Velodyne DD15 vs DD15+ Faceoff

[gene]

I just got me some DD15+'s to review and compare against my DD15s. This should be an interesting review. I will be testing both subs outdoor 1 meter groundplane and doing a thorough evaluation of the newer auto correction system and PC interface of the DD+ series. Stay tuned...

 

[Ron Temple]

Looking forward to it. I love the DD15.

 

[Warpdrv]

Thanks Gene for setting up to do this comparative shootout... with tests... I hope you have the ability to show distortion results of the 2.

I was always very impressed with the DD line - in fact the very first HT sub that ever really opened my eyes was a DD in a fully finished theater - I was totally blown away - which overwhelming sparked my journey into HT, but my true passion certainly was in the BASS dept...

Please take some time to articulate if you can the differences in sound quality and accuracy between the 2....

DD's with their onboard EQ were IMO a true leader in the HT bass realm for a very long long time !!!
Its nice to see them update their DD product line... been too long for a makeover...

 

[gene]

REistortion

I won't be doing CEA distortion tests but I do have ability to measure distortion at max SPL via a reverse sinewave sweep outdoors. Since the Velo's have a great servo and compressor, I can crank them up to max drive levels where the limiter will kick in and be very close to MAX SPL data from CEA. All you have to do is add 3dB to my measurements and they should track very closely to what Paul's CEA data from the subs he reviewed.

The point of this review is to directly compare DD15 to DD15+ to understand the performance differences. I suspect a DD15+ will perform as good as an old DD18 but that's a premise of mine, not yet proven.

 

[GranteedEV]

I just wanna see hi res pics of the new driver

 

[shadyJ]

Hey gene, why do you think the dd+ would perform that much better then the regular dd? Just curious to know.

I have two very similar subs I should compare just to see if there is any performance difference whatsoever, the Hsu VTF3 and the Outlaw LFM-1 EX, but an outdoor comparison wouldn't be fair since the ports of the VTF3 are on a different side than the driver. In-room would be the only way to fairly compare them. If I were to ever do this, what equipment would I need to compare them? How do you go about measuring maximum clean output? Just a mic attached to a computer running REW?

 

[gene]

Hey gene, why do you think the dd+ would perform that much better then the regular dd? Just curious to know.

I found the DD15+ has about 4-5dB more output than the DD15 which is significant but the shape of the curve isn't as flat. I am pleading a case to Velodyne to adjust this slightly via EQ. Stay tuned...

 

[Warpdrv]

I found the DD15+ has about 4-5dB more output than the DD15 which is significant but the shape of the curve isn't as flat. I am pleading a case to Velodyne to adjust this slightly via EQ. Stay tuned...

Nice thing about that - is that a firmware upgrade can be used to adjust the curve and that case your pleading could actually be very productive....

Nice work gene....

Now as to why this wouldn't have been found inhouse before release is somewhat odd to me....

 

[gene]

I found a workaround (kinda). I forgot you can adjust the subsonic filter. It allows you to adjust it from 15Hz to 35Hz in 1Hz step sizes and from 6dB/oct to 24dB/oct in 6 dB/oct step sizes. The unit ships at 15Hz with 24db/oct


If you turn the subsonic up to 20Hz and adjust its rolloff to 6dB/oct, it will play better in a small room and blend better with small satellite speakers.

Check out my graphs.

The power compression SPL sweeps were done in default mode (15Hz, 24dB/oct) at 1 meter GP. I adjusted the subsonic filter for the nearfield sweeps so you can see how the shape of the curve changes.

I was concerned about the excessive roll off above 40Hz likely due to high voice coil inductance but if you need to balance the output at higher F, you can do so by adjusting the subsonic filter.

I will elaborate more in my review.

 

[GranteedEV]

I was concerned about the excessive roll off above 40Hz likely due to high voice coil inductance

My sub has an Le of 4.0mH and is roughly -3db at 200hz i believe with rolloff starting just under 80hz... is this what you would call high, average, or low?