microTower bipolar ML-TL for CHR-70 or EL70

[planet10]

Inspired by exposure to the original EPI microTowers (by Winslow Burhoe) in our youth, Chris & I, with Scott Lindgren's help, have come up with a tribute to this landmark vintage product,

We have come up with a small bipolar ML-TL for either the Marl Audio CHR-70, CSS EL70, or Planet10-HiFi E70eN (with an appropriate port) that with the exception of being 1" taller is the same size as the original.



Since we were squeezing drivers into a format instead of making the boxes fit the drivers, we have held off release until actual builds were heard. We now have both a traditional microTower with CHR70eN & a castle variation with EL70eN. We like them both.

We are quite pleased with these. Bass is exceptional (a bit of port damping required if you get them too close to a boundary), WAF is high, build is easy.

The design quickly generated a bunch of variations, including a chubby/omnipole version and a halfTower that can be a floorstander or a wall-mount.

Plans are just being detailed and i will post a link within the next week.

dave

Attached is a comp of most of the variations.

Edit: 03-nov-09 microTower maps & documentation

[planet10]

An early snap of the 2 pair we've built... (CHR variation has silver drivers on the front, copper on the back -- except for the bottom there is no cosmetic difference between front & back)

[planet10]

A (slightly) closer view of the Castle & its magnetic grill

I will post more pictures & drawing excerpts over the next days.

[audiosteve]

Hi Planet 10. Thanks for doing this great work on cabs for the CHR-70! I've been waiting for this.
Would you by any chance have a variant that will work properly with a single driver per box?

Thanks much.

[chrisb]

Originally posted by audiosteve
Hi Planet 10. Thanks for doing this great work on cabs for the CHR-70! I've been waiting for this.
Would you by any chance have a variant that will work properly with a single driver per box?

Thanks much.

Yes, that's included in the documentation soon to be released.

I can tell you that having heard 2 versions of the the mT's (CHR70 and EL70), there's definitely some magic going on with the bipole/"castle" configuration.

or maybe it's just memories of selling hundreds of pairs of the original funky white EPI towers in the 70's, and countless hours of Doobies and the Brothers "Listen to the Music" (oh yes, this was the 70's, and inhaling was involved) , CCR "Suzie Q", and ELP "Lucky Man"

[Scottmoose]

Bet they worked well on Doobie Brothers material then Chris... I always did like the Harlech / Howard S3 semi-omni configuration.

[planet10]

Scott,

It was you mention of the Castles (many many months ago) that inspired the castle version, and reminded us that a BD-pipe variation should be looked at...

Here is an illustration of the concept

dave

[planet10]

and a visualization of a "BD-Pipe" variation

[planet10]

Originally posted by audiosteve
Would you by any chance have a variant that will work properly with a single driver per box?

yes, saw it in half and you get a halfTower.

I haven't done a visualization of this one yet, but have an early version of the wallMount variation on the halfTower. Note that the brace in this visualization is too short, our actual build revealed some front panel vibration just below the driver so the brace was lengthened, Also the orientation of the application has the bulk of the box above the ear & the port firing at the ceiling. Bevels were also added to match a full set of small wall mount surrounds and a centre.

dave

[Scottmoose]

Neat.