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Bluetooth "iPod" Dock on Steroids


DizRotus

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I'll be combining the Lepai 20w x 2 T-Chip amp, and Logitech Bluetooth adapter (just to the right of the amp), 2 Radio Shack 40-1197 full-range drivers, 1 Parts Express knock-down MDF enclosure, as well as sundry other parts, to make a relatively small (albeit heavy) bass reflex portable unit to play music from any Bluetooth enabled phone.

EDIT on 12/15/13:

Due to the attachment data limits of the new forum, the attachments have been deleted for the posts. If interested, there are attachments at post #17.

Edited by DizRotus
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Two of these will go into a single bass reflex enclosure. The chip amp and Bluetooth adapter will be built into the project. The goal is a relatively compact unit to play better and louder than typical such portable devices. Actually, the goal is to have an excuse to buy a router and make some sawdust.

More work in progress photos to follow.

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  • 2 weeks later...

The portable system powered by a $20.49 Lepai T-chip amp, and connected via Bluetooth is operational. Any Bluetooth capable smart phone can play through this.

Finding a socket to accept a PC computer style power cord was a challenge. This nifty unit with a lighted power switch and fuse turned up on Amazon for $5.

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The power supplies for the amp and Bluetooth adapter are inside the box. I contemplated cutting a hole for the wires. I might do that eventually, but, for now, they use the single bass reflex port for access.

The four rubber feet allow the unit to be placed with the speakers firing upward, if desired.

Edited by DizRotus
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A 15" woofer guard (also Parts Express) supports the unit and protects the amp and adapter when the speakers face forward. I put clear tubing over the bars of the guard to avoid scratching floors, etc.

The connections to the speakers are through the box using terminal strips.

Now that it 's operation is confirmed, I'll take it apart and paint it black. First it needs some Bondo, sanding and priming. There are black metal grilles that will protect the drivers and add to the industrial look.

BTW, it sounds good. The imaging is surprisingly good, even though the speakers are so close together. The sound stage seems to extend left and right beyond the unit.

I still want to experiment with the port length and add some acoustic foam to interior surfaces. Even as it sits, it sounds better (read plays louder) than the Klipsch iGroove. Best of all, SWMBO is pleased the iGroove no longer needs to be taken outside.

Edited by DizRotus
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  • 2 weeks later...

I took the "iPod" dock on steroids to the high school band room and used the Lepai to play the school's bass modded La Scalas. Every year I do a tweeter check on the 50 y.o. Ohio bar speakers I refurbished for the school. It was amazing how well that tiny chip amp played those speakers.

It's almost done. The painting will have to wait until I return from a memorial service for a fallen college friend at Craig Lake in MIchigan's Upper Peninsula. A group, including 3 of his 4 sons, is gathering to spread his ashes (probably illegal, but the ring leader works for the Governor).

With a 12 volt battery, we'll be able to add some appropriate music to the event. Music was important to Jack. I don't think he'll mind the unfinished MDF.

Edited by DizRotus
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I love this idea. We have had 3 different portable iPod "boomboxes" and all have crapped out. A well built bluetooth version would be great.

Has anyone considered one with a horn. Maybe a mono speaker like Tivoli does. Vertical orientation, would look like a small 2 way Heresy. Handle on top.

I wouldn't know where to being with a horn and drivers but it sounds doable with some wood working skills.

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The beauty of the Logitech Bluetooh adapter is that it avoids the Apple 30 pin connector. I also have a CoolSpace Bluetooth adapter that plugs into the 30 pin on a Klipsch iGroove. Using the Logitech hard-wired into the back of the iGroove is better.


As to a horn loaded boombox, power is not the issue, but size is. As stated above, the puny chip amp easily powered a pair of bass modded (slightly less efficient) La Scalas to "call the police" levels, but toting around a pair of La Scalas, or even Heresy, is impractical.


The memorial was poignant, albeit cold and wet in Northern Michigan. The photo shows 3 of my late friend's 4 sons paddling out to a small island where their dad's ashes were placed at the bass of a single White Pine.


A bald eagle flew over as the ashes were being transported to the island. That's the best kind of fly-over we could have, Sequester be damned,

I'm posting this from the historic Landmark Inn in nearby Marquette, MI.

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  • 2 weeks later...

I opened it up to swap the 12v/2A power supply (PS) that came with the Lepai for the 12v/6A LCD Monitor PS recently purchased from Amazon. The original Lepai PS is still plugged in on the right in this photo. The larger 6A unit, with yellow label, is on the table

The foam seems to improve the sound. The port is as long as space permits. I'd try it longer if it would fit. Shortening the port weakens the bass.

The plan to use screws into the glue blocks was abandoned in favor of T-nuts and machine screws. Likewise, T-nuts are used throughout, permitting the drivers to be removed and re-installed without requiring interior access to thread nuts onto machine screws. Between the 2 pair of single driver BR speakers and the dock, more than 100 T-nuts were used.

Edited by DizRotus
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A bunch of stuff is crammed onto the rear panel.

Using one enclosure with a single port for 2 drivers is a compromise necessitated by the need for portability. It's still quite heavy, but it's relatively compact.

The 6A PS (on the right) results in a noticeable improvement of bass, dynamics and clean volume, as compared to the 12v/2A PS that came with the Lepai.

The PS for the Bluetooth adapter is on the left.

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Fingers crossed, I await the arrival of a replacement SMSL-SA-S1 (see "chip amps?" thread). I'm eager to compare a functional SA-S1 to the Lepai. Right now the Lepai easily bests the SA-S1 that only produces that Simon & Garfunkel classic, The Sound of Silence." [ :(]

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  • 4 months later...

Much has happened since post #16 in August, much of which has been chronicled in "Chip Amps?" https://community.klipsch.com/index.php?/topic/144613-chip-amps/ Unfortunately, due to the data limit under the new forum regime (I love the new forum and Chad), the original attachments have been deleted. Eventually, I'll establish an account with Photo Bucket, or the like, and restore the photos.

The Lepai TA2020 has been replaced by the SMSL SA-S1 replacement of the DOA amp. The sound is better but it won't play as loudly as the Lepai.

My audio challenged friends and family are amazed at the sound from this boombox. My bother paid it the ultimate left-handed compliment when he said it sounds better than his Bose dock, which it clearly does.

 

I'm in the process of installing one of my many (7) chip amps, as well as a Bluetooth receiver, inside the enclosure. I'm also experimenting with installing a 12v battery and charger inside the enclosure, then the AC cord will only be needed to recharge the internal battery.

 

EDIT: 12/20/2015

 

Photos deleted to free up server space.

 

 

Edited by DizRotus
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Looking good Neil?

So is this a rear ported speaker box?

TIA

Yes Billy,

At present, it sits on bars (a bar grill guard for a 15" woofer from Parts Express, intended to keep the externally mounted chip amp and Bluetooth adapter off the floor) and the port faces the rear. There are also 1.5 " rubber feet on the rear that allow the unit to be placed on its back in a corner so the port faces the floor and the speakers face up. The corner loading sounds good.

After I move the amp and Bluetooth inside the enclosure, I'll remove the bars and add more rubber feet to the bottom.

Edited by DizRotus
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