# I need your blessings



## Guest (Dec 1, 2008)

ok we may recall my budget MTM thread. ive given up on MTM due to the whole 4ohm deal. anyways, im gonna do zaph's SR71, in there respective .5 cu ft box tune at 44hz, but in the same enclosure but seperate chaimber im gonna do a little 8" sub in each TMW and a plate amp for each. madisound didnt realy have anything in my price range, and partsexpress had few 8s to chose from. i would realy love to have the
Dayton RSS210HF-4 http://www.parts-express.com/pe/pshowdetl.cfm?&DID=7&Partnumber=295-456&ctab=2#Tabs
but cant aford a pair of em and a pair of 250watt plate amps, so time for plan B. a pair of Dayton SD215-88 
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-480 (one in each cabinet) and a 70watt plate amp in each. the sub enclosure will be around 1 cu each tuned in the mid to high 20s. im gonna play around some more with BBP6 and see what i can conjer up. i think the SR71 with a 8" sub lower down will look bad ace and sound good. i could do a single 10 in its own enclosure, or even build a single 10 in the side of of one of the SR71 for now, and maybe add another 10 in the other TM tower. what do you guys think!


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## JCD (Apr 20, 2006)

*Re: i need your blessings*

Ok, this is what I think -- do NOT go with option B. Those drivers don't look like they're going to do what you want them to do, i.e., fill out the bottom end solidly. 

I think I'd be more inclined to go with one 12"-15" subwoofer. Maybe the Titanic III and a 250watt plate amp? Not sure if that fits in your budget or not, but I've heard some good things about the Titanic drivers. 

Not sure if that helps or not...

JCD


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## Aaron Gilbert (Nov 12, 2008)

*Re: i need your blessings*

The SD215-88 woofer models very nicely, and it's hard to argue with the price. However, I think I will agree with JCD. They're only 1" larger in diameter, with the same Xmax, as compared to the woofer in the SR71. I don't think that's really going to cut it for a subwoofer, unless you only listen at moderate volumes. If so, then have at it! 70w would seem to be a great match to that woofer, but you will still exceed Xmax below the tuning frequency, and the 70w plate amplifier does not appear to have a subsonic filter. I personally think you would be better served going to a much larger subwoofer driver at least, and possibly a more powerful amplifier. 

Is there a particular budget you're trying to stay within, and are you absolutely decided on stereo subwoofers? The answer to those questions would help immensely. While I think your plan of 70w amplifier and SD215-88 can sound great, it's just the output abilities which are concerning. But, there's not a whole lot you can do with a budget of $162 (two 8" woofers and two 70w amplifiers) - especially if you want stereo subwoofers! Just a decent 100w+ subwoofer amplifier is going to be about $110, leaving you next to nothing for the woofer.


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## Guest (Dec 3, 2008)

*Re: i need your blessings*

i dont have a budget in mind, wich i know is stupid. when customers come in for car audio, first thing i ask is whats your budget. there resone i want stereo subs is for the clean looks and for the space savings in provides. i would realy like to have sub(s) in my towers, but would like the towers to be as slim as posible. depth and height arnt realy a concern, so its very posible for me to run a 10 in each tower side. i would agree that having a 250watt 12 in a ported enclosure would probably be the best in terms of performance and price, but i realy want to set my self apart from the norm, heance the 8 inchers in each tower. the other option i sugested was to run the Dayton RSS210HF-4 http://www.parts-express.com/pe/psho...56&ctab=2#Tabs in one tower for now, and add a second later!

i guess as far as budget is concerned, speakers will be around $450, so is $250 doable for the bottem end


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## Guest (Dec 3, 2008)

*Re: i need your blessings*

perhaps the titanic 10" with 250 watt plate amp in one tower for now. ported and tuned mid 20s. and add the 2nd later if i want to! and you guys also asked abouta LPF and botteming out below tuning, this is primarly for music so i dont think ill be to woried about it bottem out, even with some of the hip hop i listen too. ive yet to bottem out my 15" RE SE with twice its RMS rating in my truck with it tuned to 34Hz


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## Aaron Gilbert (Nov 12, 2008)

*Re: i need your blessings*

Ah, well if this is primarily for music, than indeed as you say, I wouldn't be too worried about bottoming out. Not a lot of music has information below 20 Hz certainly, and much of it isn't below 30-40 Hz. 

I do like your idea of stereo subwoofers used as bases for front left and right. So, do you want the lower boxes to be the same width as the SR71 (9") ? Based on the dimensions of the SR71, I figure that the lower boxes need to be 24" tall externally to put the SR71 tweeter at 36" off the floor, a good seated ear height. 

I would suggest a great move would be spending a little extra and using the SD315-88 12" DVC woofer. They're only $22 more, not even double the price, but they can move three times as much air! The box they want is only a little bit bigger than the 8" version. So let's speculate here. Say you want the lower box 24" tall by 9" wide, and obviously you'd need to put the 12" on the side, so let's say 16" deep. That gives you about 40 liters or 1.4 cubic feet. In a vented box, the response is extremely close to the SD215, except you get notably more output from your 70w amplifier (2-3dB) from 25 Hz and up, assuming the same tuning point. Now, if you can make the box deeper (or wider), you can get considerably more output from the 12". You won't ever get super deep due to the high Fs, but you can do very well from 25-30 Hz and up. And, you won't ever have to worry about overdriving the woofer, it will be well within excursion limits at 70w until you're below 20 Hz. But there's no real point in spending big bucks for a 100w or 240w amplifier. 240w would be way too much, and 100w won't even be a noticeable difference.

The Titanic series are great woofers, but pricey for the budget you are considering. If you're willing to spend $138 each on a woofer, I can think of much better options, especially if you still want two of them and you have low power. I honestly think the SD315-88 is one of the best bang for the buck at Parts Express. While it only has 7mm of Xmax, it's also 1/3 the price of woofers with 15-22mm Xmax. And, it's crazy efficient, with 9dB more than the Titanic III 10" at one watt, 5dB more than the Quatro 10"! Seems like a no-brainer for a stereo pair.


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## Guest (Dec 5, 2008)

*Re: i need your blessings*



Aaron Gilbert said:


> Ah, well if this is primarily for music, than indeed as you say, I wouldn't be too worried about bottoming out. Not a lot of music has information below 20 Hz certainly, and much of it isn't below 30-40 Hz.
> 
> I do like your idea of stereo subwoofers used as bases for front left and right. So, do you want the lower boxes to be the same width as the SR71 (9") ? Based on the dimensions of the SR71, I figure that the lower boxes need to be 24" tall externally to put the SR71 tweeter at 36" off the floor, a good seated ear height.
> 
> ...




thanks very much, this was very helpfull! i think i may end up with the SD315. ill play around with it on BBP6 and see what i can make happen. im thinking tuning around 26-30 casue of the higher FS. dayton sugest a 2.5 cube box, that seams a little large


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