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Author Topic: Anybody use/built the DR290 tops ?  (Read 18481 times)

Alan Star

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Re: Anybody use/built the DR290 tops ?
« Reply #10 on: July 23, 2006, 10:20:28 AM »

DAVID_L_PERRY wrote on Wed, 19 July 2006 22:03

Cheers Alan
What mackie tops are they ?

should be an awesome output system when complete.

I assume you are doing lots of large/outdoor stuff having gone for the DR300's ?



Hi David, have just been using a pair of SA1521's for smaller outdoor parties with my 2 labs. Was suprised at the mackies output though on high pass. Yes, the dr's are planned for bigger outdoor events. Probably a bit of an overkill for smaller events but I think I will sell the mackies if the dr's are sounding good, I think dispersion may be a bit of an issue with just a pair of them though. Hoping it will be ok with 2 on each side though.
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DAVID_L_PERRY

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Re: Anybody use/built the DR290 tops ?
« Reply #11 on: August 30, 2006, 06:21:27 AM »

Ok guys.  After all the comments I have completed the build of a single DR290 top pack yesterday and will be trying it out tonight at war volume against a couple of 'traditional' cab designs.

The DR290 cab is loaded with a Single B&C neo 12" driver and a pair of 1" JBL 2416 compression drivers.

The other cabs I will be testing against are
A Concert systems (respected uk manufacturer) JBL loaded 1x15 + 1x2" biamped top

My current sealed front loaded Eminence delta Pro 1x12 + 1x2" (Celestion CD3065)

An Adlib audio 1x12 + 1" top pack

Knobody is more interested in how they sound more than me after the time involved in the build.

We will be trying the cabs out with three of us there to try and get a subjective view.

I powered the cab up last night at moderate levels (as it was pretty late) and I have to say it sounded superb, but tonight will be the tester at war volume.

We will be taking down a couple of Measurement mics to try and check what the output measures at, up against the other cabs.

All of the cabs will be alligned using my Ultradrive
We will test the system using pink noise and try and obtain on/off axis readings.  We also have a good test source cd with swept sign waves and test tones (Its Binks test cd)

I will initially eq the cab to give a fairly flat response.

We are mainly going to be doing a good listenening test using various sources of playback music and a sound test CD.

I will fill you in tomorrow on the findings

Dave
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DAVID_L_PERRY

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Re: Anybody use/built the DR290 tops ?
« Reply #12 on: August 31, 2006, 04:28:39 AM »

Posting this on Bills forum as well as here as a lot of people are pretty interested in the results:-

So I had the full system settup last night at a local Hall I use along with two other PA providers I know well (Cheers Rick)

Seriously dissapointed is somewhat of an understatement....are you all ready to start pointing and laughing and shout told you so...go on have a go...I'm a big boy....oh god Im so upset

The cab sounded good, but not quite as smooth sounding as either of the other two cabs we tried it up against (we just did my existing sealed front loaded top and the Concert systems top the Adlib was a not checked). (All traditional front baffle loaded boxes)

We could eq the top end to be as smooth as the other two boxes (both had 2" HF drivers) but the mid range still didnt sound quite as good or extend as low as either of the other boxes.

Standalone it sounded good, its just when you then plugged in the other cabs and unplugged the DR that you hear it does not sound as good or any louder (other than a harsher top end without eq adjustment)

The other major factor was that the DR was no louder at all than the other cabs.  We had a DB meter running all the time so that we did not have to trust purely our ears.

We checked the cabs with purely the midrange drivers running and checked for air leaks all around the cab and within the throat assembly - none at all.  

Again when my existing front baffle loaded cab was plugged in the midrange sounded fuller and a little louder (agian checked with a DB meter and not just our ears)

Unfortunately we had reliability issues with the Measurement mic so could not use it to eq out the cabs but instead simlpy eq'd to taste.

Obviously you will have to simply take my word for it that the cab build is airtight and built to exact spec (certainly not my first cab build) so I can discount build quality error.

I have asked Bill to double check the specs of the driver agian to make sure that it is a suitable driver (He previoulsy said it was but worth double checking)

B&C 12 hpl76 :-

Nominal Diameter 320 (12) mm (in)
Nominal Impedance 8 Ohm
Minimum Impedence 6.7 Ohm
Nominal Power Handling 350 W
Continuous Power Handling 700 W
Sensitivity (1W/1m) 99 dB
Frequency Range 50 -3500 Hz
Voice Coil Diameter 76 (3) mm (in)
Winding Material Aluminium
Former Material Glass Fibre
Winding Depth 17.5 (11/16) mm (in)
Magnetic Gap Depth 10 (0.4) mm (in)
Flux Density 1.15 T

Fs 49 Hz
Re 5.7 Ohm
Qes 0.26
Qms 2.5
Qts 0.25
Vas 91 (3.2) dm3 (ft3)
Sd 522 (80.9) cm2 (in2)
Eta Zero 4.1 %
Xmax +/- 4 mm
Xvar +/- 5.5 mm
Mms 43 g
Bl 17.3 Txm
Le 1.5 mH

The two HF horns are JBL 2416 1" specs as follows:-
HIGH FREQUENCY SECTION: 2416H-1
Sensitivity’: 109 dB, 1 W @ 1 m
Input Power Rating’: 50 W continuous program
Crossover Frequency: 1.5 kHz
continuous power rating of 50 watts.

I had my subs crossed over at 120hz and the horns crossed over at 1.6k

I plan on removing the B&C and trying out in my existing tops to see how it sounds in that - It should be a far better driver than the Eminence Delta Pro

Summary so far was that it did not sound as good and no more powerfull than either of the other two boxes that I could have built in one evening.....arghhhhh....

Not thrown in the towel yet but very close.....my wife laughed a lot...

Dave


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joseph decker

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Re: Anybody use/built the DR290 tops ?
« Reply #13 on: September 01, 2006, 02:05:26 AM »

I'm not sure, but it seems like Bill might have mentioned that he didn't look at the frequency responses, but that the B&C driver should work if it had the rising response to 2.5k that the 2510 has.

Looking at the spec sheets, it looks like the 12 hpl 76 has about a 4 db bump around this frequency. The Deltalite II has a much more pronounced rise up it, as opposed to the smaller 'bump' in the B&C's response. Also, the Deltalite's response, in addition to having a rise that starts lower in frequency, is up about 9 db.

The DR's count on this rising response to overcome the attenuation caused by the 180 degree bend and horn's upper rolloff beginning. The smaller rise is probably the culprit here.

Lowering the crossover slightly or, if you have one availible, trying a driver with a more pronounced rise might give better results.

It's bad to stay in a relationship purely because there's so much invested in it that you don't want to give up, but i'd encourage you to give it another try, if only for that reason.

joseph decker
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Peter Morris

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Re: Anybody use/built the DR290 tops ?
« Reply #14 on: September 02, 2006, 10:01:58 PM »

Hi David

The problem with a 12 inch horn loaded mid is that they struggle to get much pass 800Hz.  Make a model in McBean’s Hornresp (Exp, Hyp, Conical etc. does not matter) and you will find that the critical parameters are cone mass and the motor strength (BL/Re^2).  Even with a very light cone and a strong motor, 800Hz is about the limit.  Only 80dB/W/M by the time you get to 2KHz!

However this programme assumes the cone behaves as a piston, which it does not in the higher frequency ranges. In the case of a 12, the piston range ends at ABOUT 800 Hz.  I guess you could say that the horn is then seeing a smaller lighter cone as only the centre of the speaker is moving (sort of)

Looking at bills design it appears to go really well up to about 500 Hz and then starts to rely on this behaviour.

I suspect part of your problem is the B&C driver does not suit this type of application even though it appears OK.  I would suggest you MAYBE better using the drivers that Bill suggests.
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DAVID_L_PERRY

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Re: Anybody use/built the DR290 tops ?
« Reply #15 on: September 04, 2006, 05:45:01 AM »

Prior to starting the DR build, Bill did originally state this driver was very good in the DR, but much more expensive in the US Rolling Eyes .

As the eminence Deltalite 2512 was not available to me in the UK for about 4 weeks I went for the more expensive B&C.  As the cab is crossed over now at about 1.2k the difference between the Eminence and B&C higher mid range should not be of any issue.

I am going for another full try out tomorrow night and will post results.
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bgavin (Bruce Gavin)

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Re: Anybody use/built the DR290 tops ?
« Reply #16 on: September 04, 2006, 09:07:54 AM »

DAVID_L_PERRY wrote on Thu, 31 August 2006 01:28

Obviously you will have to simply take my word for it that the cab build is airtight and built to exact spec (certainly not my first cab build) so I can discount build quality error.


Considering so MANY have great success with this design, and you do not, one cannot dismiss the probability of a build error.

Even experienced physicians kill people now and then.  That is why it is called "practicing medicine."

I don't see a post of an impedance plot or response measurement that would systematically identify the cause of your problem.  IMO, very few users on PSW have any DR experience at all, let alone experience with multiple builds.  

So I have to ask, are you here at PSW to bad mouth the DR?  If not, and you are here to find the cause of your problem, then you are in the wrong place.
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Craig Leerman

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Re: Anybody use/built the DR290 tops ?
« Reply #17 on: September 04, 2006, 05:53:34 PM »

Quote:

Considering so MANY have great success with this design, and you do not, one cannot dismiss the probability of a build error.


Or, those that are having success have not done a heads up comparison against better cabinets using similar drivers.  Don't get me wrong, I'm not knocking Bill's designs, or anyone elses, but I have found that many people who build things, will see past faults in the outcome, because they have built it themselves.

I personally used some home built cabinets loaded with JBLs successfully for years, and was very happy with the results, until I had the opportunity to directly compare them to some other cabinets loaded with the exact same drivers. Only then was it apparent to me that my design (tuned mainly by ear and not by math) was not as "optimal" as I had thought!  


Quote:



I don't see a post of an impedance plot or response measurement that would systematically identify the cause of your problem. IMO, very few users on PSW have any DR experience at all, let alone experience with multiple builds.

So I have to ask, are you here at PSW to bad mouth the DR? If not, and you are here to find the cause of your problem, then you are in the wrong place.


A lot of PSW user have experience with "multiple builds" You just don't see a lot of it posted here because A) This is the LAB SUB forum, and most folks keep the topic on the LAB SUB, and B)You don't know the people here on the site.   If you did, you would understand that MOST of the older folks here all built the majority of their gear (because back then there was little gear available to buy that fit our needs), and a good portion of even the younger folks have built a lot of gear (especially monitors and subs).  

I didn't see his posting as bad mouthing. Nor is he in "the wrong place" to find the cause of a problem. If anything, I'll bet the collective speaker design/build experience here is far greater than most of the other DIY PA forums COMBINED!

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peter.golde

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Re: Anybody use/built the DR290 tops ?
« Reply #18 on: September 04, 2006, 10:28:05 PM »

DIY is a gamble, Bill Fitz provides very good measurements for his designs, but countless factors involved in DIY are beyond his control or ability to guarantee success. Then there are other things that need to be considered such as intended usage, volume requirements, a "sound" you are looking for, etc.
I agree that speakers you build yourself tend to sound better, until you A/B them against superior systems.
I have built Bill's designs, Mr. Danleys design, and my own with very good success. I can also state then I have built the DR250, one of Bill's folded horn designs similar to Mr. Perry's DR290, compared it against several MI grade boxes, and it has fared quite well, not just my opinion, but also of other sound professionals present and listening. So my success story with these is for $200 worth of parts and my leisure time invested, I built a box that beats anything MI grade offering. At a recent rave, these little boxes had the best sound in the house. Three rooms, three different systems, one with JBL SRX dual 15 tops, the other with Yorkville fully horn loaded tops. It was easy to walk from one room to the next and listen. The Fitzmaurice horns had the best sound by far. This tells me that for this particular usage, in this particular room, I had the system that fit best. If the rooms were swapped, or if it was a live event it might have been different.
I do not agree with Bruce Gavin, that MR. Perry was bad mouthing the designs, I feel Mr. Perry's frustration in that it is a considerable investment in time to build these things, especially the first go around, and his expectations were high. I think if he built them correctly, he should end up with a very usable box. The midbass performance of these horns is impressive, and since he found his to be lacking, something might need to be fixed.
I find PSW to be an invaluable resource, there aren't many sites on the web with such dedicated professionals so eager to give up their trade secrets to help others up and coming. Where would Evan K. be without the guidance from industry professionals here Razz

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Peter Morris

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Re: Anybody use/built the DR290 tops ?
« Reply #19 on: September 05, 2006, 03:08:01 AM »

Hmmmmm …..  Your choices are:

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