5 way project - tapped, bass, mids and tweeter, big boy system

[Speedysteve7]

Yeah - prob less mess than expanding foam too. Will mass it all up further too.
I have some sand in the shed

Originally Posted by POOH

Small baggies of sand work well for that

[Speedysteve7]

9lt less on rear chamber

Small bags filled with all the kiln dried sand I have (from block paving drive).
Packed around - doesn't leave a lot of space but still some in the corners to go yet.
Measured and sure enough it's brought the lower bass extending down to 90Hz as modelled.
Still got a bit of a hump at about 120Hz in room at listening position.
It's not bad at +/- 5dB across the 90 to 330Hz range between crossovers.

As I ran out of sand for the other side only got 8lts reduction from 2 x 2lt coke bottles full of water and some 1 lt Tetra packs.

I def need foam to get the magic 12lt or more sand and filling the bags only half full to get more compliance for the corners.
Of course it makes the horns a lot heavier to.

So it measures flatter - How does it sound? More deep bass - more like the conicals in that respect but not the boom / colouration I think.

I still have proper tuning to do yet too of course.

So I win back the depth, gain some speed and dynamics, plus can drop the other drivers on the stands. Pretty happy.

[Speedysteve7]

Foam filler: bass horn chamber reduction
I got some fast setting expanding foam. Lined the chamber and driver with cling film and filled her up.
As one side of the foam was sealed it took overnight to set. This morning nice and set.

This evening I trimmed the foam down and cut it into 4 pieces. Putting each piece in a polythene bag and sucking the air out I then placed these in full bucket of water - slightly tilted so the water ran nicely out of the bucket spout into my container. Then I trimmed each piece to be clear of the driver and achieve the desired 3lts of volume. 4 x 3 = 12.
I wrapped each foam piece in tape so that there is no porosity.

I loaded the first 4 into the chamber and had a measure.
The foam is great as it does not add nearly 12kg to the weight of the thing

The Result : here's a before and after measurement. Blue - no chamber vol reduction. Red 12 lts.



Pretty flat from 100Hz to 350Hz the crossover points. Slight rises at 140 and 290 but this is in room and from the listening chair ear position! Pretty pleased with that result.

Just got the other side to do now, before I find out how they sound.

[weltersys]

Originally Posted by Speedysteve7

Pretty flat from 100Hz to 350Hz the crossover points. Slight rises at 140 and 290 but this is in room and from the listening chair ear position! Pretty pleased with that result.

Just got the other side to do now, before I find out how they sound.

That is a huge improvement in sensitivity and smoothness.
Are you going to try a further reduction in chamber volume?

[Speedysteve7]

The poorer measurement was no vol reduction at all. So driver rattling around in 26lts or so. A whole 12 lts between them. 12" lts is a lot.

I have done the other side now and they sound great as a pair.
Quite different to no volume red.
The 2nd one does measure quite as well. Could be room or other. I'll have to swap them round and see whats what.

Forgot I took some pics last night - 9 lts of sand bags


Foam on the rise

[weltersys]

Originally Posted by Speedysteve7

The 2nd one does measure quite as well. Could be room or other. I'll have to swap them round and see whats what.

Steve,

Has the back chamber now been reduced to about the volume of the speaker basket?

Art

[Speedysteve7]

Art,
No it's more than that as there is clearance around the basket / magnet and cabling. Just the basket volume would be less than 14lts by some margin I would think - I won't be wrapping the driver in a bag and vol displacement testing them though.

I'll trial more/less by 0.5lt increments of sand from here and see if I can measure.

Sounding fab now. I have all the drama and scale of the conicals but more detail and speed - presumably due to the Hyper shape which is said to be good for bass freqs.

Originally Posted by weltersys

Steve,

Has the back chamber now been reduced to about the volume of the speaker basket?

Art

[Speedysteve7]

Natural progression

I dropped the mid / upper and tweeters down by the prescribed amount this evening.
Makes me realise just how high up I had the horns way back with the large upper conical (the one I cut down and used the surplus edge as firewood).
Re-time aligned using Holmimpulse of course.

The tapped horn now tower over the the rest.



Much more integrated look



Sound wise - same signature sound of course. Vocals are particularly sweet though. Much listening and little tweaks coming up this weekend. At some point I'll finish and paint the bass horns... Job for spring in the sun that...

Have to lug the massive conicals round to storage too. Not going back, that's for certain.

[Speedysteve7]

Vitavox S2 time

I have joined the S2 owners club - that is working fully refurbed S2's.
It's taken me a while to track down single matching ones an get refurbed - the waiting list is quite long...

I got home tonight to find the 2nd one back from Mike at Vitavox waiting for me. Mike has worked his magic, demag, check tolerances (all within factory spec), remag, new diaphragm etc.

Here's one



The adapter/mounting rings turned from birch ply Quite ok as the horns are soooo light.

So now I can play the pair for the first time. Just plonked down with the obligatory clip leads. I'm just using a 3uF cap and the sound is electric. Vocals are so there, natural, definite.

Could be a while listening this evening...

Next up - a pair of softwood Tractrix 600Hz or even JMLC?

Here's a pic of the rig taken earlier, with the conical dispatched to storage.

[Speedysteve7]

So, living with them... Tonally they are more coloured / quaint even than the JBL2435Be's - I don't know how the F to describe them!
The JBL's are more accurate on simple stuff, no question . I have no doubt about that with what I shall describe as tonality. BUT and the BUT is massive here... these are the first drivers EVER that I have heard play in the vital 1KHz and above range, that actually keep up! Ok, what do I mean by keep up?
Well, simple speed. The S2 can portray a really fast complex piece like no other driver / compression or other wise, I have ever heard to date.

This is not perhaps apparent on usual dross, but it is eluded to on vocals and on really fast string sections they just do it with an ease that NOTHING I've ever heard can. Again tonally not 100% there but speed and realism all there. I will prob just get used to the tonal aspect, or perhaps other 550 - 600HZ horns will improve even this...

I am also experimenting this evening with the Raal lazy ribbons on a simple 1st order X/O cap at 12KHz and then 15KHz to infinity... Hmmm Nice. Less is def more...