Axiom Home Page Forums General Discussion Technical Questions M60 Enclosure

Regarding the Bryston A3, it is an M60 with HP drivers, more bracing, black drivers and a 20 year warranty through dealers. Note it achieves 5Hz better low end performance compared to the M60 with standard drivers.

I downloaded the manual for the Bryston A3 at the link below. The impedance and listening window curves are slightly different between the standard M60 and the A3. The standard M60 alpears to be a tad mote linear between 100Hz and 200Hz. Low frequency performance doesn't appear to be any different but I'd bet at higher SPLs the HP woofers in the A3 perform better.

https://bryston.com/passive/a3/

The A3 comes at a 30% premium over the M60HP with ICW. That 30% gives you more bracing, black drivers, a 20 year warranty and dealer accessibility. What it doesn't give you is Axiom's loyalty discount, trade-in program and access to more finishes.

The access to more finishes at no further cost is worth it right there.

I read the manual and saw one spec I haven’t seen before , max SPL. The A3 has a 90 db max SPL. I get what it s saying but at what distance away from the speakers and what level of distortion? Anybody know what the parameters are of that spec?

Edit: answered my own question. I dug deeper into the specs. Max SPL is measured at 1 meter. No distortion percentage is given. The manual says 90db for the A3 but the brochure chart states 111db. That’s plenty loud even 15 feet away!

Bryston has screwed up the specs on their speakers so bad, it's actually quite sad. The specs are all over the place depending on where you find them. For anyone who wants to know about Bryston speakers, talk to Axiom.

90dB is not the max. It is the in-room SPL with 1 Watt input at a distance of 1 meter. Distortion is virtually nil at that level across the entire specified frequency band.

As for max SPL at 1 meter, it's about 110dB for the A3 before dynamic and thermal compression kick in.

Yeah. Pretty important to keep the specs tight and in order. Just looks bad.

The Model T active plays at 118db?! (at 1 meter away) that’s nuts!The LFR actives must be able to do that too no?

That’s incredibly loud to still have clean and clear sound.

Even 110db for the m60 is impressive.

The actives are specified at 124dB continuous and 130dB dynamic in-room at 1 meter. I measured 116dBC peaks at 10 feet away and I had not yet reached amp limits. I couldn't tell you if that was audibly clean because I had ear plugs and my shooting muffs on. The HP drivers were visibly distressed though and I smelled coils and adhesive. I also smelled 1000 and 1500. I didn't want to push further.

So those specs I gave you above are likely the absolute physical limits. Distortion sets in before those limits. In any practical residential application, there really are no limits for the actives.

Edit: I can't see the T playing cleanly at 118dB. It won't destruct though.

That’s incredibly loud and entirely non practical!! But to know when you’re playing really loud at 105 db or something and still have the dynamic overhead to not compress is amazing.

Ok now this is dragging the thread off topic, however, this is where chat led us…..

How does the type or quality of recording impact the dynamic overhead when reaching those upper limits? IE: even though your system may be able to handle it the recording may not have ability to squeeze enough dynamics out of its self to feed the system. I’m kinda making this up as I go so please correct me but it seems there’s a limit to the information in the audio.

Also, why do you think the Bryston Active T won’t go clean to 118db but perhaps the LFR actives will? Better DSP? Or are both susceptible to breakup at those limits , DSP notwithstanding.

I don't know about the active Model T. I was talking about the passive. In Bryston's brochure, there is very little difference in the frequency response curve between 90dB and 110dB. That is actually incredibly impressive. It means that for typical listening (75 to 80dB nominal), a listener is afforded 30 to 35 dB of pristine dynamic range. Even if you want to liven it up a little (say 90dB nominal), that's 20dB of dynamic range. Even high quality recordings top out at 18dB between the quietest and loudest sounds. So the Model T, is for all practical purposes, a dynamo.

Based on the data presented in the brochure, the passive Model T can hit around 110dB before audible distortion kicks in. It's advertised at 118dB max which means that is likely close to some destruction limit.

The bottom line here is application. Like Ian has always said, if you are throwing parties and your space is large, you need gobs of SPL. For typical home applications though, even the puny little M2s offer adequate dynamic range at 10 feet MLP particularly when teamed up with a sub and crossed at 80Hz.

I just downloaded the Model T Active brochure and that too specs it at 118 dB SPL max. That can't be right if the passive is also 118dB. The crossover in the passive robs the drivers of 3dB of SPL so I'd expect the active to hit 121 max.