[leightoncash]

Hi,
My Dayton reference HE 12" sub sounds great in a .90cf sealed enclosure, but I've only got 1kw @ 1ohm to send it, and it seems like I'm maxing out the amp to get output where it needs to be. I've been told here that it is exactly like an SQL in that it needs about 2kw to reach xmax. I see 3 options...
1) build a vented enclosure for more output. I may do this anyway just because I like to build stuff, and I get free materials all the time. I could keep the amp I have, but the sound quality might suffer.
2) keep it wired at 1ohm, stay with the sealed enclosure, and get a new amp to send it about 2kw. The lower efficiency at 1ohm means lots of draw, and amp works harder and I'm guessing reduces longevity.
3) wire it at 4ohm, stay sealed, and get an even bigger amp that can send about 2kw to 4ohm, but at much greater efficiency than an amp sending 2kw at 1ohm.

What would you recommend? What am I missing?

 

[Nemesis87]

I didn’t think that amp was 1 ohm stable. Can some amps cut power when the impedance is too low?

Could the ‘not keeping up’ be a tuning/phase/timing issue or also break-in or perceived output based on low distortion?

Do you have another 2 ohm 12” sub you could try? 1,000 watts to a 12” sub should be plenty output in that cabin.

 

[ItsonlyaHONDA]

Option 4.... get 2 SQLs and feed the 4k baby!!!! Lol 😄 jk

I don't think power draw really changes 1ohm vs 4ohm. If you think you need power upgrade you may need them regardless. Then there's the getting 2k at 4ohm thing. If you go Korean that's 1 massive amp. Or you could do a smart 3k n such but even then that's 1700w at 4ohm.

If you can port it properly just do that.

Have you taken REW mesurments to see where you feel your laking. Maybe room acoustics is messing with output in a certain area.

 

[leightoncash]

My kenwood xr1000.1 is not listed as 1ohm stable, but it is working. What I don't know is, what does an "unstable" amp do?
I can get a lot of output, but I have to crank the gain up to 3/4 to get there. I don't like running things near max. And while it sounds good (musical, goes low, low distortion) I just think it could hit harder with more power to control it. I just don't want leave any performance on the table, when watts are cheap these days. Well, watts are but alternators are not. but still.

 

[ItsonlyaHONDA]

I don't think just doubling power is gonna make much of a difference. I'm all for driving subs to their limits. But I feel they may be something else going on here. You should take some REW measurements before trying more power. Like @Nemesis87 said it could be a....

tuning/phase/timing issue

Check all boxes before making any moves.

 

[Grinder]

I would definitely consider going vented...

WinISD results (because I was curious how these would model and took the opportunity to share in case anyone might be interested):

EBP = 62.7 (leans slightly toward vented)

Sealed WinISD default = 0.895 ft^3 (0.704 Qtc), 50.5 Hz F3, 16mm (of 25mm Xmax) excursion at 800W (10Hz), 25.3mm excursion at 2000W (10Hz).

Vented WinISD default = 1.975 ft^3 at 27.43 Fb (tuning frequency), 24.56 F3 (for example, 20 in^2 x 32.4" = 36.7 m/s at 1000W).

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Dayton Audio RSS315HE-22 12" Reference Series High Excursion Subwoofer 2+2 ohmDayton Audio 12" Reference HE Subwoofer The RSS315HE-22 12" Reference Series high excursion subwoofer from Dayton Audio will generate incredible bass response with unparalleled detail, control, and SPL capability...

www.parts-express.com

 

[leightoncash]

I would definitely consider going vented...

WinISD results (because I was curious how these would model and took the opportunity to share in case anyone might be interested):

EBP = 62.7 (leans slightly toward vented)

Sealed WinISD default = 0.895 ft^3 (0.704 Qtc), 50.5 Hz F3, 16mm (of 25mm Xmax) excursion at 800W (10Hz), 25.3mm excursion at 2000W (10Hz).

Vented WinISD default = 1.975 ft^3 at 27.43 Fb (tuning frequency), 24.56 F3 (for example, 20 in^2 x 32.4" = 36.7 m/s at 1000W).

View attachment 372720
View attachment 372721
View attachment 372722

Home

Dayton Audio RSS315HE-22 12" Reference Series High Excursion Subwoofer 2+2 ohmDayton Audio 12" Reference HE Subwoofer The RSS315HE-22 12" Reference Series high excursion subwoofer from Dayton Audio will generate incredible bass response with unparalleled detail, control, and SPL capability...

www.parts-express.com

Thank you for taking the time!
So am I understanding correctly that it's a 2cf box, with a 20 sq inch vent, 32.4" long?

 

[Grinder]

Thank you for taking the time!
So am I understanding correctly that it's a 2cf box, with a 20 sq inch vent, 32.4" long?

Yes, that is correct (2cf net cabinet volume - before vent, driver and bracing displacement).

20sq in is pushing the vent velocity a bit, but it's a compromise to keep vent length manageable, and I doubt you'd be pushing it that hard (this vented alignment should be an absolute beast by comparison to your current sealed); and depending on port opening location (trunk?) and/or proximity to your ear, you may never hear any port noise anyway.

 

[TheTodd]

My kenwood xr1000.1 is not listed as 1ohm stable, but it is working. What I don't know is, what does an "unstable" amp do?

Some produce less power. Some will distort/clip the signal. Some will overheat & cook themselves to death… some more quickly than others. Just because “it works” doesn’t mean it’s a good idea.

I’m willing to bet this is going to be a problem in the long run. Kenwood is a good reliable brand and sound good but you’re taking a big gamble running it outside its intended parameters.

I’ll second the vote for the ported enclosure. But it may be worth it in the long run to rethink the amp/load situation.

 

[Grinder]

Oh, and I forgot...

1kW sealed vs 2kW sealed vs 1kW vented SPL at 30 Hz:

Red: 0.895 ft^3, 105.4 dB (1000W).
Blue: 0.895 ft^3, 108.4 dB (2000W).
Green: 1.975 ft^3 at 27.43 Hz, 115 dB (1000W)

 

[leightoncash]

I'm going to have to build a vented box then! It'll be a fun, cheap project.
In the mean time, I need to pick a 1ohm stable amp. I like my amp but it's just a bad application. The last thing I need is for it to catch fire under the driver's seat and burn down my work truck. It wouldn't be the first time.

Funny story... I was 18 years old and my girlfriend had just dumped me. I'm driving down the road in my Ford Ranger that I had paid cash for and I really liked, and out of nowhere I see a light on my feet and I smell smoke. I quickly pull over and get my head down by the pedals and, looking up, I see a tiny electrical fire high inside the dash. I don't have any water to try to throw at it and I don't know enough to try anything else to get it to stop. I can't reach it with my hands. The fire very slowly gets bigger and I have no choice but to remove all my stuff from the truck, pile it up on the side of the road and helplessly watch the cabin go up in flames. I called for AAA roadside assistance, and they towed it to the local junk yard. Now for some reason, I had it my my head that it was a hard and fast rule that you got $50 for junk cars. This was a low miles, new tires, aluminum wheels, perfect body truck that was 7 years old. I asked for my $50, and they gladly gave it to me. As I was leaving, a worker asked the manager what they got that Ranger for, and the manager told him under his breath, "Fifty bucks". "FIFTY BUCKS! ARE YOU KIDDING??!!" the worker exploded, and the manager tried to hush him and pointed to me like "the sucker is still in the shop, shut up!".

THAT was a bad day for me.
Everything was stock in that Ranger, so needless to say, I don't think I'll ever buy a Ford again.

 

[LowBassSubs]

Some produce less power. Some will distort/clip the signal. Some will overheat & cook themselves to death… some more quickly than others. Just because “it works” doesn’t mean it’s a good idea.

I’m willing to bet this is going to be a problem in the long run. Kenwood is a good reliable brand and sound good but you’re taking a big gamble running it outside its intended parameters.

I’ll second the vote for the ported enclosure. But it may be worth it in the long run to rethink the amp/load situation.

You think that amp will take the sub with it when it goes out?

 

[leightoncash]

You think that amp will take the sub with it when it goes out?

ugh, that would be heartbreaking! I think I'm going to prioritize the amp situation now.

 

[LowBassSubs]

Good idea man. There's a few for sale here that would fit the bill.

 

[leightoncash]

There are just so many options out there for cheap power. I don't need a high end SQ amp for a sub. But part of me thinks a Taramps amp running at 1ohm is just as likely to catch fire as my much higher quality Kenwood that isn't rated for 1ohm.
I can get a new MTX jackhammer jh15001 on craigslist near me for ~$200. That should go beyond the listed 1650w at 1ohm. Then there are all those budget options you can see on Williston Audio's dyno test vids on youtube. I've only got quality gear right now, and I hate to buy some silly amp called the Bass Weasel Xtreme Turbo 4k just because it put out tons of power for $100.

 

[Grinder]

Rewire your sub to 4 ohms while you build the ported box. That may be all you need.

 

[spokey9]

There are just so many options out there for cheap power. I don't need a high end SQ amp for a sub. But part of me thinks a Taramps amp running at 1ohm is just as likely to catch fire as my much higher quality Kenwood that isn't rated for 1ohm.
I can get a new MTX jackhammer jh15001 on craigslist near me for ~$200. That should go beyond the listed 1650w at 1ohm. Then there are all those budget options you can see on Williston Audio's dyno test vids on youtube. I've only got quality gear right now, and I hate to buy some silly amp called the Bass Weasel Xtreme Turbo 4k just because it put out tons of power for $100.

My taramps smart3k hasn't even had the fan come running at 1ohm

I would absolutely buy a bass weasel xtreme turbo 4k for $100...it'd look great on my wall 🤣

 

[LowBassSubs]

Mosconi, Tru, Acoustic Elegance, Zapco, DLS, Stinger...

Mosconi Zero 3 Excellent condition $630 shipped OBO Stinger Heigh10 Brand New only open box for pics. Pre Covid unit. $680 shipped OBO Acoustic Elegance SBP15 Apollo motor 8 ohm. Excellent condition about 50 hours of play time, most of that was test tone at 50hz for burn in time. $475...

www.diymobileaudio.com

Zapco ST-2000XMII Brand new never seen power.
$330 shipped OBO

I bet if you post a wanted ad with cost in mind legit members here ( freaking good guys BTW) will get you set... local dudes will sell you anything and you never know how it was abused.

 

[Grinder]

1000W sealed (1 ohm) vs 500W (4 ohm) vented:

 

[leightoncash]

wow, that's really helpful. Thanks Grinder.