Altering CV's 3 and 4.

[Clagsniffer]

Hi there. Ive just installed a sound decoder from Howes into my Hornby class 50 and i absolutely love it. The only trouble im having is bringing the loco to a stop. It seems to stop rather suddenly before the sound of the 'brakes' has a chance to be heard. Its also as if theres a delay in the engine noise adjusting to the stop in time. I was just wondering if altering CV4 would help things? Also if i altered CV4 would i need to alter CV3? Ive never messed with CV settings before as ive just bought a dcc controller that I understand!

 

Any help would be much appreciated.

[Allegheny1600]

Hi there,

I don't know if you have a version 3.5 or V.4 decoder (I presume it will be an ESU decoder, from Howes!) and I don't have any V.4's but;

I usually start off by putting an arbitrary figure of say, 25 in CV3 and say, 12 in CV4 - if the Acc/Dec rate is too much or not enough, it is easy to guess whether the CV's need to be further altered. Why is Dec (deceleration!) different to Acc (acceleration!)?

Well, if your loco takes ages to get going, you don't necessarily want it to slow down at the same rate! Those buffer stops or last vehicle of a train come up quick, sometimes!

Anyway, once you've done that - you can find that the loco will sound much more realistic now.

Hope that helps, glad you're enjoying your sound loco - it will probably be the first of many!!!

Welcome to the forum btw!

John E.

[kevpeo]

Hi Clagsniffer (cool name!) Welcome to RMweb. Altering cv'3&4 will not affect the sounds, but will give longer for the sound segment to play, so is worth trying. Read back the values using your DCC system and make a note of them before making any changes, so you can put them back if you don't like the new ones! Altering cv's 5 (max speed) and 6 (mid speed) may also help you to tune the peformence to your liking. HTH. Kev.

 

edit, John beat me to it!

[Clagsniffer]

Hi guys. Thanks for the quick replies and thanks for welcoming me to this forum. Threads from this forum always come up when i do the inevitable google search to find answers so it made sense to join up really. I must admit i was a little wary about posting anything at first as ive read quite a few 'heated' exchanges, but never mind im pleased it isnt all bad!

 

I forgot to mention that its a v4 chip. I fitted it with 58x22mm bass reflex speaker from dcc supplies, and it just blew me away. I especially like the 'hoover' fan. Ive got the Gaugemaster Prodigy Express which i find very user friendly. Ill have a bash at looking through the cv settings tomorrow when i get home from work.

 

I also got a v4 chip for my Heljan class 47. I cant find room for anything other than the standard speaker that comes with the chip and i must admit im a little underwhelmed by it. It sounds a bit tinny. But i think it may be too loud. I might either have to turn it down or take a hack saw to the chassis!

 

Anyway thanks again!

[SRman]

Hi Clagsniffer.

 

As the previous posters have said, changing CVs 3 & 4 won't affect the sounds as such but will make a difference to the way they interact with your driving style (with higher values, for the better, IMHO).

 

I have a v3.5 decoder fitted in my Heljan 47, with two speakers in parallel (be careful as the rating for v4 speakers is 4 - 8 ohm so it depends on which rating you get as to whether they should be in parallel or series, if you go down this path). Heljan locos are particularly easy to fit sound in because the bodies simply unclip (for most of them) and the fuel tank assemblies underneath are also separate, hollow mouldings that simply unclip too. I fitted a second speaker in the 47's fuel tanks, feeding the wires up through the bogie openings with plenty of clearance to spare.

 

Try a combination of the original round speaker in the body, pointing down through the bogie well, plus a bass reflex or bass enhanced speaker in the tanks (the speakers are not expensive so it is easy to play around with different combinations until you are happy with the results). Make sure the ordinary speaker is sealed properly into its sound chamber, using a little Blu-Tac or similar, particularly where the openings for the wires are located.

 

The volume setting is in CV63 in v3.5 and I think it's the same for v4 but check the manual.

[ChrisB]

One of the advantages of the Heljan 47's wide body is that it gives you a fraction of extra space for fitting speakers. Having tried lots of available options, I have settled on a 28mm round speaker sat on the chassis behind the cab and facing down. You might have to just sand a chamfer on the base (top if it's upside down!) of the speaker enclosure to allow the body to clip down fully.

 

The difference between the 28mm round and the standard speaker is massive. In most applications, I prefer it to the 20x 40 "bass enhanced " speaker and it's easier to accommodate in some models than the even larger bass reflex. The important thing is to play around and see what suits you.

[SRman]

All of which goes to prove that choosing the right speakers for individual needs is something of a black art rather than a science - there are many possible sizes, shapes and combinations of speakers which will give differing results and the OP should certainly listen to those of us who have tried some of them out but, ultimately, he will have to settle on what pleases him the most. What I, or Chris, or anyone else like, the OP may not find satisfactory, so there could still be an element of trial and error involved. It's not really a "right or wrong" scenario but rather, a case of personal preference.

 

As Chris has pointed out, the Heljan 47 is probably a very good starting point because of its wider body, removeable fuel tanks and somewhat open chassis block, leaving quite a bit of room to manoeuvre. Also, the wiring is easy to get at if you wish to rearrange things - simply slip the body off and move things around until you are happy.

 

While I recommended pointing the speakers down towards the track, as I have found that to give betetr sound for my own tastes, some people will prefer a speaker pointing up through the fan grilles (which, I should add, are solid on the Heljan 47 model so you would need some etched brass replacements in this case).

 

As I said before, the speakers are relatively cheap to buy so don't be afraid to experiment until you get the best sound for your tastes. Certainly the one 23mm speaker with the class 47 sounds is a bit tinny sounding and it was that which caused me to start experimenting in the early days of my sound fittings (starting with Heljan's classes 33, 35 and 47 and Howes' sounds).

 

There is a thread under DCC sound where I, and others, have posted videos of our sound locomotives to try to assist others with their choices.

[Clagsniffer]

Thanks for your help regarding the speaker situation. I think i will try adding a second speaker somewhere, and also try the 28mm round speaker suggested by chris. Ive noticed whilst looking for speakers that the round ones dont seem to be bass enhanced/reflex, will adding a second standard round speaker improve the sound even though they are technically the same as each other? Also will i need to reduce the volume setting if using two speakers?

So what should be the total impedance be for the sound to operate properly? If i chose to use another 4 0hm speaker would i need to wire it in series or parrallel with the standard speaker which i presume is also a 4 ohm? I was thinking i could maybe keep the standard speaker above one bogie tower and mount another speaker above the other bogie tower?

 

Again thanks for any help.