Why do Proac 2.5 clones fail?

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academia50

academia50

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Joined 2013
Joel Wesseling said:
Understand. Thanks academia50

Thinking more about diffusion designed at about 1khz and above on the ceiling. With the delay above 10ms , I'm curious how that would sound.
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I wouldn't delay them, I don't think it helps, but I have to admit that I only use DSP to extend the response of my main cabinets from 40 Hz down with two 18 "subwoofers ... I like to hear defined and clean bass, rich in harmonics and I think that there the relationship between the SD of the speakers and the size of the room matters, but up to a reasonable limit. This is the famous iron law of cabinets, you must choose two out of three, you can never have all of them to the time.
 

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Joel Wesseling

Joel Wesseling

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The main issue with the 2.5 is excessive energy and ringing at 50hz due to the box alignment as shown on post 23 on this thread.. The big room helps to dissipate the problem - Next visit I'll measure..

I'll be designing a 4way dual 10 or 12" woofer speaker system for the room. A big step up in headroom..
 
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dudaindc

dudaindc

Member
Joined 2005
PB2 said:
I was unable to find Troels' excellent paper on his site so downloaded it from Wayback (2013):
Had to split it into PART 1 and 2 due to forum file size limits.
On page 19 he gives a summary (probably up to that point):
Version 1 is a clone of the original (not sure if this is a best guess or traced out from a real one)
Version 2 There is a noted 2 KHz bump, this adds an LCR to tame the bump.
Version 3 Is a crossover mod for an even smoother response than Version 2.

There are more versions that include modding the drivers and using a different tweeter,
read on in the document to learn about them.
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THANK YOU!
 
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mikeandmar

Banned
Joined 2004
Joel Wesseling said:
"Received an Exorbitant Price Quote from the USA ProAc Distributor so I have to ask;"

Likely, they will send you standard 18w-8535, same as you can order from likes of Solen for example! No proac name stamped on frame.
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The proper ProAc stamped and the non-ProAc stamped woofers are still available, these were purchased from the Canadian distributor Crown Mountain Imports in 2018. And yeah....they were pricey :-(
 

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D

DJLEC

Member
Joined 2021
mikeandmar said:
The proper ProAc stamped and the non-ProAc stamped woofers are still available, these were purchased from the Canadian distributor Crown Mountain Imports in 2018. And yeah....they were pricey :-(
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What exactly is the difference with the SS 18w-8535 Woofers. The blown one that I pulled from my 2.5 does not resemble your Photo with the ProAc Stamp.

I ordered one SS 18W-8535 from Madisound since they only had one and I will order a second one when available since I will change both of them.

What differences are there between a Non-ProAc Stamped Woofer in comparison to the Madisound SS 18w-8535?
 
D

DJLEC

Member
Joined 2021
celef said:
I believe the rim of the basket is what differs, proac might have changed this due to all clone speakers

But i guess we really do not know, as far as i know there has not been any real comparsion between a standard 8535 and a proac 2.5 woofer
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Many thanks for your comments. For the last number of Weekends I have been listening to the 2.5's with the 1 New Woofer installed from Madisound and I am assuming the other Woofer is an Original ProAc Woofer since I purchased the 2.5's used.

I can not hear any difference musically between the two Woofers but when available I will still change the other Woofer due to age.
 
tiefbassuebertr

tiefbassuebertr

Member
Joined 2005
tiefbassuebertragung.de
PB2 said:
I was unable to find Troels' excellent paper on his site so downloaded it from Wayback (2013):
Had to split it into PART 1 and 2 due to forum file size limits.
On page 19 he gives a summary (probably up to that point):
Version 1 is a clone of the original (not sure if this is a best guess or traced out from a real one)
Version 2 There is a noted 2 KHz bump, this adds an LCR to tame the bump.
Version 3 Is a crossover mod for an even smoother response than Version 2.

There are more versions that include modding the drivers and using a different tweeter,
read on in the document to learn about them.
Click to expand...
thank you for posting this PDF files.
The main issue resp. main deficiency (even on the genuine ProAc version) is the floor-standing cabinet and the resulting undesirable sound radiation through the cabinet. The stabilization steps in fig. 32 (page 17) and 36 (page 18 in the pdf attachment) do not eliminate this unwanted effect, but rather shift the frequency range higher to where voices have the highest energy.
I know this exact, because a comparison of two speakers with the same drivers but different cabinet outlines clearly showed that a floor-standing cabinet (compared to a compact cabinet in a bookshelf format) was significantly worse in terms of sonic quality (strong colored sound in the upper bass and lower mids similar explanation are to read in post #1 under
https://www.diyaudio.com/community/threads/proac-2-5-clone-cabinet-problem.119469/).
The only disadvantage in the bookshelf format was the lack of blackness in the bass (higher f3) - all other characters in sonic character were better (only to note in a closed version - unfortunately not in a vented version).
check out also this URL:
https://web.archive.org/web/2007042...eakers/scanspeak/classic/tekening/event_1.htm
 
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