Scan-Speak Revelator

[GK]

Hi

Just wondering if anyone has experience (positive or otherwise) with the Revelator woofers from Scan-Speak operating in sealed enclosures, this 10” unit in particular:

http://www.madisound.com/catalog/pro...oducts_id=1664

WinISD reveals a ~40Hz f3 in a relatively modest size enclosure.

Worth the money?

Cheers,
Glen

[Graham Maynard]

I can't answer your question Glen, but look at SPL in relation to voice coil impedance also maximum air displacement capability.

http://www.madisound.com/catalog/pro...oducts_id=1768

Oh, just gone out of stock, but comparisons still possible. Was $91.

You pay much for little displacement with the ScanSpeak and this is what counts by the time you get to say 25Hz.

Just one of these will move as much air at LF as 2.5x ScanSpeak -

http://www.eminence.com/proaudio_spe...8&SUB_CAT_ID=1

but then of course the nature of the cabinet/mounting might be different to your requirements.

Cheers ........ Graham.

[Graham Maynard]

Just for reading.

http://www.slottweak.com/Shiva.htm
http://www.diyaudio.com/forums/showthread/t-41267.html
http://www.adireaudio.com/Files/GroupDelay.pdf

G.

[rabbitz]

Not the same woofer but I did try the 22W8851T00 (paper cone) in 2 different applications and both times were bettered by a Vifa M22WR-09-08. Could just be a case of wrong driver, wrong application but it should have worked better as it did model very well.

I'm a great fan of Scan Speaks such as the 18W8531G00 but I found the 8" not very good value. The 10" however could be a different story.

A 10" driver which is great value and I've had a lot of customers who loved it is the Vifa M26WR-09-08 but now are very rare and last time I checked, WES were down to their last few.

Good luck with your research.

[Graham Maynard]

Hi Glen,

Don't know if you have seen this before, but is worth reading; illustrates different 'Q' responses etc.

http://www.geocities.com/cc00541/group_delay.html

Cheers .... Graham.

[GK]

Originally posted by Graham Maynard
I can't answer your question Glen, but look at SPL in relation to voice coil impedance also maximum air displacement capability.

http://www.madisound.com/catalog/pro...oducts_id=1768

Oh, just gone out of stock, but comparisons still possible. Was $91.

You pay much for little displacement with the ScanSpeak and this is what counts by the time you get to say 25Hz.

Just one of these will move as much air at LF as 2.5x ScanSpeak -

http://www.eminence.com/proaudio_spe...8&SUB_CAT_ID=1

but then of course the nature of the cabinet/mounting might be different to your requirements.

Cheers ........ Graham.

OK, thanks Graham.

18” is a bit big and Eminence sub will only really work in a ported enclosure (it will only do ~80Hz sealed).

I think David Gatti summarises the case for sealed bass enclosures well here:
http://www.gattiweb.com/delta_design.html

I also really like the look of this Sonus Faber speaker:



Hmmm....perhaps a 3-way version, except with a stained pine baffle and a gloss black enclosure, with a pair of bass drivers in parallel for high sealed box sensitivity.
With the drivers that are available that work well in sealed boxes, it looks like I will have to settle for an f3 of about 40Hz.

Fortunately I have nearly all the parts, including the heatsink and 25 pairs of genuine Motorola MJ15024/MJ15025 which I bought years ago, with which I could whack up an easy beast of a subwoofer amp, perhaps to drive an Exodus Audio Maelstrom or a Shiva-X.

With an actively x-o’ed subwoofer/amp I could then I could have my 4-way system
I think this will be a good all over compromise, rather than trying to achieve everything in a single pair of speakers.

Cheers,
Glen

[GK]

Originally posted by rabbitz
Not the same woofer but I did try the 22W8851T00 (paper cone) in 2 different applications and both times were bettered by a Vifa M22WR-09-08. Could just be a case of wrong driver, wrong application but it should have worked better as it did model very well.

I'm a great fan of Scan Speaks such as the 18W8531G00 but I found the 8" not very good value. The 10" however could be a different story.

A 10" driver which is great value and I've had a lot of customers who loved it is the Vifa M26WR-09-08 but now are very rare and last time I checked, WES were down to their last few.

Good luck with your research.

OK, cheers. Pity about the Vifa's going obsolete. If you don't mind me asking, in what area did the Scan-Speaks fail to perform?

Cheers,
Glen

[TurboFC3S]

I've used a pair of those 10" Aluminum cone Revelators in a 3-way tower, but I ran them vented. They performed extremely well I thought. Vented they dig deep, stay composed at very high SPL, and integrated well with the top - more musical I thought than a Seas L26 or Dayton RS270, and more impact than a W26 Mag cone. But they're still overall a dry bass presentation, if you want more warmth there's a paper cone 10" Revelator too. One of my favorite 10's for 3-way use is a Focal 10W, if you can find them, but it doesn't like small boxes. A Hi-Vi D10.8 also is a nice driver, and performs well in a sealed 2.5cu/ft box.

[ScottG]

Originally posted by G.Kleinschmidt


18” is a bit big and Eminence sub will only really work in a ported enclosure (it will only do ~80Hz sealed).

I think David Gatti summarises the case for sealed bass enclosures well here:
http://www.gattiweb.com/delta_design.html

I also really like the look of this Sonus Faber speaker:

The eminence is a 15" and its actually best sealed (6 cu ft +) and used as a room corner loaded sub for freq.s less than 40 Hz.

The case for "sealed" bass really doesn't "measure up" in a well designed system. Group delay is important - for fundamentals. IF you have a low enough port resonance then this is often a moot point. The same is pretty much true for excursion potential - its really a matter of low freq. content at or near the spl average. If you have a fundamental (or a loud grouping of harmonics) just below the port resonance then you can greatly increase driver excursion beyond what a normal sealed system would provide. However if that isn't the case then often a bass reflex design has LESS excursion (and lower non-linear distortion). Furthermore the driver is much better controlled near its in-box resonance (which is often within the range of fundamentals) *because* of its port. Finally a low freq. tunning point (less than 30 Hz) in a bass reflex design that is *not* "aligned" can actually match room-gain better than a sealed design.

None of the above though isn't to suggest that a sealed system isn't also good, rather that its all down to the design.

If you like the enclosure for the Stradivari then you should look at Troel's site:

http://www.troelsgravesen.dk/Diy_Lou...r_Projects.htm

specifically:
http://www.troelsgravesen.dk/Acapella_WB.htm
http://www.troelsgravesen.dk/PMS.htm
http://www.troelsgravesen.dk/PMS-EXCEL.htm

Personally if I was going for a 2 driver sealed design I'd use 2 10" Eminence BP102's in 80-100 lt enclosure. Wired in parallel (with a suitable amplifier) provides a 40Hz figure of around 90 db 1 watt 1 meter *without* taking into consideration either room OR boundary gain.

[TurboFC3S]

Originally posted by ScottG
The case for "sealed" bass really doesn't "measure up" in a well designed system. Group delay is important - for fundamentals. IF you have a low enough port resonance then this is often a moot point. The same is pretty much true for excursion potential - its really a matter of low freq. content at or near the spl average. If you have a fundamental (or a loud grouping of harmonics) just below the port resonance then you can greatly increase driver excursion beyond what a normal sealed system would provide. However if that isn't the case then often a bass reflex design has LESS excursion (and lower non-linear distortion). Furthermore the driver is much better controlled near its in-box resonance (which is often within the range of fundamentals) *because* of its port. Finally a low freq. tunning point (less than 30 Hz) in a bass reflex design that is *not* "aligned" can actually match room-gain better than a sealed design.

None of the above though isn't to suggest that a sealed system isn't also good, rather that its all down to the design.

I agree completely with all of this ... just for the record