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Thoughts on a tweeter for M100C

Posted: Fri Sep 04, 2015 5:04 am
by 4Max
Hi all,

I have found an original speaker for my M100C in good condition to replace the non-original that was in mine.

At some point a tweeter was also fitted to mine, with a capacitor (I understand that's called a "crossover" but I would have no idea how to check its the right type/spec :oops: ).

I have read various posts that a tweeter can improve sound quality, so I am planning to retain it.

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Can I get some thoughts on the one I have - when I was young I always thought Sanyo was considered a cheap option; would you guys keep it, or if you think i should replace with something better, any recommendations?

Thanks, as always!

Re: Thoughts on a tweeter for M100C

Posted: Fri Sep 04, 2015 8:15 am
by Rob-NYC
Danny, this is very similar to what I have used in these old machines:

http://www.pyleaudio.com/sku/PH25/3-x-3-Horn-Tweeter

Highly efficient (100db) small enough and, in this case, it shows power handing down to 1khz. If you add a simple two-way 12db/octave crossover it will allow you to get much of the midrange out of the woofer w/out creating a 'hole' in the response.

Or, you can just use a simple 6 db crossover consisting of two components: Capacitor for tweeter and choke for woofer.

Here is a guide:http://www.parts-express.com/resources-crossover-component-selection-guide
In this case, I'd suggest approx 5mfd (non-polarized) for tweeter and a around 1.2 milliHenry for woofer choke. Those are values I've used on G-C and B's.

Rob/NYC

Re: Thoughts on a tweeter for M100C

Posted: Sat Sep 05, 2015 12:18 am
by 4Max
Thanks Rob,

So, something like this?:

http://www.simplyspeakers.com/product.a ... Hwod_GILzg

And if so, I assume I unsolder wires from original 15" speaker and connect them to the "in" terminals, then just connect the original to the "w" and the tweeter to "t" ?

How do I know for all three connections which is + and - ?

(Yes, this highlights my level of knowledge :roll: - ask me an EM pinball question, and I'll do better!)

thanks (as always, Rob)

Danny

Re: Thoughts on a tweeter for M100C

Posted: Sat Sep 05, 2015 1:28 am
by Ron Rich
Danny,
EM pinball question---
Where can one purchase silver contact points in various sizes ??
Ron Rich

Re: Thoughts on a tweeter for M100C

Posted: Sat Sep 05, 2015 2:23 am
by 4Max
Ron, not sure about various sizes, but I would always recommend http://www.pbresource.com. While they are really the go-to place for EM's their web-site is a little, well, dated - so I always use google to search it, then Ctrl+F once on the page,

for example, enter this in google:

contacts site:pbresource.com

that will display link to this page http://www.pbresource.com/pfswitch.htm click on that and then the Ctrl+F to search for contacts and you will jump straight to their parts.

Also, they don't list everything, so often worth dropping them an email if not sure. I find Jimmy, who handles the emails, is always helpful.

cheers

Danny

Re: Thoughts on a tweeter for M100C

Posted: Sat Sep 05, 2015 4:24 am
by Rob-NYC
4Max wrote:Thanks Rob,
So, something like this?:
http://www.simplyspeakers.com/product.a ... Hwod_GILzg
And if so, I assume I unsolder wires from original 15" speaker and connect them to the "in" terminals, then just connect the original to the "w" and the tweeter to "t" ?

How do I know for all three connections which is + and - ?
Danny



The crossover you selected would be fine and the way you connect it is correct.

Phasing is usually accomplished by simply observing a dot or + sign on the speaker. Since neither exist on the Seeburg speaker, you can use a 1.5 volt battery (AA-C-D) and mark the terminal as + when the positive on the battery touches it and causes the cone to move outward. Since this is a field coil speaker, it will have to be fully connected to a working amp.

There are two schools about phasing: One subscribes to the concept that woofer and tweeter should both be in-phase. Another, advocated by some speaker manufacturers such as Henry Kloss felt that woof and tweeter should be out of phase in order to partially attenuate the small range of frequencies where they overlap. I've always done in-phase. But why not try it both ways? When everything is mounted, simply connect the tweeter temporarily and listen. You'll probably not hear any difference.
Rob

Re: Thoughts on a tweeter for M100C

Posted: Sun Sep 06, 2015 3:12 am
by 4Max
Thanks, Rob.

A new option is now on the table, due to human kindness! When I bought this M100C the couple said their dad also had a wallbox and teardrop speaker, and if they found them, they would call me. Two months later they call to say they found them in her basement and they are mine - how nice is that?!
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I was planning to mount it on the wall just behind the M100C really just for show, but given its a tweeter, do you think this achieves the better sound, with of course allowing me to keep everything original (i.e. just the original field call speaker, with this CVS4-8).

I guess what I asking in a rather clumsy way, is...does the addition of a CVS4-8 enhance the listening experience? And therefore remove need for the (non-original) tweeter / crossover addition?

What do you (and of course, others) think?

Re: Thoughts on a tweeter for M100C

Posted: Sun Sep 06, 2015 8:57 am
by MattTech
Why don't you just hook things up and listen to it?
If you don't like the sound after a while, then questions about it would be more valid.

Re: Thoughts on a tweeter for M100C

Posted: Sun Sep 06, 2015 7:16 pm
by Rob-NYC
Danny, the teardrop speaker -if original, had little treble at all. The driver is a simple, single cone and the 70v transformers that Seeburg used back then were down 5-6 db @ 12khz.

I have a mix of those and the (crap) repros in 4 of my retro locations. The location owners bought them thinking they look nice. I hooked up a few and equipped the originals and repros with modern 70v trans which test down only 1 db @ 14khz. They aren't of much use, but the more efficient originals at least squawk a bit.

I have several HFCV-2 and one HFCV-3 (corner) in use. For those I replaced the original tran and in two cases used a Jensen 8" with whizzer cone. On the 4 CV-2's I added a small dome tweeter as well.

Back to your question: If you were just using the original black or red carts, the addition of a tweeter might not be worth it due to the fact that there is little above 6KHz from these carts, and most of that is tracking distortion.

Since you have the 345-03D it does make sense to upgrade the speakers a bit.

Bear in mind that much of the mods I do are intended to make these old machines more acceptable to modern standards in commercial settings though even at home the limitations of the original design eventually detract from the pleasure of listening to them.

BTW: If you are going with an original field coil speaker, the mod(s) done in the amp will have to be reversed. This will be NBD.

Rob

Re: Thoughts on a tweeter for M100C

Posted: Mon Sep 07, 2015 6:48 pm
by 4Max
Rob, as always your posts are incredibly informative - thank you.

And yes, MattTech, you're right, I will try the various options (I'm just always keen to ask experts they advice in case there are any tips or more importantly, pitfalls I can avoid).

Rob, one last (for now!) question on tweeter placement. The one I have today has been mounted inside the woofer. Does this affect woofer performance - would you mount same place, or "outside" of the woofer?

(That's if that Pyle tweeter fits inside the original woofer - don't know until I get both. Would help if it does as it would avoid removing the mounting board and cutting a new hole!)

Danny

Re: Thoughts on a tweeter for M100C

Posted: Mon Sep 07, 2015 7:24 pm
by Rob-NYC
Mounting the tweeter co-axially is ideal simply because you don't need to cut another hole. There should be plenty of space given the depth of the 15" woofer.

Rob

Re: Thoughts on a tweeter for M100C

Posted: Tue Sep 08, 2015 1:49 pm
by eddie
I wouldn't worry too much about phasing multiple speakers on a jukebox system. Phasing is actually a mechanical action. There are many things that affect phasing. Such as cone design, magnet (or field coil strength), distance apart, size and shape of room and placement of speakers. It isn't just about reversing wires. The best test is the ear test. If it sounds good to you, the the speakers are phased correctly. (even if they aren't)

Re: Thoughts on a tweeter for M100C

Posted: Tue Sep 08, 2015 4:15 pm
by MattTech
eddie wrote:I wouldn't worry too much about phasing multiple speakers on a jukebox system. Phasing is actually a mechanical action. There are many things that affect phasing. Such as cone design, magnet (or field coil strength), distance apart, size and shape of room and placement of speakers. It isn't just about reversing wires. The best test is the ear test. If it sounds good to you, the the speakers are phased correctly. (even if they aren't)


Your post about phasing is plain nonsense, particularly the last sentence.
If manufacturers of sound equipment or speakers didn't think phasing was important, they wouldn't have detailed speakers or equipment with polarity markings, or schematics with same.
Perhaps *your* ears or tastes do not care about this subject, but by posting such misinformation on the internet leads others to believe such rubbish.

Re: Thoughts on a tweeter for M100C

Posted: Wed Sep 09, 2015 4:15 am
by eddie
Ok Mr Tech. Explain phasing for all of us. Explain how it works in a 10x10 room in a 3x3 jukebox cabinet. Each speaker having different magnets. Different cones, Different voice coils. I anxiously await your answer. Seriously. Tired of the negativity here. Let's hear what you got. Everything I said was spot on and accurate. Tell me different. Please. Phasing a set of speakers in a living room? Really? Or do you mean having all the + and - in the right place.

Re: Thoughts on a tweeter for M100C

Posted: Wed Sep 09, 2015 5:57 am
by MattTech
eddie wrote:Ok Mr Tech. Explain phasing for all of us. Explain how it works in a 10x10 room in a 3x3 jukebox cabinet. Each speaker having different magnets. Different cones, Different voice coils. I anxiously await your answer. Seriously. Tired of the negativity here. Let's hear what you got. Everything I said was spot on and accurate. Tell me different. Please. Phasing a set of speakers in a living room? Really? Or do you mean having all the + and - in the right place.



The internet is loaded with mis-information making the uneducated and vulnerable who read it, believe it as truth.
I come across it on the 'net all the time, and sometimes chuckle, knowing full well that it's bullcrap generated by uneducated individuals, for whatever reason.
And when I do come across it, I immediately call it out, in a way perhaps doing my part to eliminate potential troubles for others down the line, who rely on the internet for information.
I hear about it from people that come into my repair shop too, and correct the person who said it.
Oftentimes even showing them in person the actual fact of the matter.
I've shown across my front counter the effects of mis-phased speaker systems, and every customer will agree with the sound being "off" or "thin" if so wired.
And yes, I'm a long-time professional technician, highly regarded in my field, not sure what qualifications you posess, but your information on this matter simply doesn't "jive" with the laws of physics, science and technology that are set in stone, taught in schools, written in textbooks, and proven fact.
Furthermore, your above post contains attitude, and doesn't warrant me having to "prove" anything to you.