Axiom Home Page Forums General Discussion Home Theater Setting up my subwoofer

I have an axiom sub, I'm not sure what the model number is as I don't see it anywhere.
I'm trying to set it up properly and I noticed on the back there is a switch that can be set to audio or video. I think it's safe to assume that audio would be better for listening to music and video would be better for watching movies. I was just curious if anyone knows what is actually different between the two settings?

That must be an ancient sub. The new subs don't have a setting like that.

I don't know but if I had to guess, the audio setting engages a rumble (subsonic) filter. This filter stops low frequency noise that is transmitted via a record player from playing through the sub. This type of noise arises from vibrations due to trucks, bombs, zombies stomping around, etc.

The movie setting by-passes the filter because movies have those low frequency effects built in.

If I had to guess it's at least 10-15 years old.
I've owned it for about 10 years, my brother owned it for a while before that and he bought it from a co-worker who I don't know how long he owned it.
To date it's never disappointed me so I have no reason to upgrade just yet

I suppose there's no point informing you the latest subs may offer a more rewarding experience.

Seriously, night and day difference! I am loving my upgrade to the new EP600, best purchase ever! The old 350 was great, but man I love this 600!

Yeah, I think I'm going to upgrade my twin walnut 500s to twin aged walnut 600s.

Mojo, the white piano finish with aluminum woofers looks kinda futuristic... it's BAD ASS (yeah i've been watching Cobra Kai on netflix, lol) I guess I need to add pics at some point.

Thanks for the responses.
I believe you that new subs are better but I would never hear the end if it from my wife if I bought a new sub.
The sub is more than adequate for my needs. When I watch tv it's typically after the kids are in bed so I can't turn the sub volume up as much as I would like anyways.
I have a couple of "newer" subs in my basement setup but for the last three + years I had the volume turned right down. This weekend I tried using them but have been having issues getting them to work so I can't even say if they are any better than my old axiom sub

Yeah, if I lived in Florida, by the water, my entire system would be piano gloss white just like my luxury super yacht parked out front.

Ya know Mojo ... If you traded in that yacht for a Lear ... you could visit Ian and co when ever the urge strikes ...
Just sayin

Not right now rrlev, I tried, covid has borders shut down! Had to put the lear back on stand by, such a shame. no where to go... guess i'll listen to my M3's.

I'm sure Ian has had enough of me already. LOL!

The Dwight airport (CNF8) is going to be a bit tight for your Lear, your are going to have to use the Muskoka airport (CYQA). If would be great if you could drop by, AND you can save the shipping on those new EP600s; it is all upside to get that Lear!

Back to the original question, the audio / video switch is what we used to call today's boost switch. The video mode has the boost on.

Except paying for the fuel, maintenance, storage ...
(but then again a super yacht's cost of ownership ain't cheap either)

I think the best I can do is drive my 41 year old bLuLu a few thousand miles to Dwight. Second best is to drive my 14 year old Mazda.

Audio rich, transport poor ... at least you have your priorities right ...

LOL... the first search hit I got for CNF8 was an advertisement for private jet charter with what appear to be auto-generated web pages for every airport in the world.

The associated photo shows a business jet, paved runways, and what is presumably a couple of happy passengers (or maybe a happy flight crew, not sure).

https://www.flyvictor.com/en-gb/private-jet-airports/dwight-airport-cnf8/#/

It's worth looking up the airport on Google Maps. You have to zoom out a bit to see the runways, but its a winter shot and makes it look like the airport is in the middle of a big ski area.

Its a grass field airport ... had a look when Ian mentioned it.
Reminded me of the field I used during a 3 week course in glider flight (ancient history think late 70s)

Rich, are you happy with your 600v4? Everyone else happy? I'm planning to upgrade my two 500s, that are flanking the actives and fed by the DSPs, to 600s (below).

How many other sealed subs reach 12Hz anechoically? I know of only two others and one is the 800v4.

I think the JTR Captivator is the only other sub on the market, that can do such frequencies. Mind you that is a 15 or18 incher.
Would another 800 be enough for your needs/wants?

Mojo you should consider another 2 or 4 ep500. I’ve been reading / watching videos about subwoofer line arrays. REL is the obvious name that comes up with sub line array but I don’t see why ep500 couldn’t be used. The sub array is an interesting concept in a 2 channel setup.

Plus I know you like stacking things that are axiom.

I guess i should say it’s a bit more complex then just stacking them. The way I understand it is each tier manages a separate section of the bass frequencies. The floor tier the lowest frequencies , mid tier mid bass , and the top tier is supposed to be de coupled from floor entirely for the intangibles and room feel in the air, so to speak.

So I guess just stacking them is not going work without spe cialized mounting and crossover control.

Could this be managed in an active setup with specific frequency response with dsp control for a 3 sub bass line array added to the lfr1100? With left and right systems in an active individually amplified 3 unit bass line array this would be a RADICAL way to finish off an active lfr1100 system.

Ok Ian, get to it!!! Mojo is waiting to stack em!

The Captivator only goes to 16Hz anechoically. Paradigm is the only one I know of that can go to 12Hz. Apparently it can do 8Hz. It's also 13 grand!

Kodiak, the 500s don't help. They're "only" good to 18Hz. Adding 500s increases SPL and, depending on placement, can spatially flatten response but cannot reach lower.

What you are suggesting about sub arrays could work. Heck, you could have one 600 for each Hertz between 10 and 80 Hz. LOL!

The short answer is I'm happy. I'll eventually do some measurements ... but ... it will have to wait till I get back into the audio mode.

I currently have two 600s set up off the active DSP place just inside the LFRs (like your 500s)
The other two are set up on the side walls and are being driven by the AV8805's sub outs. I haven't really played with optimizing placement as I have a lot of construction material in the way (and moving them around is a pain). Plus, level wise I'm not sure If I set them up perfectly ...

With the LFR subs I measured the SPL at the listening position and raise the sub volume till I noticed a change. On the side subs I played white noise and set the volume of each side sub to measure the same. Then using the receiver's control raised and lowered the both side subs playing together to hit the same SPL as the fronts. After which I checked the levels by ear to see if they were far off ... kind of hard to tell in most cases.

I'm thinking of redoing the DSP sub levels by manually generating some frequency sweeps (say from 100hz on down). Now I can play the LFRs and set the sub levels to best fill in the LFRs low end ... what do you think?

You may have a better way of doing this ...

Good to know about the 600s.

I don't know what the correct way is of setting up multiple subs. I'll try to summarize what I did. I used logic but I'm not sure if my logic is logical. It sounds good. Maybe it can sound better if I was Trevor.

The essence of this is that I set up each active and its 500 individually so that they both sum equally to 73dBC at my MLP. The reason for 73dBC is that I sometimes use the "double-bass" setting on my Onk. This routes the left and right channel bass to my 800. That gives a nice boost at my MLP.

A. Preliminary steps

1. Dedicate the 800 to the .1 channel

2. Turn off the 800

3. Set the actives to full range

4. Set each 500 to 40Hz.

5. Set both 500 gain knobs to half-way

B. 500 phase adjustment

1. Turn on the left active and 500. Ensure the right 500 is off.

2. Play a 40Hz tone. Vary the left 500's phase knob until the SPL peaks at the MLP. I could have used a friend's help with this but I didn't want to skew the response so I used binoculars. LOL!

3. Shut off the left active and 500 and turn on the right active and 500. Repeat step 6 with the right active and 500.

C. 500 gain adjustment

1. Shut off the right active and the right sub

2. Play pink noise. Set the left 500 to 70dBC at MLP. Turn off the left active and 500.

3. Play pink noise. Turn on the right active and 500. Set the right 500 to 70dBC at MLP.

4. Turn on the left active and 500. Play pink noise. Measure the combined SPL from both actives and 500s at MLP. If not 73 dBC, incrementally adjust each 500 to reach 73dBC.

D. 800 phase adjustment

1. Turn on the actives, the 500s and the 800. Set the 800's gain knob to 1/4 way.

2. Play pink noise. Vary the 800's phase knob until the SPL peaks at the MLP.

E. 800 gain adjustment

1. Shut off the actives and 500s

2. Play pink noise. Set the 800 to 75dBC at MLP.

Well don’t know about the phase stuff ... I just kept mine at 0
But if you set the subs to be the same volume as the fronts ... your boosting the base (which given my hearing might not be a bad thing).

I‘m thinking that maybe a way to match the sub Level to the LFR is to
1. meter at the MLP, set the DSP crossover out of the way and play a 100hz tone with the subs level set at 0.
2. Now start raising the sub level till you see a change in SPLs at the MLP
3. Back off the sub level so it drops to the original LFR alone level.
4. Set the DSP crossover to 40 or what ever you think is right.

Think that works for match the subs off the DSP. For the subs off the receiver/processor I’d set them to the same level relative to each other, then repeat the same sort of thing raising the pair to match the LFR

Phase is important. All drivers have to be in phase alignment otherwise they are working against each other.

Each active and 500 pair is gain-adjusted simultaneously. See step B1.

Your way of adjusting would work with a 40Hz tone if that's where the cross-over to the LFRs is.

I’d have to think a bit about phase as how the pressures add is dependent on frequency and location.

Yes. Phase response is a function of frequency and position. It can never be perfectly compensated.

Geeezus! Grandpa! RESPECT!

Yeah, time has a way of doing that ... have to buy myself a rocker for the front porch.

Do I get a front porch when I start to creak?

Here are the pics. Anyone considering an EP500 should look at this pics. Kinda has a Miami Vice feel to them. The EP600 kicks hard where is matters most.

Do you feel the mid-bass? Is the switch flat (linear) or boost?

I like that white BTW. Doesn't suit my decor but that don't mean I can't appreciate it.

The phase switch is easy after you've found the best place for your sub {crawling, flattest response spot. Flick the switch go back to your spot listen which ever one is loudest without muddy, that's what you want keep it there. Ps test both or all of them back and forth one may be better. But the louder is recommended.

What’s hard about setting sub levels and phase by ear is that it requires a VAL&P device. (Voice activated levels and phase) ... In my household those are hard to come by .... a definite lack of willing volunteers.

Polarity and phase are not equivalent. When crossing speakers over to a sub, the speakers and the sub ought to be in phase at the cross-over frequency. Otherwise amplitude is diminished and the output may be characterized as slow or sluggish.

This is what's got me concerned about Axiom's ported subs. They don't have a phase control like the sealed subs.

Measuring at 40Hz is fine as long as your meter is reasonably sensitive down that low.

Rethinking ... Single tones may not be the way to go since they assume that the LFR and sub are perfectly flat ... Probably best would be playing white noise filtered thought something like a 120hz low pass.

For dialing in phase, what's important is not the absolute SPL magnitude but rather the relative magnitude. Therefore the accuracy of the meter and linearity of the LFR and sub don't matter. What matters is repeatability. Meter repeatability isn't an issue and as long as the levels are kept low, driver coil compression isn't an issue either.

I should start a thread on measuring phase and walk you through it.

Measuring spl at a given frequency can get you phase aligned, but you would be extremely luck to also be in time with the same cycle.

You need to measure using a difference tool or transfter function tool to time align,

Mojo’s breakdown is terrific btw for his setup routine. Not how I would do it, but pretty clever with your sub setup. I think speaker outputs to subs hancuffs your options a bit, but I get your strategy for sure. Pretty well thought out. Thumbs up!

It would be interesting to hear what the difference dialing in phase sounds like. What results are you expecting ... room smoothing? Better efficiency? .... Also how to do it with multiple subs.

Like clean bass without overhang. Best outcome is you can run the sub level much hotter and it still sounds incredibly clean and sharp. One of those tweaks that makes a big difference with no cost.

That's a great description, Trevor. What a difference between my 600v2 and v4 subs. I can turn them right up with no loss of satisfaction. The v2 couldn't satisfy me no matter the volume.

Yeah Mojo, the mids lows on the 600 are why I love it so much. I was able to audition a 16" sub which was fun but it was a like laying in one of the those 25 cent Motel beds that vibrate... it's only good at one thing. This 600 for me is like a modern day massage chair lol. It plays best where it matters most and can still dive deep.


Is anyone else on here using REW? I've just figured out full range speaker measurements, about to start working on sub measurements. It's really good fun to compare science (SPLs) to what we think sounds good. Using REW has really made me work my room more than work my speakers (position & EQ), in fact, getting new windows now, lol, along with window treatments, and working on solutions for the fireplace.

Wow! You are really getting into this. How cool.

Trevor, look forward to your methodology on aligning phase ... I’ll have to try it and see if I can hear the difference. In the mean time I’ll google around and see if I can find some info on what’s happening and why it matters.

Download this app and purchase the Transfer function plugin. Round trip is around 100$ I think. I can walk you through it after.

https://apps.apple.com/ca/app/audiotools-db-sound-audio/id325307477

Here is the Transfer function Tutorial vid

https://youtu.be/Fbk9QLEwdZU

I have learned more from using this software and understanding sound than $100 could ever advance my system for sure (spent on gear or other items or tweaking by guess or by ear.)

You will need a long 1/8” jack audio cable to use to send test tones from the app to your equipment. Like this.

https://www.amazon.com/AmazonBasics-3-5mm-2-Male-Adapter-Stereo/dp/B01D5H8M18/ref=sr_1_3?crid=1SMKW2F4P31XS&dchild=1&keywords=1%2F8+to+rca+cable+25+feet&qid=1601507054&sprefix=1%2F8”+to+rca+cable%2Caps%2C185&sr=8-3

There may be other software suites to do this, but I have used this many times in different setups and it is fast and reliable. And just works.

I can now phase align at the cross-over by ear. My ear is now an acoustic synchroscope.

Unfortunately I only have this super-power in my right ear. I have to now train my left.

I'll be truly proud when I can do this to any tune rather than a sine wave.

If you like it leave it.

I bought AudioTools when you last mentioned it ... have not tried the transfer function yet ... actually haven’treally gone much further then the SPL meter and RTA/FFT.

I’ll check out the Xfer video tonight ... thx

I need something like AudioTools for Android or Windows. I've been using my ears, an SPL meter, paper and pen. It's about time I embrace modern technology and compare it to the paleolithic tools I've been using.