SpeakerTalk

Innercity126 · Posted: Sun Apr 21, 2013 3:19 pm Post subject: 105.1 Acoustic Foam Top

Hi All,

Forgive me if this has been addressed here before, but I couldn't really find anything on the subject...

I recently restored my 1978 105.1's with the exception of putting the foam insert on top of the bass cabinet. My question is, how important is this foam to the overall sound of the 105.1's? From what I understand it is suposed to help with reflections from the head or something to that effect.

If I am getting any reflections they sure are not interfering with the outstanding sound these speakers produce. Still, I wonder if it is worth investigating? Wouldn't cost too much to try but, then again, I really don't know what type of foam KEF used on them back in 1978. The speakers did not have any in place when I purchased them.

William

proffski · Posted: Sun Apr 21, 2013 9:40 pm Post subject: Re: 105.1 Acoustic Foam Top

KEF audio engineers would not have put in foam for no reason.
I'd suggest you get some correct foam pads and replicate to original design parameters.

http://audiomarkoni.wordpress.com/2013/02/25/kef-105-1-bass-cabinets-reatauration-preparation/

http://audiomarkoni.wordpress.com/2013/02/25/kef-105-1-bass-cabinets-reatauration-satin-black-paint/
_________________
I contend that for a nation to try to tax itself into prosperity is like a
man standing in a bucket and trying to lift himself up by the handle.
-Winston Churchill

Innercity126 · Posted: Sun Apr 21, 2013 11:20 pm Post subject:

I completely agree. However, I am not referring to the foam that goes inside the bass cabinet, which mine do have. I am referring to the foam pad that sits atop the bass cabinet between it and the head.

proffski · Posted: Sun Apr 21, 2013 11:42 pm Post subject:

Ah, sorry! Embarassed

Must I assume be for general vibration damping, again, put there for a reason...
_________________
I contend that for a nation to try to tax itself into prosperity is like a
man standing in a bucket and trying to lift himself up by the handle.
-Winston Churchill

Innercity126 · Posted: Mon Apr 22, 2013 12:03 am Post subject:

No worries. I'm sure you are one hundred percent correct, otherwise why put it there in the first place? I am going to have to source some type of close-cell foam to put there, if anything just to complete the restoration. Cheers!

proffski · Posted: Mon Apr 22, 2013 12:09 am Post subject:

Fantastic loudspeakers, enjoy the restoration and the sound.
I first heard these at the Cheltenham Music Festival shortly after they were released. They were being used for monitoring purposes and driven by huge Yamaha amplifiers, stunning!
_________________
I contend that for a nation to try to tax itself into prosperity is like a
man standing in a bucket and trying to lift himself up by the handle.
-Winston Churchill

Innercity126 · Posted: Mon Apr 22, 2013 12:25 am Post subject:

Careful, you're showing your age now!

I had never heard a pair of 105.1's until I purchased and restored the pair I have now. I bought them last year from a friend who has 107 II's (fabulous).

The two (105.1's and 107 II's) sound completely different to me. Both stunning, but in different ways. I must admit, I prefer the sound of the 105's more. They seem to be more accurate and immediate, but I could easily live with the 107 II's.

I have been using a pair of Infinity Kappa 9's as my reference loudspeakers for many years, but these KEF's certainly have given them a run for the money. I am completely stunned by every aspect of their performance. They leave me wanting for nothing else.

speakerguru · Posted: Mon Apr 22, 2013 8:23 am Post subject: Re: 105.1 Acoustic Foam Top

audiolabtower · VIP Contributor 500+ Joined: 06 Jan 2009 Posts: 686

Have aread from the bottom of this page

http://www.hifiloudspeakers.info/speakertalk/viewtopic.php?t=1440&postdays=0&postorder=asc&start=15

and pics on next page.

I was told at the time it was there to mop up some mid range reflections from the top of the bass cab which interfered with the direct sound from the chamfered LS3/5a type head unit. Unfortunately the soft foam would rot after 20 years. But what a triumph for Kef drive units to be working fine after all this time!

rx7rotary · Intermediate Contributor 50+ Joined: 20 Feb 2012 Posts: 59

Recently I restored a pair of kef 105.1 and then i have recapped the xover etc etc...

http://audiomarkoni.wordpress.com/

Basically some of the most critical things in order that have changed the sound of my 105's and only in my oppinion:
1. Recapping from old elcaps to new ClarityCap ESA series *amazing amount of detail
2. foam surrounds around the midrange
3. midrange cover
4. felt / spongy covering of the bass cabinet *the one you are talking about* (you could swear that you almost can't notice this difference)
Cheers

Marko