Hi Everyone,
Not to beat a dead horse, but I feel vindicated enough to run through the mall in flip flops and swim trunks yelling "You reek a lot!" 😉
In previous discussions, the arguments were made that the ScanSpeak Revelator 18W series mid-woofers had particularly bad ringing. My comments, made like the genteel bohemian that I am, were that the 18W/4531 I used simply did not measure nearly as bad as the ScanSpeak spec sheets, and I wondered at the time if the drivers had not gone through some improvement.
Well, here we go, my buddy Troels independently validated my observations:
He posts the original ScanSpeak image:
As well as his own measurements which are much closer to what I measured, and published:
So, for whatever reason, when it comes to these series of driver, ScanSpeak's measurements are not up to date. These are much better measuring and sounding drivers than the spec would lead you to believe.
Not to beat a dead horse, but I feel vindicated enough to run through the mall in flip flops and swim trunks yelling "You reek a lot!" 😉
In previous discussions, the arguments were made that the ScanSpeak Revelator 18W series mid-woofers had particularly bad ringing. My comments, made like the genteel bohemian that I am, were that the 18W/4531 I used simply did not measure nearly as bad as the ScanSpeak spec sheets, and I wondered at the time if the drivers had not gone through some improvement.
Well, here we go, my buddy Troels independently validated my observations:
He posts the original ScanSpeak image:
As well as his own measurements which are much closer to what I measured, and published:
So, for whatever reason, when it comes to these series of driver, ScanSpeak's measurements are not up to date. These are much better measuring and sounding drivers than the spec would lead you to believe.
Update: The discrepancy which Troels mentions above is exactly what I see, but for a different driver. I was talking about the 18W/4531, while Troels experimented with the 18WU/8741/T00. However, his observations and conclusions are exactly the same as mine:
Even the difference in measurement from published to in cabinet are practically the same.
Troels attributes the difference to infinite vs. actual baffles, but at the top of the mid-woofer's range, that doesn't make much sense to me. I want to think this is more of an engineering change that was not documented. Let me go look at Zaphs data in a bit.
Even the difference in measurement from published to in cabinet are practically the same.
Troels attributes the difference to infinite vs. actual baffles, but at the top of the mid-woofer's range, that doesn't make much sense to me. I want to think this is more of an engineering change that was not documented. Let me go look at Zaphs data in a bit.
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Should have done this before, but here is a comparison of the 18W/8531 from the spec sheet:
From Zaph's comparison page:
And not exactly the same driver, but my own measurements with the 4531 (4 Ohm) variant:
Notice that my chart uses a fine-scale, and that there is a little hump, but it's nowhere near the magnitude of the hump in the spec, and it's certainly not a shelf.
You can see in the yellow line the final slope after 2nd order filtering applied. There is a notch filter and Zobel but they don't contribute to this discussion. They just flatten the slope. You may review the full crossover design in the attachments on this thread:
SNR-1 : Mundorf / Scanspeak 2 Way
Based on this review, I remain commited to my original thesis: The 18W/x531 mid-woofers are very good sounding and very easy to integrate with a tweeter in a two-way system.
Best,
E
From Zaph's comparison page:
And not exactly the same driver, but my own measurements with the 4531 (4 Ohm) variant:
Notice that my chart uses a fine-scale, and that there is a little hump, but it's nowhere near the magnitude of the hump in the spec, and it's certainly not a shelf.
You can see in the yellow line the final slope after 2nd order filtering applied. There is a notch filter and Zobel but they don't contribute to this discussion. They just flatten the slope. You may review the full crossover design in the attachments on this thread:
SNR-1 : Mundorf / Scanspeak 2 Way
Based on this review, I remain commited to my original thesis: The 18W/x531 mid-woofers are very good sounding and very easy to integrate with a tweeter in a two-way system.
Best,
E
Attachments
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Erik, what are your baffle dimensions? Datasheet measurements are usually in IEC (wide) baffle. Modern decorative narrow baffles give +2 or even 3dB step typically between 600-1200Hz.
Juhazi,
Yes indeed. 🙂 Edge is still my favorite.
The point I was trying to make though was that if you look at the raw spec sheets, these drivers look completely unmanageable, but the reality is they are much better.
Best,
E
Yes indeed. 🙂 Edge is still my favorite.
The point I was trying to make though was that if you look at the raw spec sheets, these drivers look completely unmanageable, but the reality is they are much better.
Best,
E
-as noted by Troels: it's the interaction with the baffle. 😉
I've heard these woofers in a few designs (all 2-ways) and didn't particularly like them anywhere except around 90-400 hz. Fairly clean and "punchy" in this region (despite not being very efficient) with a bass reflex design and an amplifier with enough current. Depth above average in this region, though not great. (..the "Illumintors" are slightly less "clear" but have more depth and better imaging in the same bandwidth.)
I'm really not sure why people would pay that much for this particular midbass (..with a design that has the potential to de-laminate). 😱
Which is clear from the quote from him in my second post, above. To refresh, Troels said this:
It is also clear, from the phrase I quoted directly, that he's very surprised at how big a difference there is overall. So am I.
We'll absolutely have to disagree. I have never ever heard a mid-bass I liked more.
Best,
Erik
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..it depends on what you are "looking"/listening for, and in what design.
I'd go for a 5 1/4" SB15MFC30-8 at about 1/4 of the price in a heart-beat (vs. the Scan), even with the loss in lower freq. extension. Provided it's loaded properly, it's substantially better above 100 hz, particularly as it transitions to any typical tweeter (for multiple reasons).
IF you can design around the limitations of tweeter integration with a 10" - then the Discover 10" 26W/4534G is quite a bit better (with everything assuming proper loading) and can also provide lower freq. extension.
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Just to be clear, my point was not that ScanSpeak mid-woofers measure better than other mid-woofers, just that the spec sheets are pessimistic in the FR range. 🙂
Whether DIYers should agree with my love of the 18W range was not what I meant to argue here.
Best,
Erik
Whether DIYers should agree with my love of the 18W range was not what I meant to argue here.
Best,
Erik
Whether DIYers should agree with my love of the 18W range was not what I meant to argue here.
Best,
Erik
🙂 I don't know why you bother, there's always someone that feels something is better
😀
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