advertisement


One for the Isobarik Experts

Id recommend doing some near field measurements isolating bass mid and top by turning off the respective amplifiers.
 
David,

As per your suggestion.

7wi4CrU.png


The peak at 35Hz is a room resonance node, the others I'd have to look at when I have more time.

The changeover from bass to mid looks OK but from mid to treble has a big 'hole'.........

Regards

Richard
 
The hole in the response between mid and top is interesting, this is something that is going to need some crossover modification or DSP to solve without changing the drivers themselves.

Given the relative levels seem ok, It might be worth looking at the naxo and measuring its response curves.
 
Interesting can't see the scan mids break up mode that's visible on their own measurements, that's always put me off that driver so good result.l would look to move the tweeters point off crossover down a bit, it can handle quite low frequencies down to around 2K.
 
The hole in the response between mid and top is interesting, this is something that is going to need some crossover modification or DSP to solve without changing the drivers themselves.

Given the relative levels seem ok, It might be worth looking at the naxo and measuring its response curves.

David,

In answer to one of your earlier questions yes this is the speakers with the tweeters now wired in series.

The trim pots for the treble frequencies in the SNAXO are right up against the anti-clockwise end-stop - with all due respect to Naim that is not ideal as it leaves no room for adjustment.

How do I easily measure the response curves of the SNAXO?

I have passed this information to Neil Hallworth as I am most definitely going to need a mission specific set of filters for when the Exactbox turns up.

It should also be possible to alter component values on the SNAXO PCB but it would need somebody cleverer than me to determine which components and what values are required. I am quite capable of carrying out the soldering modifications...................

I note the drop off in response from the tweeter. REW is running from 20 - 24,000Hz so I'm assuming the tweeter response is limited by the SNAXO??

Regards

Richard (being typed from the cabin of a boatie moored to a Navy buoy in the Forth)
 
If you take the outputs of the naxo to a line in on the computer you can use rew to measure the response.

You’d probably have to lower the tweeter filter capacitors to lower the corner frequency to account for the natural roll off of the driver.

anyone help with a circuit diagram?
 
Good Morning All,

Neil has gotten back to me and the next stage of the conversion involves making measurements of the drive units using Dayton Audio's DATS V3 equipment/ software......... guess what I just ordered???:)

Regards

Richard
 
Good Evening All,

Whilst waiting for the GP qualifying on C4 I decided to start on replacing the old Linn speaker cable plugs with the recently bought Deltrons.

MYFhJGK.jpg


qSHV0wO.jpg


Now I'll need to enter some new figures in to SO as the new plugs mean the speakers will have to stand 2cm further from the wall...........

I've still got to sort the amplifier end.

Regards

Richard
 
Good Morning All,

SoundImports are very efficient, that's the DATS V3 arrived here this morning. I know what I'm doing next, well once Neil has told me specifically what he needs............

Fortunately Kate has a back-up work Windows based laptop.............

PsmRgSq.jpg


Regards

Richard
 
David,

Not sure where that question came from. These are my original stands and they never came with any panels. As I'm sure you're aware when the interim PMS/ DMS speakers were being produced and the internal crossovers were removed and replaced with the external crossovers there were no side panels supplied.

I was tempted to change things around when selling the extra pairs of Briks recently but decided to let sleeping dogs lie.

I see them as being superfluous as the grilles - are you suggesting I need to fit some?

In the meantime a shiny new Exactbox has arrived at Hi-Fi Corner so I'd better get on with getting some impedance curves to Neil Hallworth. Ironically I'm getting some work after weeks with nothing happening and have no time to dedicate to doing this until at least Wednesday now.

Regards

Richard
 
Richard, Davids question is quite valid, I don't understand your reply to him especially as he has been so helpful to you.
Re stand panels, they can have some benefits to the overall performance, if correctly installed can reduce ringing in the metal stand, some have filled the void with materials that in their opinion aid the overall sound (I certainly did).

Regds
David
 
Just for my interest, how are the stand panels fitted to the stands?
Both our sets of Briks were/are "pre panels" :), but you are right.....they ring like h3ll - especially when head-butted by the cats!
 
some serious damping there, John.

got similar stands under our current pair ( the stands on the first pair had the earlier stand with the two vertical strut towards the middle of the front)

is the black front panel original or did the dealer put it in himself?
 
Sorry if my question came a little left of centre but it just occurred to me that it might be a good idea.

Its so long since I installed mine but I remember them getting leaner and faster as a result.

Definitely a worthwhile upgrade and I quite like the aesthetic.
 
Richard, Davids question is quite valid, I don't understand your reply to him especially as he has been so helpful to you.

David,

I hadn't appreciated that my response came across so negatively, it most certainly wasn't my intention. The question itself caught me 'off guard' as there is nothing new in the pictures I've been posting for months.

I have been thinking about adding lead shot or similar to the stands which weigh what, 14kg, already anyway?

I'm busy doing a couple of ship audits currently but will look a closer look at John's pictures anyway. I could get the joinery firm that did the cabinet rebates to make some suitable inserts and then I could make up the internal spacing bits.

Regards

Richard
 


advertisement


Back
Top