Full range drivers a question

[Ronj]

Hello DIY Gurus,


I am looking at a 3" or 4" full range drivers for doing DIY speakers to be used with my T-Amps(TA2020). I was thinking of using drivers with shielded magnets specifically. Fostex was my first preference but they seem to have discontinued the FE87E line which would have been a good choice. But even FE87E was shy of my power handling capacity that would need to be used with a TA2020. I am thinking of doing a crossover less bi-ampable enclosure with two separate chambers, letting the full ranger do everything above 200Hz. So the driver should be good from 200Hz to 20KHz. with outing shouting at the mid frequencies... Again FE87E would have been a good choice here... But they they seem to have discontinued all the 3" and 4" drivers with shielded magnets.

is there any drivers you can recommend for such an application? How good are Peerless 830987s? Are there any HiVi or Vifa drivers that could do the duty?


Your help is greatly appreciated...

Thanks,

Ron

[Ronj]

Since I can't edit this message let me rephrase the question again with more details....

I have done few DIY T-Amps(mostly assembled them from finished PCBs) and such and was considering doing a DIY speaker based on full rangers for them.

I prefer to do a simple sealed chamber for the full rangers. And want to augment the LFE by using a dedicated woofer in a separate Bass reflex chamber; one for each cabinet to cover 50Hz to 200Hz. Both as a part of a single enclosure. And the plan is to Bi-Amp, may be using two identical TA2020 boards.

So I am thinking of doing a crossover less bi-ampable enclosure with two separate chambers, one chamber for a fullranger and one bigger chamber (preferably ported/bass reflex) for the dedicated woofer, letting the full ranger do everything above 200Hz. So the full range driver should be good from 200Hz to 20KHz without shouting at the mid frequencies. And I am looking for 3" or 4" full range drivers with shielded magnets.

Fostex was my first preference but they seem to have discontinued the FE87E line which would have been a good choice. But even FE87E was shy of power handling capacity in order to be used with a TA2020 T Amps I have.

Are there any drivers you can recommend for such an application? How good are Peerless 830987s? Are there any HiVi or Vifa drivers that could do the duty?

Thanks a lot,
Ron

[2litre]

No recommendations on drivers but here is a topic that might interest you for your project.

A thread for Tysen and variations on FAST

R/
Jim

[steph_tsf]

you may try :

Monacor SPH-130, or
Monacor MSH-115, or
Monacor MSH-116/4, or
Monacor MS-100CHQ
as midrange in a d'Appolito MTM configuration
1st order low-pass filtered at 3.2 kHz

with a Monacor DT-284, or
with a Visaton CP13
dome tweeter
1st order high-pass filtered at 3.2 kHz

plus a delay line on the tweeter for time alignment

do not waste yout time (an money) thinking one membrane can handle everything beteween 200 Hz to 20 kHz
the key of your success will be the smooth phase behaviour of the midrange driver in the 1.6 kHz to 6.4 kHz range
the midrange and the tweeter will only blend smoothly and transparently with a 1st order crossover if you time-align the tweeter

if you attemp using a higher order crossover, then you'll lose the phase coherence

what I'm advising exhibits a flat phase and amplitude, a wide polar pattern, and is backed by impressive listening results

the only limitation is the maximum listening level
with a 1st order high-pass filtered dome tweeter at 3.2 kHz, do not expect generating huge listening levels
this configuration is intended for domestic listening levels
bear this in mind

this is inexpensive,
the excellent subjective results can be explained, no black magic, no unobtainium involved

this is the essence of DIY

try this first
use it as reference design when building more expensive, more ambitious stuff

it is so funny (and sometimes embarassing) seeing people challenging with elaborate & costly stuff, then agreeing that this simple MTM is sounding better, asking the blueprints (in private) for getting such MTM in their living room ... while publicly they continue advertizing elaborate & costly stuff

[Ronj]

@2litre
Thanks Jim I did see that thread... One of the threads that inspired me to think in those lines... another one is here... A conventional looking 2-way sealed enclosure but using a Fostex 3" full ranger instead of a tweeter...

Strassacker: Lautsprecher - Boxen - Selbstbau

I can't read much German... But with the help of google translator, I think this is not chambered... In that case I am afraid that it will be very difficult to tune...

Ron

[Ronj]

@ steph_tsf

Thanks a lot.. But I really want to keep it simple and avoid all passive crossover components... I just want a single fullrange driven by a TA2020. And want to use another TA2020 or 2022 drive a 6.5" woofer. I want to house both the amps in a single chassis and tweak an existing pre-amp section to do an active LF filter... And choose a woofer that doesnt go much high anyway and mount it in a Bass Reflex chamber...

Ron

[steph_tsf]

I understand you want to avoid any passive crossover components. I also started building loudspeakers this way, with the same ambition. I thus advise you to build a "no passives" system, and in case it doesn't meet your expectations, or in case it gets very expensive compared to the subjective results, please, remember the midrange drivers listed in post #4, and build the system that is described in post #4. I'm attaching the schematic and LTspiceIV simulations of the 1st order highpass plus time delay, just in case. Cheers .... & good luck !

[steph_tsf]

When you decide which drivers you will use for the bass enclosure (35 Hz to 200 Hz) and for the satellite enclosure (200 Hz to 20 kHz), please let me know and provide me their Thiele/Small parameters. I will then suggest a few crossovers and enclosures, modelling them using LTspiceIV taking into account both enclosure effects and the active crossover effects, both in amplitude and phase. You'll be surprised. Are you equipped with audioTester ?

[steph_tsf]

for the 200 Hz to 20 kHz driver, you may add on the list :

TangBand 75-1558SE (big dome with Xmax 1.4 mm)

Dayton RS100T-8 (Xmax 3.7 mm)
Dayton RS100-4 (Xmax 4.0 mm)

TangBand W4-1320SJ (Xmax 3.0 mm)
TangBand W4-1052SD (Xmax 3.4 mm)
TangBand W3-1053SC (Xmax 1.5 mm)
TangBand W3-1401SD (Xmax 3.5 mm)

TangBand W23-1287SI (Xmax only 0.9 mm)

Fostex FE87E (Xmax only 0.4 mm) http://www.toutlehautparleur.com/lar...7e-p-3355.html

[planet10]

First thing to do is to forget about power handling. Just not that important or relavent. And even less to if you are hi-passing the mid-tweeter (you can ignore x-max for that matter too).

Intentionally shielded drivers are becoming an endangered species because of LCD displays.

FF85, CHR70, Alpair 7, EL70 (last 2 shielded) are candidates.

dave