Hmmm not sure about that Mike… I thought drivers designed for closed cabinet where the ideal drivers for active / passive??? Attached is a picture of the old Gravis design which I have that is completely sealed (and the pics from my previous post which I forgot)
Attachments
In your research you should certainly explore the option of going active - fully active. Here's a link to Ground Sound (there are other manufacturers like Holm Acoustics, worth checking out): Ground Sound I recommend checking out their offerings and also the projects gallery, with user comments.
Using DSP crossovers will enable you to make quick changes to your design and evaluate different crossover approaches. It will also enable you to do some environmental acoustics correction (use with restraint).
Another way to achieve flexible design work is with software that enables crossover emulation (of either passive or active filters) before building it physically, such as SoundEasy (from your neck of the woods) Bodzio Software (scroll down for SoundEasy). Listen to how it will sound before you build it.
Been looking into active crossovers a little bit over the last week as they keep coming back up in things I read. Not sure I fully under the concept behind them but it would appear you filter / cross over the signal before you amplify it?
If I hadn’t already spent so much on the new D Class amps I bought a little while ago that would be a good option.
Just checking but the Coolback 11 600 is that price of roughly $3000 AU for 2? Says 2 pieces… Unfortunately I don’t have balanced outputs on the RSP 1570 so I couldn’t go that way anyway.
If I hadn’t already spent so much on the new D Class amps I bought a little while ago that would be a good option.
Just checking but the Coolback 11 600 is that price of roughly $3000 AU for 2? Says 2 pieces… Unfortunately I don’t have balanced outputs on the RSP 1570 so I couldn’t go that way anyway.
Umm, to my understanding it is not. In fact I did a couple of research and got some paper describing the nature of such design. But they are in Chinese.
what i mean is for passive radiator, the Qts of the driver unit is best to be under 0.38 (or 0.3x I can't remember well) and the box size would be as at Vented Port.
You have box builder you might run a simulation yourself?
For sealed driver, Qts itself could be as high as 0.5, the system Q would be too high, the bass would be out of the control
Can't remember all the theory well. Would let the others correct me if I am wrong
what i mean is for passive radiator, the Qts of the driver unit is best to be under 0.38 (or 0.3x I can't remember well) and the box size would be as at Vented Port.
You have box builder you might run a simulation yourself?
For sealed driver, Qts itself could be as high as 0.5, the system Q would be too high, the bass would be out of the control
Can't remember all the theory well. Would let the others correct me if I am wrong
Your right about the low QTS, but the low QTS belongs to closed boxed speakers not ported ones. See the driver used in the Gravis sub (or the base driver anyway).
Edit: Hate to disprove my own theory but the ported 22w has a lower QTS...
Edit: Hate to disprove my own theory but the ported 22w has a lower QTS...
Attachments
Last edited:
Tell you what Shaun you have definitely got me thinking about going active, quite possibly using something like the DCN28. I could use my existing 500w@8ohm per channel amps for sub frequency and use something smaller for mid and tweeter. It offers far more driver flexibility than passive crossovers ever could.
There are a couple of detractors from the idea... first is that I paid an extra $500 to get the better Shark DACs in my Oppo BDP-83 Special Edition which would seem to go to waste, and I already have Burr-Brown DACs in my current RSP-1570.
I couldn’t see any mention of which Burr-Brown DACs were used in the DCN28, they may be inferior to what I already have.
I will definitely be giving this some further thought, even if it gives the budget a bit of a hammering. This could quite possibly be the level of differentiation I need to step up to the next level of sound.
There are a couple of detractors from the idea... first is that I paid an extra $500 to get the better Shark DACs in my Oppo BDP-83 Special Edition which would seem to go to waste, and I already have Burr-Brown DACs in my current RSP-1570.
I couldn’t see any mention of which Burr-Brown DACs were used in the DCN28, they may be inferior to what I already have.
I will definitely be giving this some further thought, even if it gives the budget a bit of a hammering. This could quite possibly be the level of differentiation I need to step up to the next level of sound.
Adapters can be made from balanced XLR or TRS to TS 1/4" or RCA, balanced operation is not required for short cable runs.
The sonic advantages and flexibility afforded by digital signal processing prior to amplification compared to passive crossovers are quite great.
Drop Robert http://www.diyaudio.com/forums/members/robert-gs.html a pm. He's a member here. I'm sure he'll answer any question you have.
BTW, IIRC, they are PCM1704, but I speak under correction.
Thanks guys, I need to juggle some finances to see if I can go active (if it was just me I would spend the money, but I need to factor in she who must be obeyed).
But if I go active it opens up a whole new world in the bass department. Like the example on the website I could build bass drivers into an appropriately sized cabinets and put them in the corners, and build just the mid and tweeter into the main speaker cabinet.
I could sell the Gravis which I wouldn’t need any more and put the money from that back into the project. I had already budgeted a few thousand for the quality cross over components, so that could go towards the DCN28 (or similar)
I would need to buy several new amps, but the flexibility I would pick up would mean I could try numerous speaker cabinet combinations and not have to buy expensive passive crossover parts every time I change the box to fine tune the combo.
I noticed in most of the gallery rooms there was no surround sound processor, would going active mean I couldn’t use the RSP 1570 anymore?
But if I go active it opens up a whole new world in the bass department. Like the example on the website I could build bass drivers into an appropriately sized cabinets and put them in the corners, and build just the mid and tweeter into the main speaker cabinet.
I could sell the Gravis which I wouldn’t need any more and put the money from that back into the project. I had already budgeted a few thousand for the quality cross over components, so that could go towards the DCN28 (or similar)
I would need to buy several new amps, but the flexibility I would pick up would mean I could try numerous speaker cabinet combinations and not have to buy expensive passive crossover parts every time I change the box to fine tune the combo.
I noticed in most of the gallery rooms there was no surround sound processor, would going active mean I couldn’t use the RSP 1570 anymore?
I've always fancied the MiniDSP myself, the configuration options and software they offer are fantastic.
MiniDSP Kits | miniDSP
For 3 ways, or 2 ways / subs you'd need to go with the 2x8 most likely. And, it'll give you a new toy to build!
Edit: Active would mean that you'd need a dsp channel between the processor and every amplifier channel. If you're talking about multichannel or surround sound, you could easily get into several active crossover boards, plus an amplifier channel for every driver in the system. For instance, if I were to convert my entire home theater rig to active speakers, I'd need 18 amplifier channels and 3 MiniDSP units.
Last edited:
I don't see why not. There might be some latency related to the DSP, though. If it is significant, the existing system time delays would need to be adjusted accordingly. But that's about all, besides re-setting the speaker levels. If you have Audessy or similar correction implemented, that needs re-doing, too. I would, however, recommend not using any such further correction on the main speakers; rather fix the acoustics with appropropriate treatments if you can (big gains to be had here). In fact (I don't recall you saying anything about it), room acoustic treatment might even address some of the aspects of your current system that you are not too happy about.
Last edited:
I squandered the opportunity to compare a friend's MiniDSP 8x8 (or 2x8?) to my own Ground Sound DCN23 when I had it on loan, but could not find the time to use it. I did like the ministreamer, though.
Just looking at the prices of the RMB 1575, 1565, 1572, 1562 and none of them are really all that scary compared to the RB1091 and RB1092 I already have. They appear to have the same technology just with less power and have the ugly 15 series cases.
I’m not particularly looking to put woofers / sub woofers in the corners, was just thinking it opens up that options should I decide to build some 1000 litre monster cabinets and have the ability to tweak the output to match any time delays, I don’t have that option with passive.
Just thinking about whether all of the speakers need to be active or just the front two / three… I tend to listen to music in 2 channel and sometimes 3 channel but really wouldn’t need more channel than that unless I am listening to “Time” by Pink Floyd and want to get the whole spatial clocks thing.
Lots to think about, there are so many ways to skin the cat. The next question would be what brand if I do go active?
I’m not particularly looking to put woofers / sub woofers in the corners, was just thinking it opens up that options should I decide to build some 1000 litre monster cabinets and have the ability to tweak the output to match any time delays, I don’t have that option with passive.
Just thinking about whether all of the speakers need to be active or just the front two / three… I tend to listen to music in 2 channel and sometimes 3 channel but really wouldn’t need more channel than that unless I am listening to “Time” by Pink Floyd and want to get the whole spatial clocks thing.
Lots to think about, there are so many ways to skin the cat. The next question would be what brand if I do go active?
I think one needs to think about amplifier selection differently in this case. In an active system each amplifier runs at relatively lower power levels, as they are directly coupled to the drivers, with no losses of the type associated with passive crossovers. So low level performance becomes more critical. I am temporily using a 6-channel Rotel RMB-1066 to drive my active system. I expect a leap in performance (resolution of low level detail) when I finally replace them with higher-spec amplifier modules.
I hope that more experienced friends can chime in here.
I thought my RMB 1075 which now sits in its box was a nice amp until I went digital… sure there is a big difference in price, and a big difference in power output between my current D Class amps and the analogue RMB1075, but the difference was like chalk and cheese when I finally made the switch.
The Cremona’s came alive in a way I couldn’t have imagined, the improvement in clarity was immediately obvious and the driver control seemed infinitely tighter across the whole range.
So yes agree while I may need to spend more on buying more amps, they don’t need to be so over the top as the ones I bought for the Cremona’s where I was trying to buy myself some headroom.
I will get out of it relatively cheaply if they are only controlling one driver each. Still formulating a plan but thinking along the lines of using the 2 channel amps, the RB 1572 ($1299 each) and the RB1562 ($899 each) for the mids and the tweeters respectively.
That would give me 500w @ 8 ohm per channel for the Woofers (RB 1092), 250w @ 8 ohm for the mids (RB 1572) and 100w @ 8 ohm for the tweeters (RB1562). That should be enough to pretty much power any driver combination I wind up with.
The Cremona’s came alive in a way I couldn’t have imagined, the improvement in clarity was immediately obvious and the driver control seemed infinitely tighter across the whole range.
So yes agree while I may need to spend more on buying more amps, they don’t need to be so over the top as the ones I bought for the Cremona’s where I was trying to buy myself some headroom.
I will get out of it relatively cheaply if they are only controlling one driver each. Still formulating a plan but thinking along the lines of using the 2 channel amps, the RB 1572 ($1299 each) and the RB1562 ($899 each) for the mids and the tweeters respectively.
That would give me 500w @ 8 ohm per channel for the Woofers (RB 1092), 250w @ 8 ohm for the mids (RB 1572) and 100w @ 8 ohm for the tweeters (RB1562). That should be enough to pretty much power any driver combination I wind up with.
With shipping they come to 18,157 Dkr which is roughly $3,300 with GST included.
The RB 1572 ($1299 each) and the RB1562 ($899 each) are only $2200 plus shipping from Melbourne.
The DCN28 is 26,212 Dkr which is roughly $4730 (GST inc) + $2200 = roughly $7,000 and I haven’t bought a driver or cable yet.
Price yes, but I don’t think I could buy an amp I have never heard.
Do I really need all the whistles and bells? or can I put a digital crossover in-between the RSP 1570 and the amps and still get quality results?
The RB 1572 ($1299 each) and the RB1562 ($899 each) are only $2200 plus shipping from Melbourne.
The DCN28 is 26,212 Dkr which is roughly $4730 (GST inc) + $2200 = roughly $7,000 and I haven’t bought a driver or cable yet.
Price yes, but I don’t think I could buy an amp I have never heard.
Do I really need all the whistles and bells? or can I put a digital crossover in-between the RSP 1570 and the amps and still get quality results?
You should confirm this, but my understanding is that:
The Coolback 600 II already contains a DCN23 or DCN24 DSP XO. I get you concern about the amplifier; I can't comment on that.
DCN23 is the most basic; can give you 3-way or 2.1-way per module. It has selectable preset crossover slopes or custom, PEQ/delay/shelf filter/attenuation/notch filter for each channel. You can download the free application here http://www.groundsound.com/XOW.zip and play around with the software to explore the module's capabilities.
DCN24 is as per DCN 23, but with 4-way option plus a system PEQ.
DCN28 is the works. But I reckon it is too much ("bells and whistles"?) for what you need.
The Coolback 600 II already contains a DCN23 or DCN24 DSP XO. I get you concern about the amplifier; I can't comment on that.
DCN23 is the most basic; can give you 3-way or 2.1-way per module. It has selectable preset crossover slopes or custom, PEQ/delay/shelf filter/attenuation/notch filter for each channel. You can download the free application here http://www.groundsound.com/XOW.zip and play around with the software to explore the module's capabilities.
DCN24 is as per DCN 23, but with 4-way option plus a system PEQ.
DCN28 is the works. But I reckon it is too much ("bells and whistles"?) for what you need.
Thanks Shaun going off the literature the Coolback 600 II contains the DCN23.
How do you fing your DCN23? also the MiniDSP looks interesting...
How do you fing your DCN23? also the MiniDSP looks interesting...
Lots of fun! See some posts here Some just-for-fun speakers and here Tried RS52 mid as a tweeter.
I have not yet completed my current project (into which the DCN23 is now integrated), which is based on a set of re-purposed Meridian D6000's. I have replaced the tweeter with a SEAS DXT and the mid with ScanSpeak Revelator 18W8531. Sounds good, in spite of my room lacking acoustic treatment.
I hope to install a pair in my car, eventually.
Last edited:
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.