Double Bass Arnopol 8 Cabinet - A Winner!

[Jazzdogg]

With an 8 and an 88 all 3 of the speakers are seeing the same power. So with any speakers you can over power them but the three 8's go pretty loud. So---the load is equally distributed between the 3 8's. If you're starting to push too hard you'll hear it equally on all 3. The Faital is engineered to go really far before damage.

This makes sense when the 8 is 8 Ohms and the 88 is 4 Ohms.

What I failed to ask correctly (sorry for the confusion), is whether this would remain true if the 88 were the same impedance as the 8 (in order for the amp to see a combined 4 Ohm load, instead of a 2.66 Ohm load).

 

[bofferman]

Wow!

Received my Crazy 8 last week (kickback, no tweeter), and am floored by the great sound out of such a tiny cabinet.

And it was a triple surprise - it sounds terrific with double bass, Rob Allen Deep 5 and Sadowsky 5 string.

My, oh my, oh my...

 

[lowfunk99]

I want one!

Where can order one or get the plans?

 

[Jazzdogg]

I want one!

Where can order one or get the plans?

Contact Mike Arnopol. Based upon my experience buying a fiberglass Crazy8, he'll take good care of you!

Fiberglass Crazy8 - without tweeter - ~9 pounds.

 

[JxBass]

I want one!

Where can order one or get the plans?

Don at Barry Audio Design also has one or two (wood version) in stock.

 

[JxBass]

Don at Barry Audio Design also has one or two (wood version) in stock.

Apologies to Mike if this is OT from the original thread, namely the "Arnopol 8 Cabinet".

 

[Rvl]

Debating whether to go with a tweeter or none
I mostly triple on instruments , upright , bouzouki , tenor banjo
I am using a EA Micro and either a Wizzy 12 or a 112mb
I also use a AER Compact 60 or a Lunchbox

I wonder, the AER Compact 60 uses an 8 inch
Would it be possible to put the same speaker as the Crazy8 into an AER?

Thanks

Robert VanLane

 

[Mike Arnopol]

Hi
I know the AER well. It won't work well in that box at all. With such a remarkable little driver it really required doing some thinking as far as cabinet design. VERY specific size and porting. And multiple refinements. A player in Paris put one of these 8's in his Genz 8" cab. He bought an empty cab from me and said that there was a huge improvement.

With the banjo and bouzouki you'll notice a difference with the tweeter.

 

[LyleRyan]

May have missed it, but what are the power handling specs on the Crazy 8?

I realize matching amp to speaker power specs is only a crude measure, but:
- would a Genz Benz Shuttle 3.0 be too small (175w -> 8ohms)?
- would a Streamliner 600 be too big (375w -> 8ohms)?

 

[Jazzdogg]

May have missed it, but what are the power handling specs on the Crazy 8?

I realize matching amp to speaker power specs is only a crude measure, but:
- would a Genz Benz Shuttle 3.0 be too small (175w -> 8ohms)?
- would a Streamliner 600 be too big (375w -> 8ohms)?

A agree; it would be nice to see a summary of the specs for the Crazy8 and 88 in one place.

Impedance
Sensitivity
Volume Displacement (T/S spec Vd, i.e., Sd x Xmax)
Frequency range -3dB
Frequency range -10dB
Maximum SPL/distance @specified distortion
...

 

[drurb]

A agree; it would be nice to see a summary of the specs for the Crazy8 and 88 in one place.

Impedance
Sensitivity
Displacement
Frequency range -3dB
Frequency range -10dB
Maximum SPL/distance @specified distortion
...

Displacement? Do you mean excursion? Cabinet volume? If you mean volume of air displaced by the cone, then that seems of little practical value if you've got the other specs. Sort of liking asking for the free-air resonance spec. Actually, while we're making a wish list, how about anechoic or [This invalid link has been removed]-derived actual frequency-response curves both on- and off-axis? It's too bad that it's so difficult to access meaningful specs, much less gain hands-on experience with bass cabs before plunking down the cash. That's not specific to the Crazy 8. It's pretty general as such cabs go.

 

[Jazzdogg]

Displacement? Do you mean excursion? Cabinet volume? If you mean volume of air displaced by the cone, then that seems of little practical value if you've got the other specs. Sort of liking asking for the free-air resonance spec. Actually, while we're making a wish list, how about anechoic or [This invalid link has been removed]-derived actual frequency-response curves both on- and off-axis? It's too bad that it's so difficult to access meaningful specs, much less gain hands-on experience with bass cabs before plunking down the cash. That's not specific to the Crazy 8. It's pretty general as such cabs go.

T/S spec Vd - something I'd like to see all cab makers disclose

 

[drurb]

T/S spec Vd - something I'd like to see all cab makers disclose

Of what use would that be to you, given you have the performance specs? Might as well ask for the values all of the Thiele-Small parameters. They are the ingredients that go into the recipe. The proof is in the performance. Beyond academic interests, I never much cared about the values of the parameters used by a manufacturer in the design, so far as information goes that I would use to make a choice. What was always crucial to me, in terms of measures, were the ones that objectively describe the results. Beyond that, of course, you just gotta listen.

 

[Mike Arnopol]

I actually think that the xmax x sd is a useful starting place. The 8PR200 has an xmax of 8.1mm. The effective cone area is .02 meters squared. I'm not sure how people figure it, but I just multiply one by the other to get an idea of how much air comparatively a given driver can move. I guess that's called the vd or volume displacement. This way when I compare the 8PR to a Deltalite 10 the 8PR can move more air. Obviously as Les and others have stated there are many other factors that affect performance, but I think that the VD is a very practical way to start. When I compare the 8PR to a Kappalite 3012LF the 8PR can move 1/3 of the air. Which validates my actual listening tests comparing an 88 and an 8 to the Thunderchild and finding that the max volume was very similar. Tone was different but the usable volume was very similar.

 

[Jazzdogg]

Of what use would that be to you, given you have the performance specs? Might as well ask for the values all of the Thiele-Small parameters. They are the ingredients that go into the recipe. The proof is in the performance. Beyond academic interests, I never much cared about the values of the parameters used by a manufacturer in the design, so far as information goes that I would use to make a choice. What was always crucial to me, in terms of measures, were the ones that objectively describe the results. Beyond that, of course, you just gotta listen.

Who says that's a given?

Of course, listening/playing is the most important consideration. I'm in favor of specs that can help narrow a field of possible contenders to those that are worthy of an audition. Disclosure of meaningful performance specs by manufacturers surely can't be considered a bad thing considering some of the irrelevant numbers we're being fed now, e.g., "power handling."

 

[Jazzdogg]

I actually think that the xmax x sd is a useful starting place. The 8PR200 has an xmax of 8.1mm. The effective cone area is .02 meters squared. I'm not sure how people figure it, but I just multiply one by the other to get an idea of how much air comparatively a given driver can move. I guess that's called the vd or volume displacement. This way when I compare the 8PR to a Deltalite 10 the 8PR can move more air. Obviously as Les and others have stated there are many other factors that affect performance, but I think that the VD is a very practical way to start. When I compare the 8PR to a Kappalite 3012LF the 8PR can move 1/3 of the air. Which validates my actual listening tests comparing an 88 and an 8 to the Thunderchild and finding that the max volume was very similar. Tone was different but the usable volume was very similar.

+1

 

[drurb]

Who says that's a given?

Of course, listening/playing is the most important consideration. I'm in favor of specs that can help narrow a field of possible contenders to those that are worthy of an audition. Disclosure of meaningful performance specs by manufacturers surely can't be considered a bad thing considering some of the irrelevant numbers we're being fed now, e.g., "power handling."

The point is that the performance specs are what should be given and that they are far more informative and meaningful indicators than the value of a single T-S parameter. We agree that disclosing specs can be very helpful. I'm arguing for the ones that have been shown to be useful for decades.

I actually think that the xmax x sd is a useful starting place. The 8PR200 has an xmax of 8.1mm. The effective cone area is .02 meters squared. I'm not sure how people figure it, but I just multiply one by the other to get an idea of how much air comparatively a given driver can move...

...and by that you'd conclude that the 15" driver in a Klipschorn doesn't move much air. Loaded as a compression driver, it moves a fraction of an inch. That "system," (including driver and cabinet) can, of course, blow a Crazy 8, 88, and all listeners right out of a room... figuratively, of course... but closer to literally than one might think!

Okay, I gave an example of a horn-loaded system but the point is that there's much more to it. In the end, the performance specs will tell you what you need to know.

So with that, any chance of ever seeing response curves?

 

[Mike Arnopol]

Of course there's more to it Les. But we can compare apples to apples to a degree. If we're comparing speakers of similar efficiencies and similar loading we can narrow things down. Greenboy and I have come up with virtually identical cabinets twice. No big magic. We're looking at various factors to narrow down our choices . Now some of the loudspeaker manufacturers stretch the truth, but things are relatively consistent. All of the designers that I know use VD as a very useful starting point to estimate the air a speaker can move. Now we're not dealing with Klipsch horns. We're dealing with various drivers in the same alignment.
Which is why Greenboy and I before ever talking were looking at the 8PR200 over any 10's that we saw. That's because none of the 10's fit our design criteria. I'm not saying that either one of us are geniuses (well at least not me) but when we built our initial cabs (separately) we both found out that what the data suggested was born out as far as the performance of the speaker. In other words---the specs for the 8PR200 are pretty spectacular and I was mildly optimistic. The results were very consistant with our projected goals based on published measurements. And for me the starting point is VD.

 

[drurb]

Of course there's more to it Les. But we can compare apples to apples to a degree. If we're comparing speakers of similar efficiencies and similar loading we can narrow things down. Greenboy and I have come up with virtually identical cabinets twice. No big magic. We're looking at various factors to narrow down our choices . Now some of the loudspeaker manufacturers stretch the truth, but things are relatively consistent. All of the designers that I know use VD as a very useful starting point to estimate the air a speaker can move. Now we're not dealing with Klipsch horns. We're dealing with various drivers in the same alignment.
Which is why Greenboy and I before ever talking were looking at the 8PR200 over any 10's that we saw. That's because none of the 10's fit our design criteria. I'm not saying that either one of us are geniuses (well at least not me) but when we built our initial cabs (separately) we both found out that what the data suggested was born out as far as the performance of the speaker. In other words---the specs for the 8PR200 are pretty spectacular and I was mildly optimistic. The results were very consistant with our projected goals based on published measurements. And for me the starting point is VD.

Mike, we agree. We usually do! Indeed, Vd is a crucial spec, from the point of view of a designer. My point here is that, from the point of view of the consumer, who would like to be informed, it's not very high up on the list of useful specs with which to narrow down possible choices to purchase. The end user would do well to focus on performance, not design, parameters.

Indeed, it's not surprising that you and Greenboy would hit on a common solution. Over the decades, as I've studied various designs, taught about them, read patent reviews, poured over manufacturer's claims, consulted with designers, and read thorough reviews, it was difficult not to be struck by the number of times the principles of physical acoustics have been "rediscovered," with several approaches having been "reinvented" multiple times. That's not to detract from your apparently fine design and I'm not suggesting at all that you're claiming any sort of reinvention. Quite the opposite! You're far too reasonable and honest for such nonsense.

As I mentioned above, it's unfortunate that players cannot get a better handle on the desirability and performance of a specific cabinet before taking a chance and plunking down the $$$.

 

[JxBass]

I'm still digging the Crazy8. Sounds even better now that the woofer is broken in. I've also used this as a PA cab and that sounds terrific. A pair of these would be perfect for a PA at a small venue. Anyway, just received a custom padded cover for the Crazy8. I had the cover cut with the open panel at the bottom of the cab (where the four rubber feet are positioned). Very nice fit. The vendor is Custom Amp Covers, Inc.. They've made me several cab covers during the last several years. Good quality, good prices, and they really work with you to ensure a good fit. This cover was $30 plus shipping. This cover is not listed as a standard option. Request a custom cover and they will have the measurements under "Mike Arnopol Crazy 8 Cabinet."

Invalid Link Removed

Thanks for this, Dave. I just ordered two covers for my Crazy 8s.