PERSPEX QUASAR ver 2.0 prototype build
- IslandPink
- Amstrad Tower of Power
- Posts: 10041
- Joined: Tue May 29, 2007 7:01 pm
- Location: Denbigh, N.Wales
#136 Re: PERSPEX QUASAR ver 2.0 prototype build
That's a VERY small picture, Ray !
"Once you find out ... the Circumstances ; then you can go out"
#137 Re: PERSPEX QUASAR ver 2.0 prototype build
Sorry Mark et al, I've tried again...
There doesn't seem to be a website. They seem to be handmade by a small outfit in Indonesia and most of the material I found apears to be on Facebook, which I decline to use. I understand that you can get a proper spec sheet (instead of my screengrab) from the Facebook pages.
If you Google 'Aurel Bryan loudspeakers' you'll find images etc. and some references on DIY Audio - comments about them are positive. Here's one link, from where I grabbed the spec sheet;
https://www.diyaudio.com/forums/multi-w ... ost5215426
There doesn't seem to be a website. They seem to be handmade by a small outfit in Indonesia and most of the material I found apears to be on Facebook, which I decline to use. I understand that you can get a proper spec sheet (instead of my screengrab) from the Facebook pages.
If you Google 'Aurel Bryan loudspeakers' you'll find images etc. and some references on DIY Audio - comments about them are positive. Here's one link, from where I grabbed the spec sheet;
https://www.diyaudio.com/forums/multi-w ... ost5215426
Sorry, I couldn't resist!
#138 Re: PERSPEX QUASAR ver 2.0 prototype build
I think the answer to this question is 'No' but it would be good to confirm.
Assuming the use of a line level passive or active crossover and therefore separate amplifiers, is there any reason why one wouldn't mix a 15ohm Lowther PM6A with an 8ohm bass unit?
Cheers
Assuming the use of a line level passive or active crossover and therefore separate amplifiers, is there any reason why one wouldn't mix a 15ohm Lowther PM6A with an 8ohm bass unit?
Cheers
Last edited by Ray P on Sun Apr 04, 2021 10:30 am, edited 1 time in total.
Sorry, I couldn't resist!
#139 Re: PERSPEX QUASAR ver 2.0 prototype build
No.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
- Scottmoose
- Needs to get out more
- Posts: 1802
- Joined: Sat Sep 08, 2007 11:03 am
- Contact:
#141 Re: PERSPEX QUASAR ver 2.0 prototype build
There's no reason why you couldn't do that with a passive speaker level filter either for that matter. The vast majority of multiway loudspeakers do not use drive units of the same nominal impedance, which is itself an emphemera given that conventional moving coil drive units have varying impedances anyway, at resonance[s] and with coil impedance. I could point out dozens of regular cone & dome designs where the HF impedance trundles merrily over 12ohms & points north. However, concerned that the basic mid-tweeter impedance would be too high for a given amplifier to be happy? Fine: shunt it with a suitably rated resistor or a resistor grid. It'll damp the Fs impedance peak a bit too. Then design your filter with the actual impedance load from driver + resistive damping shunt. Job-jibbed.
'"That'll do," comes the cry of the perfectionist down the ages.' (James May The Reassembler)
Website www.wodendesign.com
Community sites www.frugal-horn.com & www.frugal-phile.com
Website www.wodendesign.com
Community sites www.frugal-horn.com & www.frugal-phile.com
#142 Re: PERSPEX QUASAR ver 2.0 prototype build
Yes, it's obvious when you put it like that Scott. Thanks though.
The reason for the question was actually more related to amplifier choice; if I follow Nick's lead with the PM6A units, the 15ohm silver coil version, which has a very similar FQ to the 8ohm unit, would probably allow me to use my flea-power SE-OTL amps for reasonable volume in a domestic environment - would be good to try that.
Given the LF roll-off of the Lowther units do I even need a crossover filter or could it just be run 'open'?
Hmmm...
The reason for the question was actually more related to amplifier choice; if I follow Nick's lead with the PM6A units, the 15ohm silver coil version, which has a very similar FQ to the 8ohm unit, would probably allow me to use my flea-power SE-OTL amps for reasonable volume in a domestic environment - would be good to try that.
Given the LF roll-off of the Lowther units do I even need a crossover filter or could it just be run 'open'?
Hmmm...
Sorry, I couldn't resist!
#143 Re: PERSPEX QUASAR ver 2.0 prototype build
Best to run with a filter, and preferably before the amplifier if power is limited.
Even if there's an acoustic rolloff, the cone will still be flapping around in response to LF signals - better to leave that job to the bass driver(s).
Chris
Even if there's an acoustic rolloff, the cone will still be flapping around in response to LF signals - better to leave that job to the bass driver(s).
Chris
#144 Re: PERSPEX QUASAR ver 2.0 prototype build
Yep, I expect to have to bandwidth limit the signal to the full-range unit, just concerned about insertion losses but with an active preamp I should be able to compensate for that and still use the flea-power amps.
Sorry, I couldn't resist!
- IslandPink
- Amstrad Tower of Power
- Posts: 10041
- Joined: Tue May 29, 2007 7:01 pm
- Location: Denbigh, N.Wales
#145 Re: PERSPEX QUASAR ver 2.0 prototype build
If it's a flea-power amp, I'm assuming a valve amp, in which case you ought to have a location ( coupling cap ) where you can just alter values to give you a high-pass , rather than adding a filter at the front ?
"Once you find out ... the Circumstances ; then you can go out"
#146 Re: PERSPEX QUASAR ver 2.0 prototype build
Just a quick note that if building a passive series filter Quasar then the Ze & Re does need to be taken into account ..
ciao
James
ciao
James
#147 Re: PERSPEX QUASAR ver 2.0 prototype build
Yeah, I know Mark, but then you have the dilemma of restricting how you can use the amplifier - compromises, compromises...IslandPink wrote: ↑Mon Apr 05, 2021 12:59 pm If it's a flea-power amp, I'm assuming a valve amp, in which case you ought to have a location ( coupling cap ) where you can just alter values to give you a high-pass , rather than adding a filter at the front ?
I have been contemplating one of the Pass designed active crossovers available from the DIY Audio store but this has picqued my interest too;
https://www.diyaudio.com/forums/pass-la ... sover.html
Last edited by Ray P on Mon Apr 05, 2021 7:20 pm, edited 1 time in total.
Sorry, I couldn't resist!
#148 Re: PERSPEX QUASAR ver 2.0 prototype build
I'm planning on building Nelson Pass' SLOB
Sorry, I couldn't resist!
- IslandPink
- Amstrad Tower of Power
- Posts: 10041
- Joined: Tue May 29, 2007 7:01 pm
- Location: Denbigh, N.Wales
#149 Re: PERSPEX QUASAR ver 2.0 prototype build
OK , well, it might be as simple as changing a grid-leak resistor. In which case.... could you provide two resistors, with a quality switch to choose between full-range and high-pass operation ?
"Once you find out ... the Circumstances ; then you can go out"
#150 Re: PERSPEX QUASAR ver 2.0 prototype build
Thanks Mark, food for thought. Another option, given that I have both the 13E1 and 6C33C flea-power SE-OTLs, might be to just use them for different purposes.
Sorry, I couldn't resist!