Going for a high quality 3way front stage with tweeters and mids up high and close together and Midbass in the doors. currently looking at scanspeak drivers and expect some very good results. however i am just questioning the 8 inch woofers. I was planning on using these http://www.tymphany.com/datasheet/printview.php?id=97

However i love the feeling of a good midbass kick and want to know what you guys think of replacing them with something like the DD1008s or similar. Does anyone have any suggestions? They will be playing something around 50-400Hz i think, however i dont know, will decide what sounds best. How much of an affect will this have on the sound.? i have been told the 1008's will play up to around 1kHz, i doubt i will be entering many comptitions so am talking serious differences that will be audible over the road noise. I listen to heavy rock mostly.

Was going to feed the scanspeak around 220WRMS and probably 300WRMS+ to the DD's

if you want to be playing 50hz without distortion at high volumes,
you probably will want a 8" midbass driver,

however you can't really get away with using subwoofers, unless they are infinite baffle,

suggest sticking to midbass specific drivers, the scanspeak revelator is obviously a serious contender, I believe your looking at around $1k a pair.

Juls

digital designs DD6.5LT

If you can, find an Audio Technology mid bass. This brand is the cousin of Dynaudio and Scanspeak, with little customization. If you have heard of Fabolous Acoustic, then this is the midbass they use with ribbon tweeter. It's the Cquenze unit and midbass is phenomenal (reportedly), even for the 5 inch version. Downside, can be very expensive and rather large to mount.
Seas Reference is supposedly good too, i know a guy who swap his Audio Tech mid with Seas Reference.

I was going to recommend Seas drivers as well, some of the 18 series W,L,P etc... supposedly excellent midbass and not stupidly priced either, apparently some of the best midbass performers around. Also I've heard nothing but praise for the DLS Iridium 8" midbass output, one of biggest hitters around apparently.

You have pm 37WREFGli

Luke

This is a general specification range you'll want to aim at for a door loaded mid bass driver;

Fs: 25-40hz
Vas: 40-70L
Qts: 0.4-0.7 (too low and it'll roll off too fast , no punch, too high and it'll be boomy)
Le: >1mH, preferably >0.7mH (this is critical since it limits upper response)
Mms: 20-60g (this also limits upper response)

The DD1008 is a small sub, it's not a midbass driver.

I hear this alot about using subs as midbass speakers especially 8s and 10s but from what i've heard and seen the heavier moving mass of cone, stiffer spiders and the general heavy duty build makes them less responsive(slower) then dedicated midbass drivers.

if you want something to go up to 400 odd Hz, then a sub will not be much good.

as you are mixing/matching I assume you'll be active, or custom passive/bi-amp. in which case I'd recommend the Dynaudio MW172 for strong midbass with great lower-mid smoothness - it crosses over nicely up as high as 900Hz, so you get a full octave of smooth roll-off.

the frequency region you're aiming for contains most of the power in the spectrum, so make sure you have plenty of head room - especially for those deep rythmic guitar hits, and EQ'ed drums.

Thanks for this guys, i think i will go back to a mid-bass specific woofer. ill just have to audition as many as i can to find a heavy hitter i like the sound of. cheers all, specifically to Volenti for those goals to aim for, this woofer seems to fit that profile nicely for a beginning, will search for others...
http://www.tymphany.com/datasheet/printview.php?id=167

With its low Qts value will it b nessicary to place in a sealed enclosure in the door or will it b fine to just mount in a well deadened door?





This is exctly why i inquired as to using the small subs as they have the higher power handling. i plan to be running planty of power to them. around 250WRMS+ each side i think (just to these woofers with correctly set gains of course)



Will have another look into these woofers, are actually one of few high end products i can find locally.
Yes system will be fully active at this stage, possibly passive between tweeters and mids but thats another topic.
Thanks for your reply,

Drew

It's really going to need a sealed enclosure, both for mechanical powerhandling (very compliant suspension) and to increase the enclosure Qtc.

Straight in the door I suspect it would have very "dry" bass (the bass you have when you dont have any bass ) that's the reason most car speakers have a Qts <0.7, unfortunatly this also makes it very hard to find suitable 8'' woofers.

I have always wanted to know what makes a good IB midbass driver for the car however its very rare to see specs give on car audio products to correlate specs to results.




dyn MW172 (from my experience with dyns they do sound good in IB situations)
Le 0.27mH
fs 45hz
Qms 2.3
Qts 0.51
VAS 27lts
Mms 21.4g


scanspeak 18W8545 (not a tight controlled sound but seemed to go quite deep).
Le 0.4 mH
fs 28hz
Qms 2.3
Qts 0.27
VAS 48ltrs
Mms 20g

seas reference car audio (i have yet to hear one of these but they are meant to be very good)

Le 0.45mH
fs 64 hz
Qms 4.24
Qts 0.61
VAS 7ltrs
Mms 19g

Genesis Absolute 18w Bass/Midrange

Enclosure Volume: 20 litres to free air
Fs Resonant Frequency: 54.5.0 Hz
Md Cone Mass: 19 Grams
Qm Mechanical Q Factor: 8.13
Qe Electrical Q factor: 0.67
Qts Total Q factor: 0.62
Vas Equivalent volume : 14.3 litres

morel elate 9sw

FS 40hz
Mms 21.63g
Qms 2.09
Qes 0.42
Qts 0.35
VAS 47.5ltrs

dd W6.5LT

FS 36hz
Qms 8.8
Qes 0.34
Qts 0.33
VAS 21ltrs


Puggie from talk audio uk had this to say:

"if you want snappy you need low Qts, BUT you also need a high Fs, aim for somethin g with a Qts in the 0.3 range and and Fs of 60ish IMHO, they wont play low but they will be tight"

"Higher Q drivers are generally less controlled (higher A generally implies less powerful motor and less damped suspension), lower Fs drivers require softer suspension to reach that lower frequency, this generally gives a looser less snappy driver."

"To get the 'bassiest' speaker you will need a low Fs, but this leaves you with a soft suspension, so you stand a much higher chance of bottoming them out and they will probably lack snap and impact due to the suspension not being able to control the cone so well. I prefer to have midbass with a much higher Fs and lower Q to give me a strong magnet and tight suspension, this gives a very snappy and high impact midbass. Why do you want to play your midbass down so low (Fs of 26Hz)? surely you have subs to do that, and small drivers require a lot of excursion to do low bass, less excursion = less distortion. This is just the way I prefer things it is not right or wrong.

I would also really worry about those scans in a damp door, they won't last with moisture on the cones.
"

Thats ok i will keep looking. lol shud have done some re-reading on this first really, it all makes sense now, lol. Ah i will get there.

This is just a process of narrowing down the possibilities through looking at the specs, all will be auditioned and tested before purchase and tested again before positioning.




The woofers will be playing nothing below around 50-60hz as mentioned before. This is what i was looking for, a tight, punchy driver that will give the midbass sounds a real kick. Thanks everyone for you input.

I am very happy with the mw170's and havent even tuned my system yet

Just to throw a spanner in, I heard JL Audio are bringing out a ZR 8" midbass add on too.
No idea what they are like though

you mean this... http://mobile.jlaudio.com/jlaudio_pages.php?page_id=215
lots of people hanging out for it's release lol.

Just to add in, the DD1008's can be used for mid bass and are bloody good at it too, power handling is halved when used free air.

I think jas's quote pretty much sums up my thoughts - higher Fs, still want it below 50Hz though, will be more controlled and a reasonably firm suspension is good for midbass.

I like mine to play down to 50 or 60Hz, with a steep slope.

If you don't really want a subwoofer, and you have midrange drivers above 300Hz then a lower Fs is essential - that scanspeak 18W8545 is almost an 8" sub (except for the lower Xmax).

If you are using the Dyn 240GT as in your sig, you have the MW160GT's, not the 170's.

http://cgi.ebay.com.au/ws/eBayISAPI.dll?Vi...A:IT&ih=004

just looking through ebay and found these, might be what your after

Find yourself some 2nd hand IDQ8's 150WRMS a pop...

they are a dedicated MID-bass driver, and have been used by many in the IASCA comps overseas.

Just a little hard to find in australia, youll probly have to look at ebay USA.

Actually they are very smooth to over 1k.

I've teamed a set with horns, crossed at 700Hz, it was very nice.

Phil

here is the short example of a few drivers parameters:

qts 0.51 fs 45hz 8inch (dyn 172)

qts 0.61 fs 64hz 6.5.inch (seas ref)

qts 0.62 fs 54.5hz 8inch (genesis absolute)

qts 0.35 fs 40hz 8-9inch (Morel elate)

qts 0.33 fs 36hz 6.5inch (ddW65lt)

so inother words the lower your midbass free air resonance is the higher your over all speaker control must be (which is a lower over all qts value).

the guy i quoted from believed that a good midbass unit would be fs 60hz and a qts of 0.3....none of these fit this profile.

so what really makes a top quality midbass "IB" door driver???

One that fits your requirements. If you only need a midbass to play down to 100hz, then your requirements would be different to someone needing something down to 40hz. Likewise, the low-pass frequency will also be a huge factor. I don't think you can speak generally with this sort of thing - different speakers are designed to fulfill different needs. There can't be one single factor or even group that will make one single midbass driver better than the others - it will entirely depend on the circumstances. Even then, t/s measurements alone are unlikely to give you the answer.

Leigh

Exactly.

You want a really good car mid-bass to play to down to 50 or even 40Hz, to help bring the bass up front.......

Phil

i dont like the idea of buying a product that may not work for an intended purpose.

for a dedicated midbass 40hz-800hz is a realistic figure

for example the scanspeak 18w8545 is use in a IB line array on the martin logan statement speaker, however it is used in conjuction with a woofer tower and and wide bandwidth electrostatic panel. The speaker has quite a compliant soft suspension but seems to work reasonably well for IB situations.

Exactly , thanks Phil.

What I want is a good quality Mid-bass driver that will play down to 50Hz all day long, and probably up to around 500Hz+/- or so, (i will see what works best when i have all the gear). I also want something that is going to be punchy and tight, so i can really feel the midbass kicking up front of me, i have been advised fo this i need a woofer with a tighter suspention, which means a higher Fs, so i will aim for a Fs of 40-50Hz, any higher and it wont be able to play low enough for my liking and it will also need a low Qts value to keep in tight and responsive, so i tshound be aiming for around 0.3. Is this correct so far?

A few quick answers to comments that have been popping up,
YES i will definately running a sub, to play down any lower than this, have even considered sealing up my glove box region of dash to mount it as i have no air bag this part of the dash isnt being used.

No i am not buying off specs, im having a look at the specs and you guys comments to pick drivers that will suit my needs so i can go audition them with a good idea of what i want.

YES i have decided that the midbass will be mounted in a sealed enclosure, i would of had to build a half enclosure above it to protect from the weather anyway. This will be done in fiberglass to get optimum volume while giving me the ability to mould around all door mechanisms.

YES i will be running the system active and providing them with an amplifier that has pleanty of headroom.

I greatly appreciate everyones input to this project of mine, thanks.

Of those I know, the ones that would be at the top of my list of considerations would be:

* Focal Utopia Be
* Rainbow W175 Power / W175 Platinum
* Scanspeak Revelator
* Seas Excell / Lotus Reference

The Scanspeaks, Focal's and Seas drivers I've heard a ton of good about.

The Rainbow Power driver I've used briefly in the past (still waiting for it to go into my new car). I only heard it in unsealed, undeadened doors (it was actually held in place by hand, not screwed). It still provided more impact and depth then any other mid-bass driver I've heard, while remaining amazingly smooth and detailed. I can only begin to image how it would perform in properly prepared doors and can't wait ill mine are in

My brother is using Peerless 7" mid-bass units in his car which actually sound pretty good in the midrange. Midbass is not bad, probably comparable to Rainbow Profi / Dynaudio / Morel Elate, but not even close to the potency of the Rainbow Power.

To add to the database:
Rainbow W175 Platinum (Qts: 0.35, Fs: 41Hz)
Rainbow W175 Power (Qts: 0.60, Fs: 37Hz)

In a 3 way, I normally try to keep my midbass to 200-400 to prevent steering.

Phil