Hiya folks,
Can any of my esteemed cohorts please remind me what the DCR for both the HF, and LF drivers ought to be? I should be able to remember, but I can't.
After spending a ton of time critically listening to my 604's recently, since installing my new Soundsmith Otello, I realized the L/R balance of the system was a little off.
I eliminated the cartridge (checked and double checked its setup, internal resistance, etc.), cables, preamp, and amps (G*S*G 6B4G w/604's & TAD 60 6550 w/AR3a's) by switching around ins and outs, and using my old tried-and-true Shure M97xE, etc.
I also reversed polarities of the ins, outs, and speakers, and used the Otello in another system - the problem did not follow the cartridge.
I eventually tracked down a possible explanation for the imbalance to be the following driver DCR measurements:
604 #1: HF = 6.2 ohms; LF = 6.2 ohms
604 #2: HF = 6.2 ohms; LF = 7.2 ohms
Using my PC - playing digital files through JRiver - I was able to determine (subjectively: i.e. with my ears) about a 2.5-3dB difference in channels - very slightly dependant on the recording(s) I used.
Here's how I did that, (first using the G*S*G/604-8G's; then the TAD 60/AR3a's):
1) Play a familiar record at preferred listening volume.
2) Correct the imbalance with the preamp balance control.
3) Switch preamp to PC, and return preamp balance to "neutral".
4) Play a familiar digital file.
5) Trim output volume at PC to be relatively the same system volume, as when using the TT.
6) Correct the imbalance using JRiver DSD "room correction" feature, and note channel dB difference.
8) Disable JRiver DSD "room correction".
9) Switch back to using the TT, with preamp balance control at "neutral" position, and note there's a channel difference again, just to be sure.
10) Correct imbalance again with preamp balance control.
11) All is good, channels are now balanced, and both the TT and PC are the same relative listening volume.
When using my TAD 60/AR3a's, it's the same relative difference in balance - albeit not quite as noticeable. I attribute this perceived difference to be noticeably less because of the much lower output of the G*S*G, and it's very different sound profile with the 604's. It's very revealing, whereas the TAD 60/AR3a's combination isn't quite as sensitive to minutiae.
I can equalize the channels with the balance control on my preamp, and things sound great, but you know: anal.
What do you all think? Could the difference in Woofer DCR be the culprit? Would a ~16% difference in woof DCR account for ~3dB loss of gain in one channel?
I haven't tried a different preamp/phono stage yet, to absolutely eliminate the possibility it's the preamp, but it seems very unlikely that it is.
Can any of my esteemed cohorts please remind me what the DCR for both the HF, and LF drivers ought to be? I should be able to remember, but I can't.
After spending a ton of time critically listening to my 604's recently, since installing my new Soundsmith Otello, I realized the L/R balance of the system was a little off.
I eliminated the cartridge (checked and double checked its setup, internal resistance, etc.), cables, preamp, and amps (G*S*G 6B4G w/604's & TAD 60 6550 w/AR3a's) by switching around ins and outs, and using my old tried-and-true Shure M97xE, etc.
I also reversed polarities of the ins, outs, and speakers, and used the Otello in another system - the problem did not follow the cartridge.
I eventually tracked down a possible explanation for the imbalance to be the following driver DCR measurements:
604 #1: HF = 6.2 ohms; LF = 6.2 ohms
604 #2: HF = 6.2 ohms; LF = 7.2 ohms
Using my PC - playing digital files through JRiver - I was able to determine (subjectively: i.e. with my ears) about a 2.5-3dB difference in channels - very slightly dependant on the recording(s) I used.
Here's how I did that, (first using the G*S*G/604-8G's; then the TAD 60/AR3a's):
1) Play a familiar record at preferred listening volume.
2) Correct the imbalance with the preamp balance control.
3) Switch preamp to PC, and return preamp balance to "neutral".
4) Play a familiar digital file.
5) Trim output volume at PC to be relatively the same system volume, as when using the TT.
6) Correct the imbalance using JRiver DSD "room correction" feature, and note channel dB difference.
8) Disable JRiver DSD "room correction".
9) Switch back to using the TT, with preamp balance control at "neutral" position, and note there's a channel difference again, just to be sure.
10) Correct imbalance again with preamp balance control.
11) All is good, channels are now balanced, and both the TT and PC are the same relative listening volume.
When using my TAD 60/AR3a's, it's the same relative difference in balance - albeit not quite as noticeable. I attribute this perceived difference to be noticeably less because of the much lower output of the G*S*G, and it's very different sound profile with the 604's. It's very revealing, whereas the TAD 60/AR3a's combination isn't quite as sensitive to minutiae.
I can equalize the channels with the balance control on my preamp, and things sound great, but you know: anal.
What do you all think? Could the difference in Woofer DCR be the culprit? Would a ~16% difference in woof DCR account for ~3dB loss of gain in one channel?
I haven't tried a different preamp/phono stage yet, to absolutely eliminate the possibility it's the preamp, but it seems very unlikely that it is.
