RSdC 12 vs. IDMAX 12

[icehole]

Price aside, what are your opinions of this match-up?

I've been running my RSdC 12 w/ a DDM1a for a couple weeks now.

I started out in a sealed box just shy of PG spec, 1.1 net (due to an error in measurement), and recently built a 1.9 net sealed box properly braced.

She gets pretty loud, but breaks up on the lower notes when it's really cranked, although I can't hear the distortion in the cabin of my car. I'd be totally satisfied it I could get the same output without any distortion from the sub what so ever. X-over is somewhere around 80-90hz.

Thanks, all.

[fuzzysnuggleduck]

You sure the distortion isn't your amp clipping?

[icehole]

You sure the distortion isn't your amp clipping?

Absolutely positive. It's definitely subwoofer distortion (max excursion, mechanical clicking sound).

Not only that, but the input is matched and the amp also has a clipping LED. I have it set so that the light never comes on, although it's fine to have it blink slightly.

[fuzzysnuggleduck]

You sure the distortion isn't your amp clipping?

Absolutely positive. It's definitely subwoofer distortion (max excursion, mechanical clicking sound).

Not only that, but the input is matched and the amp also has a clipping LED. I have it set so that the light never comes on, although it's fine to have it blink slightly.

I'm not going to second guess you, but I'd like to point out that you shouldn't really trust that clipping light.

[stipud]

1.9 is way too big for the RSD comp. The regular RSD woofers require large boxes, but I wouldn't put a comp woofer in anything bigger than 1.25 or so. Try your old box, or put pieces of styrofoam in your big box to take up airspace.

[icehole]

You sure the distortion isn't your amp clipping?

Absolutely positive. It's definitely subwoofer distortion (max excursion, mechanical clicking sound).

Not only that, but the input is matched and the amp also has a clipping LED. I have it set so that the light never comes on, although it's fine to have it blink slightly.

I'm not going to second guess you, but I'd like to point out that you shouldn't really trust that clipping light.

I agree. But the sound it's making is not clipped amp distortion, it's subwoofer distortion. The motor is clicking because it's reached it's limit.

[icehole]

1.9 is way too big for the RSD comp. The regular RSD woofers require large boxes, but I wouldn't put a comp woofer in anything bigger than 1.25 or so. Try your old box, or put pieces of styrofoam in your big box to take up airspace.

It's aligned to roughly .707 Qtc per AJ sealed box designer.

Either way, the larger box sounds better and has more low end extension. To achieve the same output, it distorted more in the small box. The distortion is actually why I wanted to build another box using a box building program.

As far as SQ, the woofer sounds great. It's pretty loud at the point that it distorts, and I do lose alot of sound to my trunk. It's possible that for my tastes, I just need more sound than a single one of these can produce. That's why they make higher end subs.

Unfortunately I need to be able to remove my box for full use of my trunk at times, so I want to stay with a single 12" in a sealed box so that it's relatively easy to remove it when I have to. If I had more space I'd just go ported before trying another woofer.

[eyesofra]

hi ice, whats the power rating of the amp ?
i've had that isse during the days when i was playing around with rsd12" on different boxes and amps. One instance when i was using the octane 15.0.1 on a 1.2cuft sealed box the sub did the exact same thig. The mechanical distortion sound. Was really confused since i had the amp and sub matched via the DMM method erin suggested earlier.
Then i found out that when i was doing the DMM mesurement , on the deck i had the fader completely maxed out for the rear as the sub was connected to the rear outputs and also abviously because i didnt wan the 50hz testones destroying the front rsdcs.

But when i had the subs plugged in , i had the fader at the middle point between the fornt and the backs and what my naka hu did was whenever the fader is in the iddle point , for some reason the pre-out voltage level just got so much higher for both the rear and fornt outputs. So effectively i was sending out votage level or power much higher then what the amp was capable of , which in this case was 1kW. causing the sub to distort. I ran the DMM measuremtn and calibration again but this time with the fronts unplugged and the fader in middle and voila...never heard the sub distortion after that. So in my case, the amp was clipping and that resulted in the mechanical distortion sound from the sub i guess. After that amp i had the rsdc1200.1 plugged in and again with the proper settings never heard the distortion sound.
Just sharing my experience here.

[fuzzysnuggleduck]

Definitely sounds like you're not getting enough damping from that box (too big) if your sub is hitting mechanical excursion.... although I don't know how much power the RSdC is really supposed to get before breaking up, even with the perfect box.

[icehole]

Thanks, fellas. I really appreciate all the help. However, I'm not in need of tech support. I really just need an honest comparison.

The amp is rated @ 1200 rms, which I know is double the rated power of the sub. The input is not clipping, and there's no silly bass boost circuit. I've played the sub on a couple different amps. The more power, the more I can get it to break up.

The larger box helped, but it's still cracking up a bit, though the distortion is inaudible in the cabin. I repeat, the larger box helped, not hurt.

It only breaks up on really low, loud bass hits. Listening to something with more subtle low notes without as much attack doesn't make it distort at all. And BTW, I've gotta turn it up pretty loud to distort (amp still not clipping).

I have nothing bad to say about this woofer, and would recommend it to anyone. But this woofer alone isn't enough for my particular setup, and as the cheapest component in my system, it's gonna be the first thing to go. If I was open to a dual woofer setup, I'd buy another in a heartbeat, and probably be an assload louder than any single 12" for a fraction of the price. The problem isn't the woofer, it's me. I want more than it can offer.

I'm asking you guys for input since the RSdC is new, and this forum has the most amount of support for this woofer that I've found online. And also because I've never heard an IDMAX personally, so I have no way of comparing.


To put it in the simplest terms possible: An RSdC is comparable to a JL Audio W6, and I need something along the lines of a W7.

[stipud]

For what it's worth, I ran an IDMax before my RSD, and then my RSDc. I liked the RSD much more than the IDMax, and the RSDc much more than the RSD. The IDMax was a brute on bottom end strength, but it really missed on the quick notes. It was good at being a "big bad subwoofer", but not so good at resembling the music I put on it. Plucked bass strings sounded like thor's hammer, but not like a guitar. The IDMax was louder than the RSD, but about par with the RSDc.

Have you considered a ported setup? When done properly, you can make them sound quite good as well. Many people have said favorable things about their RSDc's in ported setups. Of course two woofers would gain you 3dB, and doubling up on power again would have you at 6dB.

I still suggest you should have a little trial and error with styrofoam pieces inside of your box to take up airspace a bit. I found the sub to be a little boomy in a butterworth alignment, which is why I downsized to 1.25. That seemed to be the best compromise for my cabin gain as well.

[Bfowler]

i agree with tom.

when Errin (vw337) first tested my rsdc we put it in a 2cf sealed box. it sounds REALLY clean much of the time...but had a very odd curve other times, especially in low notes. that box (even if specs say .707) is too big.

[fuzzysnuggleduck]

To put it in the simplest terms possible: An RSdC is comparable to a JL Audio W6, and I need something along the lines of a W7.

Then why not a W7? Is the cost a factor?

[icehole]

Thanks for the comparison. That's exactly what I was looking for. If anyone else has something to contribute, please do.

Concerning the box, again, it sounds better than the PG spec box. There is much more low end, so I don't have to push the sub as hard to achieve the same output, which results in less distortion.

My roomate has a 10" RSdC in a ported box in a hatchback getting only 300w and it sounds great, and gets plenty loud - distortion free. He's not losing any sound to a trunk, though. And I do like the sound of the 12" more. It has a more natural sounding low end, and sustaining notes seem to ring out longer. I'd try a ported box, but I really don't have the room. The trunk of an IS300 is a strange place, and I designed my box to take up all my unusable space and still be easily removed. Anything bigger would have to be a more 'permanent installation' and may kill access to the spare tire.

I'm not going to send this woofer 2400w rms. It's already realized it's full potential with what I'm giving it, and I'd sooner replace a $150 woofer than a $500 amp.


I'm open to a W7, but yeah, they're expensive. None the less, I've never heard an IDMAX, and there's a ton of W7 vs. IDMAX comparisons all over the net, and not one RSdC vs. IDMAX, until now.

Thanks again, all.

[icehole]

Had to go to court today on some bullshit, and I'm sure you all can imagine what the City of Los Angeles courthouse is like.

My curiosity got the best of me to the point I couldn't even read the book I brought, so I stopped by the store before heading home to clear my head...

[fuzzysnuggleduck]

Definitely let us know what you think when it gets installed. I'd be quite interested in your take on the IDMAX vs RSdC.

[waynehead]

Definitely let us know what you think when it gets installed. I'd be quite interested in your take on the IDMAX vs RSdC.

Ditto, I had an IDmax running on a xenon 600.1 crossed at 43hz and thought it was very musical. Im expecting even better results from an IB or TB application. I honestly havent heard the rsdc series for comparison. Im deeply considering a pair for my next vehicle and using the max for an HT sub since it loves da lows.

[flogger11]

YOUR BOX IS WAAAAAY TOO BIG!!!! SERIOUSLY, that box will sound like crap, go w/ PG specs, maybe slightly larger, but thats it. Trust me on this, I have a pair of 10" RSDc's that keep sounding better and better as I make my box smaller and smaller, down to less than .6 cu ft per chamber!
Also FYI if your deck is capable, make sure your time delay is set correctly. If it is not, it can make the subs distort and sound like crap... I recently set the delay on my comps/subs and WOW, what a diff!!! Much less distortion and a much better soundstage!

[flogger11]

Also get that crossover below 70HZ brother!!

[icehole]

I speak from direct experience when I say that, for my particular system, this box sounds better than the PG spec box. Perhaps it's just the Q of my car, or the way it blends with my fronts. There was a little more punchiness in the hi-end with the smaller box, but now I have better low-end with just as much attack as before.


As far as the x-over freq, this was the best compromise for the music styles that I listen to. I had it around 70 for a while, but I needed it to be higher on a number of songs that are in regular rotation. If it seems too high, I just turn the sub down a bit and it blends well. There's a little more natural roll off with this larger-than-PG-spec box, too.

Thanks for the help.

Also, I could definitely be wrong about this but, without doing any math, and based on PG specs by proportion, isn't .6 to a 10" something like 1.7 for a 12"?

[icehole]

Got her in.

There's only about 1 hour on it at this point, but I'm already totally satisfied.

In short, the IDMAX is all around better sounding in every way than the RSdC. At low volumes I can her alot more music coming through it. Not just sound, music. And it also plays alot louder, too, with even more low end. With the power I have, I can get it to break up, but it's pretty damn loud at that point. Louder than the RSdC, for sure.

What unquestionably sucks about the RSdC is the smaller than usual basket size and bolt circle.


That said, a single RSdC was plenty adequate 95% of the time at about 33% of the cost.

[cojones]

Congrats, That IDMax is a nice woofer. Very efficient. I think everyone here forgot about the Fletcher-Munsen Ear Curve. In a anechoic chamber perhaps one could say that this is the correct box size or woofer for any given application, but in a vehicle there are too many variables to account for. If one were to listen to only classical music, you could be rather confident in recommending a .6 sealed 12. But when you listen to music with a lot of LFE, the bigger the better-within reason of course or you'll meet the mechanical limits of the woofer but you went a long way towards overcoming that when you bought a sub with nearly twice the mechanical excursion. The funny thing is with 1.9 internal you could have just ported the box without going bigger.

By the way, its the IDMax that has a larger then usual basket.

[bdubs767]

Do yourself a favor buy a killer EQ and do what ever the hell you want to what ever sub.


For a sub here is what I have to say after owing more subs than anyone could imagine.
1.) Buy in your budget
2.) Buy a sub that will work w/ the impedence of your amp
3.) One that will fit into a box that is sized correctly for your car

After meeting those requirments I persoanlly say buy the woofer that has the most cone area you can fit.


FYI I did a direct comparison of the RSd vs IDMAX vs W6v2. IMO the RSd was the best out of the box, but right now I own a 13w6v2 and I am very happy w/ it besides the cost.

[Bfowler]

brandon, get a hold of a RSDc yet?

i agree with eq statement to a point...you can't eq the quick attack and the smoothness of a sub...

[icehole]

Congrats, That IDMax is a nice woofer. Very efficient. I think everyone here forgot about the Fletcher-Munsen Ear Curve. In a anechoic chamber perhaps one could say that this is the correct box size or woofer for any given application, but in a vehicle there are too many variables to account for. If one were to listen to only classical music, you could be rather confident in recommending a .6 sealed 12. But when you listen to music with a lot of LFE, the bigger the better-within reason of course or you'll meet the mechanical limits of the woofer but you went a long way towards overcoming that when you bought a sub with nearly twice the mechanical excursion. The funny thing is with 1.9 internal you could have just ported the box without going bigger.

By the way, its the IDMax that has a larger then usual basket.

Thanks, Balls. I'm surprised that no one asked what kind of music I was listening to.

I'm not sure I could have built a ported box tuned as low as I'd like with only 2'^3. The PG spec ported box is 2.5. Possible, though, I suppose.

Also, the IDMAX has an 11" mounting diameter - Standard. If you bought a prefab box from a stereo shop it would come with an 11" hole in it.

brandon, get a hold of a RSDc yet?

i agree with eq statement to a point...you can't eq the quick attack and the smoothness of a sub...

Nor can you eq in sound that a sub can't produce without distortion.

...And tell Brandon that I have an RSdC for sale.