Connecting a velodyne

Hi

Just wondering how I would go about connecting a DD series Velodyne to my system. My preamp only has a single set of outputs (which go to the power amp). Without a second ouput on the preamp, how will I be able to connect a DD sub?

Thanks

 

wire the sub in parallel to the speakers from the power amp outputs into the Velodyne high level inputs.

 

In series between amp and preamp

The Velodyne manual has a section on this http://www.velodyne.com/velodyne/products/manuals/63-DD Rev G_ manual_English.pdf. While you are there, I recommend you upgrade to the latest v2.2.0 operating software. The sub goes first in line after the preamp. The sub has a pair of RCAs for feeding line level onto the power amp that are fed from a configurable high-pass filter in the sub that defaults to 80 Hz, 6 dB/octave. This way is usually best, because the sub and the mains do not both produce conflicting bass below 80 Hz with unpredictable but usually undesirable results.

(DD-15 user)

 

If I understand correctly, Robbo is saying connect the sub to the power amp speaker terminals in the same way as one would connect a REL (high level). But doing it this way would mean running my speakers full-range and would not utilise the Velodyne's high pass filter?

Steve is saying that I should talk a long (about 3 metres in my case) phono lead from the preamp to the sub and then another long lead from sub to power amp inputs. But this way assumes that my passive preamp (TVC) will not have any problems driving long interconnects. And would also mean potentially spending several £100s of pounds on interconnects if I wanted them to be of the same quality as my existing metre-long interconnects (Chord Anthem).

Correct?

 

Yes, that's what we said.

Long line level is preferable to long speaker leads anyway. Subs often come with their own lead. It's not IMHO worth spending hundreds on one. If you sit your power amp in the middle it might not be far from the sub.

 

from what I've tested with my setup - I repfer the sound when I use speaker cables to connect to my sub rather than a phono cable...

 

I have a DD15 set up as per Steve's suggestion. This works well for me, using the cheapest leads I could bodge up. Once I've re-decorated the living room I'll move the power amp closer to the 'speakers so wont use the 4 channel mic cable with this arrangement. If I'm feeling like cheaping out I'll simply split the 4 channel into two lengths of 2 channel cable and adjust lengths as appropriate.

 

Steve and Stuart
Can you confirm that I've got this right. Connecting the sub in series results in the high pass filter in the sub acting like an active crossover i.e. if its set at say 80hz, then only the frequencies below 80hz are fed to the sub's driver and only those frequencies above 80hz pass through to the power amp that drives the main spkrs - hence the power amp never gets to "see" those lower frequencies and doesn't have to drive them through the main spkrs. Also no duplication of those bass frequencies by the sub and the mains. Is this correct, because its exactly what i want to achieve!

Alternatively, I could use an external active xover to split out the bass frequencies and then bypass the crossover/filter in the sub (from what I've read the Velodyne DD's have such a bypass). Any thoughts on this option?

Any advice on this much appreciated

 

yes that is correct Ian.

The high pass filter means the whole sound goes through the crossover in the sub (purists will scream blue murder), but the advantage is as you describe.

I run the high pass filter on my revel to good effect.

I also just use a 5m Maplins interconnect.

Cheers
Chris

 

Ian - correct - but please note that the crossover slope is iirc a gentle 6db for the mains.

 

Yes, you have that right - you might have seen this in the manual I linked to earlier: "[3rd input option] Connect to a pre-amplifier’s main outputs and
returning them to your amplifier inputs. When installed in this fashion, your satellite speakers
will be crossed over at 80Hz, which removes the lower bass from your amplifier and
speakers, enabling them to do a better job reproducing high frequencies. By utilizing this
method, you will have a bi-amplified system, gaining improved power and headroom for
your system." T

There are also support threads/forums on avtalk and avs forums. My preference though would be to use the sub out from an AV processor, but if you just have a stereo preamp then I believe the thru-routing is the one for you. It's always possible you could get it to work with the mains still running full range, as Robbo and mr cat said, just that it is more likely there'd be problems in the crossover area due to duplication.

 

Chris
So you are running you Revel in exactly the way I described? Forgive my ignorance on this, but is then this type of configuration (whereby you split out the low frequencies, give your power amp an easier load and avoid bass duplication) possible with most decent subs?

Rgds
Ian

 

Stuart
I'm a bit of a technical dunce; does that mean that there is not an abrupt cut off at the specified crossover point, and what are the implications?

cheers
Ian

 

No, it's a gradual handover - like a relay baton being handed over

 

Hi

I only have experience (limited) of Velodyne DD's and of course my Revel.

With both of them you can do it in this way.

Also of course with Velodyne's 'DD' range and Revel subs, you can use onboard digital EQ to make sure the transition is smooth in terms of volume and frequency response.

 

Did you find it necessary to buy a SPL meter for your Revel- they don't come with microphones like the Velodynes, do they?

 

yeah I bought one. It was about £20.

Its been useful for all sorts.

 

Where from if you don't mind me asking?