[tortugaranger]

I've had Audio Nirvana 8 inch Supers running in 1.5 cubic foot cabinets for several years. Impressive performance including outstanding bass output. Recently I built 2.8 cubic foot cabinets (with the big 6" port) and tried out the Audio Nirvana 10 inch Classic drivers. While the Classics definitely have improved detail over the Supers, I was quite disappointed that it put out much less bass than the 8's in the smaller cabinet. I've discussed this with Dave at Audio Nirvana who says if anything the 10's in the bigger cabinet should have even stronger bass than the 8's. Anyone have any thoughts on this?

[JLM]

My guess is that the new box/port are too big.  What were they based on?

Someone smarter than me could verify proper box/port size if given the driver parameters.

[undertow]

They may "Bloom" more over time as most full range or "Pro audio" style surround drivers are inherently stiff with low excursion in the first place so some serious hours of break in does help, but likely will never hit super satisfactory depths... You try lining the entire cabinet with foam? Normally this will enhance some output pressure specifically with ports.

Otherwise honestly a lot of setups like this it seems need either transmission line cabinets, horn loading cabinets, or active subwoofers to really round them out all the way.

[tortugaranger]

My guess is that the new box/port are too big.  What were they based on?

Someone smarter than me could verify proper box/port size if given the driver parameters.

Everything was sized according to Audio Nirvana's own cabinet specs etc. for these drivers in their standard 2.8 cubic foot enclosure.  I did run a quick cabinet design calc using a couple of different online design tools and this driver really seems to want a HUGE cabinet. Way bigger than I'm interested in  regardless of performance.

[undertow]

The bigger you push the cabinet size especially with drivers like this the less power handling you will probably get clipping with distortion well before you can push them hard enough.

[tortugaranger]

They may "Bloom" more over time as most full range or "Pro audio" style surround drivers are inherently stiff with low excursion in the first place so some serious hours of break in does help, but likely will never hit super satisfactory depths... You try lining the entire cabinet with foam? Normally this will enhance some output pressure specifically with ports.

Otherwise honestly a lot of setups like this it seems need either transmission line cabinets, horn loading cabinets, or active subwoofers to really round them out all the way.

Cabinets are well lined with fiberglass batting. Cheap but effective according to Audio Nirvana and same as I used in the 1.5 cabs with the 8's - which have plenty of bass output! Dave at AN strongly recommended against foam.

[undertow]

Well not just any foam. I appologize, but I have used Sonicbarrier to great success...Is it better than Fiberglass, maybe, maybe not? It's pretty good though.

http://www.parts-express.com/sonic-barrier-3-4-3-layer-acoustic-sound-damping-material-with-psa-18-x-24--260-530

[FullRangeMan]

I've had Audio Nirvana 8 inch Supers running in 1.5 cubic foot cabinets for several years. Impressive performance including outstanding bass output. Recently I built 2.8 cubic foot cabinets (with the big 6" port) and tried out the Audio Nirvana 10 inch Classic drivers. While the Classics definitely have improved detail over the Supers, I was quite disappointed that it put out much less bass than the 8's in the smaller cabinet. I've discussed this with Dave at Audio Nirvana who says if anything the 10's in the bigger cabinet should have even stronger bass than the 8's. Anyone have any thoughts on this?

The bass output depends on box size and what stuffing you put inside.
What stuffing you put inside this box and how much?

Foam is a mediocre bass increaser, the best material to increase bass I know is this brown blanket in 10mm version, not need alot of it:

[tortugaranger]

The bass output depends on box size and what stuffing you put inside.
What stuffing you put inside this box and how much?

The box is lined with fiberglass batting stapled to all surfaces except the baffle. I'd say it's about 1 inch thick on average. However, there's no fill/stuffing currently in the cavity.

[FullRangeMan]

This is alot of stuffing, see if you can find this brown blanket in 10 or 15mm in your area.
Firsts areas to place are magnet, bedind the driver and top side enclousure.

[FullRangeMan]

Please note these tips:
http://www.audiocircle.com/index.php?topic=100689.0

[DaveC113]

New full range drivers rarely have decent bass, they need to be broken-in....  put on some bass heavy music at high volumes and let them rip! They should open up soon...

[JLM]

Not a fan of Audio Nirvana cabinet designs (very poorly braced).  Perhaps your cabinets are better braced than David's cabinets (believe it or not but many speakers generate more energy via the cabinets than the drivers).  That would eliminate much of the (muddy) bass.

Again, I'd find someone who is knowledgable that can run the driver numbers to verify the box/port size.

I did notice a low Qts (0.23) which would indicate it would work better with a constricted (horn) loading versus ported.

[tortugaranger]

I placed a MiniDSP 2x4HD downstream of the DAC and configure a low freq shelf of +5 dB from 200 HZ down and BOOM...plenty of mid/low bass. I was really impressed with how much a difference this made. I've read mixed reviews regarding the earlier MiniDSP 2x4 but I have to say I'm quite impressed with the 2x4HD. No hiss or background noise - black background. Didn't measure the outputs but certainly can't hear it. The Audio Nirvana 10" Classics sound fantastic - even in a very plain vanilla and not very well designed/reinforced box.

[jcake5]

Did you calculate your baffle step loss for your cabinet?  Also, did you try to measure the level difference to determine if you were seeing baffle step loss.  Bass levels do not magically increase in narrow boxs and must be compensated for just as you did digitally, or with shelf filters to level the response, or filler drivers of equal efficiency to a frequency below the baffle (my preference using two of the same drivers).  If you calculate your baffle step loss for your box you might find that your 200 Hz is two low and that you  missed some mid bass boost.  On an 11-inch wide baffle the baffles step begins at ~600Hz.   Some day I will need to try the digital level boost method since it is much cheaper than four drivers.

Just a though or two for you to think on with the solution you have in place.
Eric

[tortugaranger]

Did you calculate your baffle step loss for your cabinet?  Also, did you try to measure the level difference to determine if you were seeing baffle step loss.  Bass levels do not magically increase in narrow boxs and must be compensated for just as you did digitally, or with shelf filters to level the response, or filler drivers of equal efficiency to a frequency below the baffle (my preference using two of the same drivers).  If you calculate your baffle step loss for your box you might find that your 200 Hz is two low and that you  missed some mid bass boost.  On an 11-inch wide baffle the baffles step begins at ~600Hz.   Some day I will need to try the digital level boost method since it is much cheaper than four drivers.

Just a though or two for you to think on with the solution you have in place.
Eric

With the smaller Audio Nirvana 8" Super drivers in 1.5 cubic foot boxes I was able to get away without baffle step compensation although I did try them with and without using passive components. I wanted to see how the bigger Classics did by themselves before adding any compensation. I've since lowered the shelf to 100 Hz since it really only needs the bottom end boosted whereas mid bass got too much at 200 Hz.

I can't say enough good things about this MiniDSP 2x4HD. You can play with adjustments in real time and hone in on optimal settings extremely easily. It is sooooo easy compared to swapping out passive components not to mention less costly and so far I can't discern any audible downside to using the DSP. I have to believe that the future of audio will be seeing more and more DSP taking the place of passives whether deployed in the digital or analog domain.

[planet10]

Not a fan of Audio Nirvana cabinet designs (very poorly braced).

And IMO poorly designed.

Looking at the Classic 10 in an optimum 35L (1.24 ft^3) -- for my miniOnken alignment) they have ~70 Hz F3, ~52 Hz F10.

Many of the Audio Nirvana i have modeled just don't go that low.

dave

PS: when you say Super 8 are those the stamped basket or the cast?

[*Scotty*]

How long are your port tubes. I ran a calculation based on the Classic 10" specs from the Audio Nirvana website and it says for a box this size,80ltr., with a 6in. diameter port you need a tube length of about 10.23in. for an F3 of 49Hz
Here is a link to the calculator I used.
http://www.mh-audio.nl/ReflexBoxCalculator.asp
 I couldn't tell you if this result holds any water or not.
Here are some more links to online speaker design calculators.
http://www.mh-audio.nl/spk_calc.asp
http://www.ajdesigner.com/speaker/bcv.php
http://www.carstereo.com/help/Articles.cfm?id=17
Scotty

[planet10]

80ltr., with a 6in. diameter port you need a tube length of about 10.23in. for an F3 of 49Hz

My modeler (MacSpeakerz by Jon Murphy) says an 8" long vent. Produces a kinda ugly curve.

I can't see where  the vents for the 2.8 ft^3 cabinet are but the cabinet that a local used for his stamped basic 12s specified a 6" vent x the material thickness (¾"). We installed a MUCH longer vent for a significant improvement.

tortugaranger, can you give us the detail of your cabinet?

dave

[tortugaranger]

PS: when you say Super 8 are those the stamped basket or the cast?

Cast basket. High quality. Very stiff/robust.