pete_mac Posted June 23, 2020 Posted June 23, 2020 50 minutes ago, Doc M said: After market Acoustic lens foam Inner Outter out of stock Sadly these are a a cosmetic replacement only and don't perform correctly for acoustic purposes. 31 minutes ago, Doc M said: It appears to me that a specialist foam supplier/manufacturer needs to be considered. Possiblity is, has the nouse to fabricate as well........ food for thought Brian. I'll look into that too. A start. Yes, this would be an option, but to do this properly you'd need to test the original foams and verify the performance of the replacement foam against these. It's an extensive piece of work. There are a multitude of places that can supply foam which is a cosmetic match, and the correctly-sized leather dies aren't too expensive and are extremely accurate... but getting foam with the correct acoustic performance is the hard part.
Doc M Posted June 23, 2020 Posted June 23, 2020 18 minutes ago, pete_mac said: Sadly these are a a cosmetic replacement only and don't perform correctly for acoustic purposes. Yes, this would be an option, but to do this properly you'd need to test the original foams and verify the performance of the replacement foam against these. It's an extensive piece of work. There are a multitude of places that can supply foam which is a cosmetic match, and the correctly-sized leather dies aren't too expensive and are extremely accurate... but getting foam with the correct acoustic performance is the hard part. From what I can glean "Acoustifoam" is what EV called it. I may be wrong, but, there are stockists/specialists of it around that may assist us. The outters' density according to your above schematic look to be less important acoustically than the density of the inner.
Jack Russell Posted June 23, 2020 Author Posted June 23, 2020 Sounds like we need to do a bit of homework and research to solve this problem. Excellent input from all concerned. Thanks.
pete_mac Posted June 23, 2020 Posted June 23, 2020 59 minutes ago, Doc M said: From what I can glean "Acoustifoam" is what EV called it. I may be wrong, but, there are stockists/specialists of it around that may assist us. Correct, but there's a difference between the what EV called "Acoustifoam" back in the 70s and the modern "acoustifoam" which seems to be used to describe myriad products from different manufacturers, including backing material for flooring products. I have no doubt that an equivalent product is either being made, or could be made, in the desired thickness somewhere in the world... but our challenge is to find it and verify its performance vs the original.
Doc M Posted June 23, 2020 Posted June 23, 2020 (edited) 57 minutes ago, Jack Russell said: Sounds like we need to do a bit of homework and research to solve this problem. Excellent input from all concerned. Thanks. Spot on there Brian. Now to ascertain what frequency db density it should be. There is a way to do this I suppose. A speaker designer or acoustic engineer may be the brain to pick. I should have stayed at school or had a different career path me thinks. There was no course elective for 'Rock God' when I went to school either. Edited June 23, 2020 by Doc M
Jack Russell Posted June 23, 2020 Author Posted June 23, 2020 If it all becomes too difficult, I suppose I can leave my tweeters without their foam surrounds and adjust the treble down a bit. Not ideal, I know.....
Doc M Posted June 24, 2020 Posted June 24, 2020 (edited) On 23/06/2020 at 6:05 PM, Jack Russell said: If it all becomes too difficult, I suppose I can leave my tweeters without their foam surrounds and adjust the treble down a bit. Not ideal, I know..... I may have had some success with getting them made in Melbourne Brian! The guy said that he has had cause to find them in recent years but, has done no good like us. He's in the business and has dealt with these before, he sounds like he knows what I'm looking for. And if that does not launch, I have a possible source for the correct foam to diy the things with a die we can discuss at some point mate. I asked for a quote for a set for both of us, if that is ok with you? Edited June 24, 2020 by Doc M Added verbiage
pete_mac Posted June 24, 2020 Posted June 24, 2020 (edited) On 23/06/2020 at 6:05 PM, Jack Russell said: If it all becomes too difficult, I suppose I can leave my tweeters without their foam surrounds and adjust the treble down a bit. Not ideal, I know..... Hi Brian, I'd suggest reading the extract from the brochure that I posted earlier in this thread. The acoustic lens is not about attenuating the treble at all - it's about increasing the angle of dispersion from the tweeter. Adjusting the treble down will do nothing more than reducing the treble overall - it won't account for the acoustic lens not being used. I'm not sure if we are understanding the functionality of the lens here. 44 minutes ago, Doc M said: I may have had some success with getting them made in Melbourne Brian! The guy said that he has had cause to find them in recent years but, has done no good like us. He's in the business and has dealt with these before, he sounds like he knows what I'm looking for. And if that does not launch, I have a possible source for the correct foam to diy the things with a die we can discuss at some point mate. I asked for a quote for a set for both of us, if that is ok with you? Doc, could you please share this info widely? I'm very interested to see what you've found, and would like to understand the basis for it being the 'correct foam' which matches the original for acoustic performance. Sorry if I sound pedantic, but if this is a genuine replacement for the original, we owe it to ourselves to ensure it is functionally identical to the original. Otherwise, we might as well buy the cosmetic replacements which are already available and call it a day Edited June 24, 2020 by pete_mac
Jack Russell Posted June 24, 2020 Author Posted June 24, 2020 Firstly, thanks to Doc M for his update. I'm just up the freeway from you in Wangaratta. Is there a way we can exchange contact nos. on this site? I've had some success with the Speaker Hospital in Sydney, but still waiting on confirmation from them. And to pete_mac who I value as a helpful contributor to this thread, it seems to me that getting the exact same foam as the original EV ones may be problematic. I'm not sure how this could be achieved unless one had an instrument to measure these types of things? Methinks, and I may be wrong, that if the replacement product is "close enough", personally I don't know if I could tell the difference if put in front of the speakers blindfolded. Just my thoughts......
pete_mac Posted June 24, 2020 Posted June 24, 2020 (edited) Hi Brian, You can send Doc M a 'private message' if you click on his profile and then the 'message' icon: https://www.stereo.net.au/forums/profile/282381-doc-m/ I agree 100% that it is difficult to gauge the success of replacement foams without measurements. This could certainly be done, but one needs the right gear and expertise to do so. My concern is that a suppler will provide some form of 'acoustic foam' which is intended for outright sound attenuation and acts to the detriment of the sound. Given the intended function of the acoustic lens, I reckon it could be safer bet to err on the side of a more transparent, less dense type of foam for cosmetic dress-up purposes only, rather than something which is denser. Whilst you may not achieve the kind of dispersion as EV intended, there is less likelihood of doing harm. Edited June 24, 2020 by pete_mac
Jack Russell Posted June 24, 2020 Author Posted June 24, 2020 Good advice pete_mac. I do appreciate your input in attempting to obtain the best result possible from a replacement material that will most probably differ from the original. Thanks also for your tip on contacting Doc M via a private message. 1
pete_mac Posted June 24, 2020 Posted June 24, 2020 2 minutes ago, Jack Russell said: Good advice pete_mac. I do appreciate your input in attempting to obtain the best result possible from a replacement material that will most probably differ from the original. Thanks also for your tip on contacting Doc M via a private message. No problem - I'm looking forward to hearing how you get on! Good luck!
Doc M Posted June 24, 2020 Posted June 24, 2020 24 minutes ago, pete_mac said: No problem - I'm looking forward to hearing how you get on! Good luck! Pete_mac. I thank you too for sharing the knowledge and experience. Very helpful and awesome. The reason why I haven't divulged all is because I hate mis/disinformation with a passion and I'd be a hypocrite if I dispensed it here. I'd rather be sure than be wasting my & everyone elses time parrotting all the guff I have seen elsewhere. I have just started on this journey for these parts for the EV's. So far, it's looking promising. 1
Doc M Posted June 24, 2020 Posted June 24, 2020 1 hour ago, Jack Russell said: Methinks, and I may be wrong, that if the replacement product is "close enough", personally I don't know if I could tell the difference if put in front of the speakers blindfolded. Just my thoughts...... I agree with you Brian. Very close is good enough for me. I'll give it the best shot I can within some limits.
pete_mac Posted June 24, 2020 Posted June 24, 2020 6 minutes ago, Doc M said: Pete_mac. I thank you too for sharing the knowledge and experience. Very helpful and awesome. The reason why I haven't divulged all is because I hate mis/disinformation with a passion and I'd be a hypocrite if I dispensed it here. I'd rather be sure than be wasting my & everyone elses time parrotting all the guff I have seen elsewhere. I have just started on this journey for these parts for the EV's. So far, it's looking promising. No worries at all! I understand exactly where you are coming from. 1
Jack Russell Posted July 12, 2020 Author Posted July 12, 2020 Looks like the Speaker Hospital in Sydney can assist. Several communications have occurred between us, they are trying to source the foams and tool up for the task. In fairness, they haven't promised an exact match for the original material, but will do their best in coming as close as possible. In due course, they will let me know about their progress in manufacturing the foam lenses. Both Sal and Greg from the Speaker Hospital have been helpful and proactive with this request. I will post again once I receive more info. etc. 1
Doc M Posted July 12, 2020 Posted July 12, 2020 Thanks for the update JR. A lot of the people I have contacted either are at a dead end or haven't gained any momentum at all (as in getting back to me).
Doc M Posted July 21, 2020 Posted July 21, 2020 I have found this better resolution document of the cross section of the Superdome from thems good folk at EV! And as a bonus (no....not steak knives) my specs for the lenses. (albeit by my own shaky hand) Superdome specs 89478 EDS.pdf 1
pete_mac Posted July 21, 2020 Posted July 21, 2020 Cool - that EDS is a great find! A quick query though... is there a reason for the bevel to the inner foam? The original foam has a square finish.
Doc M Posted July 21, 2020 Posted July 21, 2020 13 minutes ago, pete_mac said: Cool - that EDS is a great find! A quick query though... is there a reason for the bevel to the inner foam? The original foam has a square finish. Call it 'artistic licence', none really, where did I put my eraser? 1
pete_mac Posted July 21, 2020 Posted July 21, 2020 14 minutes ago, Doc M said: Call it 'artistic licence', none really, where did I put my eraser? Hehe!! All good - just thought I'd ask!
Doc M Posted July 21, 2020 Posted July 21, 2020 (edited) 32 minutes ago, Doc M said: Call it 'artistic licence', none really, where did I put my eraser? And also the fact that if it was a straight square cut would it touch the dome? Some of the pix of the 19mm hole look as though it may touch. https://images.app.goo.gl/5nWfQL69xgtAB9CB6 As you can see in one of the shots the Speaker Exchange ones are both the same thickness making them really ugly. Edited July 21, 2020 by Doc M Pix
pete_mac Posted July 21, 2020 Posted July 21, 2020 16 minutes ago, Doc M said: And also the fact that if it was a straight square cut would it touch the dome? Some of the pix of the 19mm hole look as though it may touch. https://images.app.goo.gl/5nWfQL69xgtAB9CB6 As you can see in one of the shots the Speaker Exchange ones are both the same thickness making them really ugly. No, there will be more than ample clearance. You can see that the original square cut items are fine: https://www.stereo.net.au/forums/topic/312998-ev-interface-foam-tweeter-surround/?do=findComment&comment=4550154
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