Elecraft › [K3]

Re: Blue Tooth - Freq. response

Classic

List

Threaded

11 messages Options

Edward R Cole

Re: Blue Tooth - Freq. response

Slightly off the subject (Blue Tooth), but I wear Phonak Savia OTE
hearing aids and they have a high-fidelity program selection. This
is for flat freq. response up to 22-KHz for music and television
listening. I definitely can tell the improvement even with > 30dB
hearing degradation and loss above 800-Hz.

Ten years ago I agonized over whether to spend money on a nice
home-theater system or whether my hearing was too bad to enjoy it. I
am forever glad that I got the system as ordinary TV speakers are
nearly useless for me. Of course I use captioning all the time for speech.

One of the nice aspects of the k3 is that audio can be taylored to
one's hearing preferences.

73, Ed - KL7UW
BTW I just installed an upgraded soundcard (emu-0202) in my computer
and it really sounds nicer. It was not my primary reason to get the
soundcard (LP-Pan baseband processing is primary).

------------------------------

Message: 10
Date: Fri, 04 Feb 2011 06:56:36 -0000
From: "Dave Sergeant" <[hidden email]>
Subject: Re: [Elecraft] Blue Tooth
To: 'Elecraft Reflector' <[hidden email]>, 'Max Kempson'
<[hidden email]>
Message-ID: <[hidden email]>
Content-Type: text/plain; charset=US-ASCII

No, Tom, they are NOT audio loop devices, but true bluetooth, and only
work with modern bluetooth hearing aids. And I am not sure what sort of
HiFi you expect, but if you have a hearing aid it is probably academic.

Full information at:
http://www.phonak.com/uk/b2c/en/products/accessories/communication/icom/
overview.html

All in English. Confusingly they call it the iCom, which is nothing to
do with the other company...

73 Dave G3YMC

73, Ed - KL7UW, WD2XSH/45
======================================
BP40IQ 500 KHz - 10-GHz www.kl7uw.com
EME: 144-1.4kw*, 432-100w*, 1296-testing*, 3400-winter?
DUBUS Magazine USA Rep [hidden email]
======================================
*temp not in service
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

alsopb

Re: Blue Tooth - Freq. response

Unfortunately, one can't bump up audio output in FSK-D. I use a modem
which only can use 2 KHz tones. The drop in perceived audio level is
quite high there for me. Even if low tones were used, there would still
be a significant loss.

What say Elecraft? Why not let us bump up one segment? FSK-D isn't
used for any other digital mode.

73 de Brian/K3KO

On 2/4/2011 21:52, Edward R. Cole wrote:

> Slightly off the subject (Blue Tooth), but I wear Phonak Savia OTE
> hearing aids and they have a high-fidelity program selection. This
> is for flat freq. response up to 22-KHz for music and television
> listening. I definitely can tell the improvement even with> 30dB
> hearing degradation and loss above 800-Hz.
>
> Ten years ago I agonized over whether to spend money on a nice
> home-theater system or whether my hearing was too bad to enjoy it. I
> am forever glad that I got the system as ordinary TV speakers are
> nearly useless for me. Of course I use captioning all the time for speech.
>
> One of the nice aspects of the k3 is that audio can be taylored to
> one's hearing preferences.
>
> 73, Ed - KL7UW
> BTW I just installed an upgraded soundcard (emu-0202) in my computer
> and it really sounds nicer. It was not my primary reason to get the
> soundcard (LP-Pan baseband processing is primary).
>
> ------------------------------
>

-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 10.0.1204 / Virus Database: 1435/3422 - Release Date: 02/04/11

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Joe Subich, W4TV-4

Re: Blue Tooth - Freq. response

>> Unfortunately, one can't bump up audio output in FSK-D.

What do you mean "can't bump up audio output in FSK-D?" The speaker
or headphone level is controllable with the AF gain and the Line Out
is controllable with the CONFIG:LIN OUT setting.

73,

... Joe, W4TV

On 2/4/2011 5:02 PM, Brian Alsop wrote:

> Unfortunately, one can't bump up audio output in FSK-D. I use a modem
> which only can use 2 KHz tones. The drop in perceived audio level is
> quite high there for me. Even if low tones were used, there would still
> be a significant loss.
>
> What say Elecraft? Why not let us bump up one segment? FSK-D isn't
> used for any other digital mode.
>
> 73 de Brian/K3KO
>
> On 2/4/2011 21:52, Edward R. Cole wrote:
>> Slightly off the subject (Blue Tooth), but I wear Phonak Savia OTE
>> hearing aids and they have a high-fidelity program selection. This
>> is for flat freq. response up to 22-KHz for music and television
>> listening. I definitely can tell the improvement even with> 30dB
>> hearing degradation and loss above 800-Hz.
>>
>> Ten years ago I agonized over whether to spend money on a nice
>> home-theater system or whether my hearing was too bad to enjoy it. I
>> am forever glad that I got the system as ordinary TV speakers are
>> nearly useless for me. Of course I use captioning all the time for speech.
>>
>> One of the nice aspects of the k3 is that audio can be taylored to
>> one's hearing preferences.
>>
>> 73, Ed - KL7UW
>> BTW I just installed an upgraded soundcard (emu-0202) in my computer
>> and it really sounds nicer. It was not my primary reason to get the
>> soundcard (LP-Pan baseband processing is primary).
>>
>> ------------------------------
>>
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1204 / Virus Database: 1435/3422 - Release Date: 02/04/11
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

alsopb

Re: Blue Tooth - Freq. response

Add "in equalizer" to the request. Right now it knows to turn it off in
FSK-D.

73 de Brian/K3KO

On 2/4/2011 22:41, Joe Subich, W4TV wrote:

>
>>> Unfortunately, one can't bump up audio output in FSK-D.
>
> What do you mean "can't bump up audio output in FSK-D?" The speaker
> or headphone level is controllable with the AF gain and the Line Out
> is controllable with the CONFIG:LIN OUT setting.
>
> 73,
>
>

-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 10.0.1204 / Virus Database: 1435/3428 - Release Date: 02/07/11

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Joe Subich, W4TV-4

Re: Blue Tooth - Freq. response

But you don't want the equalizer in digital modes as that messes
up the response and results in poorer decoding. The only change
that makes sense in any of the digital modes is (flat) level and
that can be done with CONFIG: LIN OUT.

73,

... Joe, W4TV

On 2/7/2011 2:19 PM, Brian Alsop wrote:

> Add "in equalizer" to the request. Right now it knows to turn it off in
> FSK-D.
>
> 73 de Brian/K3KO
>
> On 2/4/2011 22:41, Joe Subich, W4TV wrote:
>>
>>>> Unfortunately, one can't bump up audio output in FSK-D.
>>
>> What do you mean "can't bump up audio output in FSK-D?" The speaker
>> or headphone level is controllable with the AF gain and the Line Out
>> is controllable with the CONFIG:LIN OUT setting.
>>
>> 73,
>>
>>
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1204 / Virus Database: 1435/3428 - Release Date: 02/07/11
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

alsopb

Re: Blue Tooth - Freq. response

Joe,

We very specifically singled out FSK-D for this request. No other
digital mode would be impacted.

If one introduced say 6 db in the segment covering 2KHz and up to the
next equalizer breakpoint, I don't see how this can mess up decoding.
The gain increase is constant in the segment.

73 de Brian/K3KO

On 2/7/2011 20:17, Joe Subich, W4TV wrote:

>
> But you don't want the equalizer in digital modes as that messes
> up the response and results in poorer decoding. The only change
> that makes sense in any of the digital modes is (flat) level and
> that can be done with CONFIG: LIN OUT.
>
> 73,
>
> ... Joe, W4TV
>
>
> On 2/7/2011 2:19 PM, Brian Alsop wrote:
>> Add "in equalizer" to the request. Right now it knows to turn it off in
>> FSK-D.
>>
>> 73 de Brian/K3KO
>>
>> On 2/4/2011 22:41, Joe Subich, W4TV wrote:
>>>
>>>>> Unfortunately, one can't bump up audio output in FSK-D.
>>>
>>> What do you mean "can't bump up audio output in FSK-D?" The speaker
>>> or headphone level is controllable with the AF gain and the Line Out
>>> is controllable with the CONFIG:LIN OUT setting.
>>>
>>> 73,
>>>
>>>
>>
>>
>> -----
>> No virus found in this message.
>> Checked by AVG - www.avg.com
>> Version: 10.0.1204 / Virus Database: 1435/3428 - Release Date: 02/07/11
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1204 / Virus Database: 1435/3428 - Release Date: 02/07/11
>
>

Joe Subich, W4TV-4

Re: Blue Tooth - Freq. response

> If one introduced say 6 db in the segment covering 2KHz and up to the
> next equalizer breakpoint, I don't see how this can mess up decoding.
> The gain increase is constant in the segment.

No, the gain is not constant across the segment, it is tapered so that
setting two adjacent ranges to the same level creates a flat response
across the "boundary." In the case of 2125/2295 (traditional "high"
tones) setting the 1600 Hz band at 0 and the 2400 Hz band at +10 dB
will create a measurable "tilt" between the two tones ... a similar
tilt will be seen with the 915/1085 Hz tone pair for the 800/1600 Hz
bands.

It's easy to see the behavior, simply use a stable oscillator like the
XG-2. Set the RxEQ to boost only the 2400 Hz band by +16 dB, zero the
dBV meter at 1 KHz and measure the level at 2.125 and 2.295 KHz. The
difference will be at least 2 dB (I measure 2.2 to 2.3 dB "tilt" at
both 2125/2295 and 915/1085).

The behavior of a parametric EQ (which the K3 is) is very different
than a shelving EQ.

73,

... Joe, W4TV

On 2/7/2011 3:26 PM, Brian Alsop wrote:

> Joe,
>
> We very specifically singled out FSK-D for this request. No other
> digital mode would be impacted.
>
> If one introduced say 6 db in the segment covering 2KHz and up to the
> next equalizer breakpoint, I don't see how this can mess up decoding.
> The gain increase is constant in the segment.
>
> 73 de Brian/K3KO
>
> On 2/7/2011 20:17, Joe Subich, W4TV wrote:
>>
>> But you don't want the equalizer in digital modes as that messes
>> up the response and results in poorer decoding. The only change
>> that makes sense in any of the digital modes is (flat) level and
>> that can be done with CONFIG: LIN OUT.
>>
>> 73,
>>
>> ... Joe, W4TV
>>
>>
>> On 2/7/2011 2:19 PM, Brian Alsop wrote:
>>> Add "in equalizer" to the request. Right now it knows to turn it off in
>>> FSK-D.
>>>
>>> 73 de Brian/K3KO
>>>
>>> On 2/4/2011 22:41, Joe Subich, W4TV wrote:
>>>>
>>>>>> Unfortunately, one can't bump up audio output in FSK-D.
>>>>
>>>> What do you mean "can't bump up audio output in FSK-D?" The speaker
>>>> or headphone level is controllable with the AF gain and the Line Out
>>>> is controllable with the CONFIG:LIN OUT setting.
>>>>
>>>> 73,
>>>>
>>>>
>>>
>>>
>>> -----
>>> No virus found in this message.
>>> Checked by AVG - www.avg.com
>>> Version: 10.0.1204 / Virus Database: 1435/3428 - Release Date: 02/07/11
>>>
>>> ______________________________________________________________
>>> Elecraft mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:[hidden email]
>>>
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>>>
>>
>>
>> -----
>> No virus found in this message.
>> Checked by AVG - www.avg.com
>> Version: 10.0.1204 / Virus Database: 1435/3428 - Release Date: 02/07/11
>>
>>
>
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1204 / Virus Database: 1435/3428 - Release Date: 02/07/11
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

alsopb

Re: Blue Tooth - Freq. response

Very interesting. There was no way to know from the documentation which
type of equalizer the K3 has inside.

73 de Brian/K3KO

On 2/7/2011 22:20, Joe Subich, W4TV wrote:

>
> > If one introduced say 6 db in the segment covering 2KHz and up to the
> > next equalizer breakpoint, I don't see how this can mess up decoding.
> > The gain increase is constant in the segment.
>
> No, the gain is not constant across the segment, it is tapered so that
> setting two adjacent ranges to the same level creates a flat response
> across the "boundary." In the case of 2125/2295 (traditional "high"
> tones) setting the 1600 Hz band at 0 and the 2400 Hz band at +10 dB
> will create a measurable "tilt" between the two tones ... a similar
> tilt will be seen with the 915/1085 Hz tone pair for the 800/1600 Hz
> bands.
>
> It's easy to see the behavior, simply use a stable oscillator like the
> XG-2. Set the RxEQ to boost only the 2400 Hz band by +16 dB, zero the
> dBV meter at 1 KHz and measure the level at 2.125 and 2.295 KHz. The
> difference will be at least 2 dB (I measure 2.2 to 2.3 dB "tilt" at
> both 2125/2295 and 915/1085).
>
> The behavior of a parametric EQ (which the K3 is) is very different
> than a shelving EQ.
>
> 73,
>
> ... Joe, W4TV
>
>
> On 2/7/2011 3:26 PM, Brian Alsop wrote:
>> Joe,
>>
>> We very specifically singled out FSK-D for this request. No other
>> digital mode would be impacted.
>>
>> If one introduced say 6 db in the segment covering 2KHz and up to the
>> next equalizer breakpoint, I don't see how this can mess up decoding.
>> The gain increase is constant in the segment.
>>
>> 73 de Brian/K3KO
>>
>> On 2/7/2011 20:17, Joe Subich, W4TV wrote:
>>>
>>> But you don't want the equalizer in digital modes as that messes
>>> up the response and results in poorer decoding. The only change
>>> that makes sense in any of the digital modes is (flat) level and
>>> that can be done with CONFIG: LIN OUT.
>>>
>>> 73,
>>>
>>> ... Joe, W4TV
>>>
>>>
>>> On 2/7/2011 2:19 PM, Brian Alsop wrote:
>>>> Add "in equalizer" to the request. Right now it knows to turn it off in
>>>> FSK-D.
>>>>
>>>> 73 de Brian/K3KO
>>>>
>>>> On 2/4/2011 22:41, Joe Subich, W4TV wrote:
>>>>>
>>>>>>> Unfortunately, one can't bump up audio output in FSK-D.
>>>>>
>>>>> What do you mean "can't bump up audio output in FSK-D?" The speaker
>>>>> or headphone level is controllable with the AF gain and the Line Out
>>>>> is controllable with the CONFIG:LIN OUT setting.
>>>>>
>>>>> 73,
>>>>>
>>>>>
>>>>
>>>>
>>>> -----
>>>> No virus found in this message.
>>>> Checked by AVG - www.avg.com
>>>> Version: 10.0.1204 / Virus Database: 1435/3428 - Release Date: 02/07/11
>>>>
>>>> ______________________________________________________________
>>>> Elecraft mailing list
>>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>>> Help: http://mailman.qth.net/mmfaq.htm
>>>> Post: mailto:[hidden email]
>>>>
>>>> This list hosted by: http://www.qsl.net
>>>> Please help support this email list: http://www.qsl.net/donate.html
>>>>
>>>
>>>
>>> -----
>>> No virus found in this message.
>>> Checked by AVG - www.avg.com
>>> Version: 10.0.1204 / Virus Database: 1435/3428 - Release Date: 02/07/11
>>>
>>>
>>
>>
>>
>> -----
>> No virus found in this message.
>> Checked by AVG - www.avg.com
>> Version: 10.0.1204 / Virus Database: 1435/3428 - Release Date: 02/07/11
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1204 / Virus Database: 1435/3428 - Release Date: 02/07/11
>
>

Jim Brown-10

Re: Blue Tooth - Freq. response

On 2/7/2011 3:02 PM, Brian Alsop wrote:
> > No, the gain is not constant across the segment, it is tapered so that
> > setting two adjacent ranges to the same level creates a flat response
> > across the "boundary."

Right. To understand this, it's important to realize that filters
implemented in DSP are simply digital simulations of ordinary analog
filters -- in this case, resonant circuits tuned for the desired
frequency and bandwidth. Ideally, well-designed sets of filters should
combine to yield minimal ripple in their amplitude and phase response if
all (or adjacent bands) are set to the same gain. The extent to which
this is achieved depends on the circuits that they are simulating, and
some circuits are far better than others in this regard.

73, Jim K9YC
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

Joe Subich, W4TV-4

Re: Blue Tooth - Freq. response

In reply to this post by alsopb

> There was no way to know from the documentation which
> type of equalizer the K3 has inside.

Any multi-band EQ beyond two bands - e.g, other than simple high
boost/cut and/or low boost/cut designs - must, by definition, be
parametric. I don't think the manual needs to specify the type
of EQ when it has eight bands. With multi-band EQ the bottom and
top "bands" are typically shelving and the intermediate bands
parametric with the Q designed for minimum ripple (smooth transition
from band to band).

73,

... Joe, W4TV

On 2/7/2011 6:02 PM, Brian Alsop wrote:

> Very interesting. There was no way to know from the documentation which
> type of equalizer the K3 has inside.
>
> 73 de Brian/K3KO
>
> On 2/7/2011 22:20, Joe Subich, W4TV wrote:
>>
>> > If one introduced say 6 db in the segment covering 2KHz and up to the
>> > next equalizer breakpoint, I don't see how this can mess up decoding.
>> > The gain increase is constant in the segment.
>>
>> No, the gain is not constant across the segment, it is tapered so that
>> setting two adjacent ranges to the same level creates a flat response
>> across the "boundary." In the case of 2125/2295 (traditional "high"
>> tones) setting the 1600 Hz band at 0 and the 2400 Hz band at +10 dB
>> will create a measurable "tilt" between the two tones ... a similar
>> tilt will be seen with the 915/1085 Hz tone pair for the 800/1600 Hz
>> bands.
>>
>> It's easy to see the behavior, simply use a stable oscillator like the
>> XG-2. Set the RxEQ to boost only the 2400 Hz band by +16 dB, zero the
>> dBV meter at 1 KHz and measure the level at 2.125 and 2.295 KHz. The
>> difference will be at least 2 dB (I measure 2.2 to 2.3 dB "tilt" at
>> both 2125/2295 and 915/1085).
>>
>> The behavior of a parametric EQ (which the K3 is) is very different
>> than a shelving EQ.
>>
>> 73,
>>
>> ... Joe, W4TV
>>
>>
>> On 2/7/2011 3:26 PM, Brian Alsop wrote:
>>> Joe,
>>>
>>> We very specifically singled out FSK-D for this request. No other
>>> digital mode would be impacted.
>>>
>>> If one introduced say 6 db in the segment covering 2KHz and up to the
>>> next equalizer breakpoint, I don't see how this can mess up decoding.
>>> The gain increase is constant in the segment.
>>>
>>> 73 de Brian/K3KO
>>>
>>> On 2/7/2011 20:17, Joe Subich, W4TV wrote:
>>>>
>>>> But you don't want the equalizer in digital modes as that messes
>>>> up the response and results in poorer decoding. The only change
>>>> that makes sense in any of the digital modes is (flat) level and
>>>> that can be done with CONFIG: LIN OUT.
>>>>
>>>> 73,
>>>>
>>>> ... Joe, W4TV
>>>>
>>>>
>>>> On 2/7/2011 2:19 PM, Brian Alsop wrote:
>>>>> Add "in equalizer" to the request. Right now it knows to turn it off in
>>>>> FSK-D.
>>>>>
>>>>> 73 de Brian/K3KO
>>>>>
>>>>> On 2/4/2011 22:41, Joe Subich, W4TV wrote:
>>>>>>
>>>>>>>> Unfortunately, one can't bump up audio output in FSK-D.
>>>>>>
>>>>>> What do you mean "can't bump up audio output in FSK-D?" The speaker
>>>>>> or headphone level is controllable with the AF gain and the Line Out
>>>>>> is controllable with the CONFIG:LIN OUT setting.
>>>>>>
>>>>>> 73,
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>> -----
>>>>> No virus found in this message.
>>>>> Checked by AVG - www.avg.com
>>>>> Version: 10.0.1204 / Virus Database: 1435/3428 - Release Date: 02/07/11
>>>>>
>>>>> ______________________________________________________________
>>>>> Elecraft mailing list
>>>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>>>> Help: http://mailman.qth.net/mmfaq.htm
>>>>> Post: mailto:[hidden email]
>>>>>
>>>>> This list hosted by: http://www.qsl.net
>>>>> Please help support this email list: http://www.qsl.net/donate.html
>>>>>
>>>>
>>>>
>>>> -----
>>>> No virus found in this message.
>>>> Checked by AVG - www.avg.com
>>>> Version: 10.0.1204 / Virus Database: 1435/3428 - Release Date: 02/07/11
>>>>
>>>>
>>>
>>>
>>>
>>> -----
>>> No virus found in this message.
>>> Checked by AVG - www.avg.com
>>> Version: 10.0.1204 / Virus Database: 1435/3428 - Release Date: 02/07/11
>>>
>>> ______________________________________________________________
>>> Elecraft mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:[hidden email]
>>>
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>>>
>>
>>
>> -----
>> No virus found in this message.
>> Checked by AVG - www.avg.com
>> Version: 10.0.1204 / Virus Database: 1435/3428 - Release Date: 02/07/11
>>
>>
>
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1204 / Virus Database: 1435/3428 - Release Date: 02/07/11
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

Jim Brown-10

Re: Blue Tooth - Freq. response

> Any multi-band EQ beyond two bands - e.g, other than simple high
> boost/cut and/or low boost/cut designs - must, by definition, be
> parametric.

Not quite. From a user point of view, there are two types of multi-band
equalizers -- graphic, and parametric. A graphic equalizer has filters
that have a fixed bandwidth and are fixed in frequency. The only user
control is to change the amount of boost or cut within that band. The TX
and RX equalizers in the K3 are graphic equalizers.

A parametric equalizer has filters that can be varied in frequency,
bandwidth, and amount of boost or cut.

A shelving equalizer is one that transitions from flat response in the
midrange to either boost or cut (usually cut) on the low end and/or the
high end. In that "cut" region" the response is also flat, thus the name
"shelf." The transition from flat to boost or cut is a gradual one, the
shape of that transition and the degree of boost or cut can be varied by
design of the analog circuit or the DSP that simulates the analog
circuit, and that shape affects the sound quality.

A high pass or low pass filter differs from a shelving equalizer in that
it is only capable of cutting (rolling off) the response above or below
the desired frequency limit, and that there is no intentional "shelf" --
that is, the gain in the cut region keeps dropping as you move away from
from the frequency limit.

All of these types of equalizers can be implemented with analog
components, or in DSP that simulates those analog components. The K3
uses high pass and low pass filters and shelving EQ, implemented in DSP,
to limit the bandwidth of the system.

In the audio world, most products called parametric equalizers also
include high pass, low pass, and shelving functionality. Nowadays,
virtually all modern products are implemented in DSP. Before the days of
DSP, parametric equalizers were used, but graphic equalizers (mostly 10
bands or 27 bands) dominated the market because they were easier to
understand, and easier to set without getting into trouble. DSP and
modern instrumentation (and display of the response) changed all that --
every filter burns processing power, so a 27-band equalizer required 5
times the DSP of a 5 band parametric, and the modern
instrumentation/display made it easier to see what you were doing with
the equalizer. TXEQ and RXEQ in the K3 is a well thought out compromise
between processing power and simplicity of use that does almost anything
an intelligent user might need.

73, Jim Brown K9YC

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html