perhaps i was a little dismissive. In my opinion, the SPH135 is a drop in replacement for 1 reason: its a rear mount driver and the cut out required is close enough to the B110 so that the baffle wont need much modification. Perhaps none. Its a fairly cheap driver, relatively speaking, and wouldnt be optimal in the same volume as the LS3.
Tell me when you get bored with the BBC theme. I've found another good polycone woofer design at Troels' site...Vifa PL14WJ-09-08. 😀
Vifa PL14WJ-
This is available at Falcon Acoustics for £57.
Vifa PL14WJ-09-08 Woofer Mid Range
Seems to be a vented magnet design with low inductance. Qts=0.38, Vas=13L, Fs=47Hz. Needs a little bit of rolloff because a small peak at 6kHz. Crossover is quite KEF-like, Kei.
Vifa PL14WJ-
An externally hosted image should be here but it was not working when we last tested it.
This is available at Falcon Acoustics for £57.
Vifa PL14WJ-09-08 Woofer Mid Range
Seems to be a vented magnet design with low inductance. Qts=0.38, Vas=13L, Fs=47Hz. Needs a little bit of rolloff because a small peak at 6kHz. Crossover is quite KEF-like, Kei.
The "Look" with perhaps a reasonable and fixable response may be found chaeply with this midrange even if the Fs is a lot higher than you would like.
Madisound Speaker Store
Madisound Speaker Store
I dunno Moondog55, I think it's all about the plastic polycones with BBC speakers. That and the floppy thin ply cabinets. 🙂
I've been whizzing along with my bargain 3.5 ohm Mordaunt-Short polycone bass drivers. Even found a promising crossover which I think I can adapt. Thing is they were used in the Epos ELS-3 AFAIK.
Some wonderful Italian guy took the Epos ELS-3 apart and published his findings:
Tecnica e Misure: Epos ELS 3 ? VideoHiFi
As usual with 5" cones, there is a troublesome resonance around 1.2kHz, but it's OK to ignore it apparently. Happy days. 🙂
I've been whizzing along with my bargain 3.5 ohm Mordaunt-Short polycone bass drivers. Even found a promising crossover which I think I can adapt. Thing is they were used in the Epos ELS-3 AFAIK.
An externally hosted image should be here but it was not working when we last tested it.
Some wonderful Italian guy took the Epos ELS-3 apart and published his findings:
Tecnica e Misure: Epos ELS 3 ? VideoHiFi
As usual with 5" cones, there is a troublesome resonance around 1.2kHz, but it's OK to ignore it apparently. Happy days. 🙂
Attachments
I still think your 1.2Khz resonance is actually a baffle diffraction issue and not inherent in the drivers 🙂 Why does it show up in lots of 5" drivers?? Because people tend to make baffles of roughly the same width with them 😉
Why does it not show up in some? Porbably if you look at the 1/2 space spl curve (of those particular divers) it will have a dip in this region, but when mounted on a narrow baffle the boost evens it out...
Of course just my oppinion 🙂
Tony.
Why does it not show up in some? Porbably if you look at the 1/2 space spl curve (of those particular divers) it will have a dip in this region, but when mounted on a narrow baffle the boost evens it out...
Of course just my oppinion 🙂
Tony.
Alas, your guesses are as woolly as your spelling. I keep telling you this sort of peak happens on ANY size baffle and is aggravated by filtering, which FWIW, reduces voicecoil damping...but you're not listening. 😀
An externally hosted image should be here but it was not working when we last tested it.
A well targeted notch can reduce this colouration, but it IS significant that half-wavelength at 1.4 kHz is of the order of the diameter of the speaker.
If I was looking for the explanation, I would say that 1.4kHz here is where the paper speaker ceases to be a cone and slips into radial and rocking modes. Material damping and rigidity then becomes a critical factor too. This link is quite deep but is a precise analysis:
Vibration analysis
As mere mortals and not rocket-scientists, we really hope the driver manufacturer has done the thinking for us to get the woofer working as best as possible. But it's all very interesting. Hope we can move on now. 🙂
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frankly System7 youre attitude to conflicting opinion is a worry 😀
Taking a wild 'stab in the dark', like many of your assumptions; I would actually, and modestly suggest that you and wintermute are both partly correct.
If i get time ill post a comparison of 2 different 5" drivers. Firstly the audax ap130z0 and visaton AL130. I recall from past boxsim exercises, the audax does have this cone resonance issue around 1khz, whilst the AL130 does not.
In summary, i believe it is more a symptom of soft cone resonance due to unfortunate dimensioning of cone diameter. With the Audax the peak shows even on a wide baffle, the visaton doesn have it at all. It just has break up at 7k instead.
Taking a wild 'stab in the dark', like many of your assumptions; I would actually, and modestly suggest that you and wintermute are both partly correct.
If i get time ill post a comparison of 2 different 5" drivers. Firstly the audax ap130z0 and visaton AL130. I recall from past boxsim exercises, the audax does have this cone resonance issue around 1khz, whilst the AL130 does not.
In summary, i believe it is more a symptom of soft cone resonance due to unfortunate dimensioning of cone diameter. With the Audax the peak shows even on a wide baffle, the visaton doesn have it at all. It just has break up at 7k instead.
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Hi,
The diffraction ripple of a typically sized baffle for typical bass/mid
drivers is not enough (its usually a broad 2dB peak) to cause a
distinct localised peak in the drivers response.
Bextrene coned drivers even with applied damping nearly always
exhibited the sort of peak S7 is talking about due to lack of
inherent damping of the material.
Polypropylene (and paper composite) has more damping but
there still can be issue depending on the cone to surround
termination, which makes or breaks a good bass/mid IMO.
Trouble is optimum mid termination is no good for bass.
Quoting Seas :
Looking at Zaphs tests for 5" drivers though, I'd say you can't
generalise 5" drivers usually have issues around 1KHz, they don't,
they may have issues above this point, unlikely any below it.
rgds, sreten.
The diffraction ripple of a typically sized baffle for typical bass/mid
drivers is not enough (its usually a broad 2dB peak) to cause a
distinct localised peak in the drivers response.
Bextrene coned drivers even with applied damping nearly always
exhibited the sort of peak S7 is talking about due to lack of
inherent damping of the material.
Polypropylene (and paper composite) has more damping but
there still can be issue depending on the cone to surround
termination, which makes or breaks a good bass/mid IMO.
Trouble is optimum mid termination is no good for bass.
Quoting Seas :
Looking at Zaphs tests for 5" drivers though, I'd say you can't
generalise 5" drivers usually have issues around 1KHz, they don't,
they may have issues above this point, unlikely any below it.
rgds, sreten.
Thanks Sreten. Could you elaborate? I understand the concept of cone edge resonance, or at least I can visualise it.
What exactly do you mean by
and perhaps why this is no good for bass?
Lol threads are cyclic. Back on topic. Id say id buy that kit, if the woofer was the Vifa P13 that was mentioned a few posts back. Same tweeter.
Hi,
Optimum cone termination is quite stiff, first done in the Mordaunt
Short Signifier years ago, and currently done by B&W's FST, see
Zaph|Audio and control F FST.
Suspension Xmax is low and Fs high, ruling out bass use.
Bowers & Wilkins - FST
For an explanation and video of an impedance matched surround.
Though like I said, it is nothing new, it has been done before.
The MS unit was smaller and x/o higher than the B&W unit.
rgds, sreten.
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Still seems like a lot more just for 2 tweeters. (£150 more than the other kit) When i've eventually got some spare funds i'll get on with this project.
So would this make those Vifa P-13s that demonstrate higher Fs MORE suitable for midrange use??
Just interested.
even I
I saw a pair of LS3/5As for sale on eBay a short while ago, I'm sure Even I could build a pair of excellent 2-Way monitors for $2400- using HQ drivers and someone elses design.
And that is assuming I could fund a months wages for the components.
i have those epos speakers , if you dont see the boxes and just ear you´ll think it´s a much bigger speaker , no problems with a 100w amp , sound is very good for a budget speaker
I wonder if the bextrene cone in the SP 1003 was only one layer of bextrene.
With all the cones Kef produced were there different gauges of the bextrene thickness?
Were some of those cones multi layer?
With all the cones Kef produced were there different gauges of the bextrene thickness?
Were some of those cones multi layer?
I'd think bextrene and polypropylene cones are a one piece hot moulding, speakerman19422. Sreten is right that the rubber-roll termination at the edge is crucial to all sorts of properties too.
Joachim Gerhard is an interesting designer. Here is his Sonics Anima compact:
This is a small reflex with plywood front and back, MDF sides. You'd guess the sides are damped. No idea what the crossover is beyond being fairly simple 6 element doubtless with a notch for taming breakup, but the drivers look like metal SEAS L18RNX/P woofer and metal 22TAF/G to me.
The sloped baffle is quite normal for time alignment. Metal drivers are not my cup of tea, TBH, but the tweeter is quite Harbeth, and it evidently sounds very good.
Joachim Gerhard is an interesting designer. Here is his Sonics Anima compact:
An externally hosted image should be here but it was not working when we last tested it.
This is a small reflex with plywood front and back, MDF sides. You'd guess the sides are damped. No idea what the crossover is beyond being fairly simple 6 element doubtless with a notch for taming breakup, but the drivers look like metal SEAS L18RNX/P woofer and metal 22TAF/G to me.
The sloped baffle is quite normal for time alignment. Metal drivers are not my cup of tea, TBH, but the tweeter is quite Harbeth, and it evidently sounds very good.
One reason I ask is because the SP1003 cone mass is slightly higher than the Sp1057 cone mass.
http://www.kef.com/uploads/files/en/kef_units/Datasheet_B110A_SP1003.pdf
http://www.kef.com/uploads/files/en/kef_units/Datasheet_B110B_SP1057.pdf
The cone mass also varied on the 8" models as well?
http://www.kef.com/uploads/files/en/kef_units/Datasheet_B110A_SP1003.pdf
http://www.kef.com/uploads/files/en/kef_units/Datasheet_B110B_SP1057.pdf
The cone mass also varied on the 8" models as well?
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I don't know quite where you are leading there, speakerman19422. It's hardly surprising that KEF would tinker with cone mass or thickness. Damping, actually PVA wood glue IIRC, was applied to the BACK of the cone in later models. Voice coils got uprated too. All this would slightly affect Thiele-Small parameters.
FWIW, the Sonics Anima has a different woofer from my initial guess. It's the £57 SEAS L15RLY/P in fact. That makes more sense for a small cabinet. 😎
H1141-08 L15RLY/P
FWIW, the Sonics Anima has a different woofer from my initial guess. It's the £57 SEAS L15RLY/P in fact. That makes more sense for a small cabinet. 😎
H1141-08 L15RLY/P
Canalis makes an improved version of the Anima. Here is some information, mixed a bit with sales blurb, sorry...http://www.canalisaudio.com/Canalis/Support_files/ What's Up With Those Animas.pdf