HiFi Subjectivist ¦ Audio Forum ¦ NVA User Group

Just ordered another four Visaton G20sc. That will mean I am all Visaton in the tweeter department The B&W and MS tweeters can now go back to their original speakers although they do need the ferrofluid changing. A job for another day.

Finally decided that two 5.25" mid bass per channel is sufficient (one up firing, one down firing). Anymore would just be greedy . I will experiment with adding another 12" to the isobaric bass cab to get the required enclosure volume down if nothing else.

I have come up with a way to keep the volume trapped between the second and third 12 inchers as small as possible. It requires the making of a cylinder the same diameter as the driver and just long enough to allow the magnet of the current inner driver to get out of the way of the cone of the added driver.

Thanks for the thanks Toontrev

As said on the diy thoughts of the day thread, I moved my speakers and did my back in during the process Now they are on a flat continuous wall rather than in front of two deep window recesses.

It sounds much better this way especially in the bass although the whole lot sounds better imo. Just playing Portishead Dummy with it's deep synthetic bass which on occasions used to rattle the capacitor banks in my power amps One track (Pedestal) was much worse than the others and the reverberation was wince inducing.

Not anymore Can't believe I never thought of moving the speakers before what a numpty I am. It's like I told my speakers they would get a slap if they didn't stop behaving badly and they listened. The Pedestal track has had me going on all kinds of wild goose chases trying to calm it down when all the time it was where they were placed in front of two window recesses of 20" depth. My subjective conclusion is that these were acting as echo chambers.

The difference is truly wonderful it has taken my mind off my crappy back. I feel now that I can more effectively bring this speaker journey to it's conclusion instead of being distracted that issues that weren't the speakers fault. I was planning on putting the final build of these speakers in the outer edges of a bay window. Not going to do that now as I expect it will have a similar echo chamber effect.

My Visaton G20sc arrived this morning so I replaced the up firing 23 year old B&W P4 1" metal domes. Didn't get round to replacing the 20 year old MS902S 1" metal domes but that is on the list tomorrow.

Bloody hell those old tweeters truly are well past it. That is the price you pay for having tweeters with ferrofluid Eventually it dries up which has significantly affected their output. Even after just changing that one pair out there is a significant improvement in the sound presented to me. I knew the old tweeters were past it but I didn't realise by how much

I will have to replace the fluid in these old tweeters as there is no way they can go back into their original speakers like they are now. Well hopefully these five visaton per channel will last longer because they are only having to do a fraction of the work that one has to do and so will not heat up as much.

These speakers are now sounding as crisp as an iceburg lettuce with more detail and composure. How much better can these things get, they must have been really bad to start with and I am running out of hyperbole. I said in the past that i did not think it was an issue to have all those different tweeters that I was using. I was clearly talking Don't believe a word I say.

The cone tweeters that I was using wouldn't have had the issues with dried up ferrofluid that these two pairs of 1" metal domes have but they were full range cheapies pulled out of broken portable CD players. Oh well they did their job and proved the concept to me.

I can't wait to get the last pair swapped out to be totally visaton in the tweeter department. I may well have to tweak things again depending on how much more high frequency content I get . It does seem to have cleaned things up a little across the board.

I know, I know - plenty of subjective twaddle in that lot.

Swopped in the last pair of visaton G20sc (out firing) first thing this morning. Listening whilst I do my paper work (back still not right). Very nice, good riddance old 1" metal domes with dried up ferrofluid. Hello all crispy new fabric domes

I played four hours of non stop music. Then decided I was going to remove the rear firing visaton pair. Done that and now listening to same music I played this morning. I am not missing the rear firers so they are not going back in It actually sounds better without them. Of course the crossover point has changed ( less impedance in the series tweeter circuit and the 1uf Russian PIO cap is still in) and is now more in line with what it should be. So four tweeters is how it's gonna be - at least something has been decided

It's amazing what small little changes can accomplish. As always when doing it all by ear nothing can be stated as fact, it's all speculation. My ears like it though which is what matters.

So why did I decide to remove the rear firing tweeters ? Well previously they were firing into 20" deep window recesses. Now they are three inch from a wall. I think the sound waves were bouncing around at the back there. That's my theory, as usual could be bollox

Apologies for hijacking this thread but was planning to maybe doc mod some Royd bookshelf speakers.
Checking the archives it seems Richards mods were
Remove wadding and ports
Fit steel sheet plates 6mm sides 20mm base ?

Do you need plates on back top and front ? What size plates ie full size to line inside completely or just smaller plates on each surface. I know Joe Ackroyd did the latter on Revolution RR3 speakers .
Thanks

Put steel on every available space. 20mm in the bottom was to stop it rocking when loud bass heavy music played. One plate covering most of the panel is probably best but i haven't compared. I went to the extreme of fitting angle iron in all the corners as well but i don't think you need to go that far.

The Doc mod process is full of pitfalls for the unwary. Aluminum cone speakers can't be doped especially the continuous cone ones. Most drivers with low Qts (which are suitable for bass reflex) will lose a lot of bass output when you seal the box up = unhappy camper. The doped drivers that Doc used to sell are quite high in the Qts department (suitable for closed box) and that is increased even further when they are doped.

You may get lucky though if the driver Qts is on the border line between suitable for vented or closed.

Many thanks.
Probably limited as boxes are sealed and removing backs could cause more damage. So I can put up to 115mm wide pieces in through driver cut out. Should still make a difference I hope.

Last night I was ready to throw everything in the bin. Funny how your mood can affect things. I even thought about getting this



Looks fantastic, probably sounds good in a orderly kind of way. Full of new devilry like room correction, several class D amplifiers, wireless connectivity. Feck me can it wipe yer arse as well?

I am sick of thinking about capacitors, resistors, ohm's law, hoffman's iron law and hifi now. It's getting in the way . I just want to sit back and listen to bloody music.


Recording quality really fecks me off at the moment. Some albums can sound really fantastic especially blue Note's offerings. But then others sound really loud and over blown. Why the need to turn all the sliders up to 11 ? Fecked off of North Yorkshire. I refuse to let my sound system dictate what I listen to. Listening to youtube through the telly I don't have to deal with all this bollox.

How about this ? I love it