The present & the future...

[synsei]

Aha, now i know where you mentioned the rack & Whittelsey which you were talking about this afternoon

Great to meet you & Jo earlier Dave You both are more than welcome round any time i'm not busy, which is as often as possible

I'm pretty sure you might have a better idea how Avatar would look on the screen now that you have sat in front of it Though it still puts a dirty great big grin on my face when i fire up the projector Attachment 4112

I really must do something about this P600 power plant, it's already getting uncomfortably warm in here & it's not even summer yet Must get to working on something pretty quickly..

Cheers once again for bringing the granite slabs over, they should make a decent difference to the Ditton 66s as the floor next door is a suspended wooden floor. No idea why it's the only ground floor room in the house which isn't concrete Can't win em all i guess...

Bests to you & yours Dave

No probs with the granite slabs Mark, as I said earlier, we didn't have to go far out of our way to get 'em to you and anyway, it was fantastic to meet you. I am insanely jealous of your setup. Your Yam hybrids in particular are sweeeeeet!!!

Fit a heat exchanger to your Mac and Krell and you'll be able to build igloos in that listening room of yours

As for the suspended floor in the other room, I'll bet you a crate of beer there's a cellar under that floor

Regards

Dave...

[Reid Malenfant]

As for the suspended floor in the other room, I'll bet you a crate of beer there's a cellar under that floor

Funny that you say that as i have been thinking that myself for a good 20+ years

I'll have to lift a floorboard & take a look, it'd be nice to have more storage space Of course i'd have to move lots of stuff before attempting it I'll take a good long look at all the documentation i have for the house (goes back to the 1800s) before going nuts though. Pretty sure there isn't one tbh but i just have this sneaking suspicion...

ATB Dave!

[synsei]

I feel a new listening room coming on...

[jantheman]

Dont think anyone has mentioned it yet so I will. Great to see that all your boxes have been externally dampened. How long did it take to grow that layer of dust and do you find that it really does make a difference with resonance.

[synsei]

Your a BAAAAAD man Ray

[Reid Malenfant]

Dont think anyone has mentioned it yet so I will. Great to see that all your boxes have been externally dampened. How long did it take to grow that layer of dust and do you find that it really does make a difference with resonance.

It takes a lot of patience Ray let me tell you

Actually i'm sure someone else mentioned it earlier on Thing is it's all free of extra external damping now or at least since everything went back into the rack, there is no difference in sound quality unfortunately

[Reid Malenfant]

Don't you just hate beyond anything an intermittent fault

Well a while back i was nearly pulling my hair out (be handy if i had any ) as the system developed a weird intermittent fault. The only way to describe it was excessive noise on the left channel which was often followed by whistling Or some odd kind of oscillation at about 5KHz

After a bit of messing about i narrowed it down to the Behringer CX3400 crossover feeding the left channel. As these are out of warranty i figured it's going to be a stripdown of the rack & take a look inside, or possibly buy a new one (though i hate spending money unnecessarily). So i kind of put up with it as sometimes it was fine, other nights it'd drive me potty

Anyway it got me looking a bit more closely at the DCX2496...

Meanwhile one evening i had enough of the thing playing up so i just happened to flick one of the potentiometers on the front panel & it STFU!!! Silence, no noise, no oscillation It's behaved ever since...

As i mentioned looking a bit more closely at the 24 bit digital crossover. Right now there are just a few little niggles that could benefit this system if i could do anything about it The Paradigm DSP-3400 has the lowest crossover frequency a tad too high. There is a pretty strong room mode at about 40Hz. The crossover at 110Hz isn't ideal as i have 12Db/octave acoustic rolloffs from both the bass & lower midrange drivers fed by a 24Db/octave Linkwitz/Riley crossover. There is no time alignment between the drivers.

I already happen to have a DCX2496 so i decided to see exactly what the thing could do by programming it. This was my first serious play with one, i couldn't find the blasted instructions manual so found a PDF online, did a bit of reading & off i went.

As i have a 4 way system (effectively 5 way with the sub) i had to set the DCX to mono, this gave me a possible 6 way crossover I decided to find out the lowest frequency i could set up a low pass filter to - turns out to be 20Hz... So if i set the crossover on the sub to the highest frequency i could use the DCX to get it precisely where i wanted it..

So having set it to 27Hz i proceeded to mess about with the bass driver xover. At this point i went into the EQ settings & adjusted the frequency to 40Hz where i have the problematic room mode. It turns out i can put a notch in the response wherever i want with a Q from anywhere between 1 & 10 in increments of 0.1 What this means is i can just about eliminate the room mode with a bit of tuning..

Crossovers can be 1st, 2nd, 3rd, 4th, 6th or 8th order with Butterworth, Bessel or Linkwitz/Riley responses. So i could do a much better job of integrating the bass to lower midrange drivers at 110Hz. That's that sorted to

Finally each driver can have a delay added to it to time align the drivers, the minimum appears to be the equivalent of 2mm in distance & can be increased in 2mm steps up to far more than i'll ever need...

Looks like i can sort out a few niggles that are small admittedly by purchasing another DCX, i think i'm going to have to do it so watch this space

[MartinT]

I hate intermittent faults, too. I last had it when the Ayre SACD player started mistracking on SACDs and I found it hard to pin down the problem at first. It feels good to diagnose it and get it fixed

[Reid Malenfant]

I hate intermittent faults, too. I last had it when the Ayre SACD player started mistracking on SACDs and I found it hard to pin down the problem at first. It feels good to diagnose it and get it fixed

They are the worst Martin, when you look for them they always behave When you don't they mess about

Anyway, i have picked up another DCX2496 on fleabay. Apparently brand new but about 8 months old, it was only removed from the box to check it visually upon delivery & never got used Should be pristine which is what i like (homage to Andr'e ).

When my back is a good bit better i'll dig down to the present crossovers & replace with the programmed DCX units, 5 way to integrate the sub better & all time delay compensation for drive units taken into account.

Well, assuming it works ok that is

[MartinT]

I'm MadeOfDeadGiantStarsThatExplodedEonsAgo.

Whaddya know, so am I

Have you listened to Moby's take on it?

http://open.spotify.com/album/3DxUnsVpofjCNk5OF1im8J