Some 5 years ago, i bought pair of used speakers, called Avance Sigma 620 AV, because they subjectively outplayed everything else available in shop room, despite other speakers age or price. These are 4 ohm, 2 way. Problem, -one of them, have broken 6,5 " woofer.
Here is picture of cabinet.
Avance Sigma 620AV
Cabinet is approximately 38cm H x 23 cm W x 27cm D
Internaly allmost divided - so volume for woofer is close to 10 liters
Can not find any accurate specifications nowhere, but this one here: Sigma 620MKII | Avance look very similar at least from exterior, except tweeter element used.
Element used originaly by factory was Vifa, 4 ohm, and there reads SR141/6 pressed to cone paper on front of it. numbers on magnet: 08, then Ohm sign and 809
Tweeter is labeled simailar way : Vifa Avance tweeter (shielded), there is obscure numbers 6 (could be month or anything) then ohm sign and 812.
Seeked internet with those numbers- no results.
I hoped to make quite simple switch replacing just both woofers with some 6,5" elements, but here the hard part starts -witch one?
As most people, i do not want to break onto bank, and there is no point spend much more than 60-80 Eur per woofer. Otherwise it is more easy to go and buy some B&W 685 or similar.
Second point is, that there is also no point to replace with first cheap woofer available on e-bay as those advance ones used to be quite Hi quality ones, and i have enaough ear to listen, but not so willed make this replacement procedure as 2 years DIE hard trial project finding perfect combination and infinitely messing with crossover.
So, i am adviced to use here these elements: Seas CA18RLY-4
link: Seas CA18RLY (4Ohm)
While looking around web, DIY sites and parts, i also found such items:
ScanSpeak Classic P17WJ00 6.5" Woofer
Scanspeak Discovery 18W/4434G-00, 7" Midwoofer, 4 ohm
SB Acoustics SB17NAC35-4 6.5" Aluminum Cone Woofer - 4 ohm (here i doubt about idea of aluminium cone)
SB Acoustics SB17NRXC35-4, 6.5" Woofer
or maybe this one: Peerless NE180W-04 'Platinum' this one should be very much second remake of original vifa element with some improvements? (a bit expensive)
Yes, i do not no what is crossover in my system (not taken it out yet)
I still hope, that somthing from list above, will work good enough without total rebuild of the cabinet or tweaking crossover.
So, what do you suggest, or from list above, or have own suggestion? Wich one would fit best? Maybe some of you have measured this Avance 620AV somday in history or know spec for some reason. Thank you ahead.
Here is picture of cabinet.
Avance Sigma 620AV
Cabinet is approximately 38cm H x 23 cm W x 27cm D
Internaly allmost divided - so volume for woofer is close to 10 liters
Can not find any accurate specifications nowhere, but this one here: Sigma 620MKII | Avance look very similar at least from exterior, except tweeter element used.
Element used originaly by factory was Vifa, 4 ohm, and there reads SR141/6 pressed to cone paper on front of it. numbers on magnet: 08, then Ohm sign and 809
Tweeter is labeled simailar way : Vifa Avance tweeter (shielded), there is obscure numbers 6 (could be month or anything) then ohm sign and 812.
Seeked internet with those numbers- no results.
I hoped to make quite simple switch replacing just both woofers with some 6,5" elements, but here the hard part starts -witch one?
As most people, i do not want to break onto bank, and there is no point spend much more than 60-80 Eur per woofer. Otherwise it is more easy to go and buy some B&W 685 or similar.
Second point is, that there is also no point to replace with first cheap woofer available on e-bay as those advance ones used to be quite Hi quality ones, and i have enaough ear to listen, but not so willed make this replacement procedure as 2 years DIE hard trial project finding perfect combination and infinitely messing with crossover.
So, i am adviced to use here these elements: Seas CA18RLY-4
link: Seas CA18RLY (4Ohm)
While looking around web, DIY sites and parts, i also found such items:
ScanSpeak Classic P17WJ00 6.5" Woofer
Scanspeak Discovery 18W/4434G-00, 7" Midwoofer, 4 ohm
SB Acoustics SB17NAC35-4 6.5" Aluminum Cone Woofer - 4 ohm (here i doubt about idea of aluminium cone)
SB Acoustics SB17NRXC35-4, 6.5" Woofer
or maybe this one: Peerless NE180W-04 'Platinum' this one should be very much second remake of original vifa element with some improvements? (a bit expensive)
Yes, i do not no what is crossover in my system (not taken it out yet)
I still hope, that somthing from list above, will work good enough without total rebuild of the cabinet or tweaking crossover.
So, what do you suggest, or from list above, or have own suggestion? Wich one would fit best? Maybe some of you have measured this Avance 620AV somday in history or know spec for some reason. Thank you ahead.
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More like 15L volume, I'd say.
But take the broken bass out and measure the cutout and rebate diameters. Also how many mounting bolts and the diameter.
Test the bass with a 1.5V penlight battery for crackle and life.
Take out the good bass and measure its resistance with a multimeter. 3R or 6R? Don't assume it's 4 ohms.
This looks a suitable 8 ohm replacement:
Vifa PL18WO-09-08 Woofer
Well behaved 6" paper bass. More detail on the tweeter wouldn't harm. The picture is a Vifa XT25 ring radiator. Not a soft dome.
But take the broken bass out and measure the cutout and rebate diameters. Also how many mounting bolts and the diameter.
Test the bass with a 1.5V penlight battery for crackle and life.
Take out the good bass and measure its resistance with a multimeter. 3R or 6R? Don't assume it's 4 ohms.
This looks a suitable 8 ohm replacement:
Vifa PL18WO-09-08 Woofer
Well behaved 6" paper bass. More detail on the tweeter wouldn't harm. The picture is a Vifa XT25 ring radiator. Not a soft dome.
Attachments
Ok, here i try provide some more detail.
If tweeter is some kind relabel, i dont know. On front there is pressed only Avance into plastic. it is exactli like on the picture here - i have same item Avance Sigma 620AV. same 8 screws on the woofer and same tweeter.
I measured woofers resistance with a multimeter: Good one measures 6.3 Ohms
Broken one measures 0nly 3,1 Ohms.
But on the label back of the speaker shelf reads: impedance 4 Ohms, Frequency response 55-20000 Hz, sensitivity 87 dB, power rating 30 - 200W
Is here possible to post pictures directly? without linking them to some website?
If tweeter is some kind relabel, i dont know. On front there is pressed only Avance into plastic. it is exactli like on the picture here - i have same item Avance Sigma 620AV. same 8 screws on the woofer and same tweeter.
I measured woofers resistance with a multimeter: Good one measures 6.3 Ohms
Broken one measures 0nly 3,1 Ohms.
But on the label back of the speaker shelf reads: impedance 4 Ohms, Frequency response 55-20000 Hz, sensitivity 87 dB, power rating 30 - 200W
Is here possible to post pictures directly? without linking them to some website?
Yup, you use the paperclip thingie to upload pictures from your desktop. Keep them small and JPEG for politeness to diyaudio's bandwidth.
6.3 ohms DC is a 8 ohm woofer. Simple as. Maybe the 4 ohms refers to the top end of the tweeter load.
Really you just want a similar woofer that is well behaved. Check what the cone is made of. Plastic cones are frequently used for their smooth and damped response.
But the main event is the woofer's cutout and diameter. For all I know that plastic surround is just cosmetic trim, and the screw or bolt holes can be redrilled.
6.3 ohms DC is a 8 ohm woofer. Simple as. Maybe the 4 ohms refers to the top end of the tweeter load.
Really you just want a similar woofer that is well behaved. Check what the cone is made of. Plastic cones are frequently used for their smooth and damped response.
But the main event is the woofer's cutout and diameter. For all I know that plastic surround is just cosmetic trim, and the screw or bolt holes can be redrilled.
Check what or what do you mean with sentence above?
If their website, then there is no papers on that historical product nor is nowhere in web as much i searched.
Ron means to write an email to Avance. I'd ask them if they have a spare driver to sell, and failing that if they have info on a substitute (similar FR and T/S parameters), or if they can provide you the FR and T/S parameters of the original driver.
Ralf
Ralf
Your answer makes me a bit confused. If speaker itself is specified as 4 Ohm device, i can not imagine that manufacturer then uses 8 ohm device with 4 ohm componet together in it. I do not doubt about that it measures like usually 8 ohm woofers measure. I do not have oscilloscope by hand nor device for doing live more specific test measurements on healthy one.
Ok, but lets assume, that woofer part is 8 ohm despite all labels. Why thymphany then? Or, can you (or somebody) else explain, why not one of 8 ohms counterparts of list manufacturers on first post above.
One thing what comes into mind is- similar spec yes volume is near 16 liters (opened box and measured it). What i know about it? 6,3 ohm, 6,5 ", cone is some kind work on paper. (its not plastic, not polycarbonat, i would say -paper handled with some chemical layers), Rigid enough to have quite good bass response on 6,5 inches. (i listen maynly jazz, blues, classics and it is/was very good at it, no need for boombox).
Or lets ask another way, what means "just woofer what behaves well"? No spikes, smooth response, sensible and and can go as low as 6,5 inches woofer does?.
Maybe my eye is not too experienced, looking at logarithmic scales, but response from the very low end of thymphany does not look like smooth.
Without deeper knolige about topic -i thougth that same kind of sensibility may be important. In this means, 87 dB of thymphany sounds perfect mach. Also i know that thymphany should be actually Vifas remake. (correct me if i am wrong). This means second plus toward thymphany.
But looking log scales, i have 3 questions. First, what is important- or better: sensitivity (and it's similarity to original) or is more sensitive element actually better?
2. frecuency response- i try to find item going as low as possible, around 40 Hz would be nice- but not on price loosing vivid and dynamic richness of mids. Some elements reach theyr sensitivity level 87dB or 90 dB or whatever @ 50-70 Hz, some (and most as much i see) do this near 100-130 Hz range. So their curve is slower at low edge. Or how flat is "flat enough" for response. In what frequency range should it actually be flat (in between +/-2 dB)?
And third parameter i do not undrestand is cross frequency. Were should it ideally be on my speakers case?
One thing what i am quite sure, that crossover area must be as close as possible to original design (but i do not know its exact nature).
If we look spec like these in comparison, what makes one feel - this one would fit and another one will not? How do you choose preference here :
http://audio-hi.fi/download/pdf/Peerless_Vifa_NE180W-08.pdf
http://audio-hi.fi/download/pdf/SEAS_Prestige_H1456_ER18RNX_Datasheet.pdf
SB Acoustics :: 6" SB17NRXC35-8
On this item, main what i see here: H1217-08 CA18RLY is too big Vas needed (32 L)
Otherwise last items response looks for me much better on range 100Hz-4 Khz.
So, what you consider actually important when maching box? Vas, F3, resistancy, crossover frequency, rise and falloff shape or what else??
So many parameters to look @...
I am just curios enough, to wish understand why some item is reccomended against/besides other.
Umm, thanks for explaining. I usually do not hope too much asking "factory secrets" (ie parameters and conditions), but it is worth of trial. So I will write and let's see what happens, idea about spare is'nt bad either.
Replacing the broken bass driver is not trivial if you want good performance without having to modify the x-over or the enclosure (different box tuning, different impedance, different frequency response).
I recently had a (much older) Avance speaker for repair, and my client was able to get original spare parts from them rather easily. Just contact them and explain what you're after -- maybe they can help you get it fixed.
I recently had a (much older) Avance speaker for repair, and my client was able to get original spare parts from them rather easily. Just contact them and explain what you're after -- maybe they can help you get it fixed.
Tell them you have an Avance product which you have enjoyed very much, but that one woofer of the pair is damaged and measures 3.1ohm instead of 6.3. Ask them if they have any stock of replacement drivers; and if not, if they have repair advice or recommendations for a modern substitute. A speaker company that appears to have been around since the 90's probably didn't succeed by giving their customers bad service. Avance is probably going to want to help you out, if for no other reason than it might be able to sell you a speaker in the future.
Only after asking the manufacturer directly would I go to a dealer (or several) that sells Avance and ask if they have any repair recommendations, or a price for repair. It doesn't really make sense to try to reinvent the wheel when others may have had the problem and there is a known (to manufacturer or dealer) solution out there.
Only if you have exhausted all those avenues would it be prudent to consider just purchasing an off the shelf replacement.
You asked why a manufacturer would use an 8 ohm woofer in a product marked 4 ohm, there could be many reasons. First and foremost, the rating is basically a made up number. They might have a dip to 3 ohms in the upper treble due to using a 4 ohm tweeter or due to some crossover technique. There are really a lot of reasons. They may rate it lower than actual to try and increase the likelihood that you buy better amplification from their dealers 😉
Ok. Thank you all for replies. I will try to contact Avance now first. Last posts made by you did make lot of sense. If somebody wishes to add something, thank you also. Have a nice weekend!
Mate, putting a 6 inch driver and 1" tweeter into a 15L reflex box is hardly rocket-science. 😕
My original suggestion was a good one, a 8 ohm 180mm type of paper cone:
Vifa PL18WO-09-08 Woofer
But, TBH, I still don't know if it will fit since you haven't measured the cutout and rebate diameters.
But this sort of woofer is pretty easy to filter. I could predict the values for a 2.7kHz crossover. A photo of the crossover would have told me everything I needed to know if it tends to the more exotic LCR bass notch type at 5kHz.
My original suggestion was a good one, a 8 ohm 180mm type of paper cone:
Vifa PL18WO-09-08 Woofer
But, TBH, I still don't know if it will fit since you haven't measured the cutout and rebate diameters.
But this sort of woofer is pretty easy to filter. I could predict the values for a 2.7kHz crossover. A photo of the crossover would have told me everything I needed to know if it tends to the more exotic LCR bass notch type at 5kHz.
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No rocket science, and I don't challenge your recommendation. But for good results you want a driver replacement that will result in good box tuning (i.e., similar Thielle-Small parameters), interact with the xover in the same way as the original (i.e., similar impedance curve), and give same acoustic output (i.e., similar frequency response).
Finding a suitable replacment is therefore not trivial, and takes a bit more than just using a driver that has the same looks and fits the hole in the box.
If Avance does not / cannot provide any useful information on how to get this fixed, I'd recommend to measure the impedance curve of the remaining good driver and to draw up the schematic of the xover. Then put this up here and ask the gurus for further help.
Also, are there any stickers, labels or type numbers on the driver (maybe on the back side / inside of the box)?
Well well, i was 3 day's away and such intrigues here. Take it easy mates. And i do not doubt that Vifa element suggestion was also good one.
This rocket science thingy makes me a bit philosophical. Nothing is rocket science IF you know what you are doing. Least is rocket science to drill some hole or screw some screws. Saying about device that have more than twenty custom parameters - "is no rocket science" means or very good gut-feel or knowledge what forms an intuitional suggestions or "predictions". Such intuition means usually a lot of experience. otherwise i can "predict that there will be good weather on this year" and lets see later how good was it 🙂
And same time we can read, that good 2 way speaker is hardest to make without big compromises, Firms spend years on development labs- on something what is "easy, no rocket science". Obviously they are not just so poor on what they are doing, that it takes so long to develop simple thing.
I said i am curious. From one part there exist several good elements, and perhaps i have chance to improve my boxes while repairing. (no idea how good they can get) That experience on "predicting" good element needs again experience. And why i asked initially was- what makes you guys feeling that one or another element is good fit. So, what do you look after on those response curves, sensitivity and etc?
Of cause i can use my gut-feel to point one element and it will probably work quite well, Some of you can point and say, hey- i have used this one, this is good because of ... here list of parameters or subjective feelings why such element excels. This is experience i am after.
I am not asking only - point me to some woofer like alphabetical letter, but i am curious why this letter (woofer) would be probably better than another one.
So 2 tasks in one event:
One - just repair the box, similar items, ask manufacturer, put the thing in, listen and case closed.
Another task.. maybe there is possibility to improve box even better. Not exactly to behave like Dali Concept but just better.
As i am back, i can provide again some info:
Cut-hole for woofer is 148 mm.
Tweeter measures also 6,2 Ohms.
Crossover: you can see it on pictures below.
All labels original woofer has you can also see on pictures. (Have not taken off magnets shield)
This rocket science thingy makes me a bit philosophical. Nothing is rocket science IF you know what you are doing. Least is rocket science to drill some hole or screw some screws. Saying about device that have more than twenty custom parameters - "is no rocket science" means or very good gut-feel or knowledge what forms an intuitional suggestions or "predictions". Such intuition means usually a lot of experience. otherwise i can "predict that there will be good weather on this year" and lets see later how good was it 🙂
And same time we can read, that good 2 way speaker is hardest to make without big compromises, Firms spend years on development labs- on something what is "easy, no rocket science". Obviously they are not just so poor on what they are doing, that it takes so long to develop simple thing.
I said i am curious. From one part there exist several good elements, and perhaps i have chance to improve my boxes while repairing. (no idea how good they can get) That experience on "predicting" good element needs again experience. And why i asked initially was- what makes you guys feeling that one or another element is good fit. So, what do you look after on those response curves, sensitivity and etc?
Of cause i can use my gut-feel to point one element and it will probably work quite well, Some of you can point and say, hey- i have used this one, this is good because of ... here list of parameters or subjective feelings why such element excels. This is experience i am after.
I am not asking only - point me to some woofer like alphabetical letter, but i am curious why this letter (woofer) would be probably better than another one.
So 2 tasks in one event:
One - just repair the box, similar items, ask manufacturer, put the thing in, listen and case closed.
Another task.. maybe there is possibility to improve box even better. Not exactly to behave like Dali Concept but just better.
As i am back, i can provide again some info:
Cut-hole for woofer is 148 mm.
Tweeter measures also 6,2 Ohms.
Crossover: you can see it on pictures below.
All labels original woofer has you can also see on pictures. (Have not taken off magnets shield)
Attachments
Hi, if you need a 4 Ω component, you can try a dual coil 8Ω( paralleled ) one, like the Monacor SPH-170TC, though it has 142 and not 148 mm cut-out diameter
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Looks a lot like a vifa TC18 series woofer.
lautsprecherkauf.com - Vifa TC18SG-68-08
If that one is no longer available, this one would probably also work, but it is no shielded:
https://www.madisoundspeakerstore.com/peerless-woofers-6-7/peerless-830657-6.5-sds-woofer/
These are cheap enough that you could just buy them and try.
lautsprecherkauf.com - Vifa TC18SG-68-08
If that one is no longer available, this one would probably also work, but it is no shielded:
https://www.madisoundspeakerstore.com/peerless-woofers-6-7/peerless-830657-6.5-sds-woofer/
These are cheap enough that you could just buy them and try.
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I've got to be honest with you, Vihmameister, I'm a bit of a star for not running away when the going gets tough! Whereas most folks here just disappear when it comes down to detail. 😀
I think you need an 6" aka 170-180mm reflex 8 ohm paper bass.
I did a bit of modelling based on your crossover pictures. What I think we have here is a 2.2kHz 8 ohm reflex bass crossover. It's not bad at all. The red element is a semiconductor tweeter fuse or cutout.
I think you need an 6" aka 170-180mm reflex 8 ohm paper bass.
I did a bit of modelling based on your crossover pictures. What I think we have here is a 2.2kHz 8 ohm reflex bass crossover. It's not bad at all. The red element is a semiconductor tweeter fuse or cutout.
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