The speaker enclosure/baffle is made from a 1" ID x 0.875" H x 0.0825" paper (cardboard) tube. I used the core from a roll of tape. The cap is 0.060" styrene. The QSI 1.06" extended bass speaker is mounted with the cone facing out. I use Zap-adapa-goo II to glue and seal everything air tight. The QSI Revolution volume setting was set to 9 on a 0-16 scale. I run a volume setting of 13 to 15 at the club layout, but anything over 9 was just too much for the sensitive camera audio. This recording was done from about 2.5 ft with a Kodak DX7440 digital camera.
There was a most obvious improvement in bass, dynamics and over all texture over the factory plastic baffle. I also tried the QSI 1.1" square framed speaker, but did not get as good results. I think this may have been, cause of the round paper tube being so close to and covering the openings in the round speaker frame itself. It might be a diffferent story if a square baffle was made to fit the square frame of the 1.1".
the recording/video can be heard at:
http://s237.photobucket.com/albums/ff259/dcfxier/?action=view¤t=100_3041.flv
DC
http://uphonation.com
That's a ... LOT of electronics, some of it I see home-made. What's all that for then? I see the QSI decoder standing on edge, and the original factory circuit board at the back there.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Randy,
The home made board up front is a full wave rectifier, regulator and filter circuit that allows it to run on DC, AC or DCC from 12 to 18v. There's 2 HO Train Engineer receivers. 1 for motor control, and running the QSI Rev in analog mode for the sound. The motive power is in 2 B units and tethered. The second HOTE (in the factory board) activates a polarity reversal DPDT relay for the QSI horn, bell and programming in analog mode. There's also lighting, some fast acting mini fuses here and there, and some jumpers so I can set it up for RC operation (regulated or unregulated) , or standard DC operation. So far, no problems for about 1500 scale miles...knock on wood. I plan on replacing the 2 HOTE receivers with one new 2.4gHz Revolution HOTE...soon, I hope.
I build speaker baffles out of sheet lead soldered together in an HO B unit(dummy). The speakers are just about as wide as the B unit and a bit longer. I put in two of them in the lead box and seal the speakers into the top edge of the box with silicone sealer. There is plenty of room in the B unit for a Soundtraxx sound only decoder to go with the speakers. I remove most of the center of the fuel tank and fire the speakers downward. I also use a permanant drawbar to consist the sets. I have a set of FTA-FTB-F2A ,a set of F-3 ABAs and a set if F-7 ABAs as well as an E7 AB set. The sound of these units beats any other thing I have heard in HO. The only drawback is there is sound for only one prime mover for more than one locomotive. I also connect the units track pick ups together with small diameter wire and small connectors. The wires look like MU hoses, so they don't look out of place. The E7 set has the wires run through the diaphragms between the units, so you do not even see those wires. I am addressing them as one unit, with the highest numbered unit in the set as the address of all the locos. I don't have to many problems with contact with the rail, especially with 24 wheel pickup. Not as much room in the GPs, but I use the same principal there also.
Paul
Dayton and Mar River RR
Hello DC,
I enjoyed listening to your sound clip and was impressed with the clear sounding EMD "music". Like the smooth horn too. I'm still learning and with the help of my friend, Carl, I hope to be installing sound in all of my P2K E-units.
One thing that I was curious about and was discussing with him was the idea of building speaker enclosures out of steel. I can weld and happen to have significant amounts of clean, mild and high strength steels (including galvanized) that vary in thicknesses from 24 to 16 gauge.
AFAIK, there is a potential problem for electrical shorts with a speaker enclosure built from steel and it would have to be covered with an insulating type of material. This is just my assumption.
I was just wondering how the sound quality from a welded type of enclosure would compare to enclosures built from plastics that are sealed with adhesives, or gasket making type materials..
"I like my Pullman Standards & Budds in Stainless Steel flavors, thank you!"
I made up another QSI 1.06" speaker with a sheet lead enclosure. Although it is an improvement over the plastic factory baffle, it did not have the bottom end and warmth of the hard cardboard/paper baffle. The paper baffle has a "beafer" horn and a more throaty engine sound. It was hard to notice any significant difference in over all volume between the two.
High quality speaker enclosures, like my JBL 4311 studio monitors, aren't made out of metal. They're most commonly made from particle/press board or wood with interior, opposite sides insulated/padded. A speaker enclosure itself radiates, can acoustical amplify certain frequencies, and is a part of the total sound. I would be concerned that thin sheet metal might make the sound too metalic, and I don' think it would be acoustically advantageous. I suggest experimentation, and using what you prefer. The QSI 1.06" speakers are relatively inexpensive. They can be had for a little over $7.
I wish I had room in my engine to install a speaker array, using a combination of these little speakers and enclosures. That might be interesting.