Linn Forums

Current time: 2017-10-17, 19:49 Hello There, Guest! (LoginRegister)

Linn Forums / Linn Music Systems & Hi-fi Separates / Network Music Players & Music Streamers v / DSM variable volume on digital out?

Post Reply 
DSM variable volume on digital out?
2017-09-26, 13:21
Post: #21
RE: DSM variable volume on digital out?
PS That ER stuff looks very interesting! Smile

KDS/1 (music) + ADSM (AV) -> KK/1 -> 350A + miniDSP time & phase aligned 345 rear sub
KDS Renew -> Homebrew fixed attenuator -> 2250/D -> 212 and Sizmik front sub (bedroom)
MDSI -> 104C (awaiting installation in my kitchen)
MDSI -> Shahinian Arc (installed at my mum's house)
Find all posts by this user
Quote this message in a reply
2017-10-03, 14:03 (This post was last modified: 2017-10-03 14:05 by Briain.)
Post: #22
RE: DSM variable volume on digital out?
(2017-09-26 12:48)Bosco Birdswood Wrote:  Hi Bri,

I think you'll be impressed by it! The latency isn't an issue for me because I run all channels through it, resulting in them all encountering the same delay. Two channels go to small ESL panels (http://www.eraudio.com.au mini panels), and the other two go to a pair of sexy Morel Titanium 10" woofers with huge voice coils!

I implemented the SPACE settings on the miniDSP yesterday using just IIR filters and it sounds brilliant.

That being said I also bought a Majik 4100 yesterday so will eventually be back to using SO again in a few months (I'm in Melbourne, amp is in the UK so I have to wait for my dear mother to come over at Christmas with an amp stuffed in her suitcase!)

Hi

I set it all up yesterday and measured the latency (with two IIR filters set, it was 3.11 ms). I then found a couple of filter combination solutions where it best tracked the phase of my 350A bass units (I need to do that 'properly' at some point soon) then packed all the kit away and replaced the 2x8 with the 2x4 HD. I just used it with the TV sound (as that is what the system is most often used for, it is something I am very familiar with) and something intriguing happened. The 8x2 was set for 2 V sensitivity and 0.9 V output (it can be set to 0.9 V or 2 V via internal switches) whereas the new HD version is set to 2 V (it doesn't have a 0.9 V option) so I expected the sub to be about 6 or 7 dB too loud, but after listening for a couple of hours, I ended up only dropping the sub level by only 2 dB.

I'll have to investigate that further as it is rather an intriguing anomaly. One thing I noted when at Linn Products (yes, I too was amazed that they let me through the front door) was that when comparing a KDS to a Katalyst KDS, the former seemed to produce a higher level of a very, very low frequency (one note on that Christine and the Queens tune) and Linn explained that what I was hearing was an artefact based on distortion (which was absent on the Katalyst version) so I wonder if the very low bass is simply a lot cleaner. Later, I'll dig out a measuring set and measure the actual levels from the two units; maybe the 2x4 was putting out a higher level than it should have been (or perhaps a combination of all these things).

Anyhow, the system sounded mighty fine, so I'll soon use some real music to set it all up and we will see how it all sounds, but my initial thoughts are that it is very good.

Bri

PS I will start a new thread explaining how to measure latency using 3 test tones (100 Hz, 1 KHz and 10 KHz) and a dual channel oscilloscope. Of course, most folks would simply generate these tones in Audacity (or the likes) or just download them from the internet, but being me, I used a rather more convoluted process involving fancy testers and signals from GPS satellites (seriously), so for other nutters like me, it should make for quite an amusing read! Big Grin

KDS/1 (music) + ADSM (AV) -> KK/1 -> 350A + miniDSP time & phase aligned 345 rear sub
KDS Renew -> Homebrew fixed attenuator -> 2250/D -> 212 and Sizmik front sub (bedroom)
MDSI -> 104C (awaiting installation in my kitchen)
MDSI -> Shahinian Arc (installed at my mum's house)
Find all posts by this user
Quote this message in a reply
2017-10-03, 18:20 (This post was last modified: 2017-10-03 18:22 by Briain.)
Post: #23
RE: DSM variable volume on digital out?
(2017-10-03 14:03)Briain Wrote:  ...The 8x2 was set for 2 V sensitivity and 0.9 V output (it can be set to 0.9 V or 2 V via internal switches) whereas the new HD version is set to 2 V (it doesn't have a 0.9 V option) so I expected the sub to be about 6 or 7 dB too loud, but after listening for a couple of hours, I ended up only dropping the sub level by only 2 dB.

I'll have to investigate that further as it is rather an intriguing anomaly...

I just measured it and they are actually only 2.5 dB adrift, so my ears were actually correct; below shows spot testing of same (ignore the absolute levels as it's only the difference that counts):
Code:
Frequency    Level 2x8    Level 2x4        Difference
20 Hz        -16.5          -15.7             0.8 dB
30 Hz        -16.8          -14.2             2.6 dB
40 Hz        -17.2          -14.4             2.8 dB
50 Hz        -17.9          -15.5             2.4 dB
60 Hz        -19.6          -17.3             2.3 dB
70 Hz        -22.5          -19.7             2.8 dB

The disparity at 20 Hz is due to me having a different roll on filter set up in each unit.

Bri

KDS/1 (music) + ADSM (AV) -> KK/1 -> 350A + miniDSP time & phase aligned 345 rear sub
KDS Renew -> Homebrew fixed attenuator -> 2250/D -> 212 and Sizmik front sub (bedroom)
MDSI -> 104C (awaiting installation in my kitchen)
MDSI -> Shahinian Arc (installed at my mum's house)
Find all posts by this user
Quote this message in a reply
Post Reply 


Forum Jump:


User(s) browsing this thread: 1 Guest(s)