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Post by sbhunterca on Dec 29, 2014 16:33:44 GMT -5
Hi, all:
I'm kitbashing a CLC H-10-64 (CN #1617) in HO, and want to plan for sound.
I'm looking for opinions on the best locations for speakers in this unit. It's a big, boxy locomotive "resembling" a Baby Trainmaster on A-1-A trucks, so I have plenty of room to work with for both sound and extra weight. My mechanism is a modified Rapido GMD-1 bare chassis, which takes up very little space.
I have two possible locations in mind for the speakers. These can be quite big, so the bass sounds should be pretty decent... I suspect I should plan for two speakers.
One possible is under the unit, behind the fuel tank skirts and access panels. The other is under the hood at each end. I can provide speaker enclosures in either location. I'm not limited by existing weights from a commercial model.
I'd be very interested in suggestions on which location would be better, as well as any thoughts on orientation of the speakers. There are no open big grille areas on these units' sides or roofs which might provide a good exit point for the sound.
I'm a Digitrax user, but brand is irrelevant for the purpose of this discussion. I could use any decoder for which a good FM sound file is available.
This will be my first sound equipped unit, so I want to get it right on the first try. Many of the ideas that go into #1617 will also go into the three H-12-44s I am building.
Thanks!
Steve
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Post by Mark R. on Dec 29, 2014 16:49:11 GMT -5
I've done a LOT of sound installs, and my experience has proven the best place for the speakers is IN the shell. I've also found I get much better sound if there are NO grill openings. A sealed shell makes for a much better resonant cavity than one that lets the sound pressure out.
In my higher end installations, I also fabricate enclosures from wood as they sound much richer. Plastic resonates at an unpleasing frequency. There's a reason your home stereo speakers aren't mounted in plastic tote boxes !
Also consider the rating of your speaker(s) when doing multiple speaker installations. If you are using a Tsunami decoder, it's optimum rating is 8 ohms. To attain that optimum rating with two speakers, you would need to use two 4 ohm speakers in series. Two 8 ohm speakers will give you a 16 ohm load and may diminish the sound quality somewhat.
Mark.
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Post by Deleted on Dec 30, 2014 11:44:46 GMT -5
Great timing on this thread. I have a speaker question as well.
First though I have to echo what Mark posted about keeping the speakers away from openings. I too find the sound is better in a closed up shell. I also face my speakers down toward the motor rather than up toward the top of the shell.
Now I have a speaker question here. I use cell phone speakers. the back of them have a solid metal plate sealing them off. Is there any reason why I would need to build an enclosure around the back of the speaker? I can understand why I would need an enclosure around a standard speaker to create an air cushion, but on the cell phone speaker there is no exposed back side to the speaker to cushion.
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Post by Mark R. on Dec 30, 2014 12:08:27 GMT -5
Great timing on this thread. I have a speaker question as well. First though I have to echo what Mark posted about keeping the speakers away from openings. I too find the sound is better in a closed up shell. I also face my speakers down toward the motor rather than up toward the top of the shell. Now I have a speaker question here. I use cell phone speakers. the back of them have a solid metal plate sealing them off. Is there any reason why I would need to build an enclosure around the back of the speaker? I can understand why I would need an enclosure around a standard speaker to create an air cushion, but on the cell phone speaker there is no exposed back side to the speaker to cushion. Cell phone speakers operate using an entirely different technology than what we are accustomed to with traditional speakers. Instead of a magnet and voice coil, they use a vibrating membrane. This vibration also comes off the back of the speaker which reverberates within the enclosure. Here's one in a custom built enclosure ....   I've also read of people fore-going the enclosure and mounting the back of the speaker directly to the inside of the shell. This causes the vibration to be sent directly to the shell itself making the entire shell resonant. Personally, I don't care for that, but it's all experimenting at this point to discover what works best. Again, even with the cell phone speakers, I prefer the wood enclosures. George at TVW Miniatures make laser-cut wood enclosures for cell phone speakers .... www.tvwminiatures.com/Cell-speaker-size-collection1.htmlMark. |
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Post by Deleted on Dec 30, 2014 12:22:54 GMT -5
Thank Mark. Those wood enclosures look great. I'll have to look into them.
When you make your cell phone enclosure. How much space to give between the back of the speaker to the bottom of your enclosure?
I am giving about 0.150" between the back of the speaker and the bottom of the enclosure. Do I need that much?
So could I build my enclosures from thin bass wood?
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Post by Mark R. on Dec 30, 2014 12:52:35 GMT -5
The speaker can fit pretty snug in the enclosure, although I'm finding giving it some breathing room does help. If you look closely at the corners on the back of the speaker, they are open (on the ones I have), so I'm not sure if this is the pressure release points, or just the design of the speaker. A larger enclosure does work better than a small one. Still experimenting with the physics of these little speakers.  I'm sure basswood would work just fine. I use 3-ply plywood that is about 0.038" thick. Mark. |
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Post by sbhunterca on Dec 31, 2014 12:42:49 GMT -5
Thanks for the responses, guys!
With wooden enclosures, is there an ideal thickness for the small speakers we need to use? I'm wondering whether the wood should be able to vibrate with the sound pressure, or resist vibration...
the good news, at least, is that the H-10-64's lack of openings in the hood seems to be a good thing.
Steve Hunter
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Post by Mark R. on Dec 31, 2014 14:18:18 GMT -5
Wood does resonate to a degree, but unlike plastic, it resonates at a much lower frequency which actually benefits the sound quality. If you want zero resonance, you can make your enclosure from sheet lead. I tried a lead enclosure, and while it was very solid, the resonance of the wood enclosure sounded better to my ear.
Not sure how important the thickness of the wood is, but rather will the thickness of the wood make the enclosure too thick to fit where you need to put it.
Mark.
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Post by sbhunterca on Dec 31, 2014 14:48:18 GMT -5
Thanks, Mark!
I'm probably over-analyzing this, a hazard of an engineering career, LOL.
The kitbash is still in its very early stages, but when I get to the decoder/ speaker installation, I'll post photos and report back on what I find. I may try a couple of thicknesses as an experiment if I have space.
Steve
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Post by emd16645 on Dec 31, 2014 20:58:20 GMT -5
I'm probably over-analyzing this, a hazard of an engineering career, LOL I thought I read in some post here that you had retired In any case this often is bane of being an engineer. |
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Post by tjmfishing on Dec 31, 2014 22:13:35 GMT -5
Post some updated photos of your CLC's, Steve.
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Post by Canadian Atlantic Railway on Jan 1, 2015 8:15:08 GMT -5
Hi, all: This will be my first sound equipped unit, so I want to get it right on the first try. Many of the ideas that go into #1617 will also go into the three H-12-44s I am building. Thanks! Steve 1636, 1639 and 16?? ? Was the third unit used on PEI? |
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Post by tjmfishing on Jan 1, 2015 18:01:44 GMT -5
1616
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Post by sbhunterca on Jan 6, 2015 9:26:23 GMT -5
Hi, guys:
I just had a reply typed and Sympatico crapped out on me... here goes the second try!
I thought I read in some post here that you had retired.
Yes, I retired 14 October. Somebody said retired people have lots of free time- I'm guessing that person wasn't retired, LOL. The "Honey do" list keeps getting longer and longer... might have something to do with the wife having 18 years (yep, 18!) to go until retirement. Having said that, I've been making sure I do at least SOME modelling every day, either personal stuff or for my Eastern Road Models line.
Yesterday I finished a first-run Walthers Russell plow that I was modifying to CNR prototype. Reworking the plow blade profile took far longer than I wanted, but it came out well... replacing all the moulded-in handrails took a while, as did deciding on the exact plow I was going to model... it ended up being a composite of a couple of plows, but don't tell anybody...
Post some updated photos of your CLC's, Steve.
I will, Taylor, as soon as I have anything worth showing! With the Russell plow done, I'm getting back to the CLCs.
1636, 1639 and 16?? ? Was the third unit used on PEI?
1632, 1636, and 1639 were the three H-12-44s used on PEI. These units were the main "mainline" power.
1616
1616 was an H-10-64... 1615, 1616, and 1617 all spent time on PEI. These units didn't live on the Island, but they were brought in during times of heavy traffic or to cover for one of the H-12-442 if it had to visit Moncton Shops.
Steve
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