This phase thing

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Scottmoose
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#46 Re: This phase thing

Post by Scottmoose »

Hmm. Interesting points Mark. In the same order,

1/ If by that it's meant speaker variations tend to have a greater influence in a macro sense than many other parts of a system, I'd probably agree, assuming the rest is set up & working well.

2/ No customers; as I made clear that speaker was designed as a favour, but yes, it had a specific set of goals. I don't personally get much pleasure from random dabbling; no issue with it, different strokes for different folks, but I'm lousy at construction, and prefer the 'design' & listening part. Re a 3rd or 4th order on a ribbon -rarely. The two speakers Colin & I have with ribbons for e.g. use low Q 2nd order filters. I would never use less than that with a small ribbon / planar variation at relatively modest XO frequencies -partly to ensure an ample margin of power-handling, but also because of the piercing distortion almost all of them possess toward the bottom of their range.

The ideal from my perspective, contrary to what is assumed from certain quarters, is to use the lowest order acoustic slopes practical for the intended use and goals. You need to factor the electrical order into that as well; I rarely use 1st order high pass filters at all < about 10KHz simply because they cannot prevent driver excursion from increasing below the XO frequency, and that rarely does performance many favours in my experience -I can usually hear the tweeter protesting, unless it gets help from other quarters, which usually means more components. On the other hand, I'm rather partial to a low Q 2nd order, especially if you work it so you obtain what amounts to a 6dB/octave slope at the XO frequency & for perhaps an octave below before increasing to a higher order acoustic rolloff. All of which is of course assuming it is actually practical to use low order XO slopes with the drivers employed, which is not always the case.

Re phase rotation, to the best of my knowledge it is not universally accepted (far from it) that the phase rotation at the XO frequency / transition band of higher order filters has such catastrophic effects on female vocal tone as you state. I can think of plenty of speakers with higher order XOs that sound superb on female vocals. Depends exactly what you're doing and how, and the listener. Personally I prefer the shallowest slopes practical; when they are not practical, I try to compensate via other means if necessary. That's just part and parcel of design, and one of the most interesting aspects of it for me. We're all picking from compromises -if I see one more advert marked 'designed without compromise...' ;)
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IslandPink
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#47 Re: This phase thing

Post by IslandPink »

Scottmoose wrote: Mon Apr 10, 2017 7:36 pm On the other hand, I'm rather partial to a low Q 2nd order, especially if you work it so you obtain what amounts to a 6dB/octave slope at the XO frequency & for perhaps an octave below before increasing to a higher order acoustic rolloff.
Yes, agree & rather like this and used it to my satisfaction with a revised version of Dick Olsher's crossover on the FE208Ez/G3 on OB . Chris V likes this approach too. I am using a 6dB LP (amp) slope on the current folded horn but with speaker-side choke to steepen this beyond 1.5k.

Scottmoose wrote: Mon Apr 10, 2017 7:36 pm Re phase rotation, to the best of my knowledge it is not universally accepted (far from it) that the phase rotation at the XO frequency / transition band of higher order filters has such catastrophic effects on female vocal tone as you state. I can think of plenty of speakers with higher order XOs that sound superb on female vocals. Depends exactly what you're doing and how, and the listener. Personally I prefer the shallowest slopes practical; when they are not practical, I try to compensate via other means if necessary. That's just part and parcel of design, and one of the most interesting aspects of it for me. We're all picking from compromises -if I see one more advert marked 'designed without compromise...' ;)
Oh ... there's a whole load of stuff that isn't universally accepted, but I don't go on the majority view on loudspeakers - that way leads madness ( sorry DIY Audio :D )
I haven't heard many conventional 2-ways sounding good on female vocals - perhaps I think,.... Art Audio ( was it ? ) with the cut-cone ScanSpeaks , not sure how the crossover was done there. Lynn's Ariels are very good but not world-class.

My own very limited list of truly successful female vocal set-ups are :

Quad 989's driven by my build ( and probably anyone else's ! ) of Lynn's Aurora PP 300B amp - maybe 57's would be even better ?
James's Quasars ( AER's working mainly in this range ) driven by Steve C's 6B4G SE with shunt-reg supply. Showed things on 'Save me' by Joan Armatrading that I've never heard before or since.
Chris661's Enable-d FE126e's in small MLTL's driven by small 6EM7 amp with Suzanne Vega.
My current set-up with 288H's into Yuichi 415Hz plus Aurum G3 ribbon coming in (1st) above 6kHz, 4P1L/300B amp :oops:
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#48 Re: This phase thing

Post by vinylnvalves »

This year at the Scalford HIFI show, Linn had a room in which they were demonstrating their exakt DSP system. They built the crossovers up step by step, explaining as went what was happening, with the same pieces of music being played at each stage. I can categorically say that when they had tweeted the FIR files to give a linear phase response throughout, the results were like night and day. Dave and myself had gone into the lecture/demo very sceptical what could be gained over classic IIR filters coming out depressed that our active systems could be significantly better, with FIR filters. Not willing to part with £4K for th linn system I am currently trying to write some FIR filters with rephrase, that I can plug into the Nadja if I have enough processing power.

Generally this year all the best sounding systems were active, with a system by "looper" which cost less than £300 with cheap drivers and FIR filters playing through a AV amp - leaving most high end speakers systems at the show in its wake. Speaker designers tricks like the " audio note" bloom and other non flat responses can be programmed in so the designers ear is being used in a different way.

So linear phase is audible and is why speakers such as the Kiii and the Grimm ls1 are some of the best around. For us diyers as processing becomes trivial in the next generation of DSP chips - FIRs will become the mainstay, allowing us to use cheap nonlinear drivers with good results.
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Dr Bunsen Honeydew
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#49 Re: This phase thing

Post by Dr Bunsen Honeydew »

Active is just another over complication borrowed from the pro market, and just like balanced lines it is marketing bullshit. When the marketing men are looking for something new to sell, one of their fav sources is the pro market, even if it is completely irrelevant to a domestic music situation.

The added complication of gumf in the signal path is even worse than a Moose crossover design. What seems to be not realised is that a simple (non phase damaging) passive crossover can sit at both output level as normal and at line level, all that is needed is to build in voltage gain to compensate for what is lost through the filters. Advantage FAR less gumf sitting in the signal path getting in the way of the music. BUT it does complicate the line level interface between pre and power which will need compensating for. I have done it, and it works, and is musically far better than op amp driven electronic filters fecking up the music. BUT IMO it shows no real advantage musically over speaker level crossovers and certainly not over doing the work of those filter mechanically.

It seems to me most of you have got trapped in the "look how clever I am" ego thing of over complicated hi-fi, creating damaged music, it is an intellectual process. You all really need to stop and think and backtrack to a simpler age and realise you have lost it - provable and I keep saying we can do it but no one seems interested. Nick is getting my Doc Mod B&W to try (when I get strong enough packing) so that may be a start, who knows but I don't hold my breath, I am too used to being a lone voice who just gets sneered at.
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#50 Re: This phase thing

Post by pre65 »

Dr Bunsen Honeydew wrote: Tue Apr 11, 2017 12:01 am

but I don't hold my breath, I am too used to being a lone voice who just gets sneered at.
I wonder why Richard, have you ever given any real thought to that conundrum ?
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#51 Re: This phase thing

Post by Cressy Snr »

Here we are again
Happy as can be
All good pals
And jolly good companee :x :x :x


Give it a bloody rest Phil........PLEASE?
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#52 Re: This phase thing

Post by pre65 »

Cressy Snr wrote: Tue Apr 11, 2017 8:29 am Here we are again
Happy as can be
All good pals
And jolly good companee :x :x :x :x :x :x :x :x
Perhaps if Richard came to Owston and met us all things could be more harmonious ?
The only thing necessary for the triumph of evil is for good men to do nothing.

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Scottmoose
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#53 Re: This phase thing

Post by Scottmoose »

Linear phase outright is an interesting concept; unfortunately it can't really be achieved in the analogue domain. You can ~'fake it' with various techniques e.g. Dulund, Spica etc., but only to a point & by making big sacrifices elsewhere. Ditto for using hyper-minimalist filters. Whether those sacrifices are worth it is very much a case of YMMV. There's a danger of focusing so much on one specific that it may be to the detriment of others. The Linn demo is very interesting but should also be seen within the context of what it is: an infomercial designed and optimised to sell their own product, using that equipment, with those drivers, cabinets, electronics and that room on that day in history. So I'd be wary of assuming universal applicability.

As a vaguely related aside though (since we're dancing in the fringes of electronic manipulation) -one of the most astonishing changes in performance I've ever heard was a back-to-back replay of a track through Foobar and then Bug Head Emperor media player. I hadn't the faintest idea what was going on, I was simply plonked in a chair and told 'listen' with no further information. No preconceptions or bias for obvious reasons, just me 6 minutes later scratching my head thinking 'bloody hell'. Because it really was a massive change, in that case, for the better. Major downside with Bug Head: you need a lot of RAM (16Gb really), a fast processor & some patience for it to load up. The interface is lousy and it's designed by a Japanese chap who doesn't speak English very well. There's a host of functions to play with also. So it takes a bit of digging to get set up right. Spline interpolation so I gather, specifically aimed at 16/44 data. Maybe. Difficult to find out. If so, I have mixed feelings about that, but since it's free, you lose nothing by trying it out. To be honest, I rarely bother, my PC doesn't have the number-crunching capacity to make it realistic all the time. If you've the patience and some processing clobber at your disposal though -certainly worth a look.
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Greg
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#54 Re: This phase thing

Post by Greg »

Interesting. I know several well respected audio hobbyists who, despite the difficulties, persist with Bug Head, so it must have something. I'm far too thick in that area to even contemplate trying it. I'll happily pay my subscription to Roon and let them do it all for me. :D
Last edited by Greg on Tue Apr 11, 2017 10:58 am, edited 1 time in total.
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#55 Re: This phase thing

Post by Ali Tait »

Greg, do you find Tidal sounds better through Roon than on it's own, or is it just ease of use that's better?
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Nick
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#56 Re: This phase thing

Post by Nick »

Just thinking, what is the legal implications (copyright) of such mathematical processing. Does it count as creating a derivative work?
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#57 Re: This phase thing

Post by Greg »

Good question, Ali and maybe relevant to what's being said on TAS. I always play through Roon and it's excellent. Nick is the man to ask, but yes, my understanding doing it my way gives the best sound. When people question the reproduction quality of Tidal, I just don't get it. I've never had my sound so good and what's more it's all totally satisfying. Just switch on, listen and enjoy. I can't remember the last time I had my system listening ears on. It's just the music these days :D
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#58 Re: This phase thing

Post by Dr Bunsen Honeydew »

Getting back to phase in speaker crossovers :roll: Ok we have had good work from Nick that has opened both good results and good additional questions, do we continue with this work or is that it!

My offer to make the process empirical and not just about theory and computer simulations still stands, will the forum take it on.
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#59 Re: This phase thing

Post by Ali Tait »

Greg wrote: Tue Apr 11, 2017 10:56 am Good question, Ali and maybe relevant to what's being said on TAS. I always play through Roon and it's excellent. Nick is the man to ask, but yes, my understanding doing it my way gives the best sound. When people question the reproduction quality of Tidal, I just don't get it. I've never had my sound so good and what's more it's all totally satisfying. Just switch on, listen and enjoy. I can't remember the last time I had my system listening ears on. It's just the music these days :D
Yes agreed, SQ is excellent, particularly with the new dac.
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#60 Re: This phase thing

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Nick wrote: Tue Apr 11, 2017 10:53 am Just thinking, what is the legal implications (copyright) of such mathematical processing. Does it count as creating a derivative work?
Greg should be along any time to give some advise that isn't appalling :mrgreen:
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