Are REL the most Musical Subs?

@travbrow wrote:

I thought the OP was interested in a good option that’s available to buy, not a DIY approach thats out of reach to most everyone? It’s interesting to read about the possibilities with DIY though, but to imply any other way is lacking enough not to be worth it is wrong IME.

The thread title and OP’s "... but was wondering what the current thinking is with subs" to some degree - and for good reason - opened a can of worms with regard to whether or how musicality applies to subs. You’re right, 20cf. behemoths are likely not what the OP has in mind to pull off LF-duties in his home, but from my chair what aids overall realism/a sense of being emotionally involved (and thus "musicality") in sound reproduction is exactly a more all-out approach with DIY subs of higher sensitivity, incl. considerations on (outboard) amp choice, DSP, etc.

While a brand like REL is often lauded for making subs that integrate smoothly with existing main speaker setups, my focus is to point at mechanisms behind this that aren’t exclusive to or even accommodated by popular sub brands because of their smaller size and other, and so saying there are in effect more successful ways to have subs aid overall realism and musicality. I’m not implying the OP can’t be happy with a REL or similar solution, however... sometimes what you’re asking can produce answers that seemingly go off-topic, but are nonetheless in accordance with what’s being brought up.

@bdp24 wrote:

On the Rythmik Audio website designer Brian Ding provides exhaustive technical information on his subs. I believe details on the servo-feedback compensation for voice coil temperature variation and other functions may be found in the site’s Technology section. Mr. Ding is not your average hi-fi designer, having a Ph.D. in electrical engineering.

I’m sure Mr. Ding is very capable in his field, but I’m calling out the relevance of servo-feedback in a different context of subs. People seem to believe small subs are everything - and yes, subs from Rythmik, REL or other are small in light of the frequency range they’re called to reproduce - and thus that the likes of servo-feedback is a qualitative measure in every regard, when it isn’t.

I do own another sub I use in my recording studio. It’s a Mackie HR120 (no longer made) with 500 a/b watts, an EAT pro 12" driver and a 12" passive radiator. Good to a very real 19hz, and many more adjustment possibilities than most home audio subs. Look it up as it's interesting. 92lbs makes it a pain to move anywhere but I have schlepped it into my hifi rig and man...what an effortless bit of woofing it woofs. That said, it’s unnecessary (one of the RELs gets into the low 30s) and the 2 RELs work so well that I’m happy as a clam in the sand with those things. Like I said...bought used el cheapo and I pat myself on the back and feel slightly superior for my sensible taste. You could do the same with your back, but don’t touch me. I’m sensitive.

@lono24 Sorry to hear about those reliability issues, I get that. From the ULD to the DD Plus my only issue was a faulty IR receiver on a Plus. They repaired it for free along with a new remote and well out of warrantee.      

For Velodyne it wasn't noted until the early 80's release of the DD series. Sadly, it seems you may have overlooked the About Room Placement and Tip sections on pages 22-23 of the User's Manual describing the "first step" which would have eliminated the trial and error and vastly improved your DD's presentation.    https://velodyneacoustics.com/pdf/digitaldrive/DDManual.pdf

You were just one model away. The completely redesigned DD Plus provided foolproof twenty minute Auto/Manual EQ room optimization for dummies like me. In the User's Manual on page 25, again the first step out of the box, the "crawl test". Manual adjustments were amazingly simplified with the unreviewed Frequency Response and Parameters Screen function of pages 10-11.  http://www.velodyneacoustics.com/.webloc

Regardless of the vast differences in our rooms and systems and my own in home comparison with a $9K Studio III, I'm certain had you properly positioned the DD's and used low frequency test tones played through your mains and adjusted the DD-18's accordingly you would have returned the sub-bass speaker. 

I'm a hack hobbyist and its clear what led to your subwoofer dissatisfaction, again, I get it. In my experience as a Bassist, due to their rolled off -6dB I respectfully disagree with your final statement. As with most things in this adventure your personal satisfaction is what matters in the end. All the best. m

Dud totally...totally 

@sounds_real_audio 

why are REL ‘duds’?