Thanks I'm flattered
So if I understand well I would lower the opening and raise everything up on the stand by the same amount, what distance have you in mind ?
I could do that, not sure that I one day go into that size of drivers but he who know, hmm that would be around 16"x16" opening then.
Hi Scottg,
I was able to run them for 4h today at their advertised resonant frequency of 52Hz (Sinus) and I end up with number 1 at 64 something and 68 something for the number 2, so one is stiffer than the other I guess.
It seem the type of tissue suspension is stiffer than the rubber one and they need a longer break-in time.
And I don't push them, as you said I raised the level until I can see the cones moving
I was able to run them for 4h today at their advertised resonant frequency of 52Hz (Sinus) and I end up with number 1 at 64 something and 68 something for the number 2, so one is stiffer than the other I guess.
It seem the type of tissue suspension is stiffer than the rubber one and they need a longer break-in time.
And I don't push them, as you said I raised the level until I can see the cones moving
68 is a bit high for the woofer, though there will always be some variance. Really you'd like to get something in the high 50's (given the typical error-rating).
Probably raise the level a bit more (as in adding a bit more gain after seeing the cones move), and doing the process for about 3 times as long. Of course make sure the woofer isn't "bottoming-out".
Probably raise the level a bit more (as in adding a bit more gain after seeing the cones move), and doing the process for about 3 times as long. Of course make sure the woofer isn't "bottoming-out".
After 6h of run I get them around that :
D 165 [mm]
Re 6.7714 [Ohms]
Fs 61.235 [Hz]
Zm 81.233 [Ohms]
BL 8.7957 [N/A]
Qms 5.4791
Qes 0.49826
Qts 0.45672
Vas 29.317 [liters]
L10k 0.24316 [mH]
n0 1.2882 [%]
dBSPL 93.2 [1W/1m]
Ms 14.796 [grams]
Cms 0.457 [mm/N]
Not really close to specs, I begin to think that kind of suspension will take a lot of time to loosen them up, not sure if they will ever reach datasheets specs
Difficult to let them run for a long time with a sine wave it generate quiet some noise in here, don't want to abuse of the patience of my neighbors too much, I'll do it a bit at a time.
I have contacted Intertechnik two days ago to feedback on the discrepancies but they don't seem in a hurry to reply yet.
As for the other order TLHP is trying to sort it out with the delivery company for three days after they received back the package already, told them I don't have to wait for them, and that they could send the what I ordered and sort it out after (13 days after order now)
Not a very good experience unfortunately
D 165 [mm]
Re 6.7714 [Ohms]
Fs 61.235 [Hz]
Zm 81.233 [Ohms]
BL 8.7957 [N/A]
Qms 5.4791
Qes 0.49826
Qts 0.45672
Vas 29.317 [liters]
L10k 0.24316 [mH]
n0 1.2882 [%]
dBSPL 93.2 [1W/1m]
Ms 14.796 [grams]
Cms 0.457 [mm/N]
Not really close to specs, I begin to think that kind of suspension will take a lot of time to loosen them up, not sure if they will ever reach datasheets specs
Difficult to let them run for a long time with a sine wave it generate quiet some noise in here, don't want to abuse of the patience of my neighbors too much, I'll do it a bit at a time.
I have contacted Intertechnik two days ago to feedback on the discrepancies but they don't seem in a hurry to reply yet.
As for the other order TLHP is trying to sort it out with the delivery company for three days after they received back the package already, told them I don't have to wait for them, and that they could send the what I ordered and sort it out after (13 days after order now)
Not a very good experience unfortunately
-well, not great.. but not bad either. Models pretty similar.
Try modeling the driver in Vituixcad with both sets of parameters to see the difference. Try 63 liters and 28 Hz for the bass reflex tuning freq. for the values you got vs. the 70 and 26 Hz for the spec. sheet.
Note: this is actually pretty normal from most driver manufacturers. (Seas is one of the exceptions). Of course it's also pretty normal for first-time purchasers to be unhappy with the differences. (..seriously, it happens all the time in the multi-way forum.)
There can also be variation in the testing condition as well.
Try modeling the driver in Vituixcad with both sets of parameters to see the difference.
Try 63 liters and 28 Hz for the bass reflex tuning freq. for the values you got vs. the 70 and 26 Hz for the spec. sheet.Note: this is actually pretty normal from most driver manufacturers. (Seas is one of the exceptions). Of course it's also pretty normal for first-time purchasers to be unhappy with the differences. (..seriously, it happens all the time in the multi-way forum.)
There can also be variation in the testing condition as well.
I guess that speaker drivers business like many other sugarcoat their specifications, but it can be a pain if you can't rely on precise specs to do you project.
Anyway Intertechnik e-mail reply was as vague as it can be, basically do with what you have kind of reply, but I can digest that better than the other.
I am more annoyed with TLHP that are really putting me on wait while they sort out what was the issue with the delivery, the package is back at the origin for many days now, it's not handled professionally at all, not in the content of the reply nor in the actions. First and last time ordering at that website.
As for the sim, to me it seem all are pretty similar, group delay shooting at the sky in the lower frequencies and I'm really not sure about Xmax that is not on the datasheets but is shown as 1.1mm at multiple sites, I don't believe it's accurate by what I have seen about the cone travel during my run-in, I just have set it to 11mm even if that is too high
As for the tuning frequency hard to tell it seem low but I don't have experience enough to translate what I see into conclusions. Without you I would probably used a sealed box because my chain of thought would lead me to think that more suspension travel would maybe result in more air pressure for a bass reflex, and that driver is far to my eyes to be equivalent to a subwoofer.
Here are all the sims :
The two with the datasheets specs, and then the two with measured specs
Thanks
Anyway Intertechnik e-mail reply was as vague as it can be, basically do with what you have kind of reply, but I can digest that better than the other.
I am more annoyed with TLHP that are really putting me on wait while they sort out what was the issue with the delivery, the package is back at the origin for many days now, it's not handled professionally at all, not in the content of the reply nor in the actions. First and last time ordering at that website.
As for the sim, to me it seem all are pretty similar, group delay shooting at the sky in the lower frequencies and I'm really not sure about Xmax that is not on the datasheets but is shown as 1.1mm at multiple sites, I don't believe it's accurate by what I have seen about the cone travel during my run-in, I just have set it to 11mm even if that is too high
As for the tuning frequency hard to tell it seem low but I don't have experience enough to translate what I see into conclusions. Without you I would probably used a sealed box because my chain of thought would lead me to think that more suspension travel would maybe result in more air pressure for a bass reflex, and that driver is far to my eyes to be equivalent to a subwoofer.
Here are all the sims :
The two with the datasheets specs, and then the two with measured specs
Thanks
you can get some idea of force and compliance vs. excursion for the 8" from the PM220's tests:
Test Bench: Dayton Audio PM220-8 Wideband Neodymium 8” Woofer | audioXpress
I doubt that xmech is even 11mm.
Again though, this is not for a high spl design (and even when you do have higher low freq. transients with a modest average spl, you'll probably run-into some compression effects at those lower freq.s).
Basically it's a large sealed enclosure with a modest bit of gain on the "low-end". What I tend to like the most about this sort of design is almost precisely that: a large sealed design ..BUT with an air-load/"brake" provided by the port's resistance acting on the cone near its movement around the driver's resonance (in-box): where the driver is usually "sloppy" with its motion (particularly stopping). This usually provides a more subjectively detailed result (and it can be further improved upon with a certain type of amp or with a low-freq. impedance correction network).
You are still "on track" despite the delays. Just keep "riding" TLHP until you get what you paid for.
Test Bench: Dayton Audio PM220-8 Wideband Neodymium 8” Woofer | audioXpress
I doubt that xmech is even 11mm.
Again though, this is not for a high spl design (and even when you do have higher low freq. transients with a modest average spl, you'll probably run-into some compression effects at those lower freq.s).
Basically it's a large sealed enclosure with a modest bit of gain on the "low-end". What I tend to like the most about this sort of design is almost precisely that: a large sealed design ..BUT with an air-load/"brake" provided by the port's resistance acting on the cone near its movement around the driver's resonance (in-box): where the driver is usually "sloppy" with its motion (particularly stopping). This usually provides a more subjectively detailed result (and it can be further improved upon with a certain type of amp or with a low-freq. impedance correction network).
You are still "on track" despite the delays. Just keep "riding" TLHP until you get what you paid for.
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That Dayton test is indeed an interesting test of similar mechanical suspension, I don't have the means or knowledge to make the same kind of tests but I can understand the analogy
I have done a crude test about the cone travel :
Placed a thin cardboard on the driver resting on his back and raised manually the cone and measured the difference, it's about 3 to 4mm (without pushing hard)
Now I suppose that measurement would be closer to Xmech than it is to Xmax, if yes it would be safe to say that Between 2 and 3 mm is Xmax what do you think
I understand better what we are doing with that woofer in relation to the enclosure, by the way I used the SBB4 and Box loss of 3 for the calculation
Yes do not SPL competitions, so in the end that speaker design should be loud enough with a few watts and that good with me, as long I can play it loud enough to absorb the details
The part of the simulation that I don't get is the excursion, it seem that bump in the very low end (28hz to 20hz) already with 2.85v is close to 2.4mm, so should I avoid to run sub frequencies to not bottom the drivers with a few watts ?
"low-freq. impedance correction network" : Is it was it called a Zobel ?
I have done a crude test about the cone travel :
Placed a thin cardboard on the driver resting on his back and raised manually the cone and measured the difference, it's about 3 to 4mm (without pushing hard)
Now I suppose that measurement would be closer to Xmech than it is to Xmax, if yes it would be safe to say that Between 2 and 3 mm is Xmax what do you think
I understand better what we are doing with that woofer in relation to the enclosure, by the way I used the SBB4 and Box loss of 3 for the calculation
Yes do not SPL competitions, so in the end that speaker design should be loud enough with a few watts and that good with me, as long I can play it loud enough to absorb the details
The part of the simulation that I don't get is the excursion, it seem that bump in the very low end (28hz to 20hz) already with 2.85v is close to 2.4mm, so should I avoid to run sub frequencies to not bottom the drivers with a few watts ?
"low-freq. impedance correction network" : Is it was it called a Zobel ?
It's a series "notch" filter: LCR.
Notch filter design calculator - for speakers | Audio Judgement
..and it's not required, but it can help subjectively depending on the amplifier. It can be expensive though because of the component cost.. even with cheaper components.
(..it's something to contemplate after basically finishing the loudspeakers.)
I'm guessing around 2mm is Xmax based on compliance.
While you can *high-pass the design (actively before the amplifier) to reduce lower freq. output - it's really down to your program (music) material. A LOT of music has a significant drop in pressure at lower freq.s.. and so the output isn't what you'd see from a sim.. Plus, its usually dynamic.
*note: IF you high-pass the design you won't need to even consider the series notch, AND you get a LOT more usable dynamic headroom. (..presumably you'd be using a subwoofer to fill-in the lower freq. response in this situation.)
Notch filter design calculator - for speakers | Audio Judgement
..and it's not required, but it can help subjectively depending on the amplifier. It can be expensive though because of the component cost.. even with cheaper components.
(..it's something to contemplate after basically finishing the loudspeakers.)
I'm guessing around 2mm is Xmax based on compliance.
While you can *high-pass the design (actively before the amplifier) to reduce lower freq. output - it's really down to your program (music) material. A LOT of music has a significant drop in pressure at lower freq.s.. and so the output isn't what you'd see from a sim.. Plus, its usually dynamic.
*note: IF you high-pass the design you won't need to even consider the series notch, AND you get a LOT more usable dynamic headroom. (..presumably you'd be using a subwoofer to fill-in the lower freq. response in this situation.)
Notch Filter seem to be indeed quiet expensive, I see already that 100uf Capacitor I bought to protect the tweeter during measurement cost me €21.46 and it's one of the cheapest non electrolytic, if I had to do that I would prefer to invest in active crossover and bi-amp the speakers.
Anyway you are right most of what I listen don't even go that low
Finally got my package, I think I understand they had me waiting because they wanted the delivery company to admit a fault and take ownership of the cost of a second delivery.
Made some measurements out of the box :
FF85WK driver 1 :
D 60 [mm]
Re 7.2852 [Ohms]
Fs 135.26 [Hz]
Zm 40.863 [Ohms]
BL 3.7808 [N/A]
Qms 3.5005
Qes 0.75949
Qts 0.62408
Vas 0.88652 [liters]
L10k 0.23637 [mH]
n0 0.27542 [%]
dBSPL 86.5 [1W/1m]
Ms 1.7535 [grams]
Cms 0.79 [mm/N]
FF85WK driver 2 :
D 60 [mm]
Re 7.2998 [Ohms]
Fs 140.64 [Hz]
Zm 38.211 [Ohms]
BL 4.019 [N/A]
Qms 3.1489
Qes 0.74363
Qts 0.60157
Vas 0.77218 [liters]
L10k 0.23968 [mH]
n0 0.27542 [%]
dBSPL 86.5 [1W/1m]
Ms 1.8621 [grams]
Cms 0.688 [mm/N]
SCR MKP PA 100uf 250v DC Capacitor
The capacitor's value is: C = 96.433 uF
f = 120 Hz, ESR = 0.338 Ohms, DF = 2.4577 %, Q = 40.69, DELTA = 1.4079 deg.
f = 1k Hz, ESR = 0.3489 Ohms, DF = 21.553 %, Q = 4.64, DELTA = 12.163 deg.
f = 10k Hz, ESR = 0.1695 Ohms, DF = 237.34 %, Q = 0.4213, DELTA = 67.153 deg.
I also did a bit of run-in on the Fostex at 95hz for around 2h and what puzzle me is that the Fs increased a very little bit instead of going lower, I don't think these need that kind of treatment, the foam like surround is very soft.
Now I will have to order the router bits I have selected, hope I am right with the specs, especially for the round-over bit (S=12 D=57,1 R=22,2 939.991.11 CMT) to cut my edges on the front faces.
Once I have more experience I may practice a wider corner like you advised but I don't feel like adding that to the equation at the moment.
Anyway you are right most of what I listen don't even go that low
Finally got my package, I think I understand they had me waiting because they wanted the delivery company to admit a fault and take ownership of the cost of a second delivery.
Made some measurements out of the box :
FF85WK driver 1 :
D 60 [mm]
Re 7.2852 [Ohms]
Fs 135.26 [Hz]
Zm 40.863 [Ohms]
BL 3.7808 [N/A]
Qms 3.5005
Qes 0.75949
Qts 0.62408
Vas 0.88652 [liters]
L10k 0.23637 [mH]
n0 0.27542 [%]
dBSPL 86.5 [1W/1m]
Ms 1.7535 [grams]
Cms 0.79 [mm/N]
FF85WK driver 2 :
D 60 [mm]
Re 7.2998 [Ohms]
Fs 140.64 [Hz]
Zm 38.211 [Ohms]
BL 4.019 [N/A]
Qms 3.1489
Qes 0.74363
Qts 0.60157
Vas 0.77218 [liters]
L10k 0.23968 [mH]
n0 0.27542 [%]
dBSPL 86.5 [1W/1m]
Ms 1.8621 [grams]
Cms 0.688 [mm/N]
SCR MKP PA 100uf 250v DC Capacitor
The capacitor's value is: C = 96.433 uF
f = 120 Hz, ESR = 0.338 Ohms, DF = 2.4577 %, Q = 40.69, DELTA = 1.4079 deg.
f = 1k Hz, ESR = 0.3489 Ohms, DF = 21.553 %, Q = 4.64, DELTA = 12.163 deg.
f = 10k Hz, ESR = 0.1695 Ohms, DF = 237.34 %, Q = 0.4213, DELTA = 67.153 deg.
I also did a bit of run-in on the Fostex at 95hz for around 2h and what puzzle me is that the Fs increased a very little bit instead of going lower, I don't think these need that kind of treatment, the foam like surround is very soft.
Now I will have to order the router bits I have selected, hope I am right with the specs, especially for the round-over bit (S=12 D=57,1 R=22,2 939.991.11 CMT) to cut my edges on the front faces.
Once I have more experience I may practice a wider corner like you advised but I don't feel like adding that to the equation at the moment.
Yup. It's got less than half a mm of linear excursion.
Hopefully no damage occurred. Note though that it's not the surround that you are really giving a work-out to - its the spider.
(..of course linen roll surrounds like your midbass DOES need the "work-out" (in addition to the spider), which is unlike most drivers.)
-good to hear you got your order!
-you could cut-down the cost with electrolytics and "charge-coupling".
Charge Coupled Crossovers Article By Jeff Poth
*Supposedly a filter like this doesn't impact the sound as much as components in the signal-path.
Note that a filter like this will do something that bi-amping (in and of itself) will not do. In other words: if you value what it can do then you would still want it for an active system.
*I've never personally tried electrolytic's in any position within a passive crossover, so I couldn't comment.
I have tried a few boutique caps and other components and the component that has always had the biggest impact (beyond what it actually does objectively) has been resistance for the tweeter.
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Yup. It's got less than half a mm of linear excursion.
Note though that it's not the surround that you are really giving a work-out to - its the spider.
(..of course linen roll surrounds like your midbass DOES need the "work-out" (in addition to the spider), which is unlike most drivers.)
-good to hear you got your order!
No problem I was very gentle with them, they are so cute (I never thought i'd say that about a driver
) Rub&buzz passed even with more sensitive settings.
Well I did multiple measurements and what I notice is the Fs result vary from 1 to 2 Hz up & down, I guess that the DATSV2 have some error margin.
Ho yeah forgot that spider in there (it's so tiny), but even I don't think I'll have much benefit running them more before frequency measurement
That charge coupling crossover is very interesting in theory, and probably I don't really understand it but adding a battery in the mix give me a bad feeling, what about when it runs out
Now you will think I am mad but my LS Plan Tweeters seem in bad shape if I thrust the tests I have done, guess I had it coming having them for more than 10 years.
I will try to repair them but I doubt my skills, in case I don't succeed I'm in for a new pair of tweeters also
Now you will think I am mad but my LS Plan Tweeters seem in bad shape if I thrust the tests I have done, guess I had it coming having them for more than 10 years.
I will try to repair them but I doubt my skills, in case I don't succeed I'm in for a new pair of tweeters also
I love it You never know it might be something good.
I just though of 2 things that helped me in my second speaker project:
Listen carefully each driver character, speed, coloration and defects, with a tone generator this will let you know what you want to KEEP, what you want out of the speakers FR range,
Listen for any major irritants like resonances, dips, and peaks. Fix that later with the XO, it should show up in your measured response, the final recorded response should no longer show the dips/bumps which are annoying.
1. measure the drivers in the final box and record the ZMA and FRD files accurately of each driver.
2. place the Phase response data, the impedance curves as measured and the FRD + distance from listening position of each driver, delay in the software.
3. spend a few months with computer simulations of different XO points, curves etc.
4. Listen, adjust, then repeat 3. and 4. for a few years.
5. don't quit, until you have the sound you can achieve.
You never know it might be something good. I just though of 2 things that helped me in my second speaker project:
Listen carefully each driver character, speed, coloration and defects, with a tone generator this will let you know what you want to KEEP, what you want out of the speakers FR range,
Listen for any major irritants like resonances, dips, and peaks. Fix that later with the XO, it should show up in your measured response, the final recorded response should no longer show the dips/bumps which are annoying.
1. measure the drivers in the final box and record the ZMA and FRD files accurately of each driver.
2. place the Phase response data, the impedance curves as measured and the FRD + distance from listening position of each driver, delay in the software.
3. spend a few months with computer simulations of different XO points, curves etc.
4. Listen, adjust, then repeat 3. and 4. for a few years.
5. don't quit, until you have the sound you can achieve.
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