DCAudioDIY.com

DC Area Audio DIYer's Community
It is currently September 13th, 2025, 12:00 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 42 posts ]  Go to page Previous  1, 2, 3, 4, 5  Next
Author Message
 Post subject: Re: A Little About JBL
PostPosted: September 11th, 2025, 2:00 pm 
Offline

Joined: July 17th, 2016, 6:24 am
Posts: 1150
cport wrote:
Quote:
@Cogitare magis: Crossover points have nothing to do with the concept of eliminating reflections.


Non Logica. The phase plug (as you state) is designed to prevent "high-frequencies" from self cancelling [the size and positioning of the phase plug only impacts higher frequencies, reflecting them outward, and is transparent to lower frequencies] -- so your statement makes zero sense -- if the driver is not fed frequencies (via the crossover) that the phase plug could impact, then the cone will not move, and there will be no reflections that it will correct for -- so crossover points have everything to do with "maintaining linearity" of a driver.


You dont understand the concept of transparency here. The ear canal is approximately 1cm in diameter. If we hear only those waves that are smaller than 1cm in wavelength, we should not hear anything less than 30kHz.

Point is, when you place an obstruction in front of a sound source, it reflects the sound back. Amount of reflection depends upon how much of the source is obstructed. If the wavelength of the source is significantly larger than the obstruction, then only that part of the source is reflected back, and most of the wave will go around the obstruction. That is the concept of "transparency". Transparency does not mean 100% of the sound magically navigates around obstructions to reach its destination.

Quote:
if the driver is not fed frequencies (via the crossover) ...


Crossovers DO NOT cut-off frequencies. Frequencies just attenuated on a sliding scale (slope). So, ALL frequences are still fed to the drivers on both sides of the crossover. The amplitude the signal reduces as you go far away from the crossover point.


Top
 Profile  
 
 Post subject: Re: A Little About JBL
PostPosted: September 11th, 2025, 2:41 pm 
Online
User avatar

Joined: February 28th, 2013, 3:31 pm
Posts: 1842
Cogito wrote:
cport wrote:
Quote:
@Cogitare magis: Crossover points have nothing to do with the concept of eliminating reflections.


Non Logica. The phase plug (as you state) is designed to prevent "high-frequencies" from self cancelling [the size and positioning of the phase plug only impacts higher frequencies, reflecting them outward, and is transparent to lower frequencies] -- so your statement makes zero sense -- if the driver is not fed frequencies (via the crossover) that the phase plug could impact, then the cone will not move, and there will be no reflections that it will correct for -- so crossover points have everything to do with "maintaining linearity" of a driver.


You dont understand the concept of transparency here. The ear canal is approximately 1cm in diameter. If we hear only those waves that are smaller than 1cm in wavelength, we should not hear anything less than 30kHz.

Point is, when you place an obstruction in front of a sound source, it reflects the sound back. Amount of reflection depends upon how much of the source is obstructed. If the wavelength of the source is significantly larger than the obstruction, then only that part of the source is reflected back, and most of the wave will go around the obstruction. That is the concept of "transparency". Transparency does not mean 100% of the sound magically navigates around obstructions to reach its destination.


Quote:
if the driver is not fed frequencies (via the crossover) ...


Crossovers DO NOT cut-off frequencies. Frequencies just attenuated on a sliding scale (slope). So, ALL frequences are still fed to the drivers on both sides of the crossover. The amplitude the signal reduces as you go far away from the crossover point.



The definition of "cutoff" depends on the slope of the crossover. At high slopes such as 48 or 96 dB/octave, for all practical purposes the audible effect of the crossover is that the sounds are cut off. Another thing to remember is that if the crossover is less than 2nd order (12 dB/octave), cone excursion will continue to increase on the low side of the crossover point, adding more excursion and probably higher distortion.


Top
 Profile  
 
 Post subject: Re: A Little About JBL
PostPosted: September 12th, 2025, 10:56 am 
Offline
User avatar

Joined: January 15th, 2015, 7:19 am
Posts: 1747
Location: Baltimore MD
I have never met a JBL that I liked, including the Everest


Top
 Profile  
 
 Post subject: Re: A Little About JBL
PostPosted: September 12th, 2025, 11:16 am 
Offline
User avatar

Joined: July 24th, 2015, 4:17 pm
Posts: 1829
Location: Parkville, Maryland
Pelliott321 wrote:
I have never met a JBL that I liked, including the Everest

It is interesting that you mentioned the Everest. That is modern JBL's flagship speaker system that is yours for a mere $70,000. Yet -- they were dumb enough to publish photos of their "state-of-art" crossover.

The three-way crossover (woofers -- mid-range horn -- treble horn) was built around bi-polar aluminum electrolytic capacitors. WTF?! And as you can imagine that's what apparently usurps the possibility that they could have been great speakers and not the super expensive mediocre devices that are being sold.

If I had the surplus of funds I would love to get my hands on a pair to have my way with them to experience what the Everest playback performance could be with a crossover-network appropriate for a $70,000 speaker system.

_________________
Walt


Top
 Profile  
 
 Post subject: Re: A Little About JBL
PostPosted: September 12th, 2025, 11:20 am 
Online

Joined: July 8th, 2016, 4:34 pm
Posts: 615
I would convert them to an active system with a dspNexus dsp/crossover.


Top
 Profile  
 
 Post subject: Re: A Little About JBL
PostPosted: September 12th, 2025, 11:35 am 
Online
User avatar

Joined: February 28th, 2013, 3:31 pm
Posts: 1842
brombo wrote:
I would convert them to an active system with a dspNexus dsp/crossover.

That would be a great choice. I have an article appearing in the November issue of audioXpress with my impressions of the Nexus I have formed over several year use.


Top
 Profile  
 
 Post subject: Re: A Little About JBL
PostPosted: September 13th, 2025, 9:55 am 
Offline
User avatar

Joined: January 15th, 2015, 7:19 am
Posts: 1747
Location: Baltimore MD
I think DSP is perfect for subwoofers only, anywhere else in the system and you get noise and distortion. Nothing beats a well-designed and sorted passive xover.
Why would anyone put all that crap between you and the music is beyond me.
Forget about the bits and bytes and listen to the music. Go to a live musical event and listen to what real music sounds like then go listen to your system and compare.
Numbers mean absolutely nothing, listen with your heart and soul not your brain and get off the equipment go around circus and chaos.


Top
 Profile  
 
 Post subject: Re: A Little About JBL
PostPosted: September 13th, 2025, 9:59 am 
Online

Joined: July 8th, 2016, 4:34 pm
Posts: 615
So it is my imperfect ear verses measurements like these -

https://www.audiosciencereview.com/foru ... iew.35661/


Top
 Profile  
 
 Post subject: Re: A Little About JBL
PostPosted: September 13th, 2025, 10:22 am 
Offline

Joined: July 17th, 2016, 6:24 am
Posts: 1150
brombo wrote:
So it is my imperfect ear verses measurements like these -

https://www.audiosciencereview.com/foru ... iew.35661/


If the measurements tell everything about speakers, what is need for auditions?

Can you deny the fact the two speakers might measure the same but sound totally different?


Top
 Profile  
 
 Post subject: Re: A Little About JBL
PostPosted: September 13th, 2025, 10:44 am 
Offline

Joined: July 17th, 2016, 6:24 am
Posts: 1150
Pelliott321 wrote:
I think DSP is perfect for subwoofers only, anywhere else in the system and you get noise and distortion. Nothing beats a well-designed and sorted passive xover.
Why would anyone put all that crap between you and the music is beyond me.
Forget about the bits and bytes and listen to the music. Go to a live musical event and listen to what real music sounds like then go listen to your system and compare.
Numbers mean absolutely nothing, listen with your heart and soul not your brain and get off the equipment go around circus and chaos.


Last year at Capital Audio Fest, I saw Rich demonstrate benefits of digital room/system corrections. The benefits are palpable for sure.

Ok, but what about preserving the purity of the signal? Any corrections in the digital domain will invariably alter the original signals.

Couple of years ago, I was using Linux based HQPlayer for oversampling with a cheap DAC. Was very happy with HQP.

But, since I got the semi-decent Holo Spring 3 DAC, I found myself preferring streaming unaltered signal with Roon directly to the DAC with DAC running in NOS (Non oversampling mode).

I am using 5-way active analog crossover. Wanted to try room correction with HQ Player's convolution engine, so purchased it.

Found myself again preferring non-oversampled signal going directly to the DAC. Gave up on the idea of room correction.

So, I tend to agree with you. Digital crossovers and room corrections are not a good idea, if the goal is purity.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 42 posts ]  Go to page Previous  1, 2, 3, 4, 5  Next

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: brombo, Majestic-12 [Bot], tomp and 81 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group