Just can't decide on an 8" sub

joeybutts

So I've been leaning heavily on using the new UM8 in a set of four for a unique IB install in my vehicle.....but then boredom and inability to make the purchase for a little while had me looking around at other drivers.....and I stumbled on the Image Dynamics ID8 subwoofer.... and the specs look almost perfect....incredibly low FS of 22.7, moderate QTS at .289 and a Vas a bit high at 1.7 cubes, but I figured that is a good trade off for the FS.  

I am truly looking to boost sub 45hz as my vehicle essentially runs a 3way front stage, tweeter in the sails, 4" woofer in the door and 8" extremely shallow and low air space under the seat.  

Also the depth and price of the ID is great as well, but I'm not going to buy something that isn't best for my situation to save $25 a driver.  I'm gonna go remeasure soon and may go with 8 8" drivers if I can fit it......

isaeagle4031

Typically for IB we want a higher q, not lower. The lower q is going to make these roll off sooner.

joeybutts

Right, but I figured that since I was looking for such a low low-pass that I could compromise on the Q......you think that is too low at approximately.3 for a QTS?

Mzisserson

Hi Joey,
   Could be wrong, but basically a higher Q allows for a rol-off similar to that as sealed since really is IB based more on the "sealed box" (trunk size). If you are looking to boost sub 45, I would compromise Fs before Qts to spite seeming counter-intuitave. I would also shoot for a woofer that has a high-ish (above 6) Qms and lowish (below 0.6) Qes. Don't forget the massive cabin gain in a vehicle whch is usually on the order of 12dB/octave starting around 50Hz, but the transfer function of it can vary from cabin to cabin. So the gain added to a natural soft roll-off with well controllled cones is a recipe for goodness. 

Mzisserson

Forgot: i would not use a deiver with a Qts much lower than 0.5 in any case if IB.  Though depending on Qms it is possible. 

joeybutts

AHHHHH...ok.... so something like an Alpine Type R 8" would be ideal you think? 

http://support.alpine-usa.com/products/documents/OM_SWR-8D2_8D4_EN.pdf

Mzisserson

joeybutts said:

AHHHHH...ok.... so something like an Alpine Type R 8" would be ideal you think? 

http://support.alpine-usa.com/products/documents/OM_SWR-8D2_8D4_EN.pdf

Yes, actually...The 4+4 looks great. Don't let the Fs fool you, in-cabin I am thinking with a quad of them you will get to the mid 20's with intense compression. 

joeybutts

AWESOME!!  So you think eight would be pretty good?     Or will too many cause negative effects? 

Mzisserson

My flavor is more SQ. Two would have plenty of output for me, but if you want the boom, have the altinator, cap, and amp for it then have at it!

I feel old, in the 90's I use to run 4 JL 10W0's sealed in my 89'Taurus. Now, One eight just for a little ass-tickle is good enough for me. 

Speaking of which. In 2004 I designed a dual 8" box around the TB W8-740P. Small and vented high passed at 35Hz 12dB/octave driven with 800W. STILL kicking today and people think its dual 10's or 12's. I am suprised the foam holds up as well as it does. Good long term test of them. 

joeybutts

It will definitely be more SQ oriented but love the low 30's/high 20's in a lot of EDM and trap music.  I also figured power handling would drop significantly since I will be going IB and that I won't really need that much power to get them going, so I was going to shoot for a monoblock or 2-ch amp that could put out a reliable 1kW-1.5kW and that power level should be ok on stock electrical.....I would think.  

Mzisserson

If you use the right driver, power handling is no issue. Thats why they make em' the way they do!

Face

Instead of 4-8 8's, why not a pair of 15's?  http://aespeakers.com/product-category/ibau-woofers/ 

joeybutts

I was considering the typical two 15's but wanted to do different, and figured I get to save some depth in the trunk....maybe I should just do 15s

greywarden

IMO, a trunk isn't IB, it's just a large, leaky, sealed enclosure.

Beau

Take a look at the Infinity 860W.  Price performance wise it is hard to beat.  It can be used small sealed or ported.

squamishdroc

joeybutts said:

I was considering the typical two 15's but wanted to do different, and figured I get to save some depth in the trunk....maybe I should just do 15s

What are you driving these days Joey? Last install I remember seeing was the regular cab Ranger with a 15 behind the front seat right?

joeybutts

Thanks Beau!  Though I'm now thinking of shoehorning two UM18s.....:p

A few iterations went through the ranger.....eD 16Ov.2, eD 13Av.2 (favorite install in there and maybe anywhere), four soundqubed 12's, custom 12" driver.....now going to put a T-lined eD 7Kv.2.

This thread is for the bimmer I bought in December.  IT's just missing the bottom end of the spectrum, otherwise it sounds quite good in there.  I really like that shake rattle and roll from sub 35hz (which is why I loved the 13A ported in the Ranger) so hoping IB with oodles of cone area, throw and power will deliver.

squamishdroc

joeybutts said:

Thanks Beau!  Though I'm now thinking of shoehorning two UM18s.....:p

A few iterations went through the ranger.....eD 16Ov.2, eD 13Av.2 (favorite install in there and maybe anywhere), four soundqubed 12's, custom 12" driver.....now going to put a T-lined eD 7Kv.2.

This thread is for the bimmer I bought in December.  IT's just missing the bottom end of the spectrum, otherwise it sounds quite good in there.  I really like that shake rattle and roll from sub 35hz (which is why I loved the 13A ported in the Ranger) so hoping IB with oodles of cone area, throw and power will deliver.

What are you running for a front stage in the Bimmer?

joeybutts

Just stock for now.  Can't afford to do full system upgrade and am acutally ok with it for now..... I have the Logic 7 system I believe..... maybe HIFI.....