Looking for a high-end 8"-10" (20cm) midbass

[Vortex]

Hi all,


I'm just looking for a quite sensitive (over 92db) woofer-midrange driver which can be used in a small vented box with the following parameters:

- high-end sound and performance (like products of Danish Sound Technology, Seas etc.)

- high or extremely highg sensitivity (7 Watt Class A amp!)

- passive 2nd order 2-way (!) crossover ability WITH a ribbon tweeter for high frequencies.



My problems:

I'm going to buy the ribbon (correctly said: magnetostat) MHT-12 tweeter from Visaton (www.visaton.de).

According to it's frequency/impedance curve, I will put the crossover frequency at about 3000-3500 Hz. Due to the 2nd order crossover circuit - which has a 12db/octave slope - I think the Visaton will be able to stay under it's original amplitude curve limits BELOW the 3000 Hz barrier (from where it works correctly), so it means, the 12db/octave below 3000 Hz won't drive the tweeter to it's limits in this range. (As you see, efficiency is sinking below 3kHz).

My question to you were: IF I put the X-over freq. to 3KHz, will I find a speaker which is able to go to these high midranges? Where they still perform without amplitude loss ?



So I'm just looking for a quite wide range midbass for a 2-way box which is able to produce more sound above 3kHz than the crossover is reducing it's amplitude by 12db/octave.

I hope you know what I mean, sorry for my english !


I found some high-end speakers which are capable of do that all,
but they were either: too small, or had strange parameters like 5 Ohm (I don't want to use any impedance correction or R-L-C circuitry.. NO WAY !!) .. or they weren't just sensitive enough.


So I cannot choose anything Perhaps you could help me out .


One more thing: the speaker NOMINAL impedance has to be 8 Ohm.


Hard to find in this 20 cm (about 8"-10") size !

The midbass would be alone so I'd just make sure it's not too small in order to avoid too few bass or too high cone movement which leads to the well-known doppler-effect...

I'm just looking for somewhat like the AudioNote AN-E's midbass. (Amazingly sounding box btw. !!!)

Thanks a lot for the help and greetings from Europe!


The AN-E:

[roddyama]

Take a look at the PHL speakers here .

[Vortex]

WOW,

that was EXACTLY what I was looking for !

I've already found not one, but more drivers according to my needs.


Thank you !

[roddyama]

Very Good.

BTW, a variation of the 10" PHL is what is used in the Pass Labs' Rushmore.

[Vigier]

Hi Vortex,

are you sure you're going for 3000-3500 Hz crossover-frequency?
If I were you I would aim for 3500-4000 Hz.
I use the MHT-12 with 2 Visaton TI-100's, and 2 Numer One SPH-165CP's. (WMTMW)
If you use a 2nd order filter, don't go under 3500 Hz, with 3rd and 4th order filters you could make it lower, but never under 3000 Hz.

Grtz, Joris

[Bricolo]

how high can a 8" PHL be crossed?
and how low can it go? The website tells 70Hz, that seems high for a 8"

[Vortex]

Hmm...

I thought it will be too low, you're right.


This just makes my 2-way midbass-project still more complicated... ah..

okay, I'll have a look at the PHL homepage once again, perhaps something around that 8" size will still have a flatter amplitude-slope than what the 2nd-order does - that would be optimal.

Thanks for the suggestion


btw... how do you like the sound of the MHT-12? I assume, you had conventional dome tweeter before (or not?) . I'm interested in your opinion of that magnetostat-sound!

[Vortex]

Yes,

I've also noticed that those PHL's won't go much down in frequencies despite their size.

I think, with a continuous decibel loss they can still go deeper, but no problem, you just make sure, you put those speakers into a vented box which will be calibrated at around 40Hz for the bassreflex tube, so in this region (and of course, like a hill - before and after this frequency) you get higher amplitude, which greatly compensates this issue.

I think these speakers are designed for vented boxes especially, no data or other information will be given on their homepage on closed box volumes..


The Visaton TOPAZ (or TOPAS) is a nice speaker with a quite small midbass - I think they managed the good-enough bass response the same way, except that they made a transmission line box, not a vented. (some kind of vented is it already).

[Vigier]

Hi Vortex,

I think the MHT-12 is NOT suitable for a 2-way speaker that has to deliver any way of pressure. (Not because of the tweeter itself, but there is no unit as good as the MHT-12 that can play low, high (4000 Hz), and give some pressure (>95 dB)
The Topas has the TI100 as a "woofer". It goes down to about 35 Hz, but with the excursion and the size of the TI100, you know you can only play it at LOW volumes.

Going to 4000 Hz with an 8 inch driver will give you problems because of the standing waves on the conus of the woofer.

The MHT-12 sounds fantastic, that is also the main reason why I bought it! Well, some movies/music sound(s) less good to me than before I had that speaker, but that's because of the frightening detail the tweeter has.
A few weeks ago I started with the design of my new front and rear-speakers (the MHT-12 is in my centerspeaker).
At this point of design, there are only a few possible tweeters left:
- ESS AMT
- Visaton MHT-12
- Seas Excel Millennium
- Scan Speak R2904 Revelator

As you see, the Seas unit is the only real dome-tweeter in the list. It is very close to the MHT-12, I don't know whether it is as good as the MHT-12, or even better, but they have a different sound, so I couldn't choose...
To be honest, the Scan Speak is above the other three, but that's my opinion AT THIS MOMENT (that means, it can still change).

Ususally I think Visaton units are overpriced, but the MHT-12 and the TI100 are really worth every cent....

Grtz, Joris

[Vortex]

Vigier:

lol


my another considering among tweeters was the Scan Speak


I don't mind if the system won't have enough power to play really loud ...

I'm going to design a high-end box for my single ended 7Watt 2A3 triode AMP ... it isn't much at all anyway but still enough I think...

I don't really want to split the phase twice in the range (it means, going for a 3-way Butterworth) ...

Anyway, I'll consider that all. If I really do a 3-way box, x-over frequencies will be 120 Hz and around 8KHz... (better ideas perhaps?)