got an interesting sub(?) here...

**no_luggage** · 10-31-2006, 01:31 PM

I'm hoarding parts preparing to build my el cheapo system and I came across a really interesting 12" driver. A friend who installs super high-end home theatres gave me a driver out of a Thiel SC7. It looks very similar to the bass driver in the current 7.2 model

http://thielaudio.com/THIEL_Site05/P...7_2/cs7_2.html

This thing is SO heavy! I think the basket is cast out of iron not aluminum. It's 40lbs plus. All I've really been able to find out about it is that it's a 4ohm driver (3 ohm real) and likes about 300w in a home audio environment. (gleaned from reviews on the net, so even this is questionable.) Anyways, when moving the cone up and down, this thing has a really supple, light feel compared to any mid-level quality subs I've ever got tactile with. It does have a different coil design philosophy (see here- http://thielaudio.com/THIEL_Site05/P...istortion.html ).

I'm just curious what sort of effect this light action will(should) have on the choice of amp I get to push it and the choice of enclosure. Despite the fact the original speakers have passive radiators in the picture I'm planning a for a smallish sealed box currently. I'd like to get a nice efficient class D or "class T" to drive it. SQ is more important than SPL to me.
If anyone has experience with a similar sort of driver or educated opinions (I'm sure people will have opinions...

) I'd love to hear it.

Thanks!

**Shadow** · 10-31-2006, 03:01 PM

300W in your house is a COMPLETELY different monster than 300W in your car. a 200W powered sub in my house will drive me out of my living room that's open to the kitchen, the upstairs catwalk and the foyer. 300W in my car is pretty loud, but not REALLY loud.

**BenOBS** · 10-31-2006, 03:23 PM

Maybe it will not be extremly loud, but it look like a good SQ sub... It sure that car environment is totaly different than home environment, but the main idea is the same, move air...

**no_luggage** · 10-31-2006, 06:58 PM

another thing to think about is the reviewer was probably using 8ohm amplification at home... it may require considerably less wattage at 4ohms (if I understand how that works correctly)... I'm taking no chances- I'll get an amp with around 300w constant 4ohm available I think. I'm not too worried about it not being loud enough... I don't listen crazy loud anymore. I just want it to sound decent.

**BassBinDevil** · 11-01-2006, 12:33 AM

The right thing to do is get or measure the Thiele-Small parameters and use a box-design program to see what sort of boxes it is suited for. Or the other thing to do is throw it into whatever box you already have and see if you like the sound.

**furball69** · 11-01-2006, 10:24 PM

Originally Posted by no_luggage

another thing to think about is the reviewer was probably using 8ohm amplification at home... it may require considerably less wattage at 4ohms (if I understand how that works correctly)... I'm taking no chances- I'll get an amp with around 300w constant 4ohm available I think. I'm not too worried about it not being loud enough... I don't listen crazy loud anymore. I just want it to sound decent.

Running an amp that requires an 8 Ohm load, at 4 or 3 Ohms would quite possibly fry the amp. The amp will (try to) run at whatever load you present to it so, an amp that requires an 8 0hm load would see a 3 Ohm load, as you mentioned that that speaker measures 3 Ohms; the amp doesn't make the speaker run at 8 Ohms.

**no_luggage** · 11-02-2006, 09:48 PM

he amp will (try to) run at whatever load you present to it so, an amp that requires an 8 0hm load would see a 3 Ohm load, as you mentioned that that speaker measures 3 Ohms; the amp doesn't make the speaker run at 8 Ohms.

furball69; Yeah that makes sense... I was thinking it was backwards of that. Ohms! So simple and so confusing!

BassBinDevil; I looked into doing the T/S measurment at home...seems like quite an ordeal. I'm interested, but I think impatience will drive me to fake around with some boxes... I have a friend with three different boxes that aren't installed right now... I think I'll throw it on each box and do some testing to see how it sounds first. If that doesn't prove satisfactory I'll have to test it. It'd be good to maybe take each speaker I'm intending to use in this install and T/S 'em all to see how they balance against one another.

anyways I ebayed an xtant 2200xi to run this guy...bridgeable 400x1 into 4ohms and great damping (which i think will help with a driver that is so easily moved- hope so!). The audio side acquiring is getting close to finished!

**no_luggage** · 11-08-2006, 08:29 PM

Little update- I have a buncha T/S information garnered directly from Thiel Audio... I politely asked and they provided everything they had on the driver. The tech mentioned he got the info from Jim, which I would assume was Jim Thiel. Very cool and a very nice experience. Now to futz around with some box design software!