GK-1 sub integration

wireburn · « **on:** 29 Jan 2003, 08:13 pm »

I have read everything at Harmonic Discord and here I could find to get answers to these questions, but nothing definitive.

1. Does the second set of outputs on the GK-1 Stage 2 and 3 bypass the tubes?
2. Since there is no HP filter on either output, will I be wasting amp power (AKSA 55) on bass that will never be able to be reproduced on my speakers (-3dB@58Hz)?

I'd like to control my sub level at the preamp, but I am concerned about running my mains full range leading to possibly muddied mid-bass. I will also use the HT bypass feature when I control the 6 ch. volume digitally.

Thanks in advance for the replies!

-Mike

AKSA · « **Reply #1 on:** 29 Jan 2003, 08:37 pm »

Mike,

The sub out on the Stage 2 GK-1 does indeed bypass the tube. The reason is that we want the maximum signal we can get at these low frequencies, and the cap coupling of any tube mitigates against this. Since a tube is struggling to deliver the punchy low end bass required in this situation, the sub out is taken from the direct coupled SS front end of the GK-1.

Its volume is controlled by the same pot as the full range signal.

No, running smaller speakers full range will not muddy the mid bass if the speakers are set up with high Fs drivers, which naturally tail off around 50Hz anyway. I use Morel MTMs in this role, run them full range, no problem at all with 'muddy' bass as you describe it. You can run them through a high pass if you want, but I don't see this as necessary.

In fact, for those using active systems, I suggest running the bookshelf speakers full range is a great idea; there should be no bandpass filtering to avoid damaging the sonics (bandpass filters are dynamite for creating weird phasing effects which seriously damage imaging); only a low pass for the sub, and a high pass for everything else.

Hope this is helpful,

Cheers,

Hugh

wireburn · « **Reply #2 on:** 29 Jan 2003, 09:07 pm »

Thanks, Hugh.

I have digital bass management on the source, but the sub out sure doesn't sound right to me. When I experimented by adding all the bass to the fronts, into the sub's built-in crossover, then out to the AKSA I got all my punchy bass back at the expense of a LOT of high-end sparkle. Sounds like I can get the best of both worlds through the GK-1. I'm in as soon as I get all my pennies in a row. You DO take pennies, don't you?

-Mike

AKSA · « **Reply #3 on:** 29 Jan 2003, 09:21 pm »

Mike,

Pennies are heaven for me; cripes, I deal in Pacific Pesos!!

Cheers,

Hugh

Oz_Audio · « **Reply #4 on:** 29 Jan 2003, 10:24 pm »

I agree with Hugh, If you want good bass from a sub, use smaller main speakers with no low cut off filter.

I use Vifa 5.5" for main speakers and these cannot go lower than 80 hz, so integration is easier. The result is a perfect integration between mains and sub, no phase shifting or any other problem. The sub is set at 100hz 18dB slope.

Larry · « **Reply #5 on:** 30 Jan 2003, 01:05 am »

I use a REL Strata II sub. I use the high input which is connected to the speaker post of Aksa. This is the recommended configuration by the manual. The manual says to use the high input for the best sonics. There is a line level input of cause, which hence I never use.

Does anyone like to comment on these two configurations?

wireburn · « **Reply #6 on:** 30 Jan 2003, 11:15 am »

I always read that you should try to use the line-level input whenever possible to get the best sound out of a sub, but your REL may be different, of course.

I thought of one more question. When using the HT bypass, will both outputs still function?

Thanks,
-Mike

U4EA · « **Reply #7 on:** 30 Jan 2003, 05:12 pm »

I ran the GK1 with 8 inch mains (they go down to 48hz) and an ACI Titan subwoofer. Most musical sub I have ever heard. Integration was a snap.

Of course the beta version had only one set of outputs so I Y adapted out of them. But still it worked great. I bet it is even better now that you bypass the tubes.

I also ran the GK1 into the pre and then hooked the sub to my amp speaker posts using line levelers. This semed to sound better. A little more snappy in the bass. But again, integration was simple.

You really realize how much you are hearing when you disconnect the GK1 and go back to your old stuff.

Larry · « **Reply #8 on:** 30 Jan 2003, 11:59 pm »

Quote from: U4EA

I also ran the GK1 into the pre and then hooked the sub to my amp speaker posts using line levelers.

What line levelers do you use?

AKSA · « **Reply #9 on:** 31 Jan 2003, 02:53 am »

Hi Wireburn,

When in HT bypass mode, only the regular output functions. The sub out does not, because it's plumbed from within the active circuitry.

Cheers,

Hugh

U4EA · « **Reply #10 on:** 31 Jan 2003, 07:58 pm »

Larry,

They came with the sub. Very cheap to buy. You can even make them.

http://www.audioc.com/information/images/hookupb.jpg

They are called speaker level converters in the pic above. ACI will sell these to you. They just take a power output signal and reduce it. Amp will not even know the sub is there.

wireburn · « **Reply #11 on:** 3 Feb 2003, 08:55 pm »

Quote from: AKSA

Hi Wireburn,

When in HT bypass mode, only the regular output functions. The sub out does not, because it's plumbed from within the active circuitry.

Cheers,

Hugh

I guess I won't be using the HT bypass, then.

Thanks,
-Mike