What are the advantages/disadvantages of running them series or parallel?
Digmoda packs 500W whats the minimum you think they could be run on?
I can get a reasonable level of sound from a single 20W Kingrex T amp, from my OB speakers that I have at the moment, that have Saba mids, tweeters & 15" Altecs in them.
A few people have expressed the opinion the Altec's are not good for OB but mine sound fine, maybe I dont play them loud enough to encounter problems.
Dipole15 (8ohm coils in parallel)
Fs: 21.7Hz
Qms: 15.2
Vas: 623 L
Cms: 0.7mm/N
Mms: 90 g
Rms: 0.81kg/s
Xmax: 12mm
Sd: 830 cm2
Qes: 1.00
Re: 3.1ohm
Le: 0.04mH
Z: 4ohm
Bl: 6.1T/m
Pe: 200Watts
Qts: 0.94
1WSpl: 90.1dB
2.83V: 94.2dB
DIPOLE15 (coils in series)
Fs: 21.7Hz
Qms: 15.2
Qes: 1.00
Qts: 0.94
Vas: 623 Liters
Cms: 0.7mm/N
Mms: 90 grams
Sd: 830 cm2
Rms: 0.81Kg/S
Bl: 12.2T/m
Re: 12.3 ohms
Z: 16ohms
Le: 0.15mH
Pe(max): 200Watts
1WSpl: 90.1dB
Xmax: 12mm
Perfect low response down to 20Hz
Amazing!Attachments
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Dipole15 (8ohm coils in parallel)
Fs: 21.7Hz
Qms: 15.2
Vas: 623 L
Cms: 0.7mm/N
Mms: 90 g
Rms: 0.81kg/s
Xmax: 12mm
Sd: 830 cm2
Qes: 1.00
Re: 3.1ohm
Le: 0.04mH
Z: 4ohm
Bl: 6.1T/m
Pe: 200Watts
Qts: 0.94
1WSpl: 90.1dB
2.83V: 94.2dB
DIPOLE15 (coils in series)
Fs: 21.7Hz
Qms: 15.2
Qes: 1.00
Qts: 0.94
Vas: 623 Liters
Cms: 0.7mm/N
Mms: 90 grams
Sd: 830 cm2
Rms: 0.81Kg/S
Bl: 12.2T/m
Re: 12.3 ohms
Z: 16ohms
Le: 0.15mH
Pe(max): 200Watts
1WSpl: 90.1dB
Xmax: 12mm
Perfect low response down to 20Hz
Looks good, I think these may be the way to go, thankyou, unfortunately I have had too many things on my mind to be able to concerntrate on giving Hornresp a go, but I will soon.
It really all depends on what your own personal version of "enough bass" happens to be. Most likely with the Altec, you are technically "bass lite" if considering studio reference quality. I attended the RMAF last year with my own demo disc mixed and sequenced at the studio. Most systems, even those with $$$ price tags were not sufficient in the low end.
My relatively humble OB with a single 15" per side is close, but not quite there yet. I would say that it a pretty good recommendation for the Ae drivers right there. I need to fit another driver on my baffle of go with some sealed servo boxes behind the OBs in the corner. No decision there until the OB AND new room treatments are complete.
I have a few measurements in the near field here:
HTGuide Forum - AE Dipole15 off axis curves
Greg
Generally with measurements dont have enough knowledge to know wether they are good or bad? For instance, in Helmuth's measurements for the Dipole15, the top response looks terrible, but probably isn't, & the bottom response looks great, & probably is. When I look at the one's in your link I think they look ok.
I was already pretty much set on the Raal when I posted this thread, the only issue I can see (apart from the cost) is they are not dipole, have you found that a problem?
I believe Raal have done a Dipole tweeter but I think the price is something like $900.00 each & they dont appear to be easily available yet. At $900 there out of my ball park.
I am now pretty much settled on 1 x Dipole15 per side, I mostly listern to classical so I expect they should be fine.
I will stay with the Saba mid for the moment & see how it pans out.
I'm also looking at buying a Behringer DCX2496 to dabble with active.
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The top respone is of the dipole 15b in a OB. And needs there for a equaliser to make the response flat 30Hz and up This means you spl at 35Hz will be your SPL at 1W. That will become about 78dB 1Wmtr
And as for this graphic Response usable up to 800Hz.
You wiil be building this OB based on theorie. Thats the normal procedure. After that it is necesary to measure the response to make it perfect.
Then you need freeware as holmrespone or arta your 16-24bit soundcard of your computer and a behringer EMC8000 mic with phantom supply mic preamp.
The bottom response is also in a OB but then without the influence of the sound of the backside of the OB. This influence is shown in combined response that is the top response. It is a circular baffle of 60cm in this case.
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Helmuts is NOT a real measurement, rather a simulation to show the hypothetical response on an open baffle. Mine is in room. Low end response is truly extended with only minor EQ needed compared to non OB specific woofers. Just a matter of how low you wanna go and what kind of headroom you might want.
Too bad you are half way across the world, I could help you out with the Raals. I am direct with them. I don't real want a dipole, but rather want to avoid boxiness, so having a monopole Raal is not a problem at all. I will be using lots of room treatments behind the speakers to lower the rear wave considerably.
Behringer DCX2496 is a great place to start to get your feet wet. Makes adjustments so simple, that I feel one can get a much more optimized system by being able to quickly audition changes.
Greg
Too bad you are half way across the world, I could help you out with the Raals. I am direct with them. I don't real want a dipole, but rather want to avoid boxiness, so having a monopole Raal is not a problem at all. I will be using lots of room treatments behind the speakers to lower the rear wave considerably.
Behringer DCX2496 is a great place to start to get your feet wet. Makes adjustments so simple, that I feel one can get a much more optimized system by being able to quickly audition changes.
Greg
Hi Guys. Interesting chat, having in my mind the project to build an OB. I am looking a lot of woofer specifications to make the final choice for the woofer bass. The AE speakers with Dipole12 or Dipole15 look very good. But I see others choices too. What is more important parameter, High Qts or High sensibility if I have to make the choice. I will go with active amplifier and equalizer for the woofers. Thx.
Well from what I have learnt so far, you dont need either if you are going to go active. The bass drivers Linkwitz user are low in both departments. I personally would go for the sensitivity as you wont need as much power to drive them, probably depends on how sensitive your other drivers are.
I have been convinced to go active, the Dipole15's are fairly sensitive but not as sensitive as I was originally looking for, but now I am going active I will be able to wind the gain up on them. It's important to get good xmax so they can supply enough SPL as you go lower.
In saying all of that, I am running Altecs 15 in my passive OB's at the moment & they have done everything I have asked of them so far, they definitly have the sensitivity, but not the xmax or Qts. It possible if I left my son alone with then they would be dead, oh I mostly play classical & not overly load.
David
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Hi DAvid. I was reading that there is two ways to approach the choice of the woofer for OB. First having a high Qts when it goes without equalizer and pasive amplifier ?. And then, the Qts do not matter if there is the amplification is active and with equalizer.
Yes, having a high Xmax, I believe, that is good in both cases. But, what is here is the cost parameter. There are some woofers at 35 Us and then at 350 Us !. I know that some building in masive cast aluminium or other details...Another parameter that I am looking for is the Mms, the mobile weight. I think that if is lighter I would have more fast" bass ?
Yes, having a high Xmax, I believe, that is good in both cases. But, what is here is the cost parameter. There are some woofers at 35 Us and then at 350 Us !. I know that some building in masive cast aluminium or other details...Another parameter that I am looking for is the Mms, the mobile weight. I think that if is lighter I would have more fast" bass ?
Hi Abelma, Hmmm, I'm a bit of a beginner so hopefully someone with more knowledge will help out.
David,
driver sensitivity usually is given for 1 kHz. This is useless if you want to compare woofers of different Qts. By their nature low Q woofers MUST have a better sensitivity at 1 kHz than at 100 Hz, if compared to high Q drivers. Forget about the spec sensitivity, but look at the 100 Hz SPL in the frequency response. You should be surprised how well high Q drivers can do in that frequency range.
Rudolf
Abelma, based on Rudolfs, bountiful knowledge, I would start looking thru frequency response charts for highish Qts drivers (0.5-1.0, 0.7 seems a good base) with the highest sensitivity you can find at 100Hz.
David
Yes, a higher overall sensitivity MAY mean nothing because the woofer could be up to 10 or 15 dB down by 30-40 range, whereas the higher QTS driver like a Lambda 12 or 15 is still a reasonably high sensitivity, but does not show ANY driver rolloff down to nearly 20Hz. In this case you only need to overcome dipole rolloff and not that of the driver itself.
In my case, the baffle is approximately 22" wide around the Dipole 15, so its not getting much help there below 100 Hz, but I am only needing to add a 6dB/oct low shelf boosted by about 6dB staring at 80Hz. The Lambda is the way to go if you've got the $. Eminence Alphas show the high QTS of the Lambda, but have many other tradeoffs concerning other parameters that don't factor into the equation with top quality drivers like the Lambdas.
Greg
In my case, the baffle is approximately 22" wide around the Dipole 15, so its not getting much help there below 100 Hz, but I am only needing to add a 6dB/oct low shelf boosted by about 6dB staring at 80Hz. The Lambda is the way to go if you've got the $. Eminence Alphas show the high QTS of the Lambda, but have many other tradeoffs concerning other parameters that don't factor into the equation with top quality drivers like the Lambdas.
Greg
Yes, the Dipole15 or 12 are good candidates....but the price is high with four drivers.
I would explore others candidates and put the cost parameter with the others driver specifications, and then compare...at least in paper.
What about the Fs resonance frequency and the Xmax ?
And Mms? If the MMs is low I would have "faster" transient bass? This why I am looking the 12" for a better choice. Thx again
I would explore others candidates and put the cost parameter with the others driver specifications, and then compare...at least in paper.
What about the Fs resonance frequency and the Xmax ?
And Mms? If the MMs is low I would have "faster" transient bass? This why I am looking the 12" for a better choice. Thx again
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