

6 ohms is a weird value, is it actually rated 6 ohms, or did you measure it?

Greg

#10

It’s rated at 6 and tested at 6 so I’m not going to use it - I’ll get an 8ohm unit that fits and keep the wattage low too. Don’t want to blow up a crest board at this point.

Mike

#11

Good choice. But an ohm meter (DC) tends to not give an accurate measurement of impedance (AC). But if that is what it is labeled, then I sure wouldn’t risk it.