AKSub (or any other sub for that matter) setup

cmscott6 · « **on:** 18 Dec 2004, 12:16 am »

After hearing small rumblings about an AKSub, I wondered if anyone could indulge me and explain how one would integrate a sub into an Aksa system. I have GK-1 into 55N into Aksonics. I assume that one would have two outputs from the GK-1 and a separate amp for the sub. (Or just a "Y" adapter???)

Does anyone currently use a sub with such a setup (or similar)? What do you use for the sub amp? Just another (two?) 55 or 100 module? I realize these may be elementary questions, but I've not used a sub before. I heard talk of a sub output bypassing the tube of the GK-1. Is this a possibility with only the entry-level of the GK-1?

Ugh. So many (elementary) questions...

Thanks for any help folks!

Chris

zachslc · « **Reply #1 on:** 18 Dec 2004, 12:59 am »

I could be entirely off base, but might the capacitance of a sub crossover be a challenge to the AKSA amps?

AKSA · « **Reply #2 on:** 18 Dec 2004, 03:44 am »

The GK1-M and GK1-R have sub-out taps alongside the main output.

The sub output is taken from the volume wiper, just before the signal enters the tube. This gives the tightest possible signal for deep bass as it does not pass through the tube. The signal is taken at this point through normal RCAs to a plate amp on an active sub. In most cases plate amps have a purely resistive input impedance around 20K - which is fine - and use active circuitry for the filters, often 24dB/octave.

Chris, while there is no such provision on the EL, it could be plumbed in without too much difficulty.

So, Zach, the short answer to your query is no problem - everything is fine!

Cheers,

Hugh

zachslc · « **Reply #3 on:** 18 Dec 2004, 05:16 am »

so, Hugh, just to clarify...

you are saying that gk1-->aksa 100-->active crossover-->sub driver is ok?

Sorry for the redundancy--I just want to make sure we are talking about the same thing.

andyr · « **Reply #4 on:** 18 Dec 2004, 06:10 am »

Quote from: cmscott6

... I assume that one would have two outputs from the GK-1 and a separate amp for the sub.

What do you use for the sub amp? Just another (two?) 55 or 100 modules? ...

Chris,

As Hugh has explained, the 'M' & 'R' versions of the GK-1 have a pair of sub-out RCAs. These would go to a pair of 'powered' subs (like what DSK has just implemented) or you could, I think, sum them into just one sub.

Or they would go into a stereo amp driving a pair of 'unpowered' subs. In this case, I think you would need at least a 250wpc ss amp to drive the subs. This doesn't have to be particularly 'hi-fi' - just with lots of grunt!

Darren's powered subs seem like a great deal - I'm going to buy some as soon as I can rake up the necessary green folding stuff!

Regards,

Andy

cmscott6 · « **Reply #5 on:** 19 Dec 2004, 03:37 pm »

Thanks for the info, Hugh.

Andy, what are "Darren's powered subs"? Any links? Thank you as well for the info!

Chris

DSK · « **Reply #6 on:** 19 Dec 2004, 11:03 pm »

Quote from: cmscott6

Thanks for the info, Hugh.

Andy, what are "Darren's powered subs"? Any links? Thank you as well for the info!

Chris

I built the Rythmik Audio DS350 DirectServo kit. Comes with a modded 385w RMS plate amp that includes the normal controls for gain, xo freq, phase (continuously variable), plus toggles for damping (hi, lo, med) and extension filter (14hz, 20hz, 28hz). The "high damping" provides a low-Q of 0.5, "med" damping is Q=0.7, and the "14hz" extension filter allows freq response to be flat down to 14hz though it sacrifices a little in max SPL to achieve this.

I built it in a 1.97 cu. ft. sealed enclosure, 1.5" walls plus bracing (weighs 93lbs). In my room, it is +/- 1.5db from below 20hz to above 200hz at the listening position. Details of how I set it up and my subjective evaluation of its sound can be seen in my testimonial on the Rythmik website.

The low-Q alignment and servo mechanism provide a very musical sub that is tighter than a virgin's ......er...... tighter than a fish's .....er.....um, it's really tight!!

This sub is about as good as it gets for 2-channel music (most audiophile subs have Q=0.7 and most HT subs have even higher Q - read looser bass) but HT buffs with a penchant for extreme SPL's may want to look elsewhere.

http://www.rythmikaudio.com/servo_product.htm

PS. I did a *lot* of research before selecting this sub, but didn't know Hugh had a sub on the horizon.

andyr · « **Reply #7 on:** 20 Dec 2004, 02:47 am »

Quote from: cmscott6

Thanks for the info, Hugh.

Andy, what are "Darren's powered subs"? Any links? Thank you as well for the info!

Chris

Chris,

They're Rhythmik Audio DirectServo subs.

Regards,

Andy

jules · « **Reply #8 on:** 20 Dec 2004, 08:25 pm »

I'm not familiar with the circuitry of a GK-1 but does taking the signal from the pot wiper mean that it is "unprocessed"?

How would this apply to an Elma ladder and would it be possible to run a sub from an Elma ladder based passive pre-amp on an Aksa55N+?

jules

SamL · « **Reply #9 on:** 20 Dec 2004, 09:58 pm »

I am about to email Rythmik to see if they have 250v version and I saw this line.

Quote from: DSK

PS. I did a *lot* of research before selecting this sub, but didn't know Hugh had a sub on the horizon.

Is it a 200+w power amp or a proper sub amp with variable phase control, frequency cut off, etc?

Sam

DSK · « **Reply #10 on:** 21 Dec 2004, 01:33 am »

Quote from: SamL

I am about to email Rythmik to see if they have 250v version and I saw this line.
Quote from: DSK

PS. I did a *lot* of research before selecting this sub, but didn't know Hugh had a sub on the horizon.

Is it a 200+w power amp or a proper sub amp with variable phase control, frequency cut off, etc?

Sam

Hi Sam,

I'm in Melbourne, I have their 240v version. Have a good read of their website, lots of detail on how it all works etc. It is a modified 385w RMS subwoofer plate amp with all necessary features for optimal integration. It is easily better (more musical, tighter, better transient response, less bloat/overhang, more extended etc) than the M&K MX series sub I had a while back. Hard to imagine anything sounding better for music, let alone at the "give away" price.

Cheers,
Darren.

SamL · « **Reply #11 on:** 21 Dec 2004, 02:53 am »

Quote from: DSK

Hi Sam,

I'm in Melbourne, I have their 240v version. Have a good read of their website, lots of detail on how it all works etc. It is a modified 385w RMS subwoofer plate amp with all necessary features for optimal integration. It is easily better (more musical, tighter, better transient response, less bloat/overhang, more extended etc) than the M&K MX series sub I had a while back. Hard to imagine anything sounding better for music, let alone at the "give away" price.

Cheers,
Darren.

Thanks for the detail on the RMS subamp. Can you still remember how much it cost to freigh the plate amp to OZ? I currently own a Lambda 10" seal sub driver and looking for a subamp to drive it.
As for Hugh's sub amp that you mention. Will that be a sub amp with all the feature or they are actually high watt power amp?

AKSA · « **Reply #12 on:** 21 Dec 2004, 03:48 am »

Sam,

I won't be doing a plate amp. Those already in the market are inexpensive and have variable slope and cutoff frequencies; I can't compete with their prices. Of course, quality is not so important in a sub amp - you really need grunt, not too much in the way of good sonics is needed!

Cheers,

Hugh

DSK · « **Reply #13 on:** 21 Dec 2004, 04:19 am »

Quote from: SamL

Thanks for the detail on the RMS subamp. Can you still remember how much it cost to freigh the plate amp to OZ? I currently own a Lambda 10" seal sub driver and looking for a subamp to drive it.
As for Hugh's sub amp that you mention. Will that be a sub amp with all the feature or they are actually high watt power amp?

Sam, the Rythmik Audio offering is a full kit. It includes the servo plate amp and the 12" servo driver. They need to be used together for the servo function to work. If you already have a 10" non-servo driver and are just looking for a subwoofer plate amp, there are numerous offerings around. Take a look at Parts Express for some options.

BTW, "RMS" was not the brand of the servo plate amp, it was meant as "385 watts RMS" (ie. "RMS" watts not "peak" watts).

Rod · « **Reply #14 on:** 21 Dec 2004, 12:33 pm »

Sam you might consider getting in touch with Acoustic Concepts here in Melbourne. They are distributors of Adire Audio products who sell some very nice plate amps. I picked up the 250W version which had a crossover bypass switch along with the usuals, nice amp. I'm sure John would be happy enough to ship you one over, then again maybe Adire have a distributor in NZ already.

I ended up building a 127l sealed sonotube with an Adire Tempest 15" driver. At this stage its my DIY pride and joy. After a good time of breakin it's an oustanding sub (Q of .707) - its a very defined sound with loads of character but will make your ba*** tingle if you turn it up!

Seano · « **Reply #15 on:** 21 Dec 2004, 11:01 pm »

Redgum in Melbourne also do plate amps for subs. Not sure if they make their own, buy them in or mod them but they are Redgum branded.

And since Redgum are no slouch when it comes to their amplifiers then I can't imagine their plate amps are duds either.

One thing though I'm not sure if they actually sell the plate amps retail. Get in touch with them and ask www.redgumaudio.com

EchiDna · « **Reply #16 on:** 22 Dec 2004, 01:14 am »

from the redgum webpage:

RGSW8 Subwoofer Amplifier Plate
1500WRMS power output into 8ohm – 3000WRMS into 4 ohms - US$5990 each... and they kindly throw in delivery free

er...
correct me if I'm wrong, but there aint many complete commercial subwoofers that cost this much.... except for 'obscene $$' offerings like Krell's - but even then the Krell almost looks cheap at US$28k compared to the redgum amp... http://www.krellonline.com/html/m_MRS_p_MRS.html

SamL · « **Reply #17 on:** 22 Dec 2004, 04:00 am »

Thanks all for the info. Most appreciated.
Comparing the feature/watt/price, Rythmik Audio's A350SE is looking pretty good. http://www.rythmikaudio.com/nonservo_product.htm
Will see how much damage this Christmas have cost me. If all goes well, I might get a plat amp.

Cheers,
Sam

DSK · « **Reply #18 on:** 22 Dec 2004, 05:42 am »

Quote from: SamL

Thanks all for the info. Most appreciated.
Comparing the feature/watt/price, Rythmik Audio's A350SE is looking pretty good. http://www.rythmikaudio.com/nonservo_product.htm
Will see how much damage this Christmas have cost me. If all goes well, I might get a plat amp.

Cheers,
Sam

Sam,
If you haven't already, email Brian Ding at Rythmik with details of your driver & system and what you are trying to do. He is very helpful.

Cheers,
Darren.

SamL · « **Reply #19 on:** 23 Dec 2004, 09:03 pm »

For those in US who wanted more power (500w) and feature (a long list) with good price ($239).
Take a look at http://www.oaudio.com/500W_SUBAMP.html

p/s only for 120v main.

Have fun,
Sam