Amp used on the Method
Is it just me, or did anyone else noticed that the amp Zu used on the $2500 Method looks exactly like the $89 plate amp sold by Parts Express? It is now discontinued, link below.
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=300-792
If it is really the same amp, then Zu sure is enjoying a huge profit margin...
The 6moons reviews couldn't stop singing praises on the Method sub...
Is it just me, or did anyone else noticed that the amp Zu used on the $2500 Method looks exactly like the $89 plate amp sold by Parts Express? It is now discontinued, link below.
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=300-792
If it is really the same amp, then Zu sure is enjoying a huge profit margin...
The 6moons reviews couldn't stop singing praises on the Method sub...
rhapsodee
I know thats what got me interested in ZU, all the good praises at 6moons.. If you read the Druid and Definition loudspeaker review they make it sound amazing... For me being into the single driver tube amp thing they are also very efficient, but I never planned on buying them for $$ reasons etc. I do agree on the sound of a good paper cone driver though, hard to beat... I wasn't able to catch what others here have with the claimed specs of the Zu subs, as I don't really understand all that. I can't understand though how their products can be hyped up so high if they don't perform as stated, it would seem a big business mistake to me to do that as a lot of audiophiles know their stuff, me I just know what sounds good to me........
Scott thanks for all the great help..
So if I have this right, build a pedestal box with legs to have the downward firing driver approx 2'' off the floor.
Have an internal volume of 5cf or 5.5cf? after the displacement of both drivers and any bracing.
The internal driver sits above the bottom driver about 4'' so I guess that the internal driver see's less than 5 or 5.5 cf and the bottom driver sits in the small cavity of 4'' from back of magnet to the cone of the internal driver?
Both drivers wired parallel ...
Should the cab be lined or stuffed with damping material?
I would only make one of these because of space, for now anyways.
And I guess the last question is would you build something like this? and if not what would be your choice for music only high sq thats not overly huge? Dave
I know thats what got me interested in ZU, all the good praises at 6moons.. If you read the Druid and Definition loudspeaker review they make it sound amazing... For me being into the single driver tube amp thing they are also very efficient, but I never planned on buying them for $$ reasons etc. I do agree on the sound of a good paper cone driver though, hard to beat... I wasn't able to catch what others here have with the claimed specs of the Zu subs, as I don't really understand all that. I can't understand though how their products can be hyped up so high if they don't perform as stated, it would seem a big business mistake to me to do that as a lot of audiophiles know their stuff, me I just know what sounds good to me........
Scott thanks for all the great help..
So if I have this right, build a pedestal box with legs to have the downward firing driver approx 2'' off the floor.
Have an internal volume of 5cf or 5.5cf? after the displacement of both drivers and any bracing.
The internal driver sits above the bottom driver about 4'' so I guess that the internal driver see's less than 5 or 5.5 cf and the bottom driver sits in the small cavity of 4'' from back of magnet to the cone of the internal driver?
Both drivers wired parallel ...
Should the cab be lined or stuffed with damping material?
I would only make one of these because of space, for now anyways.
And I guess the last question is would you build something like this? and if not what would be your choice for music only high sq thats not overly huge? Dave
DaveCan said:
So if I have this right, build a pedestal box with legs to have the downward firing driver approx 2'' off the floor.
Have an internal volume of 5cf or 5.5cf? after the displacement of both drivers and any bracing.
The internal driver sits above the bottom driver about 4'' so I guess that the internal driver see's less than 5 or 5.5 cf and the bottom driver sits in the small cavity of 4'' from back of magnet to the cone of the internal driver?
Both drivers wired parallel ...
Should the cab be lined or stuffed with damping material?
I would only make one of these because of space, for now anyways.
And I guess the last question is would you build something like this? and if not what would be your choice for music only high sq thats not overly huge? Dave
at least 2 inches - and it doesn't have to be legs.. it could be large floor spikes.
5.5 cubic feet of internal volume. It doesn't have to be a pedestal in shape however, that was just my idea of a pleasing domestic aesthetic. Note that if you wanted a lower pedestal then you would simply need to change the height and the width (to lower the length). You could of course also incorporate some frosted safety glass and some led up-lighting to get the effect of the pedestal from Hammacher Schlemmer. Note that here is an excellent thread on paint finishing:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=83141
Yup, the internal driver will "see" a little over 5 cubic feet behind it and the external driver will "see" a little less than half a cubic foot and the internal driver behind it.
Again, yes both drivers wired in parallel.
NO stuffing - you could use roofing lead sheets though to line the interior walls.
And..
Yes, for the money and the performance I don't think you could do much better than this. You could however trade for different performance aspects with another design for similar money. My priorities however align with yours - and if I were building a true subwoofer its what I would do at this particular time (..though I'd likely spend a LOT more and build 2 "pedestals", and purchase the Behringer EP2500 amp and the Velodyne sms-1.)
It should sound considerably better than the Zu Method or the WLM sub.
Excellent Scott if you'd build it then I'm feeling really good about starting the thread, and so happy to get great advice on a project that is somewhat different
I e-mailed Madisound to just double check if the driver cone is paper as it didn't say on the site, and got a reply of, 'yes paper' ,and the driver is a clone of the Fostex FW-405 AWESOME The Fostex 405 is $526.80 per driver.... This Eminence offering could just be one of the best sleeper products out there if it gets close to that Fostex driver... Dave
I e-mailed Madisound to just double check if the driver cone is paper as it didn't say on the site, and got a reply of, 'yes paper' ,and the driver is a clone of the Fostex FW-405 AWESOME
The Fostex 405 is $526.80 per driver.... This Eminence offering could just be one of the best sleeper products out there if it gets close to that Fostex driver... Dave
Scott, would doing the drivers clamshell be somewhat more sq than the tunnel method? Some stuff I've read seem to favor the clamshell as being more ideal... http://mobile.jlaudio.com/support_pages.php?page_id=154 Dave
with that configuration you have spacing problems..
1. the driver extends out of the box and might be unattractive.
2. it *might* not load the floor and walls as well (on the other hand it may do a good job - don't know).
3. with respect to #2, the diaphragm's motion may well increase non-linear distortion due to side/torsional effects.
Its up to you though, I don't know if one method will net a better result than another (..and you may come up with solutions that reduce one or more of those problems).
Note however that should you do the clam-shell method that the interior driver is electrically in-phase and the exterior driver is electrically out of phase (though acoustically both drivers are moving forward at the same time).
1. the driver extends out of the box and might be unattractive.
2. it *might* not load the floor and walls as well (on the other hand it may do a good job - don't know).
3. with respect to #2, the diaphragm's motion may well increase non-linear distortion due to side/torsional effects.
Its up to you though, I don't know if one method will net a better result than another (..and you may come up with solutions that reduce one or more of those problems).
Note however that should you do the clam-shell method that the interior driver is electrically in-phase and the exterior driver is electrically out of phase (though acoustically both drivers are moving forward at the same time).
DaveCan said:Scott, would doing the drivers clamshell be somewhat more sq than the tunnel method? Some stuff I've read seem to favor the clamshell as being more ideal... http://mobile.jlaudio.com/support_pages.php?page_id=154 Dave
I don't suggest doing a clamshell isobaric for anything except car audio where the motor noise is inaudible.
judtoff said:
Never thought of that thanks... I figured if I went the clamshell way I'd still have the drivers firing at the floor and have skirting around the exposed driver and then spikes, legs etc to keep it up off the floor a few inches.. I't may not be a problem then with the noise? Dave
DaveCan said:
Never thought of that thanks... I figured if I went the clamshell way I'd still have the drivers firing at the floor and have skirting around the exposed driver and then spikes, legs etc to keep it up off the floor a few inches.. I't may not be a problem then with the noise? Dave
Sorry I missed that part. No it won't be much of a problem then, but it still could be a pain in the ***. It wouldn't really be any worse than say port noise.
But just as an example, my 18s make alot of noice from the pole vents, at high excursion. when they sweep 22mm or so, they make a very loud chuff.
I would avoid clamshells, but it could be done.
Another route for highly efficient subs would to be horns. I've just finished my tapped horn, I'll let you know how it sounds.
Also what is your price range? You want low xmax drivers right?
Hi judtoff, I'd love to do a horn but can't cope with the size where I live at this time..
Yes please give a review of your horn project when your ready!!
I won't be listening to the subs very loud so I hope that the noise won't be a problem.
I think I may just stick to the advice I got from Scott and build it like he said, then the drivers are inside the cab....
Yes I want to use high eff paper cone drivers and price wise I'd like to keep the whole project including amp etc under $700 or so..
I won't be building right away, just researching at this time... Dave
Yes please give a review of your horn project when your ready!!
I won't be listening to the subs very loud so I hope that the noise won't be a problem.
I think I may just stick to the advice I got from Scott and build it like he said, then the drivers are inside the cab....
Yes I want to use high eff paper cone drivers and price wise I'd like to keep the whole project including amp etc under $700 or so..
I won't be building right away, just researching at this time... Dave
Well 90'' does make a statement doesn't it?
Brett to be honest I haven't really checked into the horn your mentioning, perhaps I should look into it...
I guess for me when I think of doing a horn I think of big like the 16hz tapped horn at the Cowan audio site. I just can't do that right now...
I have for my mains a pair of BIB horns that are 60'' tall and just love them to pieces... I'd love to do a giant BIB bass horn and I guess thats how I think when I think of a low frequency horn,( huge)........
The idea I got going here with the Eminence drivers and the isobaric loading is lots smaller... Dave
Brett to be honest I haven't really checked into the horn your mentioning, perhaps I should look into it...
I guess for me when I think of doing a horn I think of big like the 16hz tapped horn at the Cowan audio site. I just can't do that right now...
I have for my mains a pair of BIB horns that are 60'' tall and just love them to pieces... I'd love to do a giant BIB bass horn and I guess thats how I think when I think of a low frequency horn,( huge)........
The idea I got going here with the Eminence drivers and the isobaric loading is lots smaller... Dave
One of the things unremarked upon here is that a sealed system (as modeled here), unlike various resonant systems, goes lower "near" the average - principally because it doesn't unload the driver below a certain "tuned" freq..
This can of course be disadvantageous IF you have high level transients at infrasonic freq.s - so some care is required with music and movie selections.. however,
Its often the case that recordings have infrasonic information that extends very low (perhaps near DC), its just that they are extremely low in level.
That infrasonic information has the tendency to flesh-out the overall size of the recording's venue (real or virtual). So it is advantageous to have this capability for music reproduction.
Now with a resonant system you can eq. the driver to achieve higher sp-levels at extreme low freq.s that more closely match that of the average. However, (depending on the resonant system's behavior), its likely that your are driving the driver at these extreme low freq.s in a manner closer to free-air operation. As a result driver excursion and the resulting distortion can become obscene even with very low sp-level transients when using extreme low freq. equalization.
So long story short, both types of systems (sealed and resonant) have merit for a given design, but if you want something closer to the full measure of a recording's "soundstage" size, (recording dependent), at a level where driver doubling isn't occurring (or indeed reaching or breaching the driver's mechanical limit) - then a sealed system (depending on the design), can have a distinct advantage for a given volume.
This can of course be disadvantageous IF you have high level transients at infrasonic freq.s - so some care is required with music and movie selections.. however,
Its often the case that recordings have infrasonic information that extends very low (perhaps near DC), its just that they are extremely low in level.
That infrasonic information has the tendency to flesh-out the overall size of the recording's venue (real or virtual). So it is advantageous to have this capability for music reproduction.
Now with a resonant system you can eq. the driver to achieve higher sp-levels at extreme low freq.s that more closely match that of the average. However, (depending on the resonant system's behavior), its likely that your are driving the driver at these extreme low freq.s in a manner closer to free-air operation. As a result driver excursion and the resulting distortion can become obscene even with very low sp-level transients when using extreme low freq. equalization.
So long story short, both types of systems (sealed and resonant) have merit for a given design, but if you want something closer to the full measure of a recording's "soundstage" size, (recording dependent), at a level where driver doubling isn't occurring (or indeed reaching or breaching the driver's mechanical limit) - then a sealed system (depending on the design), can have a distinct advantage for a given volume.
DaveCan said:Scott, with the two drivers loaded iso in 5.5cubic feet as per the design, would adding another two drivers to the cab at the other end make it so the vas can be halved again?, so now 2.75 cubic feet?. The two pairs of iso loaded drivers would all share the same air space.. Dave
No.
Scott,
Would this amp also be a good candidate? http://rythmikaudio.com/amplifiers.html I'm looking at the A370-SE. It has more power into 4ohms and is a bit cheaper.. I would only build one pedestal for what I need for now, and if I built another one I could get another amp by then.. The CSS amp ( Reckhorn) and the Rythmik both have high level speaker inputs which is what I need so thats good..
Also does hooking a sub amp up via my speaker outputs along with my main speakers do anything to the load? I have a Decware Taboo amp and have Fostex fe108ez 8ohm drivers hooked up to it..
Dave
Would this amp also be a good candidate? http://rythmikaudio.com/amplifiers.html I'm looking at the A370-SE. It has more power into 4ohms and is a bit cheaper.. I would only build one pedestal for what I need for now, and if I built another one I could get another amp by then.. The CSS amp ( Reckhorn) and the Rythmik both have high level speaker inputs which is what I need so thats good..
Also does hooking a sub amp up via my speaker outputs along with my main speakers do anything to the load? I have a Decware Taboo amp and have Fostex fe108ez 8ohm drivers hooked up to it..
Dave
Regarding size and the notion that isobaric will not give you much of a benefit in that regard, I tried to do some math, with the CSS SDX15 in mind, as I had some numbers ready for that one. My results indicate at least a 20% reduction in volume requirements, plus, that is, if you choose to do it as a push/pull you can have all the benefits as that coupling provides.
A couple of examples: Cancelded odd-order nonlinearities, reduced distortion.
A couple of examples: Cancelded odd-order nonlinearities, reduced distortion.
DaveCan said:Scott,
Would this amp also be a good candidate? http://rythmikaudio.com/amplifiers.html I'm looking at the A370-SE. It has more power into 4ohms and is a bit cheaper.. I would only build one pedestal for what I need for now, and if I built another one I could get another amp by then.. The CSS amp ( Reckhorn) and the Rythmik both have high level speaker inputs which is what I need so thats good..
Also does hooking a sub amp up via my speaker outputs along with my main speakers do anything to the load? I have a Decware Taboo amp and have Fostex fe108ez 8ohm drivers hooked up to it..
Dave
I looked at everything and the Reckhorn is by FAR the better solution. (it is simply built and designed better.)
The Rythmik won't work (with respect to freq. linearity and this design), but there is another alternative:
http://www.oaudio.com/500W_SUBAMP.html
Still though.. go with the Reckhorn, the difference in price ($80) isn't worth it.
Also note that you'll not have the same gain by using 2 amplifiers and two subs vs. two subs connected to 1 amplifier (that can handle it). The difference is not an inconsequential +3db in favor of the single amp solution.
(..there is of course the possibility of DIY'ing a solution yourself - but I haven't looked into that.)
..as for the connections:
You could have grounding issues with that type of hookup. The best solution is to spit-out your pre-amp's output.. sending one grouping of rca's to your amp and the other to your sub amp.
Here is some information on Isobaric loading and Clamshell loading:
http://www.musicanddesign.com/Isobaric.html
(..thanks to JohnK.)
..its basically the bottom (of the page) 3 graphs you'll be interested in.
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