JBL 2226H & EV DH1A w/HP940 [message #52585] |
Sun, 07 September 2008 20:28 ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
Mark BT
Messages: 4 Registered: May 2009
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Esquire |
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I recently purchased a couple of JBL 2226H's and EV DH1A's with HP940 horns, and am looking for guidance with regards to cabinet size, crossover(800Hz or 1.2kHz) and porting. I was referred to this site, "Wayne" specifically, by someone on diyaudio, "Take a look at the Pi speaker site I think Wayne still uses 2226's in the same configuration you want to use them in. Robh3606" I have seen some of the postings here and look forward to building a pair of, I believe they're called 4's? Your assistance is greatly appreciated. Mark ")
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Re: While we're waiting for Wayne... [message #52587 is a reply to message #52585] |
Mon, 08 September 2008 09:50 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
Bill Epstein
Messages: 1088 Registered: May 2009 Location: Smoky Mts. USA
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Illuminati (2nd Degree) |
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Looks like the EV does well to cross at 800 but some experimentation is in order 'cause the 2226 has such a wonderful mid-range. Higher might be better. The 4Pi is a 2.5 cu ft box tuned to 40 Hz but larger, up to 4 cu ft works well, too. Wayne will arrive eventually and you'll see, "you have mail", the plans and crossover schemas, that is. In the meantime, enjoy the Rap while we all wait for our Universe to come to an end tomorrow when the LHC comes on line
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Re: four π loudspeaker [message #52589 is a reply to message #52588] |
Mon, 08 September 2008 17:13 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
Mark BT
Messages: 4 Registered: May 2009
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Esquire |
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Hello Wayne, and thank you for replying so quickly. I would appreciate any assistance with regards to building a cabinet to properly load the 2226H(approx. 3 - 4 cubic feet) and a crossover to go with the EV DH1A/HP940 combo(i.e. box dimensions, bracing, horn placement, port size/placement, 1.2kHz crossover etc.). That is a lot to ask for, I know. And, after looking at the Pi speakers and reading reviews about them, I'm sure that I would be happy with something very similar. Is it possible to do this with the drivers I've chosen? Your assistance/guidance would be very much appreciated. Mark BT
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Re: While we're waiting for Wayne... [message #52590 is a reply to message #52587] |
Mon, 08 September 2008 17:19 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
Mark BT
Messages: 4 Registered: May 2009
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Esquire |
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Hello Bill Thanx for the input and the video...very cool. Can't wait to see if that particle 'thingy' blows a hole through the earth or not, or worse, opens a worm hole that can't be closed inviting all kinds of 'species' come out and start eating our brains...ahh, that's never going to happen! *shudders* Mark BT
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Matched directivity two-way loudspeakers [message #52593 is a reply to message #52589] |
Mon, 08 September 2008 23:01 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
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Wayne Parham
Messages: 18755 Registered: January 2001
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Illuminati (33rd Degree) |
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Like virtually every other compression driver + CD horn combo, HF rolloff is predictable, since power response falls off at 6dB/octave and horn directivity is constant. The goal of designers using a horn like this is to combine it with other drivers or horns that have matching directivity. You'll want to design the crossover and set baffle spacing for a forward axis normal to the baffle, with null angles preferably just outside the vertical pattern of the HF horn. Crossover frequency should be approximately where the midwoofer's pattern narrows to equal the tweeter's horizontal pattern. Summing should be flat on axis and at all angles within the pattern.This describes the basic approach. It isn't terribly difficult, but it isn't trivial either. I put a lot of time in each of my designs to make sure they are optimized. If you don't have measurement equipment, you can calculate phase angles and determine driver spacing to approximate crossover frequency and slope but this is rather tedious. For best results, you'll want to get the design close by calculation and verify with measurements, fine tuning as necessary.
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You've got mail! [message #52595 is a reply to message #52590] |
Mon, 08 September 2008 23:16 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
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Wayne Parham
Messages: 18755 Registered: January 2001
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Illuminati (33rd Degree) |
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I've sent plans for the four π loudspeaker. This will give you a starting point.To be very honest, my suggestion is to sell the EV drivers and horns on eBay and use the money to get H290 horns and B&C DE250 compression drivers. Then you can build four π speakers as designed with JBL 2226 woofers and DE250/H290 tweeter horns. This is not to say the horns/drivers you have are better or worse, although I will say the DE250 is a very good driver and the H290 horn is perfect for this application. But even if the EV DH1A/HP940 is also very good, it will still take a fairly substantial design effort to configure the crossover and speaker layout properly. It takes dozens, sometimes hundreds of man-hours to design and optimize a speaker like this, and that's if you've already done enough of them that they're practically a templated design. So even if you start with the four π plans and modify them, I would expect several full days work with a good measurement system to get everything right.
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Re: You've got mail! [message #52603 is a reply to message #52595] |
Wed, 10 September 2008 02:45 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to previous message](/forum/theme/AudioRoundTable/images/down.png) |
Mark BT
Messages: 4 Registered: May 2009
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Esquire |
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Thank you for sending the plans, Wayne. It IS a great starting point. It looks as though I've got a lot of work ahead of me, but I'm up for it. When they are complete, I'll post a few pics. I built some subs a few years back, loosely modelled on the EV TL440(driver compliment is EVX180B). They are 9 cubic foot boxes in black piano lacquer. I've got one in each end of the living room powered by a QSC amp. More than enough bass for this place, I know. They sound fine during movies(lots of thunderous bass for explosions, soundtracks and the like), but when I want to listen to a CD, it seems as though they are lacking in the bottom end(60Hz & 90Hz area) and I have to turn up the gain. There's still plenty of bass, mind you, but it seems as though there is something missing. I'll explain... I've swept them and find that there is plenty of bottom between 40Hz and 55Hz, then it drops(-2 or -3db) between 55Hz and 65Hz, comes back hard(+3 or +4db) at around 70Hz until 80Hz, then starts to roll off because of the crossover, at 100Hz. I also noticed plenty of cone movement between 30Hz and 37Hz but not much in the way of 'air movement' from the vents. (Nothing below 30Hz as I have anything below that cut with a filter) I contacted Electrovoice to ask if there was something I could do, but didn't get any help.(I understand, though) One techie I spoke with suggested "they may be peaking to high", and that I cover one of the two vents and shorten the other one to lower the tuning? I haven't tried this because the advice I DID get from someone else, suggested that I should use 2 vents at a minimum of 6" dia. I don't know, maybe I should just leave well enough alone? I just think there should be more air movement sometimes. If I do have any questions, comments or dirty jokes, I'll be sure to post them here. Thanx again! Mark BT
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