Hi-End and Hi-Efficency loudspeakers (horn + onken)

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
I am searching fo this project a a 15" with
:
- a linear frequency band until 3-4KHz to prevent problem after the crossover frequency

- a moving mass no more than 90 gr

- a sensitivity near to 100dB

- a low resonant Frequency to have a good bass frequency band

I have found only the drivers analized in the webpage.

If there is a peak in the frequency response it is possible to esclude this only with 18dB or 24dB order filter because with a common 12dB this will keep in voice band.
 
audiodesign said:
I am searching fo this project a a 15" with
:
- a linear frequency band until 3-4KHz to prevent problem after the crossover frequency

- a moving mass no more than 90 gr

- a sensitivity near to 100dB

- a low resonant Frequency to have a good bass frequency band

I have found only the drivers analized in the webpage.

All those things together? And perhaps also into a " cheap" woofer ? :)
Anyway, becoming serious, if you have a 100 dB- 15" with 90 gr or less Mms and with low Fs, automatically Qts will be low . Thus no (extreme) bass.


If there is a peak in the frequency response it is possible to esclude this only with 18dB or 24dB order filter because with a common 12dB this will keep in voice band. [/B]


Excuse me, why not employ a LCR trap instead ?:angel:

Cheers,
Paolo
 
Been there , Andrea.

Are you sure all those graphs are in the same measurements conditions? ;)
To my eyes some are 2pistr and others (maybe) can be 4pistr .....:angel:

Moreover Fs says a little if not coupled at least with Qts when you have to extimate F-3dB point.

P.S. : IMO Dr. Geddes is right, B&C are very good drivers. Unfortunately in Italy the price is .....not aligned with States!:bawling:

Cheers,
Paolo
 
Audiodesign your requests about the 15" woofer are simply impossible to satisfy. It is just about the laws of physics!

You are basically making a quite big mistake judging the linearity and quality of the speaker only by the on-axis frequency response.

You should look a least at the 30-45 degree off-axis response and the waterfall (CSD) and would see that none of those woofers is suitable for 3-4 KHz crossover.
Also you can see all those small peaks and dips along the impedance curve from 500Hz and above: each peak is a clear sign of break-up.

You really need to go for a 3-way speaker if you want an extended frequency range and real hifi reproduction.

The B&C 6MD38-8 is one of the few high efficiency midranges (96dB) with clean waterfall (very rare in high efficiency speakers) and flat frequency response up to the its first serious break-up at 5KHz. This speaker could work very well between 500Hz and 3KHz (using a series LC notch filter in parallel to the speaker and tuned at 5KHz in order to remove that resonance and make the cross-overing effective).

45
 
Also a very good driver. And not expensive.

Beyma 12br70

2X12br70
175L br 95dB 1W/mtr
-3dB 40Hz
-10dB 26Hz

100euro

12br70.jpg
 
Ex-Moderator R.I.P.
Joined 2005
Helmuth said:
I have another option for you. Very special driver for about 75euro

2X sph315 in one box = 2x 28cm with ferro fluid in airgap
130liter BR
97dB 1W/mtr
-3dB 45Hz
-10db 33HZ

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.


sph315


If you look closer you will see that its down at 90db around 500hz, and then up again
So above 500hz its just useless
 
I would like to esclude parallel connection because I want an easy to drive loudspeakers with inpedance near to 8 ohm to the driven with any 2A3 or 300b amplifier.

Using a parallel connection of 2 x 12BR70 we can get a solution but the impedance will go near 2-3 ohm with the filter.

I am interested to a 15" to get a 35-3KHz linear frequency band but the filter will be positioned near to 800-1KHz
 
tinitus said:



If you look closer you will see that its down at 90db around 500hz, and then up again
So above 500hz its just useless

That is true tinitus only when you consider your room acoustics you know that a flat response is nice but will be disturbed by reflexions.

So I think this is a very flat response for a 94dB 1W/mtr speaker. And I ask my self if the response is the same in the box and with the balffle. Than can the dip can be gone or a raise some where else can occur.

So don't go blind on the graphic alone.
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.