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requiem
10-20-2005, 09:23 AM
Hello, I decided to go with the ar.com kit for my first DIY project. I will buy the cabinet myself and I have a few questions...

The pre-made cabinet sold at madisound has an internal volume of 15 Lt but it says more deep bass could be achieved with a larger volume (up to 20 Lt) have anyone tried this?
if i increase the internal volume the port tube lenght should be different also?

I'm also thinking about adding a variable resistor to the crossover in order to be able to atenuate the tweeter response and I would like to leave the knob outside of the cabinet... but can't figure out how to achieve this without compromissing the cabinet strength, any ideas?
finally, are port tubes included in the no-cabinet kit sold @ madisound.com?

Thanks fot your answers

kexodusc
10-20-2005, 09:55 AM
Hello, I decided to go with the ar.com kit for my first DIY project. I will buy the cabinet myself and I have a few questions...
This is a great first project. I've built some better speakers, but for the money and simplicity, there aren't many kits out there that outperform. I still have mine in my main home theater.


The pre-made cabinet sold at madisound has an internal volume of 15 Lt but it says more deep bass could be achieved with a larger volume (up to 20 Lt) have anyone tried this?
if i increase the internal volume the port tube lenght should be different also?

I've made a dual chamber reflex design that's got a larger internal volume, but to be honest it probably isn't worth the bother. But I wouldn't pay too much attention to Madisound's numbers. They obviously can't do simple arithmetic. I come up with about 10.5 L. Definitely NOT 15L .
Increasing the size isn't going to add much bass in these. Same with lengthening the port tube. There's not really much room back there as is. In room, mine have an F3 in the low 40 Hz area and these have a lot more bass than you'd think. I recommend trying the original design first. If you need more bass, add a subwoofer or two later, sealed designs for music.



I'm also thinking about adding a variable resistor to the crossover in order to be able to atenuate the tweeter response and I would like to leave the knob outside of the cabinet... but can't figure out how to achieve this without compromissing the cabinet strength, any ideas?
You can buy l-pad kits that will do what you're thinking of. Just drill a few small holes to run the wires through. Since you're building this yourself, why not buy a few extra resistor values. They are cheap, and will do the same thing, except better. Find the value that offers you the right attenuation for your tastes, and stick with it. No ugly knob, just a bit of soldering required.

finally, are port tubes included in the no-cabinet kit sold @ madisound.com? No, the kits don't come with the port tubes. Just go to the store and buy 2 " PVC, cheaper. Might want port trim rings for looks, get those from Madisound.


Thanks fot your answers[/QUOTE]

poneal
10-20-2005, 10:10 AM
well maybe I am :-). I've had 5 people that I know of (I know not a lot like the AR.Com) but these 5 people have all been very satisified with my 2 way design using the Dayton RS150 6" and the Morel MDT20. Total project cost including materials was a little less than 2 bills. I've had people email with things like my mids sound to low at low listening levels etc., so I go through a tell them what they can change, etc. and they all end back to the same design I origianlly came up with. I don't blame them because I did the same thing :-). Took me months to finally decide to keep it the way it was. Mostly the ones asking things like this made it a ported enclosure vs my sealed enclosure. They usually didn't have enough foam and poly or too much, etc.

Now I have built the AR.Coms (as a matter of fact 5 of them) and this was my HT setup for a number of years. I just recently sold them off and went bigger blah blah.... The AR.Com is not a bad kit at all but I think mine not only sounds better but is cheaper too. Of course each person perceives things differently so I guarantee nothing. It's just another opition. I have two extra boxes already made--they just need to be painted and clear coated if you are woodworking challenged. I can help you put the crossover together or just build it for you too. These are sealed boxes and are pretty small. But as they say dynamite comes in small packages :-). That being said you will have to make your decision. These are about 84.5db efficient and have about 4db of BSC built into the xover. They can handle a lot of power. I was pumping 80watts into them and they didn't break a sweat.

So enought ranting and raving here is the link:
http://home.stx.rr.com/poneal/word_docs/RS150S-8.doc

You need to either have the MS word reader or MS Word installed on your computer to view the word document.

Regards,

Paul

requiem
10-20-2005, 11:01 AM
Thanks Kex, I always find your answers most useful.

Poneal, that's an attractive project indeed. Honestly wich speaker, ar.com or poneal.com's (jk! :p ) will have better bass response? how could you describe the sound of your design compared to ar.com's? I don't have any exprience with any of those drivers (peerless, dayton, morel) other than forums and reviews.

Box isn't really a problem since I have extra MDF and I do have some soldering experience so I can make the x-over, however, what might be a problem is shipping, because I don't live in the US...

kexodusc
10-20-2005, 11:09 AM
Requiem: Paul's speaker uses two newer, highly regarded drivers. I have to say, I prefer the Dayton drivers to that of the Peerless used in the Ar.com. I've heard them used in 2 different designs now. Impressive. IMO, they don't deliver bass as well as the Peerless, but the midrange is a good step up (and the bass they do have is by no means bad). Bass is fun, but I place less importance on it than the rest of the spectrum.

Unfortunately, shipping outside of North America can be cost prohibitive for the Dayton drivers (even for me in Canada), but Seas, Morel, Vifa, Peerless, HiVi, ScanSpeak etc should all be readily available somewhere near wherever you live.

Seas in particular is quickly becoming my favorite. Their aluminum drivers are incredible. Not your typical "metal" sound.

jclin4
10-20-2005, 11:10 AM
Paul brings up a good point. There are several excellent two-way designs out there by talented DIYers. Besides Paul's design, you might check out the MB-20 and MB-27 designs by Dennis Murphy (google for "murphyblaster").

The all-RS series variation on Roman Bednarek's microbes has currently got my attention. See this write up (http://home.insightbb.com/~zacharyemail/Reference_Series_Microbes_v2.pdf).

BUT...in a first timer's shoes, I might be intimidated by the prospect of wiring a crossover on my own, from a schematic. The AR.com madisound option is good in this respect: the crossover is already built.

Also you said you would buy, not build, the cabinet separately. Are you changing the volume because you want to go with a prebuilt cabinet and don't like the madisound or speaker city enclosures? I didn't either and had a cabinet builder supply me with one that suited my taste, but I stuck with same baffle dimensions and internal volume of Ed Frias' original design. I'm glad I did.

poneal
10-20-2005, 11:26 AM
Thanks Kex, I always find your answers most useful.

Poneal, that's an attractive project indeed. Honestly wich speaker, ar.com or poneal.com's (jk! :p ) will have better bass response? how could you describe the sound of your design compared to ar.com's? I don't have any exprience with any of those drivers (peerless, dayton, morel) other than forums and reviews.

Box isn't really a problem since I have extra MDF and I do have some soldering experience so I can make the x-over, however, what might be a problem is shipping, because I don't live in the US...

To be honest, the AR.Com has lower bass extension than mine. But then again, a vented system usually does have lower bass extension than sealed. I found that in room response was in the 60hz region with these. I think the AR.Coms was in the mid 40hz region. Both handle prodigious amounts of power--well maybe not prodigious--but at least 80+ watts. I designed these to be used with a small setting and the sub takes over at around 80hz making integration fairly easy. As far as sound well you can hear the difference. The AR.Com uses peerless poly drivers while the Dayton is an aluminum cone. So I think the Dayton is more precise, clear, and the bass very clean with low distortion. The AR.Com was more laid back I guess. The big difference is the tweeter. I never liked that Peerless tweeter and it is a bear to work with xover wise. On the other hand the Morel was very easy to xover, has low distortion as long as you cross it 4th order and above 2000hz. It does have some peaks and dips but overall the sound is amazingly nice for such an inexpensive tweeter. Silky smooth comes to mind. Very nice pronounced highs. Either way I think you will be happy and it may be cheaper with shipping to go with the AR.Com. I'm not sure. I do know that Ed Frias did a very nice job of taking two drivers fairly hard to work with and coming up with a nice xover topology for them. I tried to improve on his design but gave up. My design improvements for the AR.Com just was not worth the extra cost of the extra components needed to make this design any better than it was to begin with. As far as bass goes, if you were to build a vented box for the RS150 I bet the bass would be a smidgen better than the AR.Com. BTW, Dennis Murphy made some mods to Ed's design but again at the cost of more components. Either way, I think you can't go wrong.

requiem
10-20-2005, 11:48 AM
Originally Posted by jclin4
Also you said you would buy, not build, the cabinet separately


That was a typo mistake, sorry. I will BUILD the cabinet.

Poneal: It's a hard decision but I think this time I will go with the ar.com for shipping reasons. That morel tweeter you mention seems nice, maybe next time. Thanks anyway.

jclin4
10-20-2005, 12:25 PM
That was a typo mistake, sorry. I will BUILD the cabinet.

Oh, OK. I still recommend sticking as close as possible to the enclosure dimensions specified by Ed. BTW, I find the bass response in the AR.coms quite pleasing, and I use them for about half and half music/HT, without a sub. I find they have a disciplined, tight low end in comparison to the unwieldy and boomy bass of another budget kit, the BR-1s.