The best midrange driver (cost no option) for 3-way

How exactly is a beryllium diaphragm a soft dome?

From what I recall, Accuton and AT drivers measure fairly well, but they aren't the best.

The Accuton driver linked to is one of the best on measured performance. Accuton has a lot of run of the mill drivers when it comes to measurements, but there are a few where they get it just right.

Of course you have to cross the C173-6-090 over low to circumvent the distortion peak and to minimise beaming, but I can't imagine this being too much of a problem.
 
Member
Joined 2008
Paid Member
TAD & Lowther

The best driver I've heard (used in a 2-way format so it doubled as mid/tweet) is the TAD 4002.

I certainly do not suggest that I've even heard 25% of the drivers out there much less 'all' of them. I do however, know that this was astoundingly good.

Greetings my friend, neighbor and audio buddy !

Do you remember which horn(s) you heard the 4002 on ? I have heard nothing but high praise for this unit, but, me personally have not heard them.
Right now, they are out of budget range, but, perhaps in a year or two. Are you thinking of changing drivers for your horns?
Along the lines of the OP, the best I have ever heard was a Lowther Dx-3 in an ORIS 250. That was while I was visiting Austin, but obviously chose to live here instead. As far as my own system goes, I have made tremendous progress, but still have a long way to go. None-the-less, as it stands now the system is quite enjoyable. I am working on the mid bass cabinets now, and hope to have everything done by summer 2011. I have buddies coming up from Florida... and I'd also like to have you over for a listen sometime in the not too distant future. It's been a while, I hope we can chat again soon.
 
Let's draw some lines, find their interceptions, and in the end - find a description of "best suitable driver".

Materials used:
- Tweeter: Silk, tiny dome = precise, extended up to 20k, average body weight (haven't heared 'em, someone please confirm that this is what they are).
- Woofer: Paper, tiny magnet, light cone, lush paper sound.
Which midrange driver will suit both woofer and tweeter? Paper...

Then, let's check where we get by the driver excursion/area/crossover frequency.
The woofer FR seems to be usable up to 1kHz, yet we have the directivity issue kicking in at lower frequencies, and the "blap" curve on the impedance graph around 400Hz => something going on there with cone stiffness, i wouldn't use this driver beyond 400Hz.
Tweeter... Tiny silky dome with nice excursion. Although the FR is extended downwards, we are talking about high-output system, that is going to pump some air => high excursion required => raised crossover frequencies. 3.5k-4.5k at their best.

Now we can draft a mid-driver requirements:
- Cover 400Hz-4.5kHz range.
- Paper cone.
- Cope with double 10" woofers (!!!)

Target cone diameter: pair of 5", 6.5". Or even pair of 6.5" (we can't use 8" as this tiny tweeter wouldn't go that low).

5": SB Acousics 5", Scan-Speak Revelators, SEAS 15W Nextel.
6.5": Emm... Nada. There is no 6.5" driver that can go that high (4.5k). Even 3kHz is tough point.
8542 is nice lush sounding driver. 8531 is... i wouldn't call it best for the upper midrange, yet it has the "paper" signature that may suit both woofer and tweeter.



With 0.75" tweeter i wouldn't go beyond 4.5" midrange => the best one for 10" fluffy paper woofer is 13M/8640, as well as for Hiquphon, crossed at 1.4kHz. Yes, 1.4 :)
You'll get some weird speaker... 1.2-1.4kHz - 4-4.5kHz crossover points. Weird :)
 
I built seas excel 3 ways a few years back, followed by accuton monsters that were a considerable step up in some respects, but upsettingly for me I recently found the atc mid dome is so far ahead I could cry.

how many times have I heard comments like ' the difference between_____ and______ is night and day.

Im afraid for whatever reason, in this case the difference is genuine.

No mid ive ever heard is anything like as revealing as the atc.
 
Hey lbstyling , what kind of speaker did you build with the accutons?
My dilemma is, I have atc speakers already, but my accuton project isn't finished, I was thinking to work on it more, do you think it's not worth the time and money? Considering that I already have the atc?
 
ATC SM75-150S

Subjectively speaking, the only midrange reproduction I enjoyed more was that of the Quad 2905s (but with all their known limitations in max SPL etc).

The directivity measurements (and analysis) in the thread you linked are difficult to believe...
Such a small device cannot control directivity at these frequencies. It is simply 180° in its whole frequency range of interest (and specifically ~ -0dB at 45°), and the optional waveguide will just serve to reduce this directivity in the upper range.
 
Audax HM130co performs very well as a midrange in my system. It's onaxis frequency response (no filter) approaches 9kHz and it's less than 4dB down at 5kHz at 30 degrees off axis. It's average sensitivity is about 90dB/2.83V, nominal impedance 8ohm.
It may not be the best driver in the world (that would depend on selection criteria) but certainly it's worth consideration. It's not expensive. If cost is no considertion then buy, test and keep or sell as second hand if not adequate.

cheers,
 
I have pics of the seas excel speakers I made, but none to hand of the humble statement.
STA70892.jpg


troels gravesen tjl3w.

Both have moved on to new owners now. - i should point out that any percieved sound quality shortcomings are biased to the fact that I listen at what others would consider high levels -100db+ at 1m (listening distance is 5m) the room is a rather good if not exceptional acustic space though imo.

As audax were mentioned- my favorite tweeter is the audax two34, pictured on the black speakers here.- Its got that same magic that the atc mid does. I picked these up from a refit in pinewood studios - I kid you not. Bass unit is a volt b250.2

speakers003.jpg


Ive just got to convince troels to make his dtqwt with this and im set!- (yea, like thats gunna happen!)
seriously though, im convinced this would be the best speaker ever. I keep thinking I should have a go at making it, or pay troels to.
 
I strongly agree with Cal in #2 and the audio technology recommendation in #4. We spent a long time (4 yrs?) finding THE midrange. Auditioned many, including the first Scanspeak Revelator sliced mid, and spent a lot of time with the then Accuton models, which (at that time) had more hf breakup than was easy to trap out. Also, we did not care for the dynamics, and one, for no known reason, cracked. The audio technology, with the largest magnet, and, in our case, convex dust cap worked out extremely well. We did feel that using it in an infinite baffle for the high pass function (hence no series cap) was useful. We used very rounded baffle edges and face felt to minimize diffraction, and a lot of testing of xo components, etc. Very transparent, smooth, excellent timbres, uncongested at very low levels, unfrazzled at high orchestral levels, and easy to design with.

The Scanspeak 25W8565-01, and the D2905/9900 were very compatible. Note that my comments reflect choices 4-5 years old.