Scan Speak 23W sub

[Pan]

Anyone used Scan Speak 23W?

I have a pair to play around with and would like some input. The only commercial sub I´ve seen using this driver is the one from Acoustic Reality which uses one driver and two passive radiators. I was thinking on closed box used near corner to get boost and use DSP.

/Peter

 

[DaHos]

Must be nice....While you are "playing around" could you throw one in a 1 ft^3 and a 2 ft^3 sealed box and let me know the results.... 😉

 

[Pan]

Yup, will do. Those are the alignments I´ve been thinking on primarly. Will probably start out with the smaller to see if room gain produce good results without EQ initially.

/Peter

 

[Pan]

Input anyone?

/Peter

 

[cbecker33]

A brief thread hijack........


Peter,

Have you dealt with Acoustic Reality? I'm looking to purchase an amplifier, but have read some interesting things about service.

thanks (and sorry),


-chris

 

[Pan]

I have not made any business with them but I have read the same things as you.

Guess it would be worth it anyway since the ICE amps are so reliable and of such high quality... and at such low price it´s hard to resist.

/Peter

 

[paulspencer]

I have no experience with this woofer, but have heard good things about it, and have seen it in a few projects.

Actually, the 25W ... not the 23

Stig Erik Tangen on Speakerbuilding.com:
http://www.speakerbuilding.com/content/1013/page_4.php

 

[Pan]

The 25W is old and sold. 🙂

Now they have the 26W and 23W as the bigger revelator woofers. The 23W is a little monster sub with alu-cone and Ti former.

Time will show if it´s just a cool looking beefy driver or if it has good performance as well.

/Peter

 

[Vigier]

Hi,

I have a test here in the German magazine "HobbyHifi".
It's a test with the Scan Speak 23W/4557T00 and the Visaton TIW250XS.

Just a few things about the 23W:
- (almost) flat up to 1kHz.
- 15 dB peak at 6.5 kHz
- 3rd order harmonics from 100 Hz to 1kHz at about 0,1% at 90dB
- 5th order harmonics from 100 Hz to 1kHz everywhere lower than 0,03% at 90dB
- very low sensitivity at 79dB/1W/1m in low-frequency range. (about 85/86 dB is normal for woofers. DON'T compare it to the sensitivity at a few 100 Hz that is usually given)
- it goes LOWWWWW.... : reflex: 63 liter, tuned to 17 Hz with a 60mm diameter tunnel, 440mm long gives a -3 dB of 14 Hz.
Closed in 18 liter, with a 2.000µF capacitor in series gives a -3dB of 25 Hz.

Hope this gives you an impression?

Grtz, Joris

 

[Pan]

Thanks Joriz!

Respons and sensitivity I have seen on d-s-t.com but the
low distortion was good news and what I hoped for. Question is how it perform down lower in range and esecially with some power.

That 18lit/2000uF sounds almost to good to be true. I ran some simulations and at less than 25 lit the Q started to be a little high and peaky.

Reflex loaded could be very fun but question is how that small port would cope with air flow.

No 2nd harmonic or anything below 100Hz?

Thanks very much!

/Peter

 

[The golden mean]

I´m going to help a good friend to build a high quality sub. He do not know anything about acoustics and my talk about room modes and the placement of the sub seems to mean noting to him.

I have considered the Scan Speak 23W/4557T00 and a big bunch of other drivers because a good sub should be infinite small according to my friend🙂

I hesitate to use Scan Speak bass drivers as the measurements of the same drivers by German magazine Klang&Ton show large discrepancies compared to the manufacturer´s data.
Manufacturer: Vas 45.6 liters Fs 20.5 Hz Qts 0.47
Measurements: Vas 36 liters Fs 22.5 Hz Qts 0.57

Or Vas measurements for 26W/8861T00: Manufacturer claim 234 liters and measured is 139 liters.

Does the German mag "burn the element in" Yes! Do they have the skills and equipment necessary? I think so. 😎

All Scan Speak bass drivers I have considered have the same draw back if there is some truth in the measurements done!
About a 10 % difference is acceptable but not so much more.
Of course it´s possible to buy a driver, measure it then build an enclosure, but then you may end up with an enclosure of significant different size than you planned. A bit frustrating....
Any comments is welcome, as I may disregard using their drivers.

 

[Kinnja]

Looks like they have a black version too 23W/4557T02.

But:

...........I hesitate to use Scan Speak bass drivers as the measurements of the same drivers by German magazine Klang&Ton show large discrepancies compared to the manufacturer´s data.
Manufacturer: Vas 45.6 liters Fs 20.5 Hz Qts 0.47
Measurements: Vas 36 liters Fs 22.5 Hz Qts 0.57..........

This is why I wouldn't want to spend a lot of money on any driver. Seems like I hear a lot about many manufacturers specs not being as good as quoted.

 

[rabbitz]

This is why I wouldn't want to spend a lot of money on any driver. Seems like I hear a lot about many manufacturers specs not being as good as quoted.

It's not a problem as the ratios Fs/Qts and VasFs² come in close enough..... 5%-9%. The individual values can vary quite a bit like over 20% but it all comes good. If it's really important then the drivers should be measured anyway.

There is always a question about the accuracy of individual measured results and test equipment used as well.

 

[rabbitz]

Closed in 18 liter, with a 2.000µF capacitor in series gives a -3dB of 25 Hz.

Do tell me more about the method with a cap in series as I have a sealed project coming up.

I've seen it used with mass increases on the cone but the cap value is usually huge.
C=0.234/(Re x Fc)

 

[Moondog55]

Rabbitz it works, I have used this method in several subs, using the calculation in Vance Dickinsons book, you only have to add mass if the is a light weight conductive one, if you have a driver with a heavy kapton coil the Qms is close to 10 and just calculate
The Jaycar 10 inch should be suitable of the shelf ( but i haven't used it yet)
http://www.jaycar.com.au/productVie...&pageNumber=&priceMin=&priceMax=&SUBCATID=383

This is the driver I am thinking of using for my on's 2st present but I need 6 of these for the sub box so it is in the "just thinking about " pile at this time

 

[The golden mean]

Well, I think inconsistent driver "quality" is a problem to most speaker designers. Not all have the right, like the swede Reidar Persson (of Respons Loudspeakers) to return to the factory the "inferior" drivers and keep just the good ones. BTW, he uses Scan Speak drivers. It should IMHO be possible to receive measured drivers at least at the higher quality segment .

Some years ago I ordered Volt R3143 woofers from a well-known English distributor. When I got them I assumed that these were just the one´s I had put an order for. But later I discovered that
they were marked RV3143 and it was eventually a new model were Vas had dropped from 110 liters to 76 liters and Fs had been increased from 29Hz to 34Hz. Thus I had put very much effort into building enclosures that were too big. They are weighting in at about 200 lbs so it would have been nice to know that I could have done them smaller. And simulations by my Sound Easy program clearly showed that a significant smaller air volume was the right thing. Thus I have placed bags with sand inside the enclosures and it works. It´s not an example of inconsistency but more of an example of what can happen when you invest much money in building your ultimate loudspeakers.

I mostly use Thiel & Partner (Accutone) drivers and hope for a satisfying degree of consistency and not too much derivations from specifications.

But if you always has to calculate with big differences in driver´s parameters building loudspeakers is more difficult, you have to receive the drivers before you can start building, because you have to measure the drivers. Or you can in fact find that your finished enclosure should have been twice that large. 😉

I claim that big discrepancies in parameters is indeed a bad thing.