My new system

[Decadent_Spectre]

Imagine the size you will need for 20hz

If you build something like a horn then a 20Hz wavelength is about 56 feet, acoustic "theory" often says this is the least the path length should be, many people try to make a "compromised" version by making it 1/4th wavelength. I don't know the design for this box though as I have not seen the internals/diagram but if it's like a horn then for a "real" 20Hz design, the path needs to be 56 feet (about). If you make a compromised (as per theory only, it may be good sounding) design (as all horns in that go below 100Hz usually are) it will need to be about 14 feet. 14 feet can be managed in a "reasonable" box size with folds, 56 feet is hard to do.

 

[prem]

Above is the recommended design. Some guy on a DIY forum mentioned that the driver almost goes down to 28 hz and is pretty flat upto 18000 hz. I don’t know how true this is. Hence wanted to give it a shot.

 

[Decadent_Spectre]

IIRC for a simple reflex, about 4 times the size may (driver permitting) lower the -3db point by an octave. The posted diagram is not clear on the internal structure but appears to be a simple reflex cabinet if I read it right. I may be a little off on the numbers as I have not dabbled in the science for a long time but the basic premise is applicable.

Edit: In my humble opinion something like this may not benefit from a larger cabinet or more extension subjectively unless one likes low end and/or likes music with low end that is beyond the scope of the current cabinet.

 

[prem]

It is a simple reflex cabinet. You have a point. I get where you are coming from.

 

[Decadent_Spectre]

It is a simple reflex cabinet. You have a point. I get where you are coming from.

Most people don't realize but a system with a lower cutoff (especially a ported system) than the same system with a higher cutoff will often result in more "perceived" boom/slowness and bloat, this might be preferable and varies from person to person. The system may also measure to possess more phase issues and more "imperfect" impulse compared to the higher cutoff system. Now again these are not necessarily worse, but the character is different.

If you feel like a small experiment that will barely cost anything and is easily reversible, try plugging the port with some local foam (about 2" thick), the difference might not be preferable but it could be an interesting insight into two types of the same system. One sealed and one ported. The system with the foam (if done right) will essentially be sealed. Do note that if you choose to do this, make sure to operate it at low volume as excursion increases with a sealed system, also if possible, do simulate the excursion in a program to make sure it is safe with the power you will send to it. I will add the disclaimer that this is at your own risk, I understand the driver may be expensive and I can not be held responsible, I offer the idea simply for insight. Simulating it and only using at low power will be ideal. If you possess the ability to put a high pass then you should do so in case you decide to do it in accordance with the sim, as it suggests. I will note I did experiment like this and the results were interesting (subjectively) with some ports, both in a ported system and somethings a bit more complex. Both speakers and subs.

Happy experimenting, either this or the larger cabinet, or both.

 

[prem]

That it will get a bit bloated and sound a bit slow is exactly what I was told by others. It’s the reason I went with the aperiodic vent one.

Thanks for your insights. Appreciate.

 

[Decadent_Spectre]

That it will get a bit bloated and sound a bit slow is exactly what I was told by others. It’s the reason I went with the aperiodic vent one.

Thanks for your insights. Appreciate.

Most welcome.

Whoever told you this is wise, they understand the subjective difference typically found in some general aspects of design. They are also experienced and likely experiment, such knowledge usually comes from first hand experience. I used to think "lower cut off? what's the harm, more extension", now I high pass around 40-45Hz.

Good luck.

 

[prem]

Understood. Thanks once again.

 

[shafic]

I had them, Axiom 80, longtime back. I have tried with different cabinets. I realised that on increasing the cabinet size the bass becomes bloated.
If one goes for ulta big cabinets, room size has to be very big like concert hall.
This is my experience with Goodmans Axiom 80.
Regards

 

[Gerry_the_Merry]

Prem. What isolation under TT have you used? It will surely not be specific only to EMT I guess?

 

[prem]

The isolation is made by EMT. It’s specific to the 930 model. Similarly they have a specific one for the 927. And ditto with 950 too

This is the one for 930

EMT 930-900 shock-absorbing frame

EMT 930-900 shock-absorbing frame

www.jpvanvliet.nl

What I use is a replica made by Studiotechnik Dusch. It costs 2000 euros. The original is very difficult to get and costs about 3000 euros.

 

[square_wave]

square_wave, I don’t think my priorities have changed at all. I have always been clear what sound I want. For me the thrill is in experiencing different topologies to achieve the sound I am looking for. Be it multi driver or a single driver or a panel. Be it digital or vinyl. Be it SET or PP or hybrid or SS class A

I normally don’t change a component because I didn’t like it but it’s more because I want to experience something new.

In my present system what excited me was that I was experiencing an idler for the first time and also a single driver which supposedly can play full range. What piqued my interest in Axiom 80 was Vladimir Lamm claiming it to be the best driver ever designed. The amp was a fallout of what is likely to work best with the Axiom 80. The F2a11 tube was chosen because it was a fairly linear tube with good dynamics and good extension at both ends. This tube came highly recommended for this driver.

In my present system, it’s only the driver cabinet I will experiment with.

I guess I used the wrong word to express what I was thinking. I was meaning to say that how adventurous one can get if you keep evolving as an audiophile. I am yet to meet another audiophile who has traversed such a wide range while always maintaining the highest standards. I have seen people just buying a wide range of gear in such a haphazard manner and boasting about wide and varied experiences.

 

[prem]

square_wave, one thing I have realised over the years is once your ears are used to a certain quality, you cannot go down on that level. Parallel shifts are fine. So I need to be very careful that when I am replacing any component I need to ensure the quality doesn’t come down. At least the same level should be maintained. And that’s what’s been happening with me since I have been playing in broadly the same price range, I have only managed parallel shifts. To go to the next level, I would need a larger room for sure. And that’s not happening anytime in the near future. It only makes sense for me to buy better equipment, if I can manage a larger room. To me it’s all about letting the bass breathe. In my current room, anything below 40 hz is going to be an issue. Fortunately for me I don’t listen to music which demands speakers go down to 25-30hz.

 

[Hari Iyer]

I am happy with 45 hz. Even the JBL 4343 went down to approx 35-40hz only.

In 6 months I will be building a large cabinet for the Axiom 80 to just understand what it does.

Larger cabinet could hamper with the cone stifness and is better avoided. I would suggest you to try an OB version instead if you are looking for an even more articulate bass. The distance of the OB from your front wall is the key for getting this articulate bass and is tuned by listening.

 

[jenson]

I did check out some videos on YouTube to get a feel for them... They are scary alive; it must be a killer for vocals. All videos played minimalistic jazz and such, so I couldn't get a feel for how it plays different genres, like lets say disco/70's rock But from what I did experience, they sound very different from conventional speakers. Prem scores, yet again

p.s. any hint on how does it image/soundstage in comparison to rethms you have had (presuming it was lowther era)

 

[prem]

Jenson I have owned Rethms with the Lowthers as well as with Jacobs own drivers.

The Axiom 80 plays in a much higher league. Tone, macro and micro dynamics, immediacy, are all far far better. Imaging and staging is pretty much the same. Axiom sounds much more real. As you said it’s scary in some recordings. I have tried Derp Purple, Daft Punk. It plays them with aplomb. No issues. I have gone upto only 95 db spl. Above that I am scared to go. It’s a very delicate driver. It can handle a max of 6 watts only.

Unlike what you heard on YouTube, the Axiom 80 is not a mid centric driver. It’s very even handed in its handling of frequencies.

It definitely cannot play as loud as my JBL 4343. Bass also doesn’t go as low. But whatever bass iit throws out, it’s very alive. JBL bass was not as alive. Apart from SPL handling and bass below 40 hz, the Axiom 80 is superior to the 4343

 

[prem]

All experimentation done.

Vera wood coasters between amp feet and steel plate works. A more real sound

Speaker position finalised. Speakers work best directly on carpet. Tried felt pads, wood blocks, tin can to raise height. But none worked. Sounded most natural with the speaker base directly on the carpet. That’s what is recommended in the design too. Also people in the know advised me the same. They said if feet were required, the designer would have provided for them in his cabinet design.

So now to sit back and enjoy music. And allow the bass to break in completely.

 

[keith_correa]

And allow the bass to break in completely.

Bass needs break in too? Who knew?!

 

[prem]

Keith, now you know

Tubes need to run in. Also I find with vintage drivers that are like 60 years old, the cone material gets a bit stiff. So it sounds a bit closed in. With run in, it begins to open up. That’s always been my experience with vintage drivers.