[mvppsu]

I am trying to figure out if I can use the Audessey AS-EQ1 from SVS to EQ my subwoofers when used in a 2 channel and surround system.


My system:

For 2 channel, I'm using a Parasound 2100 preamp fed by a PS Audio DLIII connected to an Apple TV. The Parasound is connected to Paradigm Studio 20's and 2 Rythmik F12's. Additionally I have a Marantz SR5003 surround receiver that uses the HT bypass on the preamp.


Ideally I'd like to place the Audessey EQ between the preamp and 2 subwoofers. This would allow it to work for 2 channel audio and surround sound when the HT bypass is used. There would be no issue integrating the EQ into the surround system in this configuration, but I'm worried about the 8.5ms delay introduced by the EQ. The preamp does not have a way to introduce a delay into the front speakers like the surround processor does.


I'm wondering if the phase adjustment on the subs can compensate for the delay. And if it did, would it mess up the integration with the surround system. Anyone try this configuration? Do the other sub EQ's have less of a delay? I know I've seen people mention using the BFD or SMS-1 in a 2 channel system but I'm not sure how much of a delay these units have or whether these systems are also part of a surround system. Is the delay small enough that I don't need to worry about it?


Thanks,

Mike

 

[TJHUB]

I'm not a pro at this stuff, but you are thinking correctly regarding where to install the sub EQ. I too run a 2100 for 2-channel with a receiver for HT. I had a BFD installed between the 2100's sub output and my sub.


It was my understanding that the delay caused by the processing time of my BFD (1124P) was equal to about 1' of distance. I never took issue with this and I'm not certain I could hear the difference anyway. I am VERY picky about the sound of my 2-channel setup, and a sub EQ brings far more to the table than a small delay could ever hurt anything. I'd say just give it a try and figure out whether or not you can hear the difference.

 

[mvppsu]

My concern with the AS-EQ1 is this paragraph in the FAQ on the SVSSound website:


"Question 10: I have a 2-channel system without any distance controls in my pre/pro. Can I still use the AS-EQ1, and are there any special requirements?


Answer: Yes, the AS-EQ1 can be used in 2-channel systems. It does, however, have a fixed electrical latency (delay) of 7.5 milliseconds (ms). This will require the subwoofer to be placed about 8.4 feet closer to the listening position than the speakers in order to achieve the correct time alignment

between the speakers and the subwoofer. This is often physically infeasible, so you can also purchase a digital crossover (such as the Behringer DCX 2496) which can impose a 7.5 ms delay on the loudspeaker channel outputs. This will also provide the proper time alignment between the speakers and the

subwoofer without resorting to moving the subwoofer closer to the listening position."


I won't be placing a "digital crossover" in my analog signal path to introduce a delay. I think that would defeat the purpose of my 2 channel setup. The 7.5ms delay concerns me though. Maybe I need to find an EQ with a shorter delay. Does anyone know the delays introduced by the BFD, SMS-1, or Antimode?

 

[mvppsu]



Quote:
Originally Posted by mvppsu /forum/post/16894232


Does anyone know the delays introduced by the BFD, SMS-1, or Antimode?

The Hometheatershack BFD guide says it only has 1ms delay. ~1ft distance correction. If that is correct then I agree that probably wouldn't matter too much.


The Stereophile review of the Antimode says it has a 3.8ms delay. ~3ft distance correction.

 

[TJHUB]



Quote:
Originally Posted by mvppsu /forum/post/16894276


The Hometheatershack BFD guide says it only has 1ms delay. ~1ft distance correction. If that is correct then I agree that probably wouldn't matter too much.


The Stereophile review of the Antimode says it has a 3.8ms delay. ~3ft distance correction.

WOW!

I had no idea the processing time of these EQs was this slow or what the even equated to in distance.


I would skip both the Antimode and SVS with your setup. Why not try the BFD? Room EQ Wizard is only tough until you get threw it. After that it's incredibly easy. The BFD is child's play and it is VERY flexible. I used mine for about a year without any issues.

 

[Kal Rubinson]



Quote:
Originally Posted by TJHUB /forum/post/16899292


WOW!

I had no idea the processing time of these EQs was this slow ......

It depends on the type of DSP filtering.

Quote:
....or what the even equated to in distance.

Of course. That is why you need to adjust the delays for speakers that are not equidistant from the listener.

 

[mvppsu]

anyone have an idea of the Velodyne SMS-1 delay? I have not been able to find any info for this one.

 

[TJHUB]



Quote:
Originally Posted by Kal Rubinson /forum/post/16899385


It depends on the type of DSP filtering.


Of course. That is why you need to adjust the delays for speakers that are not equidistant from the listener.

Thanks Kal, but I'm not THAT dumb.

I'm surprised at the amount of processing time and just how MUCH distance it adds.


I know that the OP and I are not the norm by running subs with a 2-channel preamp with no processing ability. It just seems that these EQ systems don't work well for our setups.

 

[TJHUB]



Quote:
Originally Posted by mvppsu /forum/post/16899401


anyone have an idea of the Velodyne SMS-1 delay? I have not been able to find any info for this one.

Here you go:

Quote:
Originally Posted by virtual-human /forum/post/13902349


Well after placing my order for an SMS-1 earlier today I called Velo product support to ask how many feet they recommend compensating to account for the delay. After being told that my question was "silly", that nobody else had called to ask in the three years they'd been selling it, and that the gentleman I was speaking to had never thought about it because he only thinks about things that matter [no I am not making this up], I was informed that the SMS-1 introduces a 2.5 millisecond delay.


Can anybody here convert that to a distance for the purpose of settings in the AVR or alternatively the degrees of phase to add?


As an aside, I pointed out that it would be very easy to test before and after adjusting by looking at a graph at the crossover, but instead he suggested that I do a blind test with a friend adjusting the phase and suggested that I wouldn't be able to tell the difference. Thanks, Velo support.

 

[Kal Rubinson]



Quote:
Originally Posted by virtual-human View Post

Well after placing my order for an SMS-1 earlier today I called Velo product support to ask how many feet they recommend compensating to account for the delay. After being told that my question was "silly", that nobody else had called to ask in the three years they'd been selling it, and that the gentleman I was speaking to had never thought about it because he only thinks about things that matter [no I am not making this up], I was informed that the SMS-1 introduces a 2.5 millisecond delay.


Can anybody here convert that to a distance for the purpose of settings in the AVR or alternatively the degrees of phase to add?

The speed of sound is about 1130feet per second at STP. So, 2.5msec comes to 2.8feet. Rule of thumb is 1foot per msec and close enough.