2 'lesser quality' subs = 1 'good' sub? (1 Viewer)

[Mike Thomass]

you guys are too kind!

 

[Mike Thomass]

robert, you said you were bulding some D3s. im looking at the page, and theres more than 1 crossover shown. theres a note that says "(only use this crossover if you purchased your Dayton Tweeter between July. 2001 and May 2002)" under one of the diagrams. theres a handwritten diagram that shows a schematic for an old and new 275-070 http://www.speakerbuilder.net/web_files/Projects/D3/Newxo.jpg. 275-070 is the tweeter. im going to guess i should use the schematic for the 'new' tweeter, correct? also, is it safe to assume i can use the schematic for the woofer without problem?

 

[Robert_J]

Only use that diagram if you have a tweeter from those dates. There was a slight difference in the frequency response and the crossover compensates for it. Tweeters before or after use the original diagram. There are no changes to the woofer circuit.

 

[Mike Thomass]

i was confused i guess because i assumed the new diagram was posted due to the change that was current at the time ( may 2002) and couldnt figure out how the guy could know what to use in the future. i figure the old was old and the new was for that point forward. why did they manufacture the tweeter differently for a year and go back to the old specs? know what i mean? the drawing with the new info has a date of 8/19/01 on it. how could he know that in may 2002, you would need to switch back to the old numbers? anyway, i think im going with the d3 instead of the d2 for the center and the surrounds. if you have some free tim, i would like to start talking subs as well. you said theres new things available now? based on the results of the d8, im willing to budget $600 for the sub(s) not including mdf, paint, wires, etc. $600 for the amp(s) and driver(s). size should be approx. 21-22" cube i think i would prefer 2 subs over 1 because i have ocd, but will let you convince me either way. if you come up with something hot for a little more than $600, lay it on me, im easily swayed.

 

[Mike Thomass]

also, it references an 'optional' 0.1uF bypass cap on one of the drawings (dotted lines) http://www.speakerbuilder.net/web_files/Projects/D3/Oldschem.jpg do i want to include these or not? i have no idea

 

[Robert_J]

Use this diagram - http://www.speakerbuilder.net/web_files/Projects/D3/mtmxover.jpg The hand drawn one came after people noticed a change in the tweeter sound. Wayne and other posted at the PE Tech Talk site and it turns out there was a slight change in materials for a short period that required a different crossover to compensate for the change. PE went back to the old materials and the original tweeter came back. Some people say the option bypass cap improves the sound. They were cheap so I used them. I'd rather be safe than sorry. This will be easy. Here's the enclosure design - http://www.danmarx.org/audioinnovation/tc3000.html . That one driver would blow your budget through the roof. I know because I use a pair of them. This driver - http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-190 . It's proven over the years that this is a great sub. Or this driver - http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-468 . More expensive but it is one of the best sound quality subs on the market. This amp to drive either set of subs http://www.parts-express.com/pe/showdetl.cfm?Partnumber=248-6560 . You may have to change the fan so keep $10 out of your budget for that.

 

[Mike Thomass]

youre the man for the extra $100 total, i will go with the reference drivers. three immediate questions: clearly i wont be installing the amp onto the back of the sub, so i guess i need to pick up a couple extra terminals like i used for the D8? or wait, maybe i should use the post style things to maintain the 'sealed box' integrity? this guy screwed everything together. im guessing thats necessary due to impending earth shaking? i might need a new fan? how would i know that? how difficult is replacing the fan?

 

[Robert_J]

I did some modeling and the cheaper drivers will play slightly lower. But the reference drivers will definitely sound better. I like the terminal plates will work - http://www.parts-express.com/wizards/searchResults.cfm?srchExt=CAT&srchCat=417 I'm not a fan of glue and screw. In fact, Tightbond II glue will hold stronger than an screw and you same time and materials. You just need more clamps. If you don't have clamps, then a few screws will work. You can remove them after everything dries and fill the holes with Bondo. Behringer amps, except for the fanless A-500, sound like a Cessna when powered up. They are made for clubs and concerts where a little fan noise will go unnoticed....You will notice it. I guarantee it. Here's what I followed for my fan swap - http://www.hometheatershack.com/forums/subwoofer-amps-high-pass-filters/3658-quieter-fan-mod-behringer-ep2500.html . This guy needed a new fan and chose incorrectly - http://www.hometheatershack.com/forums/subwoofer-amps-high-pass-filters/31557-behringer-epq1200-my-impressions-need-help-thermal-runaway.html . After reading that, I'm not sure if I want to recommend that amp. The EP-2000 is $30 more and a proven series. I run the older EP-2500 (same as the current EP-4000). I can crank my system to ear bleeding levels without the amp even getting warm.

 

[Mike Thomass]

so im going with the ep-2000 i guess. see? im easy

 

[Robert_J]

Let me give you 1 more option: A pair of these - http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-185 Powered by this - http://www.parts-express.com/pe/showdetl.cfm?Partnumber=248-749 Using this design (the first one in the PDF) - http://www.creativesound.ca/pdf/SubDuction-plans-290307.pdf It's much smaller. It's cheaper. No fan mod since that amp doesn't have one. But it will still perform in a medium sized room. I ran the same sub, same design but a 250w plate amp in my home theater for a while. Unless you are going for concert levels, its a great combination. If you are going to really crank those D8's, then the 15's are a better choice.

 

[Mike Thomass]

rob, the fan runs constantly on the ep-2000, or does it turn off and on as necessary ? like, am i going to be watching a movie and be bothered by the fan noise? or would it probably never come on during a movie, cause theres little work for the subs? for music im not worried as im sure the music will cover the fan noise.

 

[Robert_J]

It runs 100% of the time. A variable fan would add to the cost. I was bothered by the fan. Now I don't even hear it when the rest of the system is turned off. What movies are you watching? There is more work for a sub during an action movie than anything else. I had to put my subs back in place after watching "Battle: Los Angeles". Music will probably cover the fan noise if you really crank it up. As I said a few posts ago, it's like a Cessna. The replacement is $10. I think I may have an extra fan.

 

[Mike Thomass]

not sure what movies. probably whatever we pick up at redbox or whatever. no specific genre. i saw the cessna commetn, thats why i asked about whether it was on full time or periodically. this week im going to start making things happen again

 

[Robert_J]

If you are watching a movie with a lot of quiet parts, the fan will be annoying. With my theater room Ethernet switch, I went from an old factory D-Link to the same one with a quiet fan added to a Rosewill model with no fan at all. Even a 1" fan was annoying sometimes.

 

[Mike Thomass]

im guessing these behrigners are head and shoulders above the competition for people to be putting up with the noise?

 

[Robert_J]

Not really. They are a great value. If you want head and shoulders above the rest then get a Crown, QSC, or Carvin. I'd like a Powersoft digital amp but they are extremely expensive. Behringer gets a bad rap in the pro-audio game because they can't stand up to the beatings on the road. But use them in the home or for a bar or club and they work great.

 

[Mike Thomass]

rob working on ordering the crossover parts for the d2 heres the parts list im going by: http://www.speakerbuilder.net/web_files/Projects/D2/D2Wparts.htm heres the crossover im going by: http://www.speakerbuilder.net/web_files/Projects/D2/d2xover.gif you mentioned you were working on/have these if you look at the parts list down toward the bottom, there is a note to combine an 8ohm and a 30ohm resistor in parallel to make a 12ohm resistor instead of the 13ohm resistor specified by the schematic. multiple questions: 1. 8 and 30 ohm in parallel doesnt equal 12 or 13. comes out to like 6, right? wtf are they talking about? what am i missing? 2. if i am going to have to combine resistors to create a 12 ohm or 13 ohm resistor, why wouldnt i put a 10 and a 2 (or 3) in series? 3. is my goal to have a 13ohm resistor or a 12ohm resistor?

 

[Robert_J]

1. I didn't catch that years ago. It is 6.3 ohms according to http://www.1728.org/resistrs.htm 2. If you can't find a 12 ohm non-inductive resistor now, try a pair of 24 ohm ones. Or your 10 & 2 in series since they are NI. 3. Either one. It's close enough to get anywhere between 12 and 13 ohms. I need to check mine now. I might need to swap some parts.

 

[Mike Thomass]

rob do i need any special screws to mount these subs, or can i use the regular wood screws i used for the d8. not that you know exactly what i used for the d8, but they werent heavy duty or anything.

 

[Robert_J]

Wood screws work fine. In fact, that's what the owner of http://psicaraudio.com/ uses on his subs. They are monsters and hold with no problems at all. I like pan head, sheet metal screws. Check out the sub mounting kits at PE for exactly what I'm talking about. I ordered mine with a square drive head from Fastenal.