High Sensitivity midbass drivers

[req 5,000+ posts]

yeaaa. um.

my CD2's are 109db 1w\1m .... thats like. 20db //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

lawl.

 

[djdilliodon 10+ year member]

If CDT works something out and makes the 06+ a reality you can get solid results from a power range of 75-150xrms at 4ohm in a well deadened door IB. I have a pair myself and these things can extend super low and play to 1khz very cleanly. I have them off 150x2rms but with gains set very low matched to a pair of CDT es-02 2" midranges (also not out yet) with 75x2rms all run active with the 06+ at 40-1khz and the 02's from 1khz up. The 06+ has 15mm of xmax and has all the output i can ever imagine any 6.5" can have and how low they can play in even the bass freq is just amazing. You would never think they are 6.5's. CDT should release these after ces but since these drivers are built by hand and believe me they are top notch quality they are just working on how they can make them affordable. Knowing cdt they will work out something and when these are first released they will have a special on them but eventually will go up.

 

[T3mpest 10+ year member]

If CDT works something out and makes the 06+ a reality you can get solid results from a power range of 75-150xrms at 4ohm in a well deadened door IB. I have a pair myself and these things can extend super low and play to 1khz very cleanly. I have them off 150x2rms but with gains set very low matched to a pair of CDT es-02 2" midranges (also not out yet) with 75x2rms all run active with the 06+ at 40-1khz and the 02's from 1khz up. The 06+ has 15mm of xmax and has all the output i can ever imagine any 6.5" can have and how low they can play in even the bass freq is just amazing. You would never think they are 6.5's. CDT should release these after ces but since these drivers are built by hand and believe me they are top notch quality they are just working on how they can make them affordable. Knowing cdt they will work out something and when these are first released they will have a special on them but eventually will go up.

15mm 1 way or 2?!?!

 

[req 5,000+ posts]

thats def a wrong figure.

its eaither 15mm 2 way or not right at all. theres no way an 8" will be doing 30mm of movement and keep up the transient response for midbass action...

i just cant see it.

any pics of these cdt hand built thingies?

 

[JonJT 10+ year member]

I'm also working on a similar install to yours and have had similar issues. The B&C's seemed like the a good choice to me. Other good midbasses for horns are hard to find. Here's a couple ones though. One driver that might be a decent choice, again it's discontinued is the peerless xls. It's 90db effecient, which isn't terrible, but is a good sized 8 and handles alot of power. I think it might have the dynamics needed for a horn system. What midrange are you planning on using, audax?
IDQ 8

JL IB8

JBL2 118

Audax and PHL both have high sensativity midbass, I've been told PHL mids are REALLY nice, by quite a few sources. Not sure how they'd work in a car environment though, it'd take some work, that's for sure.

The Xls crossed my mind but as you said its discontinued so I'm taking themoff thei list

I'll look at those other woofers as well.

And yes, I will be using the Audax

 

[JonJT 10+ year member]

Yes, primarily QTC is the controller of the transient. The actual transient is a function of the acoustical model of the speaker as current/voltage is applied to the voice coil over a period of time. Sensitivity is more or less efficiency (amplitude in the output function). But sensitivity can be an indicator of damping. Unfortunately, increases in damping decreases bass output. So a highly sensitive speaker will generally have low amplitude bass output.
People will tell you to match sensitivity because of the large difference between a horn and standard woofer...over 10db in some cases. What a horn does is takes a transducer and helps to match air loaded impedance. So it increases efficiency. It also reduces distortion due to lower power needed to meet the same DB level, and lower air impedance distortion.

IMO, it's better to have a linear woofer, which can handle a lot of power to match the output of the horn, than to have a highly efficient woofer and EQ the low end sometimes 6-10db.

Even if a highly efficient woofer has a large cone and great pistonic movement, it still not be that great at reproducing low frequencies?

 

[JonJT 10+ year member]

yeaaa. um.
my CD2's are 109db 1w\1m .... thats like. 20db //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

lawl.

dam, that sucks....................

 

[T3mpest 10+ year member]

The Xls crossed my mind but as you said its discontinued so I'm taking themoff thei listI'll look at those other woofers as well.

And yes, I will be using the Audax

Figured, I'm trying to get some phl 2520's for my midranges 8 inches of midrange, hells yeah! Kicks are going to be half my floor, the other half being some IDQ 8's......hahaha. Hopefully my system will give me the impact I'm looking for. IDQ's 8's will have ohh, 500 watts or so EACH.....

All the drivers I mentioned are hard as heck to find, unfortunately. The 8IB4's are still in production. Look for the JL stealthboxes in BMW's for the most common source. The B&C driver is probably the easiest driver to find that will work well. Dyn 170's have been known to do ok as well.

 

[JonJT 10+ year member]

Figured, I'm trying to get some phl 2520's for my midranges 8 inches of midrange, hells yeah! Kicks are going to be half my floor, the other half being some IDQ 8's......hahaha. Hopefully my system will give me the impact I'm looking for. IDQ's 8's will have ohh, 500 watts or so EACH.....

8 inch midrange? jeez, wouldn't such a large driver start beaming at a pretty low frequency?

 

[T3mpest 10+ year member]

Being in my kicks, I can afford to put them pretty much on axis. With horns, I won't be running them really high. I can probably get away with 1k or so with a shallow slope. I've seen some 9inchers that won't start really beaming badly until 1.5 or so. Odds are I'll be ok, plus they are 100db effecient and can't handle 200 watts of power (like I'd ever give them that much closer to 50).

 

[JonJT 10+ year member]

o, well good luck with that then.

 

[Thnking 10+ year member]

Even if a highly efficient woofer has a large cone and great pistonic movement, it still not be that great at reproducing low frequencies?

Large is relative to the audio industry standards. 18" cones have large air load impedances, a 100hz wavelength is over 11'. The same goes for the speakers displacement, it's relative to industry standards and design linearity limitations. Typically as displacement increases, distortion increases. As displacement increases non-linearities in parameters increase.

 

[djdilliodon 10+ year member]

thats def a wrong figure.
its eaither 15mm 2 way or not right at all. theres no way an 8" will be doing 30mm of movement and keep up the transient response for midbass action...

i just cant see it.

any pics of these cdt hand built thingies?

The xmax figure i was told is 15mm and believe me they move. I have a vid of them you can see here http://www.realmofexcursion.com/videos/CDT%20Audio/es-06+.1.wmv each mid is seeing around 90wrms or less full range. Oh and these are not 8's they are 6.5's //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[squeak9798 5,000+ posts]

So far I would have to agree with what most of the others have said.

Transient response is dictated by inductance and the final system Q of the driver. Sensitivity, as was pointed out, is simply amplitude in relation to input power.....and high sensitivity and low frequency extension don't get along very well. Due to that stinking law Hoffman identified, high sensitivity midbass drivers are going to need large airspace (and possibly need to be ported) to have good authority in the lower frequencies. The main saving grace in car audio is the reasonable amount of transfer function gained by the enviornment. This could be enough, depending on the vehicle/etc, to extend the low end response by a reasonable margin.

But, it really depends on who you talk to. There are many who subscribe to the high sensitivity ideology when mating drivers with horns. There are those on the other side of the fence who don't consider this a mandate (atleast for dedicated midbass). Look at the Team ID guys....how many of them are using a midbass with a sensitivity higher than 92-93db? Heck, the IDQ8 is the #1 recommended mid to use with horns....and it comes in at 90.8db.

Overall, I would have to say that for a dedicated midbass like you are wanting....I would have to agree with Helotaxi to find a midbass with low distortion and good displacement and feed it power.

 

[joe duce 10+ year member]

The xmax figure i was told is 15mm and believe me they move. I have a vid of them you can see here http://www.realmofexcursion.com/videos/CDT%20Audio/es-06+.1.wmv each mid is seeing around 90wrms or less full range. Oh and these are not 8's they are 6.5's //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

//content.invisioncic.com/y282845/emoticons/eek.gif.771b7a90cf45cabdc554ff1121c21c4a.gif

what kinda mounting depth do these have? i too am looking for some nice midbass to mate with horns but i want something with a small mounting depth so i do not have to carve up my door panel.

joe