Can we start a thread for folks who run a SET amp with a subwoofer or two?


I moved down a pathway that was an offshoot from the mainstream of this hobby-a single end triode 300b amp.  So what I got with a SET was more than I gave up.  But bass lacking can be tough to live with. A brought in a couple of subs that took CONSIDERABLE tuning experiments, measurements, and ultimately following my ear.  

Who has experimented or uses a subwoofer or sub bass condiment with a low powered SET amp? 
jbhiller
If you have excellent SET amp like Line Magnetic 508 or Silbatone, then you can get tight and powerful bass out of SET.

Or you can try Arion Apollo system which can be driven by 3W SET amp with 105 db/W supplemented by subwoofer.

https://forum.audiogon.com/discussions/105db-w-high-efficiency-speaker-suitable-for-low-power-set
Years ago I had a pair of Omega Alnico 8 XRS with a pair of Omega Deep hemp subs. My amp was a highly modified 8w 300b Antique Sound Labs AQ1005 and ANK M3 preamp. I wired the subs using a second pair of speaker cables for the amp to the speaker inputs on the sub amps .

It took a while but I was able to get the sound pretty well balanced at my listening chair. Then I purchased a Dspeaker Antimode 8033s (dual sub version) and the bass improved dramatically but still had some integration issues since I had to split the signal from the preamp and use the RCA outs and ins on the 8033s. Later I purchased the Dspeaker Antimode Dual Core which did a better job with the bass and integration, but still not perfect. I have a friend who purchased the latest Dspeaker X4 and integrated his horns with subs seamlessly. The X4 will is an amazing product but comes at a high cost in the $4000.00 range.

Since then I sold the Omega XRS and subs and now have a pair of Charney Audio Horns with ANK 8w Interstage Monos and ANK L4 modified preamp. Charney uses the Tractrix theory to build his rear loaded horns. I have listened to his complete line and can say that no sub is needed! The six inch Companion with Omega, Lowther, or Voxativ drivers are magical with bass that’s pure and low. Move up the line and the results increase exponentially.

Don’t want to hijack the thread but I found that pure engaging sound can be had in the SET amp category with the right speaker. No need to augment the low end and use a lot of expensive high tech gear to do it.

https://www.underwoodhifi.com/products/dspeaker
http://charneyaudio.com/
@jbhiller,

Thanks for starting this thread. I have recently acquired 40W SET mono’s to mate with Canterbury’s. While they are quite adept in driving my 96db efficiency speakers, I do miss the sub at times. 

IMO, no tube amp or speaker can come close to pressurize a room with low bass the way a subwoofer is capable of. 

Would you mind listing your speaker/sub and amp setup? I will be looking into adding a REL sub in near future. I have past experience with B1’s and regret selling my pair. 
I lived with my Omega Super 3i Monitors for about a year before adding a DeepHemp 8 Subwoofer. As much as I enjoyed the Super 3i's sans sub, I really missed what good bass brings to the mix. The sub is wired to my 2 wpc Decware SE84UFO via speaker-level connections. The Omega sub is, of course, a perfect mate to the speakers and once I got it dialed in .. well, I'll just say it was well worth the cost and effort.
@lalitk, I built an Elekit TU8600 300B amp with substantial upgrades (Takman resistors, Mundorf caps, Lundhal power transformers).  My source is either vinyl or Tidal streaming.  In vinyl, I use a Technics 1200 GAE, Manley Chinook phono pre, and an Audiotechnica ART9 MC cartridge.  With Tidal, I pull the stream through a Bluesound Node 2 and feed it to a Doge 7 tube DAC or an NAD M51 DAC.  I also use a Schitt Freya as a control/preamplifier because the Elekit only has one set of RCA line level inputs.  My loudspeakers (in the SET amp system) are the newly released Klipsch Forte IIIs.  I have decent cabling but nothing crazy (Mogami speaker wire, soldered DIY to Cardas spades, and Chord RCA cable, several DH Labs cables (RCA and digital).  

For the subwoofer, I'm using an REL T9i.  It's dialed in very light and smoothly so as not to interrupt anything.  I've set it up with software and a special mic, BUT it always sounds better set by ear using tracks like Neil Young's "Out on the Weekend"--whereby I tune the sub to the kick drum to make it sound as resonate and real as I recall from playing music with others.  That track gets me closest to proper than other setup methods.  
+1 on the Line Magnetic reference above.  I was looking at them last week and was very very tempted just to give it a try.  

I should also note that even though my speakers are upper 90s in efficiency, I have a big room (well, big for me and bigger than I ever dreamed)--it's 15' wide by 23' long with 10 foot ceilings.  The acoustics are really nice without alot of "nodes".  

I should also note that when I use a Primaluna Dialogue HP integrated or NAD m22 Masters amp there is no need for a subwoofer because there's so much grip on the large drivers.  But 8 watts a side is a little light for this room.  I don't like to listen that loudly anymore and prefer the accuracy and romance of the 300B SET.  But the REL brings everything into focus.  If I put decor over it or obscured it from view somehow I don't think anyone would say, "oh, I hear a subwoofer".  It's set to do a vanishing act and I really use it to tune the room as opposed to pounding out bass or what have you.
PS I wish Elekit would make 300B monoblocks. I'd buy and build them right away.  
@jbhiller, 

You have a very nice system. Thanks for sharing! 


IMO, no tube amp or speaker can come close to pressurize a room with low bass the way a subwoofer is capable of.
I have a set of Classic Audio Loudspeakers model T-3s. They employ two 15" woofers, one of which has a 22Hz free air resonance. They have no problems pressurizing a room with low bass without a sub. System efficiency is 98db and impedance is 16 ohms.
“a set of Classic Audio Loudspeakers model T-3s” 

And they are powered by? Amp specs please? 
I built Bottlehead 2A3's, Madisound BK-16's with Fostex drivers, super tweeters and added a Mirage SA-8 sub.  The sub makes it a party system.  Just add beer.
“a set of Classic Audio Loudspeakers model T-3s”

And they are powered by? Amp specs please?
I run them with an Atma-Sphere S-30 (a triode OTL with only one stage of gain) which can make about 45 watts into 16 ohms. The S-30 is full power to 2Hz so I run it full range on the T-3s. It literally can shake the house :)
I use 2 REL subs with a Dennis Had 12wpc Firebottle SEP...works great, although I have to pile up the REL cable spades on the speaker posts...no strain on the amp though due to very high impedance with the RELs, and bananas for the main speakers (99db 8 ohm Klipsch Heresy IIIs) get the mojo to the mains.
I guess I qualify. I run a pair of Avantgarde Duos which have an integrated powered woofer system that takes a high level signal from a jumper cable from the mid horn. That horn is fed by a pair of Lamm ML 2, which are 18 watts, not exactly flea power, but still SET. (the tweeters also get their signal from a jumper cable from the mid horn). I augment with a pair of subs, 15" sealed box, dialed down fairly low, and have also used the DSpeaker 8033II to help tune the subs. Those are not fed by the SET amp, but are also self-powered and take signal via long interconnects from the line stage. Getting all to cohere took a little time in placement, phase adjustments, crossover point and loudness, but it works and the subs aren't really noticeable unless you turn them off. They do add some foundation to the system and make it sound more spacious. I don't consider the woofers that are part of the Avantgarde to be subs in the true sense, more just woofs.