PERSPEX QUASAR ver 2.0 prototype build

Dedicated to those large boxes at one end of the room
User avatar
Paul Barker
Social Sevices have been notified
Posts: 8875
Joined: Mon May 21, 2007 9:42 pm

#31 Re: PERSPEX QUASAR ver 2.0 prototype build

Post by Paul Barker »

I know Perspex is fantastic but expensive. I may try Briggs’s sand filled front panel. I thought my plasterboard panels sounded good, maybe boost those with a skin of sand held in place with a plywood frame sandwiching with plasterboard layer of sand fill between.
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
User avatar
Ali Tait
Eternally single
Posts: 4374
Joined: Fri Jun 08, 2007 8:10 pm
Location: Galashiels

#32 Re: PERSPEX QUASAR ver 2.0 prototype build

Post by Ali Tait »

I was given some material by John G- a highly compressed foam type material that I think would be ideal for OB baffles and TT plinths. If John’s amenable it could be used for this?

It’s currently in Leeds so could be picked up Nick?
Ant
Shed dweller
Posts: 2332
Joined: Mon Jul 31, 2017 6:45 pm
Location: Yorkshire

#33 Re: PERSPEX QUASAR ver 2.0 prototype build

Post by Ant »

Cast resin?
If folks can make tables out of it there's no reason I can see that the same methods wouldn't work for an o/b
Also starring Rex Hamilton as Abraham Lincoln

www.bte-designs.weebly.com
SimonC
Old Hand
Posts: 545
Joined: Mon Sep 24, 2007 11:34 am
Location: West Yorkshire

#34 Re: PERSPEX QUASAR ver 2.0 prototype build

Post by SimonC »

Ant wrote: Mon Jun 01, 2020 1:56 pm Cast resin?
If folks can make tables out of it there's no reason I can see that the same methods wouldn't work for an o/b
Its surprisingly easy to work with, its all in the preparation and having somewhere dust free to pour it. Vacuum de-gassing helps if you are going for see-through perfection, but for anything tinted or opaque you can get great results by being careful with the mixing and pouring. Loads of info on the internet, just look for resin river tables to get the basics.
JohnG
Old Hand
Posts: 418
Joined: Sat Mar 25, 2017 10:59 am

#35 Re: PERSPEX QUASAR ver 2.0 prototype build

Post by JohnG »

[quote="Ali Tait" post_id=176400 time=1591015380 user_id=21]
I was given some material by John G- a highly compressed foam type material that I think would be ideal for OB baffles and TT plinths. If John’s amenable it could be used for this?

Hi Ali
The Phonotherm is yours to decide how it is used, I am amenable with any usage that will produce a Prototype and test it.
If there is a wish to check out the Materials Properties, it can be found under Phonotherm or Purinit.

When it was passed onto yourself it was intended for use as part of an Open Baffle Design, so your redirection is in keeping with the the original plan put in place for it..
If it helps I believe the 2 Boards you received at Owston 2019 were H 1500mm x W 700mm x D 30mm

The Link is to a Company that works with Plastic Sheets, they do Bespoke work as well.


https://www.puffinplastics.co.uk/store/ ... rylic_no_4
User avatar
The Stratmangler
Shed dweller
Posts: 2890
Joined: Fri Aug 24, 2007 1:50 pm
Location: Rossendale, Lancashire

#36 Re: PERSPEX QUASAR ver 2.0 prototype build

Post by The Stratmangler »

I popped in at Colin's place today, and had a quick listen to the drivers run full range, and without crossover.
To clarify, I heard the Lii drivers on their own, and then I heard the Supravox drivers on their own.

I like the Supravox drivers.
They sound really good, and image remarkably well (so good presence).
Chris :happy3:
User avatar
Paul Barker
Social Sevices have been notified
Posts: 8875
Joined: Mon May 21, 2007 9:42 pm

#37 Re: PERSPEX QUASAR ver 2.0 prototype build

Post by Paul Barker »

Great
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein
User avatar
IslandPink
Amstrad Tower of Power
Posts: 10041
Joined: Tue May 29, 2007 7:01 pm
Location: Denbigh, N.Wales

#38 Re: PERSPEX QUASAR ver 2.0 prototype build

Post by IslandPink »

I was hoping you'd say you like the Lii drivers !
"Once you find out ... the Circumstances ; then you can go out"
User avatar
Ali Tait
Eternally single
Posts: 4374
Joined: Fri Jun 08, 2007 8:10 pm
Location: Galashiels

#39 Re: PERSPEX QUASAR ver 2.0 prototype build

Post by Ali Tait »

Phonotherm, that was it. I’d forgotten what it was called.

Yours to use if you want it Nick.
User avatar
Toppsy
Shed dweller
Posts: 2400
Joined: Mon Jul 23, 2007 12:10 pm
Location: red rose country

#40 Re: PERSPEX QUASAR ver 2.0 prototype build

Post by Toppsy »

IslandPink wrote: Mon Jun 01, 2020 6:26 pm I was hoping you'd say you like the Lii drivers !
I have pondered long and rewritten this initial driver listening feedback a few times not wishing to paint a wrong impression of the Lii Audio Fast-10s driver.

From Chris's posting above you would be right to think that both he a me did not endear ourselves to these Lii Audio Fast-10s drivers. They were a little disappointing after all the hype we have read about them. This personal opinion needs some qualifying.

As Chris said the Lii drivers were driven on their own without any filtering via a 300b SET amp. This is not how they are intended to be used in the Quasar's but folk seemed eager to my opinion how these sounded. My opinion may not reflect other folks listening experience and I may be influenced by my prejudice towards wide band drivers with whizzer cones. We all like and dislike different things, right?

To be fair to the Lii driver, I don't believe the quasar baffles are right for this driver as a single stand alone wide-bander without filtering and/or bass/super tweeter assist. I reckon It either needs a much wider baffle if used such or mounted in a big box to do it justice. It also should be noted as said above that both Chris and I generally do not like wideband drivers with whizzer cones. Notwithstanding this I had high hopes for this one.

Most, if not all, similar type wideband drivers, I have heard I can hear the whizzer adding a certain nastiness. We heard sibilance and a tizzyness on Nick Drake voice on his album Five Leaves Left that we both attributed to the whizzer. This issue was also heard on other albums we listened to. But the biggest failing was a lack of harmony and tone that made the sound rather dry in comparison to the Supravox. Like Chris, I also rate and like this Supravox a lot. It simply is in another league.

Having said all that the jury is out until I have had the opportunity to listen to the full design with both drivers hooked up to the 300b SET and through the series and parallel XO'ers. I'm sure the whole will integrate much better. As said this is just my opinion and should not be taken as anything other than that. Nick has yet to listen to these speakers and he has a much better perception and a keener 'ear' than me and he picks up and nuances' in the sound that I definitely do not pick up on so I'm really keen for Nick's opinion.

Should get the XO'ers up and running by Wednesday so I can then invite Nick over. Tomorrow I'm off for my first ride on the Harley since lockdown.

Apologies if this has been a long and pontificating rant.

Edit: If you check out the photos of the Lii Audio Crystal 10 replacements to the Fast-10s you may observe they have made changes to the whizzer by adding a shall rounded profile around the lip of the whizzer. To me this indicates the designers were aware of this whizzer issue and have made some attempt to rectify the problem.
Last edited by Toppsy on Mon Jun 01, 2020 8:17 pm, edited 1 time in total.
User avatar
Toppsy
Shed dweller
Posts: 2400
Joined: Mon Jul 23, 2007 12:10 pm
Location: red rose country

#41 Re: PERSPEX QUASAR ver 2.0 prototype build

Post by Toppsy »

Another question for JamesD (sorry James).

Are there any specific boundary considerations when positioning the speakers?
User avatar
IslandPink
Amstrad Tower of Power
Posts: 10041
Joined: Tue May 29, 2007 7:01 pm
Location: Denbigh, N.Wales

#42 Re: PERSPEX QUASAR ver 2.0 prototype build

Post by IslandPink »

Toppsy wrote: Mon Jun 01, 2020 8:02 pm
Apologies if this has been a long and pontificating rant.
Nothing of the sort. Sounded like an honest appraisal of them after some listening. Thanks !
"Once you find out ... the Circumstances ; then you can go out"
User avatar
Toppsy
Shed dweller
Posts: 2400
Joined: Mon Jul 23, 2007 12:10 pm
Location: red rose country

#43 Re: PERSPEX QUASAR ver 2.0 prototype build

Post by Toppsy »

IslandPink wrote: Mon Jun 01, 2020 8:16 pm
Toppsy wrote: Mon Jun 01, 2020 8:02 pm
Apologies if this has been a long and pontificating rant.
Nothing of the sort. Sounded like an honest appraisal of them after some listening. Thanks !
Thanks Mark.
I have added a EDIT to the bottom of my appraisal posting regards what looks like whizzer profile changes on the new Crystal 10 replacements.
JamesD
Old Hand
Posts: 997
Joined: Tue Oct 09, 2007 4:26 pm
Location: North Yorkshire

#44 Re: PERSPEX QUASAR ver 2.0 prototype build

Post by JamesD »

There are no real boundary considerations with the Quasars - I've used then hard in the corners of a room 10' by 12' and right out in some very large rooms with the nearest boundary 10' away and they sound much the same in both situations. They are designed to be tolerant of positioning.

Having said that - there is, of course, some room interaction but the boundary concerns are below the effect of the room modes itself. The biggest effect is if they are not sitting flat on the floor - that can effect the low end response and the way the speaker interacts with room modes.

Agree about the excellence of the Supravox driver - I have used then in the QUasar on there own and found the music came through and could be enjoyed - its why they could keep up with the AERs to the degree that they did.

On the Lii AUdio drivers it should be said that all full range drivers tend to have a running in period where they sound below there best - hopefully they will improve...

Never a problem to respond to questions - feel free to ask away...

I might not be right but I'll always have an answer :D
chris661
Shed dweller
Posts: 2556
Joined: Mon Feb 22, 2010 7:29 am
Location: Sheffield

#45 Re: PERSPEX QUASAR ver 2.0 prototype build

Post by chris661 »

Just a thought, Colin, that the Lii drivers might be like the Fostex FE range, which needed a good thrashing (I played the FE126Es with music with lots of bass aiming for ~5mm p/p cone travel for hours on end) before they got close to acceptable.

There's also the option of putting some foam between the whizzer and main cone to dampen whizzer resonances. IIRC Dave at Planet10 found that improved things.

I remember being impressed by the 8" Tang Band drivers that I heard at your place a good few years ago - time flies.

Cheers,
Chris
Post Reply