My 2019 Update Thread - My final system I think.

[Gazjam]

Been refurbing my Impulse H2 speakers during lockdown...
Heres a ‘before’ picture.

[brian2957]

[Gazjam]

Love the sound, and short of a lottery win probably endgame for me.
Not so much the look in my room?
70s church organ Teak not really working for me, so what better time to start my “cunning plan” when off work during lockdown.

So what’s the Plan?
Modernise the look, make them fit better in my room and maybe improve the sound along the way if I can?

Specifically looking at the following:

VISUAL LOOK
* Convert them into the “white version” that was never made to fit the look of my room and make the huge cabinets less imposing.
So all panels, horn enclosures and acoustic cloth all need changed to white.
All materials chosen and sorted, will blend in much better in the room even despite the speaker size I think.

Drew up some sizes for replacement cloth, panel sizes etc. To let me buy in what I need.



PERFORMANCE
* Sound fantastic as is, but any improvements I can do along the way?
Decided not to go down the route of changing the crossovers, as I don’t want to change the basic character of the sound.

The internal wiring wiring between crossover and drive units doesn’t fill me with the warm fuzzies...
Very stiff thick solid core with evidence of oxidation along the cable length, the solder joints seem less than ideal too.
The cable may have been good at the time, but the speakers came out in 1991 so nearly 30 years old!
I use Duelund DCA16GA tinned copper stranded wire in cotton and oil as my main speaker cable and it’s the best I’ve had in my system, love it’s “Tone”, it’s just right.
Decided to internally rewire the H2’s with the same stuff, though after some research I’ll be using the same 16GA for mid and top, thicker 12GA for the bass.
Thinking synergy with using the same cable throughout the speaker chain?
Once speakers are done and had some time on them, I’ll try some 12GA as my main speaker cable too and compare.

Comparison of old and new internal wire:


OTHER POSSIBLE PERFORMANCE IMPROVEMENTS
One of the changes the successor to the H2 had was how the downward firing bass horn interacted with the floor, giving sometimes inconsistent results...
I found spiking straight into carpet wasn’t as good as putting a stone slab under the speakers, so some truth in this.
The successor basically had its own “floor” built in standardising the result in different rooms.
An acoustically damped metal plate 2” from the mouth of the bass horn better controlling how the bass interacts with the floor.
I won’t be doing THAT but I will be doing similar.

So interaction with the floor can be improved.
To do this I’ll be disposing if the old (and rusty!) floor spikes and fitting “outriggers” from a Company called Soundcity in the US, who specialises in this stuff.
Will be replacing the basic spikes with IsoAcoustics Gaia speaker footers.
The IsoAcoustics stuff really works, recently got a set of their footers for my Turntable and works great.
So basically something like this:

but with the spikes replaced with far better IsoAcoustics speaker footers. The do “spike plates” for the feet to sit if you have carpet, to spike through to the floor below.


The “improved” H2’s had a damped metal plate built in near the bottom of the speaker to better control the bass firing down?
I’ll be experimenting with putting a similar damped plate of some kind on the floor or maybe even a few inches above it below the downward firing bass horn, to try and recreate that improvement.

So,
Thats then Theory...on with the Practice!

[Firebottle]

'Internal requiring' ooh err missus..

Take it the auto correct kicked in and you meant internal rewiring.

[brian2957]

Nah..he probably meant that 1st post Alan

[Gazjam]

'Internal requiring' ooh err missus..

Take it the auto correct kicked in and you meant internal rewiring.

Yeah, typo-tastic

[Gazjam]

Yup, even with a quick blast of white, concept approved.

Time to start destroying them!
Cabinets need to be disassembled, drive units and crossover removed, all spikes and cloth to be removed.
Basically stripped right back to their shells to let the refurb start.

[Gazjam]

Spikes off first...to let me remove grill cloth.

[Gazjam]

Mid horn removed, cloth being removed.
Too late to change my mind?


Cloth and side trim mostly removed

[Gazjam]

While the H2’s are out of action brought through the Dali’s from the 2nd system to keep music going, really give an idea of the size of the H2’s and how a white speaker is much less imposing in the room.