Speaker Comparison: Knowles Fox vs. Star Micronics SCP-08B

[jdcolombo]

Another chapter in my speaker comparisons.

Knowles Fox (9mm x 16mm) vs. Star Micronics SCP-08B (8mm x 12mm), each in a sealed enclosure of the same depth (6mm overall) made from .020 styrene.  Sound source is an ESU LokSound Select Micro with the 73827 sound file (ALCO 16-cyl 251 prime mover).  I think the Fox is the winner, but the Star Micronics does well enough that I would consider it for space-constrained installations.  I'm pretty sure the Star Micronics is the same speaker sold as the Zimo "sugar cube" (with a molded or 3d printed "sound chamber").  The Knowles Fox will be discontinued as of January 1, so if you want them, get them now.

Here's a photo showing the difference in size:



Video here:

https://www.youtube.com/watch?feature=player_detailpage&v=uaJqEsH5X0E

John C.

[carlso]

 Thanks John. Valuable info. I think I agree that the fox is the better of the two but the Star would certainly do in a "pinch".

Carl

[BCR 570]

Thank you very much John - now I can order in confidence.  I enjoyed listening to the ALCO 251 16 cyl sound as that is what most of my engines will need.  I would love to hear the Holden K5H at some point if that were possible and not too much trouble.

Tim

[Day One]

I'm interested in picking up a few for some upcoming projects.  Where are you buying from and what's the rough cost for these speakers?

[BCR 570]

John:

May I ask you to confirm that I have the right item - product code 423-1177-ND?


Thanks,

Tim

[jdcolombo]

Yes that's the number.

From Digikey; $2.73 each or $2.27 in lots of 10.  They still have 2600 of them available!

John

[PGE_Modeller]

Thanks for the comparison sound clip John.  I agree that the Knowles Fox has the better sound (as expected from a larger speaker) but was very pleased that the Star Micronics 8 X 12 sounds as good as it does.  I have ordered 5 of the SCP-08Bs from Newark Canada to supplement the stash of Knowles Foxes that I already have.

Thanks also for your comment regarding my post on the LokSound Yahoo! Group.  I would have thought that, with the title of your thread  specifically talking about N-scale Modellers and the dimensions of the available space that I quoted, it should have been clear to everyone else that I was also talking about N-scale.

Cheers,

[jdcolombo]

Hi Greg.

Yes, I'm pretty impressed with the Star Micronics; beats the pants off anything else close to that size.  I've got 10 of them, and probably will use them in the remaining GP9's since then I don't have to mill the frame as much to fit the speaker behind the plastic number board insert in the shell.   But I'll continue to use the Fox on my larger diesels (e.g., the SD9 - did one today, and it sounds terrific, plus I only had to make very minor mods to the frame and shell).

I hope LokSound listens up.  Given the lack of viable competition (I don't consider the MRC boards viable because of the terrible motor control circuits, and nothing else with US prototype sound files fits the space), I think ESU has a chance to pretty much sweep the N scale market, particularly if the Atlas S-2 is a hit.  I didn't pre-order any S-2's, figuring that an NKP paint scheme is down the road, but now I think I'm going to have to get one or two of the undecs with sound and see . . .

John C.

[bdennis]

I would be happy with either to replace the 2 round speakers in my U33C GE.. that is attached to a Locsound Micro 3.5! The leslie sounds great also!

[BCR 570]

Greg:

The firm you cite lists the speakers as "not currently stocked".  Was this the case when you ordered?


Tim

[PGE_Modeller]

Greg:

The firm you cite lists the speakers as "not currently stocked".  Was this the case when you ordered?


Tim

Tim,

Sorry, I neglected to mention that the 5 I ordered were the last ones Newark Canada had in stock.  I would have ordered 2 more if they had them - I am thinking of 4 for my RS-3s, 2 for the GE 70-Tonners, and 1 for the GE 65-Tonner to be made from a Bachmann 44-Tonner.

They were a little more expensive: $3.33 Canadian each compared to $2.73 Canadian for the Knowles Foxes from Digi-Key.

Edit:  Searches on Newark (US), Farnell (UK),  and Amazon (Canadian, US & UK) - these are sites that came up on a Google search - plus an earlier search on Digi-Key have failed to locate any more.  Perhaps John will be able to suggest another source.

Greg

[reinhardtjh]

It may well be that the SCP-08b is out of production.  I've done a lot of searching on the Star Micronics web site and can find no reference to this speaker.  This is what they currently list http://www.star-m.jp/eng/products/transduc/index.html and even the SCM-09C-J (which is 9mm x 18mm x 3mm) is out of stock everywhere you look.

Wait, I just found a news announcement that Star Micronics has transferred it's micro-audio product line to a company called Foster Electric. http://www.foster.co.jp/en_index.html 

The Foster Electric web site is worse than the Star Micronics site.    Their last product catalog for speakers is from 2012 and most are too big for our uses.  http://www.foster.co.jp/products/pdf/2012_microspeakers.pdf

We may be "stuck" with whatever Knowles replaces the Fox with.

A 50 unit order for Knowles Fox from Digi-Key isn't looking like such a bad idea...

It's also interesting how many vendors who list the SCP-08B as "in stock" then fall through to the Newark or Farnell site when you click the "buy" icon.

[JanesCustomTrain]

John have you tried an iPhone 4 speaker or do they have the wrong impedance ?

Jane

[jdcolombo]

Hi folks.

I bought my Star Micronics speakers at Newark Electronics, which is now out of stock.  Here is a potential other source, although I do not know if they actually have them:
http://www.1sourcecomponents.com/store/product_info.php/star-micronics-scp-08b-speaker-8mmx12mm-8ohm-250mw-p-884498

I am pretty sure that this speaker is the same one sold by Zimo as their 8x12mm "sugar cube" - although it is sold with an enclosure that fits on the top of the speaker, leaving the solder terminals open (you essentially install the speaker upside down, which works fine, but is a bit inelegant, and there is an increased potential for a short if you're not careful).  Since the Zimo sugar cube is still being sold and stocked by several retailers, either the speaker is still in production somewhere, or else Zimo bought a ton of them and is selling them until their stock is depleted.

I haven't tried the iPhone 4 replacement speaker. 

I do note that Knowles sells a bunch of even smaller speakers that it lists as "receivers" - I'm not sure exactly what this means.  They are listed here:

http://www.knowles.com/search/product.htm?x_sub_cat_id=23

But these "receivers" are all 32-ohm impedance.  Somewhere on ESU LokSound's web site, there is a statement that their decoders will work with any speaker that is 4-32 ohms, though they recommend 4-8 ohms.  The result of using a 32-ohm speaker is that the audio amplifier will have a much-reduced power output; however, this may not matter because the sensitivity of these Knowles "receivers" is extremely high - for example, the 8mm x 12mm "receiver" listed by Knowles has a maximum sine wave power input of 5mw (!); the ESU LokSound Micro is capable of delivering 1 watt into 8 ohms, so it has more than enough headroom to drive this speaker (I think that if I remember my basic electronics, using a 32-ohm speaker would reduce the potential power output to 1/4, or 250mw instead of 1 watt).

I may order some of the Knowles "receivers" to see what they are all about, IF I can get confirmation from ESU LokSound that I won't blow up the decoder by using a 32-ohm load.  It should be OK, but I'd like to get solid confirmation of that before I do a test.  They are certainly intriguing in their specifications - for example, the 8mm x 12mm spec sheet shows useable frequency response down to 400hz and a maximum output of 110db (though I'm not sure how that was measured).  It may be that these "receivers" are only useful for near-field applications (e.g., a headphone or earpiece).  I note, for example, that the "air pumping capacity" listed for these receivers is much lower than for the Knowles dynamic speakers - for example, the Fox is listed as having an air-pumping capacity of 55 cubic mm, but the "Petra" (the 8x12mm "receiver") is listed at just 20 cubic mm.  I just don't know (if someone does, please enlighten me!).

In the meantime, you can still get the Star Micronics in its Zimo "sugar cube" form, though most places sell it for $10 in that configuration, as opposed to the $3 each I paid for the bare speaker.  And if anyone tries the link above as a possible supply, please let us know what you find out.

Meanwhile, I'm going to order some more of the Fox speakers, which will fit in most N-scale applications (though the 8x12mm would be an easier fit in some of the early diesels, like a GP7 or RS3).

John C.

[lajmdlr]

Have heard Railmaster Hobbies speakers at several MR shows in SoCal. Their speakers are way better sounding than any others including those that come w/ DCC/sound locos & other speakers sold separately. Here's a link to their website: http://www.railmasterhobbies.com/Speakers.htm
You can call (after 400P PST) or email them w/ any questions about which speaker fits your locos, installation, etc. And they ship world wide.