# Speakers in general



## Totalwrecker (Feb 26, 2009)

For what I'm running and through my old ears the stock Aristo Speaker in the C-16 sounds ok

The speaker supplied (on request) from SmallScaleRailways w/ a soundcard is tiny, much smaller than the stock Aristo shown on Navy Tech's thread. This one is going in a HLW 4-4-0. I can't see it having enough bass.... so I salvage a couple of speakers from my PC's supply of blown powered subwoofers and satelite spkrs. Anyway I have 2 nice 4 ohm spkrs wired in series, (look like the Litchfields same thread) will I loose volume? And what other things should I beware of?

I cut out plenty of sound passages (holes)and wonder if plastic rattle can paint caps are ok for the enclosures, clearances are tight, is it bad if it touches the magnet?

I'm cheap and don't want to buy another spkr if possible.

Thanks,

John


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## Hagen (Jan 10, 2008)

Plastic should be fine, wood is fine. it can touch the magnet just fine, but make sure the air gets past the magnet, or else the enclosure isn't doing anything.

The point to the enclosure is that it should be airtight (or with a calculated bass port) and as rigid as possible.

And for the best bass response as large as possible, within limits, this is a fine art, but an enclosure is better than no enclosure in most cases.

You can also simulate a larger enclosure by adding insulation/'damping wool' in the enclosure, glue it to the 'rear wall' i/e the top of the lid to keep it in place.

Preferably you should seek to mimic the size of the original enclosure, most of these powered subs come with bass ports, and they add a lot to the low frequencies. but we usually don't have the room.

Also, did you order the add-on amplifier from small-scale or just the regular? I am not sure the regular has enough wooomph for such a speaker.


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## Greg Elmassian (Jan 3, 2008)

You open a huge topic, and also more than one topic, John. 

I will try to address just one first, which is about wiring speakers, and really impedance and load on the amp. 

1. Amplifier output impedance capability 

Most audio amplifiers have their output power, frequency response and distortion rated with a certain speaker load. 

Changing the load will normally affect some or all of these parameters. 

Output power is usually greatly affected by speaker impedance. Some amplifiers put out twice the wattage on 4 ohms as they do on 8 ohms. Usually the amount of power into a speaker (watts) will result in more volume. 

BUT! Most amplifiers are also rated at a minimum speaker impedance... so you usually do not have ANY latitude in going to a lower impedance speaker that you started with. 

What happens if you do this? Usually the amplifier overheats, or the distortion gets WAY worse, or it destroys the amplifier. 

Bottom line, unless the amplifier is rated for a certain impedance, don't try it unless you are ready to risk replacing it. 

(What happens if you use a higher impedance speaker? Less power and less volume... probably lower harmonic distortion, no one is usually interested in this situation). 

OK, that's a beginning on the topic. 

Wire two 4 ohm speakers in series to get one 8 ohm? Yep, works fine, keep them phased properly, electrically and acoustically. 

Let's stop here and see if you have any questions.... we can go onto enclosures next... you have ported vs. sealed vs. infinite baffle to learn about, and volume vs. performance. 

Regards, Greg


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## Totalwrecker (Feb 26, 2009)

Posted By Hagen on 26 Mar 2010 04:11 PM 
Plastic should be fine, wood is fine. it can touch the magnet just fine, but make sure the air gets past the magnet, or else the enclosure isn't doing anything.

The point to the enclosure is that it should be airtight (or with a calculated bass port) and as rigid as possible.

And for the best bass response as large as possible, within limits, this is a fine art, but an enclosure is better than no enclosure in most cases.

You can also simulate a larger enclosure by adding insulation/'damping wool' in the enclosure, glue it to the 'rear wall' i/e the top of the lid to keep it in place.

Preferably you should seek to mimic the size of the original enclosure, most of these powered subs come with bass ports, and they add a lot to the low frequencies. but we usually don't have the room.

Also, did you order the add-on amplifier from small-scale or just the regular? I am not sure the regular has enough wooomph for such a speaker.


Thank you for the feed back. There won't be much room for wool, these are the 'larger' mid range spkrs from a 5.1 system, not from the subwoofer enclosure. Late summer Monsoons generate electrical surges through power lines. Although all equipment is surge protected, the powered sub woofers always seem to end up as burnt toast, I assumed the amp part is what fried and not these satellite speakers.

I just have the basic card, it is plenty loud in my C-16. Infact might be a tad loud, I live at the end of a dirt road out in the country. I rarely hear the freeway 6 miles away, but do hear the UP dismals as they cycle up to leave the hole 4 miles away.... I may be different, but I want 'scale' sound not earth shaking drown out everything else sound. I've heard some scale sounds that are as loud as 1:1...well seemed that way! lol

John


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## Totalwrecker (Feb 26, 2009)

Greg, 

First thank you for the time spent replying and your generosity sharing your knowledge.

I wondered if the double mass would harm the amp, but the 8 ohmer on hand might fit an Annie, but not The Jupiter, so that left the HO speaker that is stock with the card. I've seen ear buds with bigger voice coils! lol

I understand phase and stereo, but in series it's + to - between and + to + and - to - on the ends right? that covers phase no?

Sound card stated 8ohm only and I read a diff thread regarding use in series... I'm doing a battery conversion and want the speakers in first, but before frying the card I thought of my favorite bunch here.... I haven't tested this unit as I'm just beginning the install. The battery car is nearly done too.

Speakers are from mid range satelites in 5.1 surround.

John


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## Bill Swindell (Jan 2, 2008)

For phasing, if the speakers are the same and one terminal on each speaker is marked + then hook the + on 1 speaker to the - (not plus) terminal on the other speaker. Then hook the remaining terminals, one from each speaker , to your amplifier.

As far as what the sound difference is if the phasing is wrong, there will be more bass if they are hooked correctly that if they are backwards.

By the way, Phoenix sells a 1", 8 ohm speaker that sounds pretty good if you put it in a box. I have used several in my projects.


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## Greg Elmassian (Jan 3, 2008)

Yes John phasing is plus to minus when in series, just like batteries, diodes, etc. 

The whole goal is to get the speaker cones to both go in the same direction when making the same sound. 

The next thing you talked about was an enclosure. 

There are many ways to run speakers, one way is a "ported" enclosure, where there is a hole in the speaker. The "Trick" is that the wave from the back side of the speaker is combined with the wave from the front, and it reinforces the sound. But there are limitations to this, and it takes precise tuning. (Thus the old name "tuned port" speakers). 

Suffice it to say without going really deep, it's not for us (unless you remove a complete enclosure from a working speaker and keep it unmodified... and I have found a few of these in small tv's and laptops) 

Better way is a completely sealed enclosure. What the main purpose of the enclosure is is to act as a big shock absorber to stop the speaker cone from "crashing" at the extreme limits of excursion, just like a shock absorber stops your car suspension from hitting the limits of the suspension on big bumps. 

This "shock absorber" then lets you run more power into the speaker (run it harder) to get more volume and more bass. Why do I keep mentioning bass? Because it's the hardest to make, since you have to move a lot of air, just like a piston. 

It then follows that you want your enclosure to be as rigid as possible. Thin plastic or a styrofoam cup are ok, but not as good as something sturdier. 

Now how much volume? Well that is a good one, and is really controlled by mechanical and electrical parameters that we won't be supplied by the manufacturer/distributor. 

The larger the speaker and the more capable of bass it is, the larger the enclosure can be, and you just can experiment. I recommend about 1/2 the tender in a steamer with a good speaker 3 inches or more, but it varies all over the place. 

Getting airtight and rigid will get you 90% there. 

By the way using an ohm meter reading the resistance is not the same reading as "impedance" which is sort of like reading resistance while it is getting a signal, more of a true measurement. 

Hope that helps, 

Greg


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## Hagen (Jan 10, 2008)

The main reason for the enclosure is to stop soundwaves from the rear of the speaker 'shorting out' the soundwaves from the front of the speaker. Basicly an 'open air' speaker has the same problems as two speakers wired out of phase in the same enclosure, they will 'short' or 'cancel' each other out.
 Here's a couple of diagrams

The first diagram illustrates the effect of a tuned port enclosure 

The second illustrates an open air or 'opposite phase speakers' (the best diagrams I found after 30secs of googling )

Of course this illustration becomes less and less true the higher the frequency because of wavelength, but in phase speakers are always preferable.
The other reasons for the enclosure are those that Greg lined out


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## Totalwrecker (Feb 26, 2009)

Posted By Hagen on 27 Mar 2010 03:02 PM 
The main reason for the enclosure is to stop soundwaves from the rear of the speaker 'shorting out' the soundwaves from the front of the speaker. Basicly an 'open air' speaker has the same problems as two speakers wired out of phase in the same enclosure, they will 'short' or 'cancel' each other out.
 Here's a couple of diagrams

The first diagram illustrates the effect of a tuned port enclosure 

The second illustrates an open air or 'opposite phase speakers' (the best diagrams I found after 30secs of googling )

Of course this illustration becomes less and less true the higher the frequency because of wavelength, but in phase speakers are always preferable.
The other reasons for the enclosure are those that Greg lined out 


__________________________________________

I'm assuming that each speaker needs it's own enclosure, other wise why couldn't the tender body act as such?
Turns out I erred in my original post, I am using smaller speakers than stated, but still 4 ohm. They are wired correctly and are even mounted in similar orientation.










Sorry about it being so fuzzy, one on right is too tall. The pair are mounted over a nylon screen, to keep the bugs out.










I'll lower the can caps and glue to the deck. The speakers were ported, but I'm thinking It's a Toy! and the learning curve is kinda steep! lol









Because the spkrs are so close together there will be a flat plane of plastic glued in where the caps meet (like two bubbles) That part I can control and can maintain equal volumes inside the enclosures.
I think the harmonic demonic being lives there.... .

I was happy to read on that site (thanks for the link) that my volume will be doubled, am I right to assume that 2 spkrs halves the original loudness? 
What the Lord taketh.... a happy harmonic demonic gives back! Neato!!!

Thanks to all for all the great advice and help.

John


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## Hagen (Jan 10, 2008)

Posted By Totalwrecker on 27 Mar 2010 03:33 PM 

I'm assuming that each speaker needs it's own enclosure, other wise why couldn't the tender body act as such?
Turns out I erred in my original post, I am using smaller speakers than stated, but still 4 ohm. They are wired correctly and are even mounted in similar orientation.


Thanks to all for all the great advice and help.

John


You can put two speakers in the same enclosure, as long as they are identical and in phase.
The tender body can act as enclosure if its airtight and rigid (enough) .



The volume will not be doubled, more like +3dB, a perceived doubling is +6dB, the effect may be doubled (effect and volume/soundpressure/dB is not the same thing)


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## Totalwrecker (Feb 26, 2009)

OK but.... they were ported and that wasn't airtight...? I know big can o worms... it's where the hole(s) are that makes ported better and without proper position makes it worse. 

Got it on the effect / vol ... effect is good.









I found some wool in other enclosures, should I pack my caps with it? 

Thanks. 

John


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## Greg Elmassian (Jan 3, 2008)

a little might keep some reflections from distorting the sound, and dampen any vibrations of the cups. 

I know about keeping the back wave away from the front wave, but an "infinite baffle" does that fine, and will still let a small speaker cone move too much. Similar to putting a hole in a sheet of plywood... the distance between the back and front of the speaker is too long for the "cancellation" that can occur if the back wave gets to the front of the speaker. 

But in these small speakers, when it is hardest to extract bass because you don't have a 12 inch woofer, the major benefit of a sealed enclosure is the "shock absorber" benefit. 

If you don't think so, try putting that same speaker in a hole in a 4x8 sheet of plywood. No front to back cancellation, but no "shock absorber" either... your bass will suck, and the speaker will distort at levels that will be fine in an enclosure. 

So, both things are right, I just put the priority on the "shock absorber" part of the equation. 

Regards, Greg


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## Loco Lee (Feb 17, 2010)

In addition to the enclosure problem, Most small speaker don't like to go below 150 Hz. Most people would consider this to be High mid Bass. To make the problem even worse, some decoders won't hardly produce frequencies much below 100 Hz. That's a far cry from the low of 20 Hz at the bottom of the Bass frequencies that most of us can hear. The reason for this is because they think that most all of us are going to use cheap speakers, and we won't know the differance. 

Loco Lee


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## Greg Elmassian (Jan 3, 2008)

I sort of have the expectation to try to get to about 100 or 90 hz. It would be great if the electronics could go there. 

I probably would then try a ported enclosure to try to get a bit more bass in the larger steam tenders. Diesels might take an entire substructure inside. 

It would be cool to see what could really be accomplished. 

Could you imagine how it would sound if you could get to 60 or 50 hz? 

Many people will say "oh my hearing is shot so it does not matter", but it's usually your upper frequencies that go, most everyone can hear/feel bass. 

Regards, Greg


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## Loco Lee (Feb 17, 2010)

You can get down to 20 Hz if you use the QSI XB file, and the XB speakers from Tony's, That's what I've got in that GP9 i just did. A guy heard it today, and orderd 3 QSI decoders on the spot. 

Loco Lee


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## Totalwrecker (Feb 26, 2009)

Loco Lee, hello nice to meet ya. 
How does your last statement add to this thread? 

I'm a cheap old fart and nothing you promoted answers any of my needs. 
'Thanks again. Snazzy pic. 

Greg seems like Vandy tenders would give that boombox bass enclosure w/downports.... since all the mergers you've got Vandy bloodlines! yeah it's a stretch... 

John


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## Loco Lee (Feb 17, 2010)

Sorry you didn't catch that John, 

I was expanding on something that Greg, and I had talked about on the phone. As far as what it does for you, well if you want to hear the lower frequencies from the speaker, you need a sound file that has them, and a decoder that will produce them 

Loco Lee


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## Totalwrecker (Feb 26, 2009)

Didn't get what? 
Oh I got it, but you were derailing my thread by going where you did. 
From the beginning I made it clear that I want to Optimize what I have, not pay for top o the line stuff.... I don't need it. 

Greg, as is his nature kept emphasizing bass, I appreciate that and will apply all that I can, but in the beginning I have stated what sound card I have. 

So sir it matters not. I liked the educational nature of your first post, but after that, nope. 

Sincerely 
John


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## Loco Lee (Feb 17, 2010)

Well sorry if you thought that I derailed your post. I know that you said you were a chap old fart. but a good speaker could be hard for 6 to 10 buck


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## Hagen (Jan 10, 2008)

I am fairly certain the small scale sound unit can produce the lower frequencies discussed earlier, atleast the unit I have goes very low.
The 'problem' is with the speakers and the amp in an out door setting. 

That is why I will build a powered sub, based on a computer sub in a trailing car to add for those diesel rumblings.


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## lownote (Jan 3, 2008)

As a bass player I'm inclined to say don't waste your time trying to find speakers that can produce below 100 hz, because below that the problems of reproduction get exponentially worse. Look at any band and see which guy has the biggest amp--it's the bass player. You want good bass? Big speaker cabs, lots of watts. Getting around that is very difficult--I've spent a lot of time and money trying to find small, light gear that reproduces bass well. And as a guy who has played a lot of gigs the most useful tool in my kit if a hi pass filter, so I can selectively roll off the low end. Most people don't hear bass very well, they hear midrange and think it's bass 

In my opinion a better approach is to let the bass frequencies go, and focus on the mid/low mid. If you want it to rumble like a diesel it's going to take a lot of watts and a big enclosure. Maybe a 50 foot boxcar would work, if you ported it. I did an experiment a while back where I put a speaker in the boiler of an aristo Pacific and the ported the boiler--I drilled a hole in the backhead and stuck a brass tube in it. It significantly improved the sound, but it was totally random--you can rarely find specs on small speakers, so I had no idea how to actually figure the correct port. 

I suppose you could make a subwoofer out of a tender, include a crossover, and put the tweeter somewhere else. I still doubt you'd get much bass response. I have a pair of studio monitors that are considered very small for the job--they are twice the size of any tender I've ever seen. I think you'd end up reinforcing the low mids, which people hear as bass if the overtones sound "bassy."


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## Totalwrecker (Feb 26, 2009)

I started this thread only because the speaker supplied was too big to fit in the tender and the the standard HO speaker was too small. So I salvaged from what was on hand...2 - 4 ohm spks. 

I got 2 sound cards from SSRco, put one in the C-16, no enclosure, sounds great. Ran into the dual speakers situation in the 4-4-0 and asked for help... And I appreciate all that has been offered. 

Mui Loco Lee, I live rural and you can double the price of your quality speaker if I have to go get it, the round trip will take $10 in gas minimum, if it's on my side of Tucson... never is! lol No real savings having one shipped either.... I really wish this forum could have side bars which would have been perfect for your conversation w/ Greg, but we don't and I didn't want to wade through all your knowledge that doesn't apply to my needs. 
So I asked that you get rerailed and your reply seemed to talk down to me, my back goes up and I'll get snarky... it's one thing for me to call myself an old fart and something less when you repeated it. 

I don't need a dismal rumble nor do I wish my 'scale' loco to have 1:1 sized sound! On some videos that's all you hear, you never get to hear the clickrty clack on the rails or the birds singing or yourself thinking.... 

So Gentlemen, thanks for your help, I'll keep you posted on my success. 

John


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## Greg Elmassian (Jan 3, 2008)

Sorry John, I was emphasizing bass because that will be the hardest to achieve, the treble will just come, and is almost always independent of enclosure size, or even having an enclosure. 

With the smaller speakers you have, your treble should be great, so the steam hiss and chuff will be no problem. 

I guess I should have stated this earlier. 

Regards, Greg


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## Totalwrecker (Feb 26, 2009)

Greg, 
No problem really and I do like bass and will do what I can to acheive the best ....with what I've got. So I do thank you for all the info you gave. I did look for the largest mags and voice coil drivers (?) from what I had in the junk pile. 
When QSI and speakers from Tony came into the conversation, I wished that I could have shunted that to a side bar. I'm sure others would have learned from it, but as we too well know those discussions usually deteriorate into mine's better than yours... as well as being off topic with Speakers in general.... 

My feelings aren't hurt.... lol 

Have a great day and stay between the rails! 

John


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## Totalwrecker (Feb 26, 2009)

One final question. 
When I salvaged the enclosure wool, I found it just occupying part of the enclosure. 
I won't have that much space, should I pack the wool in tight or leave it loose? and all around or not? 

Thanks 

John


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## Hagen (Jan 10, 2008)

On the other side








in the lid


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## Greg Elmassian (Jan 3, 2008)

The use of "wool", sometimes felt wool, sometimes fiberglas is for a couple of reasons. 

1. It's thought that putting it inside speakers will dampen vibrations. (true in cases when you have really high power or a flimsy enclosure if glued in) 
2. It's thought that it will dampen "Excess unwanted sound" inside. Well, that would have to be treble, I don't think much of this idea. 
3. By putting wool inside, you basically "lengthen" the distance from the back of the speaker to the "box", thus effectively increasing the volume of the enclosure. I believe this has some merit in small enclosures. 

So, my opinion is that it might have some beneficial effect on bass in small enclosures, worth a try. 

Regards, Greg


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## Totalwrecker (Feb 26, 2009)

Thanks guys, 
I appreciatte all your help. 
Looks like fibreglass wool... I'll put some in. 

When it gets too hot outside I come inside and head for the carshop... yesterday it was at 86...., but now they're saying we could have snow by Friday! Been nice outside and the new bridge trestle is coming along nicely... yet with coming rain and cold looks like I'll be wrapping up this speaker issue real soon! 

Thanks again, 
John


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## Loco Lee (Feb 17, 2010)

Hey John, 

You want the inside of the tender to look like a birds nest. The deepest part of the nest will be where the speaker magnet goes, and the rest will be filled with your fiberglass, or I use polly fill, like they put in pillows. 

Loco Lee


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## Totalwrecker (Feb 26, 2009)

Thanks Lee, 
Earlier I was advised to use enclosures over the speaker(s) for better sound as I will also be stuffing the Rx and sound card in the tender, batteries trail in an aux water tender. 
Can I omit the enclosures and use the tender shell as the enclosure? I would be tempted to install a bulkhead divider to halve the tender and keep all the wiring out of the nest of wool. 

I'd like to apologise for my negative attitude earlier. I should be careful of which threads I read before trying to communicate...lol 

John


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## Greg Elmassian (Jan 3, 2008)

My opinion again, for those 2 speakers, tender is too much volume, and hard to make airtight. Part of the sealed enclosure "idea" is to limit excessive speaker cone travel, and that much volume won't help there. 

Also, it's hard to seal a tender completely airtight, a much higher priority than the "icing on the cake" of adding some dampening material inside. 

Half the tender would make sense, but I'd build a separate styrene enclosure around the speakers so you can take the tender shell off without "breaking the seal". 

Regards, Greg


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## Totalwrecker (Feb 26, 2009)

Thanks again! You guys are great.... 

I don't care what anybody says!!!! lol 

I think I'll pick up a sheet of styrene on my way home today and build a box, those paint can caps are way too thin and flexible, I modified the first of two last night, not too pleased with the result.... So when Lee suggested the birds nest in the whole tender; my two cells got busy, brain cells.... 

Thanks, 

John


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## Greg Elmassian (Jan 3, 2008)

If the styrene is not real thick, one or 2 cross braces inside will be fine. 

Often in home speakers, they will put a 2x4 inside a large cabinet. 

This may be overkill, but never hurts. 

Regards, Greg


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## toddalin (Jan 4, 2008)

The more cone area you have, the more air you can move and the more bass you can reproduce. At 2.25" x 5", 8 ohms, 5 watts power, and $1.49 each, these recent offerings look very promising for stuffing into large scale rolling stock. Note the foam, rolled surround allowing for a more extended cone excursion, and more bass/volume. Goldmine has similar small speakers at similar prices also.









http://www.goldmine-elec-products.com/prodinfo.asp?number=G16458

http://www.goldmine-elec-products.c...?dept=1217


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