Hello Rosmadi Mahmood,
I have read the whole this thread and still have some questions I would like to ask you to kindly answer. Below are mostly my guesses and common logic conclusions, could you be please so kind to point where I am right and where I am wrong?
Q1) Is analog ALC in 180 and 185 models the same? If not what is a difference?
Q2) Data which is transmitted via RF band in models RS 1x0 (like RS 170 etc.) and 1x5 (like RS 175 etc.) is digital: "MSK Digital" and "8-FSK Digital" format accordingly. User mark2410 had gave us very good and useful review for RS 185, I am thankful to him. He supposed (and not only he) that there is an internal DAC in 1x5 models. Maybe the statement was based upon a price, maybe he has another information source, I do not know, I could not find any official information concerning to it.
Do models 1x5 (like RS 175 etc.) really have a DAC?
Q3) If they have a DAC, why it is needed?
I will try to illustrate in more details my logic below.
Is there is no DAC, processing for digital input data might go like this:
a) digital input data --> processing of digital data (maybe bass boost, surround modes in 175, balance control in 185, balance control, speech clarity etc. in 195) --> Sennhieser (not Kleer’s) digital data processing (prepare for transmission) --> transmitting digital data over RF --> RF read by phones and Sennhieser (not Kleer’s) digital data reverse processing/decoding --> phone’s DAC --> phone’s amplifier.
b) analog input data --> analog data processing (like setting sound level, ALC, MLC) --> ADC --> here we get the same digital data as in case 3-a and further processing goes the same way.
The mentioned above "processings" (bass boost etc.) work for both analog and digital input and could be controlled from phones remotely too, so they should logically be in digital circuit, but analog data processing (like setting sound level, ALC, MLC) is available only for analog input.
I suppose the architecture is a correct one, am I right?
If there would be an internal DAC within, then processing for digital input would rather go like this:
c) digital input data --> DAC --> analog data (like setting sound level, ALC, MLC) --> ADC --> digital data --> processing of digital data (maybe bass boost, surround modes in 175, balance control in 185, balance control, speech clarity etc. in 195) --> Sennhieser (not Kleer’s) digital data processing --> transmitting digital data over RF --> RF read by phones and Sennhieser (not Kleer’s) digital data reverse processing/decoding --> phone’s DAC --> phone’s amplifier.
d) analog input data --> analog data processing (like setting sound level, ALC, MLC) - here we get the same analog data as in case 3-c and further processing goes the same way.
If case 3-c would hold true,
I) we would have sound level adjustment possibility for digital input too;
II) Sennhieser would not suggest always to use digital input, but only in cases when external DAC is not so good as one from TR 1x5 (SNR values from specification for analog and digital input also says about it).
III) There could be possibility to use ALC for digital input (good feature btw.).
So it looks like it is not the case we have.
Please correct me where I am wrong and point me where I am correct.
Q4) If one looks upon the very first page of manual for RS 1x0 and RS 1x5 models one can see in pictures that 1x5 models do have more curved holder "springs", I mean ear pads have bigger angle between them. It looks firmer in TR holder, but IMO it is not good for head. Someone also writes that 1x5 version has much more pressure to head then 1x0. I just do not understand why it is done so (comparing to 1x0 models)... For my mom bigger pressure is a big disadvantage. For Hi-Fi phones one might not wear them for whole day, but for TV usage it could be the case. One even can fall asleep accidentally with phones on, how would he feel after waking up? People with good health might not pay much attention to it (which IMO is unwise), but my mom has a headache after such ones - I bought her once phones she could not use. I might understand it if the phones would be made for sport. I do like how Sennhieser phones sound in general, especially good ones and give a big and sincere credit to engineers’ hard work, but I would like to ask them in the particular case - why?
Q5) In my wild dreams
I can see in phones spec. information about how much pressure (i.e. in Newton) each circumaural and supraaural phones put to a "standard" head (or ears in case of supraaural ones) to be able to compare the values before buying. Could possibly Sennheiser be a pioneer in the field? I think buyers would appreciate such care about them.
Question @everyone who possesses 1x5 models:
- How much maximal time could you spend wearing them?
- How pressure to head is compared to HD-650 (which I have, so can get an impression comparing to it)?
Many thanks to Rosmadi Mahmood and everybody in advance!