Apollo
GATTI AUDIO

I reject your reality and substitute my own - Adam Savage.

 

Construction blog

 

15/01/2010 - First sheet of 18mm MDF arrives, precut to basic sizes with great accuracy by Allboards.
After trimming and shaping, these pieces will be used for the tops, bottoms, and internal bracing of the woofer enclosure.

 

 

19/01/2010 - 2 x Rotel RB1072 power amplifiers arrive today. One of the Class D (ICE) amps will be driving the woofers in the Apollos and the other amp will be driving a separate LFE subwoofer. Power output is 100W/channel into 8 ohms, and I'll be giving these a listen on my main speakers in a few weeks. These were chosen over professional amps because of their quietness (no fans), efficiency, size and remote switching.
Not much info of this model online, but the reviews of the 5-channel version (RB1077) have been very positive :

Review 1
Review 2

Review 3

Review 4

Review 5

Review 6

 

 

23rd January 2010 - 2 days of measuring, cutting and routing and the internal bracing is now complete.

 

 

 

31st January - baffles and back panels cut to size.


 

2nd February - bevels routed on edges

 

 

 

3rd February - holes routed.

 

 

 

7th February - preparing to glue the interlocking bracing to the front baffle.

 

 

 

10th February - bracing structure completed.

 

 

 

12th February - 1 inch side panels attached.

 

 

23rd February - Bevels installed and woofer hole widened to accomodate the the change of driver to Morel UW1258.

 

 

 

 

 

 

 

25th February - Morel UW1258s arrive. Everything about this woofer says quality, speed and performance. It's more woofer than subwoofer, which is what I'm looking for.

 

 

 

 

March 1st - Fitted mid/tweeter crossover terminals, wiring, and damping.

The internal damping consists of 12.7mm acoustic felt, 40mm acoustic foam (AT600/40 ), and Acousta-stuf (yet to be fitted).

 

 

 

 

4th March - The point of no return - backs glued into place. Now ready for trimming, filling, and sanding. Carboard inserts are there to prevent dust ingress.

 

 

 

 

16th March - Grill frames constructed from 9mm MDF (giving the right amount of strength and driver clearance) and 10mmx3mm neodymium magnets
glued into place on the frames and baffles. I used templates to ensure an exact match from frame to baffle.
The frame edges were bevelled on the sides and curved on the inside edges to reduce diffraction.
Horizontal slots are cut into the satellite baffle frame to allow for the next step - bending of the frame over the midrange and tweeter.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2nd April - Completed 2 undercoats using MDF primer.

 

 

 

 

 

9th May After 3 rounds of sanding and undercoats ....

 

 

 

19th May. Making progress as the cool Melbourne Autumn weather permits.
Finishing with "pale-stone" Dulux full-gloss super-enamel, thinned about 10% with mineral turpentine. Each brushed-on coat is sanded back with 400 grit sandpaper.

So far, 3 topcoats have been applied, each coat looking smoother and deeper than the last.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

July 1, 2010 Base completed and attached.

 

 

 

 

 

 

 

 

 

Listening

 

So as over 12 months have passed since completion I can say that I'm very pleased with the results and that there's nothing significant I would change. I am not feeling any need to upgrade to something else which is surely a good sign.

Every driver is doing it's job beautifully and they are all integrating very well. Maybe the tweeter could be a little "sweeter" but I haven't yet made up my mind for sure on that.

I have tried several arrangements of my listening space and have finally settled on having the speaker on the narrower wall, about 3 feet from the front wall, and 2 feet from the side walls. Previously it was on the wide wall . This is giving me a far more 3-dimensional presentation and less room boundary effects. The wide baffle succeeds in reducing the room signature, in particular side reflections when compared to my previous narrow-baffle designs.

Probably the biggest difference I notice when compared to previous designs is the bass & mid bass which has a powerful, dynamic, natural and effortless quality which is very addictive. Is it the bi-amping (Rotel RB1072 + Primare A33.2) , the wide-baffle, the 12" Morel, or the 7" Scanspeak? I think its probably the wide baffle.

Vocals of any kind sound very natural, never harsh or chesty. Classical music has a richness and power that I love. I think the bass and mid bass improvement just improves all kinds of music a great deal. Also, the 12MU midrange is really exquisite in it's retrieval of detail whilst always remaining composed.

The only negative I can think of its that the speaker does soak up a lot of power, but then maybe I listening a lot louder than I used to. The imaging maybe doesn't have the pinpoint image of a narrow baffle, but it's still perfectly fine and toeing in the speakers improved that area. I've now removed my centre channel speaker as it only detracts from the overall presentation from multi-channel sources.

 

Apollo design

Apollo crossover

Gatti Audio