Help me choose subwoofer! Dynamo 1500x vs SB13 vs PB13

[maxedout2134]

Hello,
My name is Hayden and I am just starting my home theater setup with the help of a friend who works at a electronic store with a fair discount. I'm looking to complete the system with a nice subwoofer.My room currently is 25 x 15 and is a sealed guest bedroom. This is a temporary setup and I plan to move the equipment into an open basement once it is finished. So far I have Bowers and Wilkins CM series speakers with the Cm10 in front, Cm5 in the rear and the Cmc2 center upfront. I am a fan of watching movies and listening to music and I don't want to compromise either. Although my viewing tendency's would probably sit at 60/40 movies music. Through reading ive narrowed it down to three or four sub-woofers that his store carries to get the discount. The martin Logan dynamo 1500x comes in just under 500$, where the SB13 sits just under $1000, and the PB13 sits around $1200. I'm fine with paying either of the prices if the cost is worth it. I would gladly pay the extra money for the PB13 if it would be worth it. My main concern is is there a significant increase in sound for either the SB or PB over the martin Logan. Or if there any other sub-woofers you would recommend more for the price let me know! -Thanks

 

[shadyJ]

The Dynamo 1500 is very close in performance to the SB13, and at that price it is a steal. However, in deep bass below 50 Hz it will get murdered by the PB13 Ultra. If it were me, I would get three Dynamo 1500s, that isn't that much more expensive than a single PB13 Ultra, and three will match the Ultra's deep bass output while vastly outperforming it in mid bass. Multiple subs will also give you a smoother response if you place them correctly.

 

[maxedout2134]

Would just two of the dynamo 1500x subs, be a better value than the PB13 ULTRA? Would the pairing of them be able to reach those deep notes that the SVS is known for

 

[shadyJ]

I think a picture explains the differences better than written description. Here is a chart that compares them both:

As labeled, the purple line represents the PB31's performance, the thin blue line represents the Dynamo's performance, and the thick blue line is about what two dynamos would do. You can see the dynamo and PB13 are even down to 50 Hz, but below that the SVS subs has a huge performance advantage, especially around its tuning point of 20 Hz, where it has four times the output of the dynamo. Getting two Dynamos will achieve parity with the PB13 down to 40 Hz with a sizable advantage above that point, but between 40 and 16 hz, the PB13 still dominates. Three Dynamos would add another 3 dB in output on the thick blue line and probably achieve parity with the PB13 down to 30 Hz and up to 18 Hz, which would greatly shrink it's advantage.

That all happens only in an ideal space, but normal room acoustics can really warp these smooth frequency responses and create peaks and valleys in the response. Multiple subs can deal with room acoustics by placing the subs in spots where they can compensate for frequency response nulls, and give you smoother, more even bass, so that is an argument in favor of the Dynamos.

I might still take two Dynamos over a single PB13, but just barely, and only for the response smoothing effect of multiple subwoofers, but three Dynamos greatly reduces the PB13's deep bass advantage and can give you some very powerful mid bass.

 

[BoredSysAdmin]

I do disagree with Shady. For movies you'd want bass to be extended to 20hz. Not even 3x
Dynamo could hope to achieve good output at low bass. See output below 50hz
If you have a chance to buy PB13 Ultra for 1.2k instead of 2k - buy it today and don't look back.
It's an excellent sub for both music and movies.

 

[shadyJ]

Three Dynamos would be close the PB13 at its tuning point and smash it everywhere else. It would easily be a superior bass system. The PB13 would only have a 3 to 4 dB advantage at its tuning point. All you have to do is add 9 dB on the Dynamo's CEA score to see how they compare. Here they are, by frequency, the PB13 vs three Dynamos:
Hz: PB13 / Dynamo 1500x X 3
12.5: --- 98.9
16 : 97.4 101.6
20 : 110.6 106.4
25 : 113.5 110.4
31 : 115.5 114.3
40 : 117.5 119
50 : 117.8 123.1
63 : 116.6 124.3
80 : 115.3 123.4
100: 114.4 122.2
125: 114.1 121.1

 

[BoredSysAdmin]

To gain 9db you'd have to place them on top of each other and have uneven bass across other aeats

 

[shadyJ]

True, but a 3 1500x system is not likely to leave any serious nulls unlike a single PB13 system. The advantages outweigh the disadvantages.

 

[agarwalro]

Three Dynamos would be close the PB13 at its tuning point and smash it everywhere else. It would easily be a superior bass system. The PB13 would only have a 3 to 4 dB advantage at its tuning point. All you have to do is add 9 dB on the Dynamo's CEA score to see how they compare.

True, but a 3 1500x system is not likely to leave any serious nulls unlike a single PB13 system. The advantages outweigh the disadvantages.

These two statements are incongruous in that, the first claims gains from collocating 3 Dynamo's and the second from placing them across three locations. Pick one.

Your logic is sound but the calculations are flawed.

In the first case, you need 3 Dynamo subs collocated (not stacked, not side by side, collocated = literally 3 drivers playing from the same physical space) to claim the 9dB gain. So, if you place a Dynamo across three locations, you'll have 1/3 PB13 for the first and then +1 dB for each non collocated Dynamo with more even response across the room.

To the OP,

Hz: PB13 / Dynamo 1500x X 3
12.5: --- 98.9
16 : 97.4 101.6
20 : 110.6 106.4
25 : 113.5 110.4
31 : 115.5 114.3
40 : 117.5 119
50 : 117.8 123.1
63 : 116.6 124.3
80 : 115.3 123.4
100: 114.4 122.2
125: 114.1 121.1

This is an ideal scenario. If one Dynamo could magically produce 3x the output. Stacking them or placing them side by side will not yield the 9dB ideal.

If your dealer will allow it, bring home 3 Dynamo's and a PB13, try both options and return the losers. Skip the SB13. Your room is too big and a ported design will give the visceral movie experience. You'll need a much more powerful sealed design to match the PB13 output above 25Hz.

 

[maxedout2134]

Unfortunately the store my friend works is rather small and they don't actually carry either of the sub's in store. To get them at that price he has to special order them from the manufacturer which takes 2-3 weeks and it removes the in home trial period. So Now its up to either the multiple dynamos, or the PB13. If you guys had to choose one option that is more likely to last and satisfy what would it be.

 

[Steve81]

I'll toss in one other idea:
http://reaction-audio.myshopify.com/collections/subwoofers/products/gamma-18?variant=1107645869

In terms of sheer output, the Gamma 18 will hold its own against a pair of Dynamo 1500s; however, there's a little more to this story. If you read the review of the Dynamo 1500X here and look at the frequency response, you'll note that it essentially pisses away the big advantage of being a sealed subwoofer with a steep high pass filter around 20Hz. This has consequences both in terms of effective extension as well as performance in the time domain.

IMHO, even a single Gamma 18 would make for a fun ride. If you could eventually pony up for a second, you'd have an extremely impressive setup.

 

[shadyJ]

A Gamma 18 may be able to match two Dynamo 1500xs, definitely worth considering. Another thing is, if you were considering a PB13 Ultra, for 1300 you can get an Echo 18 which will be more than a match for the PB13 Ultra as well.

 

[shadyJ]

These two statements are incongruous in that, the first claims gains from collocating 3 Dynamo's and the second from placing them across three locations. Pick one.

Your logic is sound but the calculations are flawed.

In the first case, you need 3 Dynamo subs collocated (not stacked, not side by side, collocated = literally 3 drivers playing from the same physical space) to claim the 9dB gain. So, if you place a Dynamo across three locations, you'll have 1/3 PB13 for the first and then +1 dB for each non collocated Dynamo with more even response across the room.

To the OP,

This is an ideal scenario. If one Dynamo could magically produce 3x the output. Stacking them or placing them side by side will not yield the 9dB ideal.

If your dealer will allow it, bring home 3 Dynamo's and a PB13, try both options and return the losers. Skip the SB13. Your room is too big and a ported design will give the visceral movie experience. You'll need a much more powerful sealed design to match the PB13 output above 25Hz.

There are a lot of factors involved with room acoustics, such as boundary gain, pressure vessel gain, cancellations and summations, etc. You can't predict what will happen (at least unless you have some sophisticated room analysis software. Placement will make all the difference. I would consider one in the corner, one to shore up the worst null left by a corner placement, and a near-field placement. Or put all three in near-field, that could be a lot of fun. Three subs gives you a lot of flexibility to get the response you want.

 

[agarwalro]

There are a lot of factors involved with room acoustics, such as boundary gain, pressure vessel gain, cancellations and summations, etc.

That's disingenuous. First you make some numbers up (ignore what the Dynamo can or can not actually do below 20Hz) to back up your poor recommendation, then follow-up with, IDK YMMV. Nice going.

You can't predict what will happen (at least unless you have some sophisticated room analysis software.

For frequency response, one only needs a SPL meter and test tones. Both are readily available online. I'll concede that time domain issues are harder to diagnose.

Placement will make all the difference. I would consider one in the corner, one to shore up the worst null left by a corner placement, and a near-field placement. Or put all three in near-field, that could be a lot of fun. Three subs gives you a lot of flexibility to get the response you want.

Inflexible placement guidance is questionable. Maybe, in your case it works. I recommend the Bass Crawl or ideally measurements.

 

[maxedout2134]

I do apologize beforehand for my lack of experience. But would that 18" woofer give me as tight or accurate sound as either the dynamos or the PB13 with the ports plugged up?

 

[shadyJ]

That's disingenuous. First you make some numbers up (ignore what the Dynamo can or can not actually do below 20Hz) to back up your poor recommendation, then follow-up with, IDK YMMV. Nice going.

I don't know what you are going on about. I really doubt that anyone who would compare three properly placed ML Dynamos 1500xs against a single PB13 Ultra is going to walk away wanting a PB13 Ultra more. Both these subs have a thorough and comparable set of measurements on them. It is pretty well understood how to optimize the frequency response using multiple subs. Will you get a 9 dB increase in output across the board if you space the subs out throughout the room, no; in certain frequencies you get less, and in other frequencies you can get more, but if done right the amount over overall acoustic energy increase remains the same. Also, if you wanted the full 9 dB increase across the board, you do not have to superimpose the subs, as you say, you only have to place them a quarter wavelength apart, so next to each other would work for that. The Dynamo is not a great sub at its MSRP, but its not a bad sub, and for 500, it is a steal.

 

[shadyJ]

I do apologize beforehand for my lack of experience. But would that 18" woofer give me as tight or accurate sound as either the dynamos or the PB13 with the ports plugged up?

Since that 18" has not been measured, it's hard to say. I wouldn't be surprised if the bass was as articulate as the Dynamos or PB13 Ultra. By the way, plugging the ports on the PB13 Ultra robs it of its chief advantage, and pretty much negates any reason for having it.

 

[Steve81]

I do apologize beforehand for my lack of experience. But would that 18" woofer give me as tight or accurate sound as either the dynamos or the PB13 with the ports plugged up?

As shadyj mentions, the Reaction sub in question hasn't been measured to know definitively (it's relatively new). Still, it's a myth that larger drivers are inherently less "tight", "musical", etc.

http://www.data-bass.com/data?page=knowhow&type=1

If you'd like some practical evidence, you can compare the impulse response of the old TC Sounds LMS Ultra 5400 18" driver to their LMS-R 12", both in sealed cabinets:

Same story looking at the waterfall & group delay graphs.

 

[djreef]

OK, so who here is going to bring up DIY?

DJ

 

[maxedout2134]

After looking into prices I did manage to get a better deal on the PB13 than I expected and went ahead and ordered two of them. Thanks for explaining the differences and opening me up into the idea of multiple sub's!