Mid range drivers

Archived from groups: rec.audio.tech (More info?)

In article <19txwlxv6e32f$.1mgzuub252zc6.dlg@40tude.net>,
Morgan Ohlson <morgan.ohlson@comhem.se> wrote:

> The mid should naturally have the proper sensitivity for balance.
>
> But, is there any way to judge or understand anything more about the sound
> quality or characteristics of a mid without listening?
>

Can you draw with your eyes closed?

> ----
> Stupid statement: Since the mid is "just in the middle" most manufacturers
> and even very cheap drivers are excelent.
> ----
>
> I there any naturall limit how to understand the sound strength (dB's) for a
> (certain) mid? (thumb of rule for size or something?)
>

Well I'm not quite sure if you're describing sensitivity or power
handling. Usually a quick look at the motor structure or suspension will
tell you about power/heat dissipation. Check the driver's spl
measurement for its general sensitivity.

> Morgan O.

hth,

--
Cyrus

*coughcasaucedoprodigynetcough*

Archived from groups: rec.audio.tech (More info?)

In article <1tuh1qs2i6sdp$.1i2t5kq1ctejc.dlg@40tude.net>, Morgan Ohlson <morgan.ohlson@comhem.se> wrote:
>On Thu, 15 Sep 2005 02:07:21 GMT, Cyrus wrote:
>
>> In article <19txwlxv6e32f$.1mgzuub252zc6.dlg@40tude.net>,
>> Morgan Ohlson <morgan.ohlson@comhem.se> wrote:
>>
>>> The mid should naturally have the proper sensitivity for balance.
>>>
>>> But, is there any way to judge or understand anything more about the sound
>>> quality or characteristics of a mid without listening?
>>>
>>
>> Can you draw with your eyes closed?
>>
>>> ----
>>> Stupid statement: Since the mid is "just in the middle" most manufacturers
>>> and even very cheap drivers are excelent.
>>> ----
>>>
>>> I there any naturall limit how to understand the sound strength (dB's) for a
>>> (certain) mid? (thumb of rule for size or something?)
>>>
>>
>> Well I'm not quite sure if you're describing sensitivity or power
>> handling.
>
>That should be power handeling ... but, also (secondary) as a result of
>sensitivity.
>
>I have understould that a 4" mid somtimes isn't enough to produce the dB's
>wanted to match something like 2 x 10" woofers.

Thats one reason to use two vertical midrange drivers to get a 6 db boost.

>
>> Usually a quick look at the motor structure or suspension will
>> tell you about power/heat dissipation. Check the driver's spl
>> measurement for its general sensitivity.
>
>Yes.
>
>Let's say we by random pick 10 different mid drivers (4" - 6½" that should
>support 1-4KHz) and listen to them in only the that range 1000 - 4000Hz.

The big problem is listening to them in this range. Even with a sharp cutoff,
the high frequency rolloff may come into play. Its that transistion
at rolloff thats very inportant. Its usually not very smooth. A peaking
effect happens often. Many systems still use the midrange up into the
natural rolloff region, and of course if a passive crossover is used, it
must function following the drivers opperation.

>Will a normal music lover recognise any major sound quality difference?
>
>For instance... is there any noticable sound difference between coated paper
>cones and polypropylene?
>
>
>Morgan O.

Archived from groups: rec.audio.tech (More info?)

On Thu, 15 Sep 2005 13:10:53 GMT, GregS wrote:

> In article <1tuh1qs2i6sdp$.1i2t5kq1ctejc.dlg@40tude.net>, Morgan Ohlson <morgan.ohlson@comhem.se> wrote:
>>On Thu, 15 Sep 2005 02:07:21 GMT, Cyrus wrote:
>>
>>> In article <19txwlxv6e32f$.1mgzuub252zc6.dlg@40tude.net>,
>>> Morgan Ohlson <morgan.ohlson@comhem.se> wrote:
>>>
>>>> The mid should naturally have the proper sensitivity for balance.
>>>>
>>>> But, is there any way to judge or understand anything more about the sound
>>>> quality or characteristics of a mid without listening?
>>>>
>>>
>>> Can you draw with your eyes closed?
>>>
>>>> ----
>>>> Stupid statement: Since the mid is "just in the middle" most manufacturers
>>>> and even very cheap drivers are excelent.
>>>> ----
>>>>
>>>> I there any naturall limit how to understand the sound strength (dB's) for a
>>>> (certain) mid? (thumb of rule for size or something?)
>>>>
>>>
>>> Well I'm not quite sure if you're describing sensitivity or power
>>> handling.
>>
>>That should be power handeling ... but, also (secondary) as a result of
>>sensitivity.
>>
>>I have understould that a 4" mid somtimes isn't enough to produce the dB's
>>wanted to match something like 2 x 10" woofers.
>
> Thats one reason to use two vertical midrange drivers to get a 6 db boost.

Are you talking about "band drivers" ? ...or just the positioning of 2
normal cone mid drivers?

6dB?

>
>>
>>> Usually a quick look at the motor structure or suspension will
>>> tell you about power/heat dissipation. Check the driver's spl
>>> measurement for its general sensitivity.
>>
>>Yes.
>>
>>Let's say we by random pick 10 different mid drivers (4" - 6½" that should
>>support 1-4KHz) and listen to them in only the that range 1000 - 4000Hz.
>
> The big problem is listening to them in this range. Even with a sharp cutoff,
> the high frequency rolloff may come into play. Its that transistion
> at rolloff thats very inportant. Its usually not very smooth. A peaking
> effect happens often. Many systems still use the midrange up into the
> natural rolloff region, and of course if a passive crossover is used, it
> must function following the drivers opperation.

Your answer seems fair in technical sense.

But if we try to, intellectually eliminate the technical problem to do that
test...

What kind of differences would the music lover possibly /likely then hear?
I'm simply trying to adress the differences of mid drivers in practical
use...

Morgan O.

Archived from groups: rec.audio.tech (More info?)

In article <vsxvjh0dmql5$.1e9nxs0vqd6gl.dlg@40tude.net>, Morgan Ohlson <morgan.ohlson@comhem.se> wrote:
>On Thu, 15 Sep 2005 13:10:53 GMT, GregS wrote:
>
>> In article <1tuh1qs2i6sdp$.1i2t5kq1ctejc.dlg@40tude.net>, Morgan Ohlson
> <morgan.ohlson@comhem.se> wrote:
>>>On Thu, 15 Sep 2005 02:07:21 GMT, Cyrus wrote:
>>>
>>>> In article <19txwlxv6e32f$.1mgzuub252zc6.dlg@40tude.net>,
>>>> Morgan Ohlson <morgan.ohlson@comhem.se> wrote:
>>>>
>>>>> The mid should naturally have the proper sensitivity for balance.
>>>>>
>>>>> But, is there any way to judge or understand anything more about the sound
>>>>> quality or characteristics of a mid without listening?
>>>>>
>>>>
>>>> Can you draw with your eyes closed?
>>>>
>>>>> ----
>>>>> Stupid statement: Since the mid is "just in the middle" most manufacturers
>>>>> and even very cheap drivers are excelent.
>>>>> ----
>>>>>
>>>>> I there any naturall limit how to understand the sound strength (dB's) for
> a
>>>>> (certain) mid? (thumb of rule for size or something?)
>>>>>
>>>>
>>>> Well I'm not quite sure if you're describing sensitivity or power
>>>> handling.
>>>
>>>That should be power handeling ... but, also (secondary) as a result of
>>>sensitivity.
>>>
>>>I have understould that a 4" mid somtimes isn't enough to produce the dB's
>>>wanted to match something like 2 x 10" woofers.
>>
>> Thats one reason to use two vertical midrange drivers to get a 6 db boost.
>
>Are you talking about "band drivers" ? ...or just the positioning of 2
>normal cone mid drivers?

Band? I guess you mean horn. No. 2 cone drivers.

>
>6dB?

You get a 3 dB power boost from having 2, plus an efficiency increase of 3 dB.

To answer another question, the cone area is onlty important in
determining low frequency matching with the woofers, having an effect on
efficiency, and upper frequency dispersion.

The type of materials used are basically trying to get a good fast response, yet
have an even stable damping. On a waterfall plot, it is ideally straight across.

greg


>
>>
>>>
>>>> Usually a quick look at the motor structure or suspension will
>>>> tell you about power/heat dissipation. Check the driver's spl
>>>> measurement for its general sensitivity.
>>>
>>>Yes.
>>>
>>>Let's say we by random pick 10 different mid drivers (4" - 6½" that should
>>>support 1-4KHz) and listen to them in only the that range 1000 - 4000Hz.
>>
>> The big problem is listening to them in this range. Even with a sharp cutoff,
>> the high frequency rolloff may come into play. Its that transistion
>> at rolloff thats very inportant. Its usually not very smooth. A peaking
>> effect happens often. Many systems still use the midrange up into the
>> natural rolloff region, and of course if a passive crossover is used, it
>> must function following the drivers opperation.
>
>Your answer seems fair in technical sense.
>
>But if we try to, intellectually eliminate the technical problem to do that
>test...
>
>What kind of differences would the music lover possibly /likely then hear?
>I'm simply trying to adress the differences of mid drivers in practical
>use...
>
>Morgan O.

Archived from groups: rec.audio.tech (More info?)

On Fri, 16 Sep 2005 12:56:10 GMT, GregS wrote:

> In article <vsxvjh0dmql5$.1e9nxs0vqd6gl.dlg@40tude.net>, Morgan Ohlson <morgan.ohlson@comhem.se> wrote:
>>On Thu, 15 Sep 2005 13:10:53 GMT, GregS wrote:
>>
>>> In article <1tuh1qs2i6sdp$.1i2t5kq1ctejc.dlg@40tude.net>, Morgan Ohlson
>> <morgan.ohlson@comhem.se> wrote:
>>>>On Thu, 15 Sep 2005 02:07:21 GMT, Cyrus wrote:
>>>>
>>>>> In article <19txwlxv6e32f$.1mgzuub252zc6.dlg@40tude.net>,
>>>>> Morgan Ohlson <morgan.ohlson@comhem.se> wrote:
>>>>>
>>>>>> The mid should naturally have the proper sensitivity for balance.
>>>>>>
>>>>>> But, is there any way to judge or understand anything more about the sound
>>>>>> quality or characteristics of a mid without listening?
>>>>>>
>>>>>
>>>>> Can you draw with your eyes closed?
>>>>>
>>>>>> ----
>>>>>> Stupid statement: Since the mid is "just in the middle" most manufacturers
>>>>>> and even very cheap drivers are excelent.
>>>>>> ----
>>>>>>
>>>>>> I there any naturall limit how to understand the sound strength (dB's) for
>> a
>>>>>> (certain) mid? (thumb of rule for size or something?)
>>>>>>
>>>>>
>>>>> Well I'm not quite sure if you're describing sensitivity or power
>>>>> handling.
>>>>
>>>>That should be power handeling ... but, also (secondary) as a result of
>>>>sensitivity.
>>>>
>>>>I have understould that a 4" mid somtimes isn't enough to produce the dB's
>>>>wanted to match something like 2 x 10" woofers.
>>>
>>> Thats one reason to use two vertical midrange drivers to get a 6 db boost.
>>
>>Are you talking about "band drivers" ? ...or just the positioning of 2
>>normal cone mid drivers?
>
> Band? I guess you mean horn. No. 2 cone drivers.
>
>>
>>6dB?
>
> You get a 3 dB power boost from having 2,

Is that from the doubled cone area?

>plus an efficiency increase of 3 dB.

The lowered, halfed impedance (ohms) by prallell wireing?


Morgan O.

Archived from groups: rec.audio.tech (More info?)

In article <19txwlxv6e32f$.1mgzuub252zc6.dlg@40tude.net>, Morgan Ohlson <morgan.ohlson@comhem.se> wrote:
>
>The mid should naturally have the proper sensitivity for balance.
>
>But, is there any way to judge or understand anything more about the sound
>quality or characteristics of a mid without listening?

We said the waterfall plot should be straight, meaning the response
should be flat. This is a measurment that can vary, especially
with some drivers, and likewise vary according to the measuring
angle. The surrounds of drivers don't always act in unison with the
cone at some frequencies. There can be sharp nulls on axis, whereas
the offaxis may be more flat. In a listening environment, the on axis
response will be influenced by the off axis sounds which can tend to
reduce the effects of on axis nulls.

greg


>Stupid statement: Since the mid is "just in the middle" most manufacturers
>and even very cheap drivers are excelent.

A cheap driver may work or be a nightmare. An expensive driver
doesn't mean it will all be easy, be is more likely to be easier to
use.


>
>I there any naturall limit how to understand the sound strength (dB's) for a
>(certain) mid? (thumb of rule for size or something?)
>
>Morgan O.

Archived from groups: rec.audio.tech (More info?)

On Fri, 16 Sep 2005 18:57:20 GMT, GregS wrote:

> In article <16cjymtk2rosq$.g8xs73ftvzig.dlg@40tude.net>, Morgan Ohlson <morgan.ohlson@comhem.se> wrote:
>>On Fri, 16 Sep 2005 12:56:10 GMT, GregS wrote:
>>
>>> In article <vsxvjh0dmql5$.1e9nxs0vqd6gl.dlg@40tude.net>, Morgan Ohlson
>> <morgan.ohlson@comhem.se> wrote:
>>>>On Thu, 15 Sep 2005 13:10:53 GMT, GregS wrote:
>>>>
>>>>> In article <1tuh1qs2i6sdp$.1i2t5kq1ctejc.dlg@40tude.net>, Morgan Ohlson
>>>> <morgan.ohlson@comhem.se> wrote:
>>>>>>On Thu, 15 Sep 2005 02:07:21 GMT, Cyrus wrote:
>>>>>>
>>>>>>> In article <19txwlxv6e32f$.1mgzuub252zc6.dlg@40tude.net>,
>>>>>>> Morgan Ohlson <morgan.ohlson@comhem.se> wrote:
>>>>>>>
>>>>>>>> The mid should naturally have the proper sensitivity for balance.
>>>>>>>>
>>>>>>>> But, is there any way to judge or understand anything more about the
>> sound
>>>>>>>> quality or characteristics of a mid without listening?
>>>>>>>>
>>>>>>>
>>>>>>> Can you draw with your eyes closed?
>>>>>>>
>>>>>>>> ----
>>>>>>>> Stupid statement: Since the mid is "just in the middle" most
>> manufacturers
>>>>>>>> and even very cheap drivers are excelent.
>>>>>>>> ----
>>>>>>>>
>>>>>>>> I there any naturall limit how to understand the sound strength (dB's)
>> for
>>>> a
>>>>>>>> (certain) mid? (thumb of rule for size or something?)
>>>>>>>>
>>>>>>>
>>>>>>> Well I'm not quite sure if you're describing sensitivity or power
>>>>>>> handling.
>>>>>>
>>>>>>That should be power handeling ... but, also (secondary) as a result of
>>>>>>sensitivity.
>>>>>>
>>>>>>I have understould that a 4" mid somtimes isn't enough to produce the dB's
>>>>>>wanted to match something like 2 x 10" woofers.
>>>>>
>>>>> Thats one reason to use two vertical midrange drivers to get a 6 db boost.
>>>>
>>>>Are you talking about "band drivers" ? ...or just the positioning of 2
>>>>normal cone mid drivers?
>>>
>>> Band? I guess you mean horn. No. 2 cone drivers.
>>>
>>>>
>>>>6dB?
>>>
>>> You get a 3 dB power boost from having 2,
>>
>>Is that from the doubled cone area?
>
> Right. You have effectively doubled sound intensity.
>
>
>>>plus an efficiency increase of 3 dB.
>>
>>The lowered, halfed impedance (ohms) by prallell wireing?
>
> Right.
>
> Many D'Appolito configurations need the extra amplitude to
> compete with the woofer. In, fact, I first learned this
> when reading his paper.

But why do speaker manufacturers so often choose woofers much over sensitive
compared to mid and tweeter?

.... isn't loudness enough for disco and techno freaks?

Or could a 3way system sound as balanced that way?

Example: They call this a Hifi speaker...
http://hifikit.se/show_prod.asp?id=46
Tweet: 92dB Mid: 93 Woof:98dB


Morgan O.

Archived from groups: rec.audio.tech (More info?)

Suppose you have an 8-ohm driver of sensitivity 90dB (measured at one
metre).

If you drive it with a signal of one watt, it will deliver a sound output of
90dB.

If you now put two of the drivers close together, and driver them with
identical signals of one watt each, they will deliver a combined sound
output of 96dB.

If you now put two of the drivers close together, and drive them with
different signals of one watt each, they will deliver a combined sound
output of 93dB.

If you now put of the drivers far apart, and drive them with identical
signals or different signals of one watt each, they will deliver a combined
sound output of 93dB.

This is all to do with the physical characteristics of drivers and air, and
is nothing to do with the electrics. It's called "acoustic coupling".
"Close together" and "far apart" depends on the frequencies being
reproduces. Low-frequency drivers in the same speaker enclosure are "close
together", so if you drive them with one watt each, you'll get an extra 6dB
of output compared with having a single driver driven with one watt.

Acoustic coupling also occurs at low frequencies when you have two separate
enclosures (eg stereo systems), so you can get a useful boost in LF signal
if it is panned centre in the stereo mix.

Speaker sensitivity is defined for a signal of 2.83 RMS - that's one watt
for an 8-ohm speaker.

If you connect two of these speakers in parallel inside an enclosure, there
will be a signal of 2.83V across each one, so each will be receiving .35
amperes, each will be produing 90dB, the combined sound output will be 96dB,
and the amplifier will be delivering two watts. So the efficiency is
93dB/watt, and the sensitivy is 96dB/2.83V.

If you connect two in series inside an enclosure, there will be a signal of
1.41V across each one, each will be receiving 0.17 amperes (which means 0.25
watts), each will be producing 84dB, the combined output will be 90dB, and
the amplifier will be delivering 0.5 watts. So the efficiency is 93dB/watt,
and the sensitivity is 90dB/2.83V.

Many modern amplifiers can deliver more power into 4 ohms than into 8 ohms.
So if the sound output is limited by amplifier power, then using two drivers
connected in parallel can often give you an increase in achievable sound
level of 4-5dB from the same amplifier.

Tim

Archived from groups: rec.audio.tech (More info?)

In article <dh8r6m$n1g$1@usenet01.srv.cis.pitt.edu>, szekeres@pitt.edu (GregS) wrote:
>In article <BFuZe.4711$K77.1391@newsfe2-gui.ntli.net>, "Tim Martin"
> <tim2718281@ntlworld.com> wrote:
>>Suppose you have an 8-ohm driver of sensitivity 90dB (measured at one
>>metre).
>>
>>If you drive it with a signal of one watt, it will deliver a sound output of
>>90dB.
>>
>>If you now put two of the drivers close together, and driver them with
>>identical signals of one watt each, they will deliver a combined sound
>>output of 96dB.
>>
>>If you now put two of the drivers close together, and drive them with
>>different signals of one watt each, they will deliver a combined sound
>>output of 93dB.
>>
>>If you now put of the drivers far apart, and drive them with identical
>>signals or different signals of one watt each, they will deliver a combined
>>sound output of 93dB.
>
>Close or far apart has nothing to do with changing the amount of
>coupling as far as changing dB. I can put two driver close together or
>20 feet apart. As long as the phase is identical, they will combine.
>The trouble is, is a small room, the phases are not identical 20 feet apart.
>In my backyard I have done it 20 feet apart at a fairly high frequency.
>
>greg
>
>>This is all to do with the physical characteristics of drivers and air, and
>>is nothing to do with the electrics. It's called "acoustic coupling".
>>"Close together" and "far apart" depends on the frequencies being
>>reproduces. Low-frequency drivers in the same speaker enclosure are "close
>>together", so if you drive them with one watt each, you'll get an extra 6dB
>>of output compared with having a single driver driven with one watt.
>>
>>Acoustic coupling also occurs at low frequencies when you have two separate
>>enclosures (eg stereo systems), so you can get a useful boost in LF signal
>>if it is panned centre in the stereo mix.
>
>It doesn't matter what frequency, as long as the phases combine.
>
>>Speaker sensitivity is defined for a signal of 2.83 RMS - that's one watt
>>for an 8-ohm speaker.
>>
>>If you connect two of these speakers in parallel inside an enclosure, there
>>will be a signal of 2.83V across each one, so each will be receiving .35
>>amperes, each will be produing 90dB, the combined sound output will be 96dB,
>>and the amplifier will be delivering two watts. So the efficiency is
>>93dB/watt, and the sensitivy is 96dB/2.83V.
>>
>>If you connect two in series inside an enclosure, there will be a signal of
>>1.41V across each one, each will be receiving 0.17 amperes (which means 0.25
>>watts), each will be producing 84dB, the combined output will be 90dB, and
>>the amplifier will be delivering 0.5 watts. So the efficiency is 93dB/watt,
>>and the sensitivity is 90dB/2.83V.
>>
>>Many modern amplifiers can deliver more power into 4 ohms than into 8 ohms.
>>So if the sound output is limited by amplifier power, then using two drivers
>>connected in parallel can often give you an increase in achievable sound
>>level of 4-5dB from the same amplifier.
>>
>>Tim

It just occured to me, how does listening to headphones change the perceived
levels. Are the same effects noticable. If they were not, sounds would be
very different than listening to speakers.

greg