2 Dayton RSS 12s or 1 RSS 15 or Soundsplinter

[saabracer23]

Hello all, I am wanting to build a subwoofer or a pair of subs. I was thinking a pair of dayton RSS 12s with a 500w amp on each or a single 15 RSS with a 1000w amp. Also would you guys go with the HOs or HFs? What setup would get louder and go deeper. They will be put in ported cabinets and be paired with a pair of Pinnacle arctics (5-1/4 inch two way monitors). Then eventually an even higher quality diy monitors, using like Scan Speak Revolators or such. Then eventually intergrated into a home theater setup.

I am also looking at using some Soundsplinter rpl series.
http://www.soundsplinter.com/rlp12_s...formation.html
I have a friend that has a 12 inch that he will sell me for about the same price as a RSS. That woofer with a 1000 watt amp.

Thanks for your help.

Dan

[saabracer23]

No help?

Dan

[liasom]

Hi Dan,

I'm preparing to build a 2.1 system now and while researching the subwoofer part of that I found two projects that use the 12", HF in one and HO in the other. The HO is on the Parts Express Project Showcase, it's called the Drake. The other I found is Zaph's HF version. I found that on his archive page. I did search for them but I don't recall finding any projects using the 15".

IMHO low distortion is THE key to rock-solid bass. If your budget is flexible the Rythmik sub kits might be worth a look. They are discussed in several threads on this forum.

Hope this helps. - Mike

[saabracer23]

Hey thanks for the input. The Rythmik subs look very nice, I looked at them before. I wonderered if they would get loud enough for me. Can anyone chime in on the output of these. Has anyone tried the DS15 kit? Is there a better one to choose from?

Thanks
Dan

[tade]

I am interested in this topic as well. I have a pair of the RSHF 12" subs in 0.7 Q sealed enclosures directly behind my couch. The bass is very nice but rolls of at 43hz. They still make a rock solid foundation for my system. I have them wired for four ohms and fed by 250 watts. I would really like to apply a linkwitz transform to the subs; straight down to 20!

I am in love with these woofers by the way!

[pjpoes]

there are those that will argue otherwise, but personally I don't like eq being used to boost, such as in a LT cuircit. Especially if its used in a Home Theater, less of an issue with music. If you look at the type of bass recored into that LFE channel, the levels and frequency, then look at what it will do to your subwoofer and amp needs, you will see that it will quickly limit your output before the amp is clipping and the speaker is exceeding xmax. To me this is only a reasonable solution if you have the ability to measure your in room response, do the eq that way to flatten in room response, and then also be quite aware of your typical listening level, and how it compares with what the eq is doing to amp need and woofer excursion.

I would recomend enlarging the enclosures to a Q of .5-.6, Mine are currently in sealed boxes of about Q.57 and the roll off is more in the lower 30hz range in room, but I believe upper 30hz range free space. I also am having a very robust ported box using a slot port tuned to 21hz. I will have some limitations in ultimate output, though we are talking in excess of 110 decibles in room. None the less, bass will be well into the 20hz and probably teens in room. That is of course another option. The final decent option is a 3-3.5 cubic foot box with passive radiators. That would be a more compact option.

As for comparing the Dayton to the SP woofers, its a tough call, but my opinion, having owned both now, is that the SP will play much louder without audible distortion, but has higher IMD at normal listening levels less than 100 decibles. I believe this is audible in listening as well, and feel the Dayton is a better sounding sub. Also, the frequency response of the Dayton is better than the SP both because of lower inductance and a smoother overall response. The Dayton has a nice smooth response going way up, allowing it to even be used as a good woofer in a 3-way speaker if one really wanted. It may sound like I prefer the Dayton, and for SQ I do, but if you can be honost with yourself and think that clean loud output is what you want, and that these fine details are not something you will notice, then go for the SoundSplinter woofer.

[rythmikaudio]

Originally posted by pjpoes
there are those that will argue otherwise, but personally I don't like eq being used to boost, such as in a LT cuircit. Especially if its used in a Home Theater, less of an issue with music.

On the other hand, if you check how one achieves lower extension without EQ, you may consider twice. The reason that without EQ you cannot get flat frequency response with sealed box is that the fs is not low enough. How do we lower fs? Use a heavier cone and the consequence: lower efficiency at mid bass and upper bass without efficiency improve at lower bass. It now needs larger amp and a lot more force to move the cone. A lot of people like to see EQ as boost as the lower end. How about seeing EQ as attenuation at the higher end (because the driver is too efficient in the band)? It really depends on how you see it. I subscribe Speaker Builder magzine before it was merged to become Audio Xpress. There are quite a few people literally just add lead beads to the cone to lower fs. Is that a better idea than EQ? I guess not.

On the other hand, larger box has its own problem as well. The enclosure is more difficult to build. If one uses the same driver, larger enclosure means smaller amp (not to bottom out the driver). After you balance the cost difference between larger and smaller enclosure and larger and smaller amp, the cost is about the same in the end. Not only that, the max output at the lower end is the same.

[pjpoes]

Well I respect Ryhtmik AUdio's opinion, and obviously you have products that use technology to achieve outcomes. I even have one of your servo sub systems I bought used from someone who couldn't build the box. I actually do like servo systems, and feel they are more effective than LT's at achieving that goal and lowering distortion. None the less, there is no replacement for displacement. When you look at the reality of adding even 3 decibels of boost at 20hz to a subwoofer with a Q of .75 and an FS of 45-50hz, it often means achieving far more power and excursion than is possible at 20hz. One example I used before was that the amp produced 30 watts at 80hz and was 100 decibles, it modeled at needing 600 watts to produce the same 100 decibles at 20hz with the necessary LT circuits. However on my test bench I was unable to do that because my amp clips at around 500 watts, and was clipping at that frequency. The model also suggested overexcurions of the woofer, but I couldn't really confirm that because the amp was clipping. The exact same woofer in a 4.5 cubic foot enlosure producing 80hz required the same 30 watts or so, and at 25hz required only 27, and at 20hz 22 watts, which I confirmed well with testing as well. Thats a huge difference in efficiency, and the speaker is well within its excursion capability thoughout that. I disagree that at 20hz the output is the same, and everything is the same. At 20hz a ported system, designed correctly, can output greater amounts, all other things being equal. All of this testing was with the Dayton speaker I have. However, I have done the same modeling and listening tests with other more capable drivers from TC, but have not yet had the chance to measure anything.

[rythmikaudio]

Originally posted by pjpoes
None the less, there is no replacement for displacement. When you look at the reality of adding even 3 decibels of boost at 20hz to a subwoofer with a Q of .75 and an FS of 45-50hz, it often means achieving far more power and excursion than is possible at 20hz.

I agree. I just want to clarify that excursion is limited by driver. To get larger excursion, one need to use bigger driver.

[pjpoes]

Oh yes, I'm sorry, I thought I had mentioned that. Well rather, I guess I assumed that was known. Then of course, then you have the added problem that, once you start getting into higher excursion woofers, even using linear motors, distortion will increase. I don't have the room or budget to build such a thing, but I would like to build a couple of "arrays" for bass sometime using very low distortion woofers, and lots of them. My experience with subwoofers has been mostly of the high excursion nature, which offers loud deep bass at relativly low levels of distortion at affordable prices, and reasonable size. None the less, I imagine a box with 10 Scan Speak woofers might offer even better sound in the 40-80hz range.