ScanSpeak D3806 - anyone used it?

[Ian J]

Hi all,
Have just bought a pair of these on ebay, tempted I must say by the potential of a low x-o freq. (specs mention 100W handling with 12db x-o at 1kHz), though I appreciate a supertweet is required for above ~13kHz. Can't find a DIY design that uses these - anyone any experience/comments?
Thanks
Ian

[grantnsw]

Hi,
I realize this is a question about an ancient post, but I'm wondering why
there were no replies? In another thread somewhere, I read that maybe the Seas 27TDFC will cross nearly as low, but its much cheaper. thanks, grant

[Michail Bugaria]

http://www.troelsgravesen.dk/SP_38.htm

[grantnsw]

Many thanks Michail,
It looks good, its ..Scanspeak and I probably don't need much response
above say, 13kHz.. I have old ears! Could you comment on the D3806 compared to the Seas? Also , I wish I could read your website. thanks

[Michail Bugaria]

Sorry it's not my
http://www.troelsgravesen.dk/Diy_Lou...r_Projects.htm - it's Troels Gravesen's website

[Pano]

Hey Grant,
the D3806 is a great driver - one of the best out there.
Scan Speak seem to know it, considering how much they charge for it!

The Seas 27TDFC is also a very good tweeter. Probably not many other dome tweets that can touch it.

Yes, I know both drivers.

But John B is the really the one to ask, he has used them both in many designs. He may chime in on the subject later today or tomorrow.

[grantnsw]

Hi Pano,
I just re- searched, and indeed it was your favourable comments on the D3806 in a 2-way with up to an ( unbelievably huge ) 18" woofer that appeals to me. The Scanspeak is available here, but I might get a real shock when I find out how much $'s they want. Comparing the two tweeters, I think for me the D3806 solution with an overall better midrange would be preferable to the Manzanita, although very good no doubt, might have a xo dip.

Yes it would be great if your friend John B drops by with his impressions. ( John B sounds like a 'sloop'..haha, no offence, you know , the Beach Boys song)

Michail,
Oops, I was referring to your personal homepage website that is of course in Russian.

paging IanJ,
I see you were online last October, so maybe you would also like to describe your D3806 project please? thanks, grant

[John Bsuch]

OK ...... Here goes.

Have used both extensively. For the money.... if you can get away with a 1,375 hz fourth order acoustic out come... the TDFC is a giant killer. Very little for anything approaching it's every day price and availability comes close. And you can get a 4th order with a simple cap and coil. Add the usual single resistor pad... it doesn't get much simpler. John Krukte over at his Zaph Audio site has a great deal of both test and application information on his excellent site. WWW.zaphaudio.com .

Now to the SS3800. The truck.... hell semi truck of tweeters. Just how it is built. Huge magnet.. as much copper on the cap as you will ever see.... (SD-1 motor) ventilated pole piece, tuned rear chamber and so on. My only two knocks on this thing are the cost (now approaching prohibitive here in the US (even at dealer wholesale) ) & cheesy connecting loops. Can be run down around 950 hz with a single cap and series resistor to acheive a 2nd order acoustic with the -3 at around 1,000 hz. Several application notes. This thing has been around for approaching 20 years that I am aware of. So there have been changes. Original version had a hand doped dome with a bit more xmax. The newer versions... guessing late 90's.... a plain and lighter no dope version with a bit less x-max. No fero but a very smooth resonant peak like it does. Great motor design!!

Each had it's advantages.... earlier more like a dedicated extended range mid.... the later more like a heavy duty mid-tweeter.

You have to be carefull about the woofer you mate to it. It is a very low distortion tweeter and will show up crappy woofers pronto. Likes big paper and harmonically couples with them to the point of wonderment. Does not like aluminum and some poly pro cones. No rime or reason.... just what I have noticed.

Also it does have a mid - upper band rise and if you mate it to a small tweeter you will want to add a series inductor... say .15-.35 milli henry. And if you are padding more than 3 db to match your woofer a small by pass cap can help fill out the very top end if you are using this thing full range. Experiment... but .5-.75 MFD is a good place to start.

You can forth order acoustic at the bottom end if high power handling is needed. Will require a lot of experimentation to get right. Larger than standard inductor values tend to work better with a calculated 1,150 hz corner is a good starting place.

A bit long on this .... hope it helps.

Bottom line ..... both are close to state of the art and especially with the TDFC a great bargain and the 3800 can do things that NO OTHER off the shelf driver I am aware of can!!

Best

[grantnsw]

Hi John,
Many thanks for your very informative and detailed post. Your experience with, and knowledge of, these drivers clearly shows! I had no idea that the SS3800 series had been around for so long, whaddyaknow! As much as I would like to buy a pair, sadly the price seems prohibitive to me.

2nd order acoustic @ 950 on the Scan doesn't seem to justify the exponential price hike over the Seas at about 400Hz higher.

So 4th order acoustic at 1375Hz on the Seas seems simple, doable and most importantly affordable to me. Vaguely, from memory , I think Zaph MIGHT have said its distortion characteristics were ok that low, but I will check. Anyway its acceptable to you, so why would I bother!

John, I really appreciate your post. It was very kind of you to relate your experience. A longer post would still have been gladly received!

Hmm, now I'm wondering.... if my 4 x 8" woofers Qts(manuf) 0.47 , 2 per side, would work OB with the 27TDFC? Happy holidays! ..grant

[Ian J]

What a surprise seeing this resurrected after all this time...
I must admit I bought the 3806s in a hurry on ebay without checking too closely - I assumed they were similar in size and performance to 9500 series and was hoping for an easy upgrade to the Seas 27TFFCs in my IPL A2s (this is a UK kit speaker no longer available as it used the Audax HM170Z18). What a surprise when I found out how big and heavy they were! Mine must be the later version as the dome is practically transparent. Well, as we've all found out the 27TFFC and it's brethren aren't so easily dismissed - though without measuring gear my attempts were limited to just using existing x-o (2nd order at 3KHz) and removing the attenuating L-pad as the 3806 is a good ~4dB less sensitive. Being so robust I keep meaning to try a series x-o with the 3806 but still haven't got around to it. Sorry can't help more, but good to see there are other users out there. I think it's used on one of the big Troels G. projects too.
Ian