New SI DS4-18" subwoofer

neo_2009

Well-known Member
It seems SI will have a new 18" Subwoofer.

Specs:

4" diameter copper voice coil
27 mm Xmax
220 mm OD advanced FEM optimized triple stacked magnet structure
234 mm OD nomex spider with bolt-down ring
Flat sewn-on leads
Large 4 AWG speaker terminals
One piece inverted dust cap
High-roll rubber surround
Cast basket
Magnet ID shorting ring

Cutout: 16.7"
Mounting depth: 9.5"
Weight: 50.0 lbs


T/S parameters:

Re: 3.9 Ohms
Fs: 18.7 Hz
Qes: 0.65
Qms: 2.19
Qts: 0.50
Le: 1.52 mH
Sd: 121736.4 mm^2 (18869 in^2)
Vas: 270 L
BL: 19.9
Mms: 561.42 g
Cms: 128.2 uM/N
SPL; 86.1 dB 1W/1M
SPL: 89.1 dB 2.83V/1M
Xmax: 27 mm
Xmech: 50 mm
RMS Power: 1200 w

Enclosure recommendations:

Sealed: 4 ft^3
Vented: 6 to 20 ft^3

Price will be under $270.

Source: SI DS4-18" subwoofer with 4" coil
 

mattkhan

Distinguished Member
thread was pulled, seems avs has a similar polict to avf when it comes to non advertising manufacturers
 

MemX

Well-known Member
Generally I tend to work by the rule that whatever it costs in USD, change the $ sign to a £ sign and you're probably in the ballpark!
 

mojogoes

Remembered (1961-2016)
The final prototype is finished for the 4" coil DS4-18" subwoofer and here are the T/S parameters:

Re: 3.9 Ohms
Fs: 18.7 Hz
Qes: 0.65
Qms: 2.19
Qts: 0.50
Le: 1.52 mH
Sd: 121736.4 mm^2 (18869 in^2)
Vas: 270 L
BL: 19.9
Mms: 561.42 g
Cms: 128.2 uM/N
SPL; 86.1 dB 1W/1M
SPL: 89.1 dB 2.83V/1M
DS4-Production-Rear.jpg

Xmax: 27 mm
Xmech: 50 mm

Redirect Notice
subs/2206417-stereo-integrity-ds4-18-a.html&sa=U&ved=0ahUKEwiYsrfFkLvLAhUiS5oKHaKKA7oQFggEMAA&client=internal-uds-cse&usg=AFQjCNHPeOqqv6A2RP65TBV10mSDFLkjhQ

Stereo Integrity DS4-18 - Page 6 - AVS Forum | Home Theater Discussions And Reviews
 
Last edited:

mojogoes

Remembered (1961-2016)
blah450
AVS Special Member



Join Date: Jan 2010
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"The Fs is actually a little bit lower than the HT-18 due to higher mass with a similar [slightly higher, not lower] compliance.

I will post a complete list of T/S's once I get back to the office on Monday."

Stereo Integrity, Facebook
http://www.avsforum.com/t/1455958/pe...-to-inukes-dsp
 

mattkhan

Distinguished Member
He has said the final params have an Fs below that of the HT18 so I would ignore those prototype params. He has said this himself a few times BTW. I imagine there isn't a massive difference but you never know.
 

mojogoes

Remembered (1961-2016)
There still seems to be some doubt about the spec's of the Si HT18 D4's being off in spec's and being / measuring so different that the Si HT18 D2's and that of both prototypes .

Members are now asking Nick why such a difference? And so basically this difference in spec's may roll over to the new Si DS4 18 driver also..........

" AVFORUMS Si DS4 thread.....
Quote:
Originally Posted by rhodesj
He's seen that thread linked, and responded directly. He replied, "The parameters are different for the D2 and D4 HT 18's but they model exactly the same." Swapping drivers: HST-12 for 12" Titanic MK III

Personally, I'm pretty happy with my four HT18s, and I'm glad that there are companies who want to specialize in DIY home theater. We're a pretty niche bunch, and I'm glad for options. And I don't think I would have gotten hooked on bass if not for the HT18 in the first place.

But I really have trouble feeling sympathy for the thread going off-topic when Nick himself is the one jumping in to argue with his customers whenever the HT18 comes up.
Quote:
Originally Posted by Electrodynamic
Haha, funny discussion so far.

AKA: Ignoring important facts to push other irrelevant specifications to make one driver seem superior to another while most forum members sit quitetly aside in hopes that no one says anything. I think there is an LMS-U disussion somewhere that supersedes this discussion. Price is not mentioned.
Ok so here is the perfect opportunity. Nick, Can you please explain why the HT18 D4 specs are so different from the D2 that Josh tested? You mentioned that they model the same but they do not. Why are they so different? Does the D2 also measure differently than the prototype? Things can happen with production, I know. I hope you dont think we dislike your products. Thats not true at all. We are just trying to protect the forum. I would love to buy from you again but I feel like this issue should be cleared up.

Everyone else please let Nick answer. He's they guy that designed them and deals with the production. Lets put this to rest once and for all."
 

mojogoes

Remembered (1961-2016)
He has said the final params have an Fs below that of the HT18 so I would ignore those prototype params. He has said this himself a few times BTW. I imagine there isn't a massive difference but you never know.

So i'm now being told that the quoted spec's about will be pretty close to the final figures of what the si ds4 18 will make give or take.
 

marvinwright1

Active Member
I've been waiting for the Dayton UM18-22 to come back in stock at PE but I like the look of this driver too. How does it compare?
 

mojogoes

Remembered (1961-2016)
Thanks Matt!

" After doing some invoicing today I whipped open the paramaters file for the DS4-18 D2 "

Yeah but i thought a slightly odd way of introducing the spec's to everyone.

Plus its no surprise that all that went on with the Si ht18 d4 that there will no longer be a D4 ohm unit made.
 

marvinwright1

Active Member
FYI, they are taking orders on these drives now according avsforums site, not sure if this forums rules allow it so I didn't include the link.

Marv.
 

mojogoes

Remembered (1961-2016)
The thing is with that is that the specs haven't been verified driver fully tested , but funnily enough there already on sale !! So it could be another case as with the Si ht18 d4s ! Of them not coming up to quoted specs but hey there nearly all sold anyway , so we can either not talk about it or and move on to something else.

Or better still this next time around we won't even make a d4 version!!
 

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