Searching for Midrange from 250Hz to 7Khz, >97db/1W

[RussianE39]

Hi!
I'm building a new loudspeakers for home, which will be based on JBL's 2226 with sensivity 97db in Onken enclosure, and with JBL 2405 tweeters. AFAIK JBL 2405 want lowest cross-point in a 7 khz range, and IMHO 2226 won't sound good at frequencies above 250Hz, so maybe anyone know good midrange that will suit my need. The listening room is rather small,so I think horn & compression drivers won't do the job right.

[Josephjcole]

I cann't say that I've ever heard it before, but it looks pretty nice on paper.
Joe

http://www.partsexpress.com/pe/pshow...number=294-650

[mgoedeke]

Cross the 2226 at 400Hz, which may or may not be the downfall of the Onken. In a well designed enclosure the 2226 should easily be crossable 600hz if you don't particularily want to cross with very shallow slopes.

Many Pro Midranges have problems below 350Hz, though there are some (like one of the new neo 18Sound models) that can be taken down to 200Hz.

[Notax]

Lowther DX2.

DX2

Measurement:

Measured DX2

[ScottG]

under 10 inches there are:

6" (none of which really are truely averaged at 97db - though close):

Audax PR17MO
Max Fidelity PR65 Neo
B&C 6MD38
B&C 6PEV13
B&C 6MDN44
Beyma 605Nd

8" (some of which don't meet 97db either):

B&C 8PE21
BMS 8N215
Beyma 8MI100

These of course are all "pro" drivers.. and NONE of them will meet 97 db at 250 Hz in an IEC baffle context. This virtually gurantees that unless the driver is horn or reflex loaded well into the midrange that the none of the driver/box combinations will reach 97 db in the baffle step region (..i.e. which 250 Hz is in).

There are also some less conventional approaches from Supravox and Fostex..

In particular the Fostex 225K (originally based on a JBL design no less) should work for you "fairly" well in a small aperiodic "enclosure". It averages 97db, is quite "flat" on-axis in the upper midrange and has a minor "bump" in response near 300 Hz (..which should help with baffle step loss). It will reach 6kHz before naturally "rolling-off", and its off-axis response is better than any other 8" driver I can think of. It also isn't horribly expensive.

[el`Ol]

You could combine the JBL tweeters with Supravox 285GMF in Onken and use the JBL bass drivers for an other project.

[xstephanx]

i say go with the fostex, becuase the silver dustcap white cone and pincushion frame look like those old 8" jbl midwoofers.

[noah katz]

http://www.eighteensound.com/index.a...roduct&pid=244

although doesn't quite make it to 7kHz; perhaps cross a bit lower w/steeper slope on JBL tweeter

[kevinkr]

I'm crossing over my Onken cabinets at 800Hz and have not observed any problems doing so. The driver used is an Iconic 165-8G.

The midrange is a JBL 4333 which is 2420/2312 horn/clone of 2308 diffuser. I would have prefered a lower cross-over point, but the 2420 when used with the 2312 should not be crossed over lower than this, there is an alternate horn for this driver that allows cross-over at 500Hz, unfortunately it escapes me at the moment. The lansing heritage site has the details. The tweeter is a JBL 2402H.

The high frequency cross-over point is 8kHz which was chosen to allow me to try the JBL 077 or 2405 as well as Fostex T900 or T925 should I want to change in the future. (I have a friend who has pairs of both of the cited Fostex drivers, so I will have the opportunity to determine whether I like either of them better than the 2402 before plonking down any money for a pair.)

Integration between the mid horn and tweeter is just about seamless, I'm not aware in any sense of there being two separate drivers.

The woofer to mid cross-over seems fine, I'm not really aware of that happening either even on vocals.

I designed the cross-overs for these drivers based on 2nd order butterworth filters, there are individual LPADS for the mid and tweeter horns.

My Onkens as tuned are about 97dB efficient, ignoring room gain. The mid horns are about 108dB and the tweeters about 105dB.

See the onken enclosure thread. I do have some tuning issues at the low end that I am slowly investigating and will resolve once that phase is completed. (Cabinet builder made a port length error which is fairly easily fixed, and the driving source impedance is somewhat higher than I designed to, oops.)

Measure and know your source impedance exactly before you design the cabinets! Design for a slightly higher impedance and resistively pad if you want some flexibility, that was my intention.

[KBK]

The max fidelity 4" driver might go that low, with a 18 db slope. 100 watt power handling, the voice coil is on BOTH sides of the former, it is a vented extreme powered neo motor.

I was talking with Frank (designer of said driver), and it's a 20k gauss gap! holee smokes. It's likely the most wicked motor out there.

I'm sensitive to magnetics and when holding it..it makes my hand go numb and itchy by a huge degree. Wicked.

100db efficency. It needs a wide notch filter, but I believe, in the case of a midrange use, it can be a shelf filter instead. Even with all that, after midrange bandpass filtering, the efficency should be a solid 97-98 db. The unit, unfiltered, IIRC (was looking at response curves right on Franks measurement set up), measures about 104db in the region were the broadband filter is needed. It is, as usual, mostly a on axis issue. 4 gram cone, IIRC. See solen for images and numbers. It really is a 'true' 100db efficency.

Light MMS, extreme motor =... extreme fidelity. Traces the sginal like nothing else.

I have a pair I am fooling with. Dey's LOUD!

I'd say that Frank has likely been in China (manufacturing-designing drivers) longer than anyone else - he's been making drivers there the whole time. And..he's become very, very good at it, as time has passed.

This is shaping up to be world class. From China. This driver would likely street at $300, if manufactured in the US.