GR Research Open Baffle Sub for Quad ESL??

WFCkeyman · 2nd December 2020, 10:41 AM

Hello!
Anyone has tried the GR Research Open baffle sub for Quad ESL 57??

No high pass filter and just blend the sub with the Quad ESL to fill up anything under 40hz.

Thnaks!

WFCkeyman · 2nd December 2020, 10:42 AM

Sorry this is the pink of the GR Research open baffle servo sub

Servo Sub Kit 5

bentoronto · 3rd December 2020, 02:39 AM

Prolly good to keep the low freq signals out of the Quads. You'll likely be using an active XO.

Why open baffle - to match Quad shape or sound or size or....? My best "match" to ESL sound was a Klipsch corner horn that just floated great gobs of very clean bass all over the room, like a dipole does for treble.

I think motional feedback is really great. But I haven't seen information on how they do it.

B>

drewmc · 3rd December 2020, 04:45 AM

The GSR sub uses the Rythmik coil feedback servo control. It uses a secondary coil for sensing, and the coil output is used in the negative feedback in the amplifier. I have not heard them personally, but have all reports say they work well. Like all such systems the motion feedback limits the bandwidth.

I also recommend limiting the bass in the Quads. Play close attention to phase tracking in the crossover as I believe this is most important in achieving good integration. I am using a Harsh crossover configuration between my Maggies and the sealed box subs. I am also using a Linkwitz transform on the subs to reduce group delay and extend the response. The Rythmik amps have something like a Linkwitz transform built in. Adding the subs to the Magnaplan 1.7's really improved the depth and dynamics of the system. Using a phase optimized crossover helped the overall coherence and also the cleanness of percussive attacks.

bentoronto · 3rd December 2020, 01:24 PM

Custom-wound feedback coil seems a good approach. And everybody cranks up the bass to some degree of satisfaction.

But fussing about phase adds a new complexity to OPs task, popular as this topic may be at the forum everlastingly. Esp with panel speakers you get into spatial locations that make fretting about phase moot.

Ridiculous as it may sound to the wannabee-engineer, you can try reversing polarity to a sub or subs (as per the effective room acoustics strategy using some out of phase subs). Even reversing polarity, you may be hard pressed to decide which wiring is better. So if 180-degrees is hard to parse, then bits of degrees in a little narrow crossover freq band surely must be too.

B.

drewmc · 3rd December 2020, 01:38 PM

Yes, with a standard 2nd order crossover and no eq, it is frequently equally wrong regardless of the absolute polarity. Once the crossover is optimized, it is clear when it is reversed as you will have a suckout in the crossover region.

bentoronto · 04:00 PM

... till you move your head a few inches or the bassist moves a note.

drewmc · 3rd December 2020, 04:54 PM

I will agree, move out of the listening chair and it all falls apart. But this is true of the ESL 57 or Maggie anyway

2nd December 2020, 10:41 AM	#1
WFCkeyman diyAudio Member Join Date: Aug 2014	GR Research Open Baffle Sub for Quad ESL?? Hello! Anyone has tried the GR Research Open baffle sub for Quad ESL 57?? No high pass filter and just blend the sub with the Quad ESL to fill up anything under 40hz. Thnaks!

3rd December 2020, 02:39 AM	#3
bentoronto diyAudio Member Join Date: Jan 2008 Location: Toronto and Delray Beach, FL	Prolly good to keep the low freq signals out of the Quads. You'll likely be using an active XO. Why open baffle - to match Quad shape or sound or size or....? My best "match" to ESL sound was a Klipsch corner horn that just floated great gobs of very clean bass all over the room, like a dipole does for treble. I think motional feedback is really great. But I haven't seen information on how they do it. B> __________________ HiFi aspirations since 1957. "When the toilet paper of Experience is depleted, the backside of Reason goes unwiped"

3rd December 2020, 01:24 PM	#5
bentoronto diyAudio Member Join Date: Jan 2008 Location: Toronto and Delray Beach, FL	Custom-wound feedback coil seems a good approach. And everybody cranks up the bass to some degree of satisfaction. But fussing about phase adds a new complexity to OPs task, popular as this topic may be at the forum everlastingly. Esp with panel speakers you get into spatial locations that make fretting about phase moot. Ridiculous as it may sound to the wannabee-engineer, you can try reversing polarity to a sub or subs (as per the effective room acoustics strategy using some out of phase subs). Even reversing polarity, you may be hard pressed to decide which wiring is better. So if 180-degrees is hard to parse, then bits of degrees in a little narrow crossover freq band surely must be too. B. __________________ HiFi aspirations since 1957. "When the toilet paper of Experience is depleted, the backside of Reason goes unwiped"

3rd December 2020, 03:57 PM	#7
bentoronto diyAudio Member Join Date: Jan 2008 Location: Toronto and Delray Beach, FL	... till you move your head a few inches or the bassist moves a note. __________________ HiFi aspirations since 1957. "When the toilet paper of Experience is depleted, the backside of Reason goes unwiped" Last edited by bentoronto; 3rd December 2020 at 04:00 PM.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Open Baffle Dipole Bass for ESL's?	kazap	Multi-Way	31	24th August 2015 10:18 AM
Upwards aligned open baffle? ( pop box meets open baffle )	OllBoll	Full Range	3	28th March 2011 02:00 AM
Open baffle vs ESL?	Ridin '24'z	Planars & Exotics	63	30th December 2010 05:33 PM
Full range ESL vs ESL + sub	Jacobus	Planars & Exotics	18	24th September 2007 03:50 AM
CD player Drawer open close open close open close	qguy	Digital Source	7	23rd November 2006 09:58 PM


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

2nd December 2020, 10:42 AM	#2
WFCkeyman diyAudio Member Join Date: Aug 2014	Sorry this is the pink of the GR Research open baffle servo sub Servo Sub Kit 5

3rd December 2020, 04:45 AM	#4
drewmc diyAudio Member Join Date: Jan 2006 Location: Granite state	The GSR sub uses the Rythmik coil feedback servo control. It uses a secondary coil for sensing, and the coil output is used in the negative feedback in the amplifier. I have not heard them personally, but have all reports say they work well. Like all such systems the motion feedback limits the bandwidth. I also recommend limiting the bass in the Quads. Play close attention to phase tracking in the crossover as I believe this is most important in achieving good integration. I am using a Harsh crossover configuration between my Maggies and the sealed box subs. I am also using a Linkwitz transform on the subs to reduce group delay and extend the response. The Rythmik amps have something like a Linkwitz transform built in. Adding the subs to the Magnaplan 1.7's really improved the depth and dynamics of the system. Using a phase optimized crossover helped the overall coherence and also the cleanness of percussive attacks.

3rd December 2020, 01:38 PM	#6
drewmc diyAudio Member Join Date: Jan 2006 Location: Granite state	Yes, with a standard 2nd order crossover and no eq, it is frequently equally wrong regardless of the absolute polarity. Once the crossover is optimized, it is clear when it is reversed as you will have a suckout in the crossover region.

3rd December 2020, 04:54 PM	#8
drewmc diyAudio Member Join Date: Jan 2006 Location: Granite state	I will agree, move out of the listening chair and it all falls apart. But this is true of the ESL 57 or Maggie anyway

New To Site?	Need Help?
Register to Participate Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read