Subwoofers of AXPONA 2019

[shadyJ]

Even though AXPONA focuses on two-channel setups, there were still a fair number of subwoofers on display at the 2019 show, and it may be a sign that audiophiles are becoming more receptive to the inclusion of subwoofers in their systems. AXPONA is also growing increasingly popular among the home theater crowd where subwoofers are nearly mandatory. In our final segment of our AXPONA 2019 coverage, we looked at a selection of the subs that were exhibited at the show. These subs range from affordable and reasonably sized to insanely expensive and gigantic. They run the gamut from high value to luxury brands. There is a sub for everyone at AXPONA 2019, so maybe one of these subs would be a great fit for your system. Read our coverage of some of the subwoofers that we saw at AXPONA to see what could take you to bass nirvana.

​

READ: Subwoofers of AXPONA 2019

 

[MandM]

Quote "the Q-Subs proved not to be invulnerable when the Magico reps allowed a guest to play an organ recording that had some low-frequency notes that managed to bottom out all of the drivers"
I'd be seriously embarrassed if I was a Magico rep. Guess you could say that was a 36k oops!!

 

[shadyJ]

Quote "the Q-Subs proved not to be invulnerable when the Magico reps allowed a guest to play an organ recording that had some low-frequency notes that managed to bottom out all of the drivers"
I'd be seriously embarrassed if I was a Magico rep. Guess you could say that was a 36k oops!!

It was a $70K oops since there were two subs. They probably are OK, but I wouldn't blame that one a rep. That is a design flaw.

 

[Matthew J Poes]

It was a $70K oops since there were two subs. They probably are OK, but I wouldn't blame that one a rep. That is a design flaw.

It’s my fault really. I asked about how the sub was designed and the rep told me something about how it was eqed so it was flat down to like 10hz. I misunderstood him and thought he was saying it was limited to the output at 10hz. Turns out there is no limiter, just a lot of eq.

What I find sad is that I doesn’t take a lot of genius to setup the DSP correctly on something like this. I am basically a DIY enthusiast. I don’t manufacture anything and I have no formal training in DSP. All of my subs are setup with two types of protection. First is dynamic EQ. This applies a bell or shelf cut filter at the frequency and Q that matched the excursion limit of the driver. Basically by the point at which the driver becomes non-linear I am cutting output only at the frequencies that cause the non-linearity. Second is an overall limiter that prevents the amp from sending sustained amounts of power to the driver that it can’t handle. These two types of limiters make it so you can’t overdrive the sub. It is what most pros do and it is what Magico should have done.

 

[Matthew J Poes]

@shadyJ you should have mentioned my talk at the end on subwoofer integration. Clearly the key to audiophile subwoofer acceptance is going to require appropriate integration.

While I’m teasing a little here, I do think that what I presented on has merit for sound quality. Even if the research I found suggesting that just 2ms of LF group delay is audible is wrong, I know of no conventional wisdom that ever suggested that 2,3, or even 10 periods of group delay was inaudible. These fall well into the problematic by any measure category. My talk showed a totally reasonable pre-optimization scenario in which YPAO caused 2.5 cycles of delay at 100hz down to 30hz and it only go worse from there. My optimization reduced it to 0 and was nothing fancy.

I think that when audiophile or sound quality zealots ,or whatever we call them, complain about sound from subs it’s often because the sub has been poorly integrated. The sub is too loud, crossover too high, new modes were excited and not eqed our, and...maybe...a lot of LF group delay was added.

 

[Verdinut]

I don't understand why Dayton did not use their RSS390HF-4 subwoofer drivers instead of the RSS390HO-4's in their enclosures.
The HO version which they use is for Automotive applications and for small cabinet use in small rooms while the HF is for larger rooms and can be used either in a seal or ported cabinets and is for Hi Fi use.

In my opinion, the HF version is closer in design to the other subwoofers which were shown at the Axpona exhibition.

 

[Matthew J Poes]

I don't understand why Dayton did not use their RSS390HF-4 subwoofer drivers instead of the RSS390HO-4's in their enclosures.
The HO version which they use is for Automotive applications and for small cabinet use in small rooms while the HF is for larger rooms and can be used either in a seal or ported cabinets and is for Hi Fi use.

In my opinion, the HF version is closer in design to the other subwoofers which were shown at the Axpona exhibition.

Did you see the size of that enclosure? The primary reason to use PR’s is with drivers suited to small enclosures. Ports would add so much volume to the enclosure it would defeat the purpose. They wanted to offer a high output subwoofer in a small form factor and the HO is better suited to that.

 

[Verdinut]

Did you see the size of that enclosure? The primary reason to use PR’s is with drivers suited to small enclosures. Ports would add so much volume to the enclosure it would defeat the purpose. They wanted to offer a high output subwoofer in a small form factor and the HO is better suited to that.

However, the use of PR's doesn't have to be limited to drivers suited to small enclosures. I agree in that an enclosure for the HF version would have to be substantially bigger than for the HO model. But you need a rather large listening room if you want to drive those subwoofers to their linear excursion limits, and cabinet volume is less of a concern.

 

[Verdinut]

I don't think that most of the subwoofers exhibited at Axpona were designed to be operated in a small room.

 

[hmscollingwood]

I've checked out the Aurasound and it's 800 WRMS. 3200 WPeak (+6db). Which is fair enough for a 4" flat-wound, aluminium wire, glass fibre voice coil. Standard for high power PA speakers of the best quality, like Electro Voice, JBL, Cerwin-Vega. The organ pipe speaker bottoming, commonly caused by overdriving and underdamping, is typical of overenthusiastic demonstrators on an ego trip, as no loudspeaker can be expected to approach the output of a cathedral organ, or monster concert organ which can have anything from 10 to 600 horsepower (7.5-450Kw) blowers (600hp Atlanta). People expect a bit too much of relatively-small, round pistons.

If a person were playing a giant-organ recording at something approaching natural church or concert hall auditorium levels, which would require a wall of professional PA speakers to do true justice, then they need to be in a house at least 1/4 mile from neighbours, otherwise it's all very unnecessarily loud and uncivilised. Like your local yob, in his thumping subs with rattling windows and panels car, parked at the end of your street and entertaining the whole neighbourhood.

Alternatively, use audiophile headphones and stick bass pistons under your settee feet to get appropriate gut-wobbling 'special effects'.

All that antisocial stuff aside... I was a bit sceptical for many years about the argument for 'boom-tizz' speakers where a small bookshelf speaker was coupled with a sub-bass floor speaker. As I found out, after reading the wonderful article about the Rel Studio III installation, in Stereophile October 2004, the secret to 'open breathing' is to have suitably matching main speakers and adjust the rollover and placing/phase correction, so that the transition between the sub and main speakers is subjectively seamless. It also requires a degree of room tuning. Sometimes the sub is too big or too small for the room it is placed in. So many factors and a degree of experimentation to consider. Subs are, like their owners, a matter of individual taste and media preferences. Some people have the view that a sub should be a 'one size fits all'. Nothing could be further from the truth.

 

[Matthew J Poes]

However, the use of PR's doesn't have to be limited to drivers suited to small enclosures. I agree in that an enclosure for the HF version would have to be substantially bigger than for the HO model. But you need a rather large listening room if you want to drive those subwoofers to their linear excursion limits, and cabinet volume is less of a concern.

Yes but there is no point in using a PR when a port can be used. They are Lossy. The PR developed by Dayton is HIGHLY lossy. A PR is a suboptimal port, so why not just use a port. If the enclosure is already large you can make a better sub using an optimally designed port. The PR can’t compete.

 

[Matthew J Poes]

I've checked out the Aurasound and it's 800 WRMS. 3200 WPeak (+6db). Which is fair enough for a 4" flat-wound, aluminium wire, glass fibre voice coil. Standard for high power PA speakers of the best quality, like Electro Voice, JBL, Cerwin-Vega. The organ pipe bottoming is fairly typical as no loudspeaker can be expected to approach the output of a concert or cathedral organ, which can have anything from 200 to 2,000 horsepower blowers (Atlanta). People expect a bit too much of relatively small, overdriven round pistons. If a person were playing an organ recording at something approaching church or concert hall auditorium levels, then they need to be in a house at least 1/4 mile from neighbours, otherwise it's very uncivilised. Or use headphones and stick bass pistons under your settee feet to get appropriate 'special effects'.

All that antisocial stuff aside... I was a bit sceptical for many years about the argument for 'boom-tizz' speakers where a small bookshelf speaker was coupled with a sub-bass floor speaker. As I found out, after reading the wonderful article about the Rel Studio III installation, in Stereophile October 2004, the secret to 'open breathing' is to have suitably matching main speakers and adjust the rollover and placing/phase correction, so that the transition between the sub and main speakers is subjectively seamless. It also requires a degree of room tuning. Sometimes the sub is too big or too small for the room it is placed in. So many factors and a degree of experimentation to consider. Subs are, like their owners, a matter of individual taste and media preferences. Some people have the view that a sub should be a 'one size fits all'. Nothing could be further from the truth.

Right next door to the sub in question was a large number of 18” subs from JTR that would not have bottomed out with the same test material. The problem. Wasn’t the sub driver. Any sub driver eventually runs out of steam. It was the dsp setup in the amp. A commercial offering should be setup to protect itself. In today’s world that is easy to achieve. Even I can do it.

 

[Verdinut]

Yes but there is no point in using a PR when a port can be used. They are Lossy. The PR developed by Dayton is HIGHLY lossy. A PR is a suboptimal port, so why not just use a port. If the enclosure is already large you can make a better sub using an optimally designed port. The PR can’t compete.

I agree with you here. According to Vance Dickason, PRs have two important advantages over vents:
1. They eliminate vent colorations (such as resonant pipe sounds), wind noises, and the internal high frequency sound reflected out of the vent.
2. As already discussed, they are practical for small enclosures which call for vent lengths in excess of internal box dimensions.
On the downside, PRs have a steeper cutoff, less transient stability, a slightly higher cutoff frequency, and greater overall losses (Qt) than vented designs.

 

[hmscollingwood]

Sounds as though the 'sound engineer' didn't understand his craft or run a proper sound check? I hate DSP settings and regard them as Harajuku 'Japanese Cosplay' for ignorant 'gai jin' tourist audiences. I prefer a 'straight wire with gain'.

Speaking of 'real DSP'... Have you experienced 'SENSURROUND' in the original version of the film Earthquake (1974)? Probably long before your time. I have. Outside on the pavement waiting for the next showing, about 30 yards down the queue for the Empire Leicester Square, London, in the middle of the pedestrianised precinct, we felt what seemed like a London Underground train passing below us. SENSURROUND, by Westrex, was a very complex intermodulation of several low-frequency and subsonic frequencies which had the effect of causing the rows of seats in the auditorium to oscillate like a bass string when it was switched on, during special timings during the film. (In initial Chinese Theatre, Hollywood, test screenings, they took out the whole original exponential horn, midrange effect, because the audience couldn't stand 20 kilowatts <125db of deafening explosions, etc. They also put up netting above the audience which frightened them even further - with the possibility that the ceiling might come down). Lots of women in the Empire auditorium screamed during this sonic earthquake-effect experience. It was a bit too much for many people (110-115 db of rumbling, gut wrenching bass). Sadly, the DVD doesn't do it justice. It was also used in and The Battle of Midway (1976) and Rollercoaster (1977). None of which have been re-recorded with the Sensurround effect despite all being released in Blu-ray...

The trouble was that it was impossible for Sensurround to be staged in emerging multiplexes (apart from requiring huge 6ft cube subs, driven by 7-10Kw amplification, typically 4 in the auditorium, with 4 x 25" 600 WRMS Italian RTR drivers with 6" voice coils in each, as was the case with the Empire, Leicester Square, ) because it would interfere with other films in the same auditorium, such as The Godfather where patrons complained about the building shaking during a quiet part of their film. I saw one of these monsters, with air cooling like a single-cylinder motorcycle engine head, being re-coned in Wembley Loudspeakers when they were in Hammersmith - I could have bought it for £100 in 1979. If I'd only known... Blue Aran sell a similar Precision Devices 24 inch driver here in the UK for around £776 or neodymium magnet version for £856.