It’s a shame I can’t see all those nice products going to waste. They’ll probably get bought by a Chinese company.
Yes, but the coupling efficiency of a given size of diaphragm goes down with decreasing frequency. I can't remember the exact formula but it's in there somewhere.
Too late to edit obviously.
I would consider an array of smaller drivers basically the same as 1 larger driver. What I would consider not the same is using a smaller driver with a higher excursion, because 1) again, the diaphragm-to-air coupling efficiency, for whatever that's worth, 2) additional excursion-related distortion factors, etc. So when you say "lots of 18s with EQ" it could go either way, I guess? With "lots of 18s" the low-end sensitivity should be there still, as long as the overall physical volume is comparable.
That's what I meant; this isn't my first rodeo. As the large unit was a sub driver, I was thinking of an array of say SI18s with high Sd and Xmax to get an equivalent Vd in total.
Multiples of 18s would allow them to be placed for mode amelioration in some circumstances, room use considerations would determine that and I personally would prefer this arrangement over one monster driver that may not be able to be optimally placed.
My HT subs in the new room will be nearfield, ported FTW21s (2) which are able to play loud enough for all but nutters. A further 2 FTW21s will be sealed as the lower section of my 4 way L/R. Add in a BOSS and Crowsons and there will be a ton of LF capability at a tiny fraction of the cost.
The measurements of the ScanSpeak 12W/4524G00 midwwofer and SB Acoustics SB14ST-C000-4 tweeter have been added:
https://hificompass.com/en/speakers/measurements/scan-speak/scanspeak-12w/4524g00https://hificompass.com/en/speakers/measurements/sbacoustics/sb-acoustics-sb14st-c000-4
I would like to express deep gratitude to Tihomir Haralovic for his help in replenishing our measurement database and for kindly providing the ScanSpeak 12W4524G00 midwoofer for testing. Tihomir Haralovic graduated physics in Zagreb University, Croatia, and is the owner and chief audio engineer in Neutrino Audio company, which develops high-end analog active crossovers and loudspeakers. Tihomir and his team believe that an analog active crossover is a much better choice for an audiophile than digital (DSP).
https://hificompass.com/en/speakers/measurements/scan-speak/scanspeak-12w/4524g00https://hificompass.com/en/speakers/measurements/sbacoustics/sb-acoustics-sb14st-c000-4
I would like to express deep gratitude to Tihomir Haralovic for his help in replenishing our measurement database and for kindly providing the ScanSpeak 12W4524G00 midwoofer for testing. Tihomir Haralovic graduated physics in Zagreb University, Croatia, and is the owner and chief audio engineer in Neutrino Audio company, which develops high-end analog active crossovers and loudspeakers. Tihomir and his team believe that an analog active crossover is a much better choice for an audiophile than digital (DSP).
ScanSpeak 12W/4524G00 : Nice FreqResponse without blibs and fair price but outdated basket design . VCoil could be 32mm from the bigger brother along with 90mm ferrite magnet and shorter coil for better midrange purposes . Outside diameter is too large (very old basket design around late 80ties) ... and a bit ugly . And no copper or aluminium shorting ring nor copper cap on pole piece!
Rubber surround seems to be SR100 from DKM in Krefeld/Germany .
There is always something serious to complain about ... you never get a driver that is designed beyond 90% satisfaction! Typically you get 60-70% at best ...
Sorry for the lament .. but the demon in me has just his free day today 🙂
Rubber surround seems to be SR100 from DKM in Krefeld/Germany .
There is always something serious to complain about ... you never get a driver that is designed beyond 90% satisfaction! Typically you get 60-70% at best ...
Sorry for the lament .. but the demon in me has just his free day today 🙂
The Wavecor WF118A01(A02) is a hard rival design : Diameter 118mm , 85mm magnet , 32mm aluminum wire voice coil , Xmax 3mm , 8 Ohm version has 86dB and is also flat within plusminus 1dB , but no peak up to natural cutoff!
Data sheet shows peak but measurement in Hobby Hifi 06/2009 (MLSSA/B&K/infinite baffle) at 1m shows no sign of peak!
I think they use a softer paper (front side coated) not reinforced like stated in the data sheet , with more internal damping , to get such a smooth response .
Demon Lament #2
🙂
Btw - there is a PDF where all drivers are tested by the exact same conditions : http://hobby-hifi.de/Archiv/PDF-Downloads/221_Chassis_Testubersicht.pdf
Data sheet shows peak but measurement in Hobby Hifi 06/2009 (MLSSA/B&K/infinite baffle) at 1m shows no sign of peak!
I think they use a softer paper (front side coated) not reinforced like stated in the data sheet , with more internal damping , to get such a smooth response .
Demon Lament #2
🙂
Btw - there is a PDF where all drivers are tested by the exact same conditions : http://hobby-hifi.de/Archiv/PDF-Downloads/221_Chassis_Testubersicht.pdf
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Demon Lament #3 : Original price for the WF118 was around 30 to 35 euros here in germany , but a few years later the price has DOUBLED for no apparent reason!
It's a nightmare this hobby!
drivers come and go .. now recently we have lost FOUNTEK and their whole driver range ... I am not happy about the situation!
It's a nightmare this hobby!
drivers come and go .. now recently we have lost FOUNTEK and their whole driver range ... I am not happy about the situation!
Brett I am disappointed I thought you might have used the same magic credit card I borrowed off TK and purchased 2 of these subs ! https://www.whathifi.com/au/news/magicos-titan-15-subwoofer-promises-6500w-of-earth-shaking-bass Why build your own when Magico can deliver a bargain
. the margins must be tight on this oneMerry Christmas
Undoubtedly, despite its stamped basket WF118 is better speaker than 12W/4524
You need to get your hands on those new HiVi 3" domes 🙂 . I'm wondering that maybe they'll be willing to send some drivers your way if You ask?
Hmm. Are you sure about this? The website just says they are down for maintenance.
😢
Member
Joined 2003
Yeah, the problem with WF118 is just the price, most DIYer will demand cast frame for that price, even if it makes no difference to performance, it doesn’t look premium. For a little more money the WF120BD03/04 offer the balance drive motor and nice cast frame, still a little bit pricey but there’s very little to complain about otherwise.
Hello! I am quite surprised to see the Fountek website now ... I tried for weeks but no reaction ... okay good to see some sign of life of them , but I'm sceptic it has much to do with maintenance . Would be nice to see them back in business! And I'm thrilled to see where their prices are going too! Thanks for info regarding Fountek!
Member
Joined 2003
HiVi DM7500
Here in the attached picture I detected a truncated back cup with 6 screws , so the aluminium front plate could be taken off and machined to personal requirements without damaging the driver! The flat back cup needs probably a stiffening disc , I have seen Amazon.de has plates in a wide variety of sizes and thicknesses .
Looks like the front plate allows to cut off some material that you will get two paralell edges , probably down to a distance of 100mm! And the inside opening allows probably a fine metal mesh added (sphere shape) for protection of the dome! Amazon.de has a fine shiny copper mesh , must be a copper alloy because it appears to be not being easy to corrode . Look for the name Copper Garden ... Oh here found : https://www.amazon.de/CopperGarden-...=kupfergewe,outdoor,179&sr=1-7&language=en_GB
For some of you important for mounting drivers as close together as possible .
I would like to recommend also to put the dome driver in an extra chamber inside the box (acoustically isolated and air tight to the woofer pressure waves), and maybe a decoupled mounting on the baffle .
https://img.alicdn.com/imgextra/i1/2935715108/O1CN01AEFUMC1nbVk2RahcV_!!2935715108.jpg
Here in the attached picture I detected a truncated back cup with 6 screws , so the aluminium front plate could be taken off and machined to personal requirements without damaging the driver! The flat back cup needs probably a stiffening disc , I have seen Amazon.de has plates in a wide variety of sizes and thicknesses .
Looks like the front plate allows to cut off some material that you will get two paralell edges , probably down to a distance of 100mm! And the inside opening allows probably a fine metal mesh added (sphere shape) for protection of the dome! Amazon.de has a fine shiny copper mesh , must be a copper alloy because it appears to be not being easy to corrode . Look for the name Copper Garden ... Oh here found : https://www.amazon.de/CopperGarden-...=kupfergewe,outdoor,179&sr=1-7&language=en_GB
For some of you important for mounting drivers as close together as possible .
I would like to recommend also to put the dome driver in an extra chamber inside the box (acoustically isolated and air tight to the woofer pressure waves), and maybe a decoupled mounting on the baffle .
https://img.alicdn.com/imgextra/i1/2935715108/O1CN01AEFUMC1nbVk2RahcV_!!2935715108.jpg
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Btw - the shown FR in the specs for the DM7500 below 300Hz is quite questionable! There should be a 12dB/octave downward slope ...
We need to investigate this further!
We need to investigate this further!
SORRY ... on editing I run out of editing time (only 30min) so here the full new text :
HiVi DM7500
Here in the attached picture I detected a truncated back cup with 6 screws , so the aluminium front plate could be taken off and machined to personal requirements without damaging the driver! The flat back cup needs probably a stiffening disc , I have seen Amazon.de has plates in a wide variety of sizes and thicknesses .
Looks like the front plate allows to cut off some material that you will get two paralell edges , probably down to a distance of 100mm!
Maybe for some of you important for mounting drivers as close together as possible .
And the inside opening allows probably a fine metal mesh added (sphere shape) for protection of the dome! Amazon.de has a fine shiny copper mesh , must be a copper alloy because it appears to be not being easy to corrode . Look for the name Copper Garden ... Oh here - found : https://www.amazon.de/CopperGarden-Kupfergewebe-25-quadratisch/dp/B00IRNZ9X0/ref=sr_1_7?crid=3AJNACF7XEO1F&keywords=kupfergewebe&qid=1640658027&s=garden&sprefix=kupfergewe,outdoor,179&sr=1-7&language=en_GB
For dust protection of the fabric dome (collects dust like a magnet , over time) it would be wise to apply some thin transparent silicone coating on the dome . But use of course a small and fine flat brush , avoid any thinners to make the silicone more flexible . Alternatively , maybe a sprayed on "Lotus Effect" coating is an option for dust protection .... has the advantage to be of very low added mass! (but no idea how well it bonds to the surface of the fabric)
I would like to recommend also to put the dome driver in an extra chamber inside the box (acoustically isolated and air tight to the woofer pressure waves), and maybe a decoupled mounting on the baffle .
https://img.alicdn.com/imgextra/i1/2935715108/O1CN01AEFUMC1nbVk2RahcV_!!2935715108.jpg