* Offical Velodyne Support Thread * - Page 295

Hi Rob,
What is the unit of the displayed volume on the DD+, is it dB or just a simple index?

Thanks,
Xavier.

Each change in volume unit (ie changing the volume from 30 to 31) increases the output approximately 0.4dB. This is true throughout the majority of the volume scale, however at the upper end of the volume scale this is likely reduced when the gain compression kicks in.

Originally Posted by zephyr35

Hi Rob,
What is the unit of the displayed volume on the DD+, is it dB or just a simple index?

Thanks,
Xavier.


Good question, I've actually thought about asking that but it slipped my mind. Right now my DD-15 is set to number 1, and my DD-12 is set to 5. Thats 75 db at calibration. I think I have plenty of head room.

If you are running your subwoofer that low, I would look to trim the input signal. The DD subwoofers work best when the volume is above 5, between 10-40 is typical.

I will give the manual eq a go. Hope I can figure it out, seems kinda over whelming. It says to self eq one sub and then do a manual calibration on the second sub. Should I do a full calibration with the main speakers too? I will end up turning off the crossovers because of audyssey.

Interesting info on the subs running good above 5, and typical at 10-40. When I recalibrate my system I will run the subs a little hot. This way audyssey will trim them lower. Right now there at 75 db and trimmed to -0.5 and -3.0.

With two DD subwoofers, run self EQ on the subwoofer that is the Slave, and manual EQ on the Master, assuming you are hooking up the RS-232 master/slave connection. If you are running them as two independent subwoofers and not in the master/slave configuration, then you should manually EQ both subwoofers.

I always recommend running Audyssey with the subwoofers set between 15-20 on their volume output. Let Audyssey adjust all the levels, then go back in manually and look at the LFE output. If the LFE output was turned down too low or too high, that is not a good thing. I prefer to keep my LFE output at the neutral 0dB setting but plus or minus 5 or less can be acceptable. Then feel free to adjust the subwoofer volumes to taste. Most people will prefer a bit more subwoofer than how these auto calibration systems will set due to the difference between the microphones measured response and our perceived response. Most folks hearing rolls off more in the low end than the microphones pick up does.

Yea I'm using the master slave configuration. The problem I have is that my slave (dd-15) is right next to my couch, about 3-4 feet away from MLP. So when I run self eq, the test tone is to loud and doesn't seem to do anything on the graph. The spl is pinned on the graph. I know you said self eq is set at a predetermined loudness, maybe I should do the opposite? Self eq master and manual slave? Even after I do that...how do you manual? Hook both subs up to out put test tone and just move eq bars up or down to make the graph as flat as possible? I noticed you can cursor left or right on each frequency (Q?).

In the past I've just run self eq on both avr and subs and just left it at that. Now that I have my system complete, I know it can sound much better then it does with the self eq. So I'm kinda a noob at doing the manual eq stuff. Do you know of any installers/calibrators in the area? Someone that can come to my house and dial in my tv, and audio? I've called around to places like century stereo, and places like. They say only if you bought equipment from them that they will come out.

Given the proximity of the slave, you will need to EQ this subwoofer manually. You will need to EQ these two subwoofers as individual subwoofers, one at a time. You can not have both subwoofers playing the sweep tone at the same time. While the sweep tone plays you can move the cursor from band to band and press select for the band you wish to adjust. From there you can raise or lower the gain, and shift the frequency you are adjusting up or down (so instead of adjusting at 40Hz, you can adjust at 35Hz, etc).

Now in addition to those adjustments you also can adjust the Q factor, this is how wide or precise the audio filter is. It can be thought of like a paint brush, if you want to paint a thin line you need a fine brush, trying to do so with a large thick brush will end up with paint outside of your desired area. With the Q factor, adjusting a the gain at one frequency effects the other frequencies around it, some times this is good, and sometimes this is bad depending upon your rooms curve. Adjusting how precise the filter is can help to provide better results.

Unfortunately I do not know of or make recommendations regarding other companies and their work. Most stores will typically only work with equipment purchased from them. If your dealer does not provide this service, check with local TV and stereo repair shops. Some of the larger shops have started to add calibration services to their offered services.

Ok....starting to get a grasp. One more question, I shouldn't have to worry about the x-over frequency right? I mean auddyssey will take care of that right? All I should worry about is making the sub work with my room, not my mains.

Thx

On the subwoofer you can turn the cross-over all the way up to defeat it as the crossover will be controlled by the receiver. Now we can enter a debate about the crossover point. I have never been impressed by any automated set up when it comes to determining the crossover as they tend to set the point way too low in my opinion. It is our belief that for the best overall sound, most full range speakers should have the crossover set between 60-100Hz. Remember that crossovers are not cut filters, most receivers utilize a 6 or 12 dB/octave slope which means you will still have bass extension to the main speakers well below the crossover point.

At the moment I have the dd x-over set to off. If you cursor to the x-over and hit reset on the remote, it turns it "OFF". After running audyssey it set my mains to 40hz, center 60hz, and rears to 70hz. I then manually changed them all to 80hz.....and there's where the debate begins. I find that it sounds quite good there.

I always say, it does not matter what any so called expert says, all that matters is what sounds good to you. It's your system, listen to what you like!

first time posting. i have an spl 1500that developed a lund humm. the hum is present whether connected to the amp or not. Suggestions please?[

Hi Rob,
My main speakers are directly connected to the preamp and have a cutoff near 60 Hz. Running Auto EQ gave a crossover frequency of 65 Hz and some other time 91 Hz.

This gave me the idea of trying to supplement my main speakers under 200 Hz.

Therefore, I have the following setup :
- crossover at 199 Hz,
- slope at 6 dB/Oct
- Phase at 135°
- Two filters with a small Q between 60 Hz and 200 Hz.

I had to push up the phase quite a bit. I have kind of a feeling that this is not so good between 60 Hz and 200 Hz if you are not listening at the sweet spot.

What's your view on this?

Is there any other inconvenience to such a set up vs a lower crossover frequency?

If you remove the RCA cable from the LFE input on the subwoofer, so that only the power cord is connected, and the hum remains, then there is an issue with the subwoofer. If the hum goes away, need to do some trouble shooting. Either way, you should either email service@velodyne.com or call product support Monday-Friday from 7am-4:30pm Pacific time at 408-465-2851.

The first and most important thing is do you like the way it sounds, if so, then all other opinions are invalid. Traditionally the crossover has been set below 100hz to keep male dialog from coming through the subwoofer. This primarily matters in a hometheater set up. If you are using your system purely for music, then depending upon the music you listen to, I could see some valid arguments for some setups similar to yours.

Well I am also listening to movies and operas with male bass voices... So I'll follow your advice and stick below 100 Hz.

One additional question, in the documentation it is said not to EQ dips too much. I have a filter at +6 dB at a dip, but it does not improve the dip too much. I am under the impression that this filtering has more negative impact than positive...

What would be your advice for the amount of filtering at a dip frequency ?

Hello everyone,
This afternoon I'm going to look at a Velodyne HGS 15. I'm told by the seller that it functions and is in good condition. I'm able to buy it for $250. Am I playing with fire? Because I hear the amps break easily. Is there anything in specific I should look for? Thank you for any help.

Sent from my Galaxy Nexus using Tapatalk 2

The idea that the amps break easy is incorrect. The fact is that the HGS subwoofer was produced in three variants all commonly referred to as the HGS over a period of 10 years. During this time many units were put into the field, some of them are now 16 years old. Overtime you will have failures occur, and in 98% of all failures the point of failure is electronics as opposed to the driver. Because all the electronics, including the amplifier, are attached to the back panel, all the electronics are mistakenly commonly referred to as the amp. Since people report failures on the internet and not that their subwoofer is failure free, a distorted image is painted that the HGS has issues with the amplifier.

What you should know is the HGS is an amazing subwoofer and is fully serviceable by Velodyne.

Thank you for the response. Can't wait to pick it up.

Sent from my Galaxy Nexus using Tapatalk 2

Hi Rob, my DD-18's microphone clip holder snapped, the one that attaches to the supplied stand. I'm all the way in the Philippines, any way I could get just that part? TIA

The least expensive way to acquire the part would be to look for a replacement at a local music supply store. Velodyne does not manufacture those parts and gets them supplied as complete mic stand. We would need to sell you the entire stand assembly in order to provide just the clip. Alternatively, you can use the mic without the stand entirely, I do.

Thanks for the promp reply as usual Rob. I've looked around musical instruments shops to no avail. The mic of the sms1 is thinner than the ones commonly available. Nothing a rubber band doesn't fix anyway:).

True Story.

Rob,
In the DD+ documentation it is said not to EQ dips too much. I have a filter at +6 dB at a dip, but it does not improve the dip too much. I am under the impression that this filtering has more negative impact than positive...

What would be your advice for the amount of filtering at a dip frequency ?

In order to raise a dip up, we must boost power to that frequency, if that dip is the result of a room issue, it can be extremely difficult to correct by boosting the power trying to overcome the room. It is much easier to reduce the other frequencies to match the dip or have the dip and peaks meet halfway, then boost the overall signal intensity via the master volume.

Does anyone know how low a dd-15 will play at referance levels?

The original DD-15 plays down to 15Hz at plus or minus 3dB.

Thanks Rob, I was cruising the "bass in movies" thread and people are saying they have bass down to 5hz. Just wondering how they get so low.

The ultimate frequency response of the DD-15 can extend near 5Hz, but the roll off is quite significant at that point.