2 12 type r vs 1 15 type r

aznboi3644 wrote: The group delay is not noticeable between the different sized enclosures...the design plays a part. To me having a bigger enclosure gives better efficiency...also the the added output from the port can be adjusted with the port area. Type R's have a ridiculous mechanical power handling...so the bigger enclosure doesn't hurt. I've given my Type R 1200 watts free air basically (t-line) and it never complained. If I was use the Type R for more of an SQ install I would do around 1.5 cubes tuned to 33Hz. But if the space can be used I'll always go with the bigger enclosure for better efficiency because I never worry about the Type R having mechanical issues. I like big ported enclosures...Screw Hoffman's Iron Law I'll give up size lol. Also I will never install a Type R in a sealed enclosure...they sound horrible IMO...the roll off is way too high. Low end sucks.

I totally agree witht that. I do use pretty much that exact design for the SQ, of 1.5 cubes @ 32 or 33Hz. I do typically go around 2 cubes for more output. I wouldn't really ever recommend sealed either. Thanks.

joeb3845 wrote: i got a qestion. i got some 15" type Rs a few months ago used and they came with a prefab ported box that was 2 cubic foot and of corse i had to see how loud it really was. i hit 146.7 DB with them in my S10 blazer. that was with my kicker 1500.1 amp. now i heard some one say i needed to build a biger box so i looked all over and i found in an old post on here the specs for a 4 cubic foot ported box and i copyed it to ever detail. it seemed to be louder but it didnt sound as good IMO and when i finally tolk it back to see how much louder it really was the best i could get was 141.4DB thats with the same amp same head unit and i had to turn the amp up just a tuch. what gives? i feel i should of keep the smaller prefab box it did better. why?

could some one please help me understand? im not trying to make this hard i just want to understand.

joeb3845 wrote: joeb3845 wrote: i got a qestion. i got some 15" type Rs a few months ago used and they came with a prefab ported box that was 2 cubic foot and of corse i had to see how loud it really was. i hit 146.7 DB with them in my S10 blazer. that was with my kicker 1500.1 amp. now i heard some one say i needed to build a biger box so i looked all over and i found in an old post on here the specs for a 4 cubic foot ported box and i copyed it to ever detail. it seemed to be louder but it didnt sound as good IMO and when i finally tolk it back to see how much louder it really was the best i could get was 141.4DB thats with the same amp same head unit and i had to turn the amp up just a tuch. what gives? i feel i should of keep the smaller prefab box it did better. why? could some one please help me understand? im not trying to make this hard i just want to understand.

It depends on the overall specs of the enclosure. You said you used a 2 cubic foot and a 4 cubic foot enclosure. That would explain a little bit of it but what is also important is the tuning frequency of the enclosure. The tuning frequency of the enclosure will greatly impact the overall sound of your subs. You said you have a 2 cubic foot prefab enclosure. Is that per chamber? The prefab enclosure probably has a higher tuning frequency then the other enclosure. That would mean more output from your subs. What you think sounds good may be different then what someone else thinks sounds good so I cannot really tell you for sure why you would think the 2 cubic foot enclosure sounded better. It could be you like the sound of the higher tuning or it could be the 4 cubic foot enclosure is sounding "sloppy". With the tuning frequencies of the enclosure we may be able to tell you more about why this is.

So I am thinking I should go with the 2 12" since it will be more efficient and play louder at lower wattage, since it has more cone area. I will build a 3.8-4 cu.ft box let me see what will fit in the back of this Honda Civic.

Oh... My... God...

bumflik wrote: So I am thinking I should go with the 2 12" since it will be more efficient and play louder at lower wattage, since it has more cone area. I will build a 3.8-4 cu.ft box let me see what will fit in the back of this Honda Civic.

<rant> Have you heard NOTHING that has been said? If an 8 can play as low as a 15, why can't one 15" driver be louder than two 12" drivers? Cone area has nothing to do with how loud, how "fast", or how deep a woofer can play. It is all in the motor, not the diaphragm. My Eclipse Ti 10" played NOTICEABLY lower and every bit as loud as the Ti 12" (both drivers were DVC 4 ohm - so the amp was making the same amount of power), both in JBL SpeakerShop spec'd enclosures, with the SAME amplifier, and placed identically in the car. The 12 actually had more "punch" though, and I was amazed by that... The larger driver "sounded faster". And no, I didn't use published Theil/Small parameters; I hand-spec EVERY driver I model an enclosure for. (I spec every driver because published specs can be as much as 10% off on any given or even multiple parameters - a significant amount.) Oh, and there is no such phrase as SQL... We've debunked it many times here. (Well... except for Microsoft database engines, but that's not what we're discussing, is it?) Oh, and do the math: area of a circle = pi*r² 7.5 * 7.5 * 3.141592 = 176.71455 square inches for one 15" woofer 6 * 6 * 3.141592 * 2 = 226.194624 square inches for two 12" woofers That is just over 49 square inches of difference, in favor of the two 12s. In order to gain even a noticeable difference in output, you would have to have slightly over three 12s surface area. Two 12" drivers versus one 15" driver, with all sensitivities being the same, you'll have less than 1dB advantage, and probably give up more enclosure volume in the trunk. </rant>

haemphyst wrote: Dear God... PLEASE make it stop! The voices...! <fetal position> I can't take anymore. </fetal position>

It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

gotcha...thnx I decided to buy 1 Alpine type R . I will run it with 1200 RMS from a kicker AMp with a 3.6 cu.ft @ 33 hz.

Another quick question before I get the 15". Which would have more SPL, 2x12" Type R or the 1 15" type R?

you just got one type R 15?? I'd go with 4 cubesCustom Enclosure Design

bumflik wrote: Another quick question before I get the 15". Which would have more SPL, 2x12" Type R or the 1 15" type R?

haemphyst wrote: That is just over 49 square inches of difference, in favor of the two 12s. In order to gain even a noticeable difference in output, you would have to have slightly over three 12s surface area. Two 12" drivers versus one 15" driver, with all sensitivities being the same, you'll have less than 1dB advantage, and probably give up more enclosure volume in the trunk.

I think this pretty much explains it. The output would be nearly the same or less then a couple of decibels in difference.

ok thnx im goin to get da 15" alpine type R and make a build log soon