Hi everybody.
I want to restore (maybe rebuild - if otherwise not possible) older bookshelf speakers rated 30-200W and need to replace 6,5" elements on both. Cabinet is 15L and does have 2x 40mm bass ports on front side. Tweeter is some Vifa 29 mm soft dome shielded one - no proper labels on shield.
Original woofer elements are custom Vifa Sigma 6,5" rated 8 ohm with double magnets and metallic shield on magnets front view like here: 6,5" VIFA basenhed i 8 ohm brugt til AVANCE Omega serien.
Magnet side resembles more this one:Głośnik vifa bc14sg06-04 avance dana 630, 640 - Galeria zdjęć i obrazow na imgED
Physical dimensions are 184 mm overall diameter, 170mm screw ring and 148 mm cutout from panel.
Original speaker measures 6,3 Ohm (30-200W) think this has related to modified magnets on original item. I don't know other parameters of this drive.
Now, considering replacement, i prefer clean acoustics, classics, jazz and etc, so to have some power is good, as long it's not boomy.
What do you think about these options:
Vifa PL18WO-09-08 Woofer (problem is limited availability 1 everywhere i look)
vs Peerless HDS-P830875 (Vifa HDS N 6-33/08) - Nomex-Paper buy at hifisound.de
This one Looking for a Peerless HDS-P830874 woofer? - SoundImports looks similar to previous, but has much lower power rating and relatively high Fs @ 58 Hz
Paper vs aluminum? Can these do:
https://www.soundimports.eu/en/peerless-by-tymphany-hds-p835025.html or https://www.soundimports.eu/en/visaton-al-170.html
or https://www.soundimports.eu/en/dayton-audio-dsa175-8.html
This speaker https://www.soundimports.eu/en/seas-ca18rly.html looks nice on paper too, but needs twice Vas volume, i have to rebuild crossover?
So, advice is needed - which one of those speakers to choose?
Another question about magnets on original items. Avance has doubled them. There is an additional full sized ferrite magnet ring placed on top of Vifa original speaker and that one is on additional metal box. So double the original magnet size. Why this has been done??
I want to restore (maybe rebuild - if otherwise not possible) older bookshelf speakers rated 30-200W and need to replace 6,5" elements on both. Cabinet is 15L and does have 2x 40mm bass ports on front side. Tweeter is some Vifa 29 mm soft dome shielded one - no proper labels on shield.
Original woofer elements are custom Vifa Sigma 6,5" rated 8 ohm with double magnets and metallic shield on magnets front view like here: 6,5" VIFA basenhed i 8 ohm brugt til AVANCE Omega serien.
Magnet side resembles more this one:Głośnik vifa bc14sg06-04 avance dana 630, 640 - Galeria zdjęć i obrazow na imgED
Physical dimensions are 184 mm overall diameter, 170mm screw ring and 148 mm cutout from panel.
Original speaker measures 6,3 Ohm (30-200W) think this has related to modified magnets on original item. I don't know other parameters of this drive.
Now, considering replacement, i prefer clean acoustics, classics, jazz and etc, so to have some power is good, as long it's not boomy.
What do you think about these options:
Vifa PL18WO-09-08 Woofer (problem is limited availability 1 everywhere i look)
vs Peerless HDS-P830875 (Vifa HDS N 6-33/08) - Nomex-Paper buy at hifisound.de
This one Looking for a Peerless HDS-P830874 woofer? - SoundImports looks similar to previous, but has much lower power rating and relatively high Fs @ 58 Hz
Paper vs aluminum? Can these do:
https://www.soundimports.eu/en/peerless-by-tymphany-hds-p835025.html or https://www.soundimports.eu/en/visaton-al-170.html
or https://www.soundimports.eu/en/dayton-audio-dsa175-8.html
This speaker https://www.soundimports.eu/en/seas-ca18rly.html looks nice on paper too, but needs twice Vas volume, i have to rebuild crossover?
So, advice is needed - which one of those speakers to choose?
Another question about magnets on original items. Avance has doubled them. There is an additional full sized ferrite magnet ring placed on top of Vifa original speaker and that one is on additional metal box. So double the original magnet size. Why this has been done??
What is the problem? If a damage in a speaker driver can be repaired, it is almost better to do that instead of replacing the failed driver with a non equivalent one.
In order to replace a woofer you need to find one that has the same properties of the original one, and there are a lot:
1) Vas, Qts and Fs (some of the T/S parameters) should be the same as the older unit, or be a combination that have the new woofer work the same in the cab you have
2) the impedance should be pretty the same, and I mean the full impedance not the nominal one, specially near the crossover point, so the old crossover will work the same with the new woofer
3) the FR should be pretty the same, at least before and slightly after the crossover point, again so the old crossover will work the same with the new woofer
4) SPL should be pretty the same, if not you have to adjust the tweeter level (if it is possible)
Frankly, if you don't know the T/S parameters or even worse if you don't know impedance and FR of the original driver you don't have any clue in how to choose an equivalent driver. The probability to random buy a woofer based on appearance, material or whatever else and have it work reasonably well in the cab and with the crossover you have is almost zero. OTOH if you want to redesign the speaker (new driver(s) and new crossover), you need measurement gear and some prior experience.
Ralf
The Vifa PL18 is way too expensive these days.
I'd roll a dice on the 830874 and the 830875. 15L suits most 6" woofers.
https://www.diyaudio.com/forums/multi-way/23208-system-pictures-description-257.html#post3993609
The paper 830875 is more suited to reflex, but not much in it. The polycone 830874 is slightly smoother and easier to deal with. Lojzek liked it. You can always stuff a sock in one of the ports is if the bass is wrong, but it shouldn't matter.
Peerless 830874 HDS 164 PPB MidWoofer Speaker
Peerless 830875 HDS 164 NOM MidWoofer Speaker
Avoid metal drivers like the plague. You will need to redesign the crossover to notch breakup ringing. Worst that can happen is the balance needs adjusting with a $1 resistor on the tweeter if significant mismatch on loudness, but I wouldn't expect even that.
Have a go. We'll help if the balance needs adjusting. And I wouldn't worry about rebating woofers, doesn't matter much. 😎
I'd roll a dice on the 830874 and the 830875. 15L suits most 6" woofers.
https://www.diyaudio.com/forums/multi-way/23208-system-pictures-description-257.html#post3993609
The paper 830875 is more suited to reflex, but not much in it. The polycone 830874 is slightly smoother and easier to deal with. Lojzek liked it. You can always stuff a sock in one of the ports is if the bass is wrong, but it shouldn't matter.
Peerless 830874 HDS 164 PPB MidWoofer Speaker
Peerless 830875 HDS 164 NOM MidWoofer Speaker
Avoid metal drivers like the plague. You will need to redesign the crossover to notch breakup ringing. Worst that can happen is the balance needs adjusting with a $1 resistor on the tweeter if significant mismatch on loudness, but I wouldn't expect even that.
Have a go. We'll help if the balance needs adjusting. And I wouldn't worry about rebating woofers, doesn't matter much. 😎
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I get the plague... and in the bass ! (sb23NBAC45-8) 😀 ... furur little 3 Ways Classic, certainly with no classic but prehistoric sound...
If a 3 ways is no working there I will consider a bad 4 ways for the fun of it (though the price of copper springs rolls today 😱)
8" till 200 Hz
6" non metal 200-800 Hz
3" 800-3000 Hz
3/4 or 1"
All of that to say the 6" & 3" if designing from scratch would be better with one 4.5" in spite of. Perhaps !
Aluminium when having good integration have something right if coloration from break-ups are avoided from my everyday experience with a 4.5 mid and a 1 tweet aluminiums !
If a 3 ways is no working there I will consider a bad 4 ways for the fun of it (though the price of copper springs rolls today 😱)
8" till 200 Hz
6" non metal 200-800 Hz
3" 800-3000 Hz
3/4 or 1"
All of that to say the 6" & 3" if designing from scratch would be better with one 4.5" in spite of. Perhaps !
Aluminium when having good integration have something right if coloration from break-ups are avoided from my everyday experience with a 4.5 mid and a 1 tweet aluminiums !
OP,
If you located the reference for the Vifa tweeter maybe you can start a new project (kit) from there.
If you located the reference for the Vifa tweeter maybe you can start a new project (kit) from there.
That took now quite a lot having busy with other doings to reply here.
I like your approach -focus and concentration on topic: "what can be done", instead, why something is nearly impossible. 🙂 Thank you for you time and knowledge.
Those two drivers were my main "suspects" for good replacement candidate, as original items are not available anymore.
This time i pulled trigger on 830874 and hopefully get them on close 3-4 days. It looks more smooth and more similar. Frequency range original did 50 Hz >up. Last but not least - looks like every shop in the world have only one 830875 item in stock,
probably from same warehouse source and most stores currently do not take back-orders, or if they do- back-order times are horrible: 4-6 months. I am not that patient.
I hope finish this box successfully first and then look to another project if i do not settle down - maybe based on some better DIY kit or similar. But everything i like to build - tend to be like 3K parts only... That DIY thing will be then different thread.
I like your approach -focus and concentration on topic: "what can be done", instead, why something is nearly impossible. 🙂 Thank you for you time and knowledge.
Those two drivers were my main "suspects" for good replacement candidate, as original items are not available anymore.
This time i pulled trigger on 830874 and hopefully get them on close 3-4 days. It looks more smooth and more similar. Frequency range original did 50 Hz >up. Last but not least - looks like every shop in the world have only one 830875 item in stock,
probably from same warehouse source and most stores currently do not take back-orders, or if they do- back-order times are horrible: 4-6 months. I am not that patient.
Inductor said:
I hope finish this box successfully first and then look to another project if i do not settle down - maybe based on some better DIY kit or similar. But everything i like to build - tend to be like 3K parts only... That DIY thing will be then different thread.
You choose the answer you liked not necessary the best answer. That recommendation is not based on facts. What you end up is unpredictable, and to me it is difficult to understand what your goal is. Simply put a new woofer? Having the speakers sound better than before? You didn't even take the (small) time to explain what is the problem with the old woofers.
Ralf
One drive motor is broke (impedance 0,2 Ohm). Shielded magnet is put on factory that way it couldn't be taken off probably without special equipment. As frame is plastic and 20 years old, the risk just damage the frame is quite big.
I think replacing the drivers with similar enough model (here i mean really similar, not just physical dimensions) and small modification of XO is easier than repair of the driver. And there are always plan B or C
giralfino said:
People often choose answers they like most and sometimes they even have success doing so, but that is really unpredictable beforehand. And there is nothing wrong doing so. Also there is always possibility to build on same woofers new box from scratch, so i think there is nothing to loose, only some fun with experimenting.
While you are waiting for the 830874 woofers, why not drop Michael Chua an email an see what he has done here. He will send you the circuit and occasionally the modelling files.
Cardinal-TBFC-DCR (the Final Cut) – AmpsLab
Different tweeter shouldn't affect things much. They are all about 90dB and 6 ohms DCR.
He is a top man. A real gent.
Cardinal-TBFC-DCR (the Final Cut) – AmpsLab
Different tweeter shouldn't affect things much. They are all about 90dB and 6 ohms DCR.
He is a top man. A real gent.
Lastly i got my new UMIC1 microphone and could measure replaced speaker in the Sigma avance 620 box.
Original speaker - SPL is blue line on the graph and new peerless 830874 SPL is green line.
See attachement below.
Inplace woofer replacement, no any crossover modifications done.
Only difference i can hear is small offaxis response difference. Sound from 830874 is little more straight than original vifa one.
i see no reason to modify anything else, than just replace both midwoofers 🙂
Original speaker - SPL is blue line on the graph and new peerless 830874 SPL is green line.
See attachement below.
Inplace woofer replacement, no any crossover modifications done.
Only difference i can hear is small offaxis response difference. Sound from 830874 is little more straight than original vifa one.
i see no reason to modify anything else, than just replace both midwoofers 🙂
Attachments
Looks like a result! We had this one before, Sigma Avance 620 AV:
I suggested the Vifa PL!8 woofer back then:
Advice on speaker repair needed.
Even worked out the crossover:
All good. 😀
I suggested the Vifa PL!8 woofer back then:
Advice on speaker repair needed.
Even worked out the crossover:
All good. 😀
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