Flex Your PCD Mettle:

[Pete Schumacher]

Re: Need help with crossover

ThAnk you for the very clear and concise answer. I think I will go for the 12s. Do you get similar numbers modeling the td12s? I know we are talking posted numbers here.

Of course, every enclosure model is only one along an infinitely varied set of curves. That's one that looks quite reasonable.

[buzzforb]

Re: Need help with crossover

]I am going to try the Deltalite 2512. I am still keeping my eye on the TDwoofers, but for slightly large box and less money, I can get down as low and maintain more SPL headroom at low power levels. IF I like this, I will have to decide on goig with td12M in selaed box, crossed to TD15s/H sub or some other system. Really trying to keep the boxes small and in monitor format.
Deltallite 2512 in 3.5^ft box, tuned to 42Hz
Ae TD12s in 2.5^ft box, tuned to 36Hz
TD12vsDeltallite F3.pdfTD12vsDeltallite SPL.pdf

[Pete Schumacher]

Re: Need help with crossover

]I am going to try the Deltalite 2512. I am still keeping my eye on the TDwoofers, but for slightly large box and less money, I can get down as low and maintain more SPL headroom at low power levels. IF I like this, I will have to decide on goig with td12M in selaed box, crossed to TD15s/H sub or some other system. Really trying to keep the boxes small and in monitor format.
Deltallite 2512 in 3.5^ft box, tuned to 42Hz
Ae TD12s in 2.5^ft box, tuned to 36Hz
[ATTACH]39290[/ATTACH][ATTACH]39291[/ATTACH]

You really ought to check out DIYSoundgroup.org. I'm pretty sure they have a kit for the Deltalite 2512 there.

[carlspeak]

Re: Need help with crossover

...............

Econowaves in general are designed to be turned up, since they use pro drivers for the most part and are able to handle the power. However, they also have higher than average sensitivity which means you don't need a lot of power to get them playing pretty loud. What these woofers are able to do is deliver dynamics, uncompressed. That brings a lively quality to the music regardless the average SPL.

Zilch was a huge JBL fan and thus the econowave development gave DIY'rs a way to get great sound with highly efficient speakers at bargain prices relative to the likes of JBL. The key is you have to like that approach and 'west-coast sound' if you want to go that route.

[buzzforb]

Re: Need help with crossover

Yes, but i dont want the baffle or the passive components, as I am going active. I guess i should consider that having an active system will allow me to manipulate the woofer quite a bit, so maybe the Kappalite should be considered as well. I believe this was the favorite of Zilch in the variations he built, correct.

[Pete Schumacher]

Re: Need help with crossover

Yes, but i dont want the baffle or the passive components, as I am going active. I guess i should consider that having an active system will allow me to manipulate the woofer quite a bit, so maybe the Kappalite should be considered as well. I believe this was the favorite of Zilch in the variations he built, correct.

The "Deluxe" model used the Kappalite 3012LF, and I do think it may have been one of his favorites.

If you're going active, you need to be able to create a transfer function that mimics the passive crossover version. The textbook filters simply will not do what you need.

[buzzforb]

Re: Need help with crossover

Pete,
One last bothersome question. All things are relative and one of the factors in the decision of which speaker to build, is size. Using the two JBL monitors as a refernce point, I can build a box similar to jbl 4429 or one similar to jbl 4365. THe smaller one with Kappalite 3012LF or TD12s and the larger one with Altec 416 or TD15m. Horns will be sized accordingly. In your opinion and based on your experience, if the modeling program shows a similar response(disregarding final sensitivity level) will a woofer in a bigger box sound better than a woofer in a smaller box. The bigger box definitely has better group delay.

https://www.google.com/search?q=jbl+4429+box+size&source=lnms&tbm=isch&sa=X&ei=D50aUrbyBpWx4AO2poCwDw&ved=0CAkQ_AUoAQ&biw=1111&bih=538#fp=289d649f6a19ebc9&q=jbl+4429+living+room&tbm=isch&facrc=_&imgdii=_&imgrc=9UuqFVlE5zbgLM%3A%3BZcZBBltnKy5ViM%3Bhttp%253A%252F%252Fwww.trimira.com.au%252Fwp-content%252Fuploads%252Fjbl44291-e1367382506303.jpg%3Bhttp%253A%252F%252Fwww.trimira.com.au%252Fbrands%252Fjbl-studio%252F%3B600%3B450

https://www.google.com/search?q=jbl+4365+horn&source=lnms&tbm=isch&sa=X&ei=VZ0aUoP2K9bd4APQw4CABg&ved=0CAkQ_AUoAQ&biw=1111&bih=538#facrc=_&imgdii=_&imgrc=_V99EDQJLd6YmM%3A%3Bs8AVgPPzitTeZM%3Bhttp%253A%252F%252Fwww.h3.dion.ne.jp%252F~yamaden7%252FJBL4365c.jpg%3Bhttp%253A%252F%252Fwww.stereo.net.au%252Fforums%252Findex.php%253F%252Ftopic%252F52599-jbl-43xx-series-speakers-kenrick-sound%252Fpage-3%3B747%3B496

[Pete Schumacher]

Re: Need help with crossover

Pete,
One last bothersome question. All things are relative and one of the factors in the decision of which speaker to build, is size. Using the two JBL monitors as a refernce point, I can build a box similar to jbl 4429 or one similar to jbl 4365. THe smaller one with Kappalite 3012LF or TD12s and the larger one with Altec 416 or TD15m. Horns will be sized accordingly. In your opinion and based on your experience, if the modeling program shows a similar response(disregarding final sensitivity level) will a woofer in a bigger box sound better than a woofer in a smaller box. The bigger box definitely has better group delay.

https://www.google.com/search?q=jbl+...2F%3B600%3B450

https://www.google.com/search?q=jbl+...-3%3B747%3B496

The larger enclosure, using something like the TD15M, will offer incredibly palpable presentation, an effortless delivery of gut punching bass, and do so with as little as 50W behind them. There's just something about a 15" woofer that anything less just doesn't match.

[buzzforb]

Re: Need help with crossover

Oh the horror.
Was watvhing two JBL 2452-sL w/ aquaplus on EBay. THe way the seller had them presented, it looked like just the diaghrams, but was in fact a matched pair. I was in the mountains and had bad internet connection. I would have easily one them. THey sold for $610. Where is the crying emoticon.

[dtruck]

Re: Need help with crossover

The larger enclosure, using something like the TD15M, will offer incredibly palpable presentation, an effortless delivery of gut punching bass, and do so with as little as 50W behind them. There's just something about a 15" woofer that anything less just doesn't match.

I have some with TD15M. They sound pretty great I guess, but the driver has significant problems above ~900Hz. I mean "significant" as in it doesn't look like a high end driver above that because it develops a strange resonant ripple. Seems to be a combination of the cone-VC junction and the decoupling of the outer cone, but I certainly don't know. Pretty normal for a 15" to be not so good above 1kHz, but the lore is that this driver is magic and is good up to forever.

I've been using pretty steep slopes 1.3-1.4k, which works but is a real wrestling match to keep the HF happy, and get reasonable phase alignment, and pull it down enough to get bass. Speaking of which, the acoustic center is quite far forward for a 15". I guess my point is that I would go 3-way or choose a smaller driver if using AE again.

[Pete Schumacher]

Re: Need help with crossover

I have some with TD15M. They sound pretty great I guess, but the driver has significant problems above ~900Hz. I mean "significant" as in it doesn't look like a high end driver above that because it develops a strange resonant ripple. Seems to be a combination of the cone-VC junction and the decoupling of the outer cone, but I certainly don't know. Pretty normal for a 15" to be not so good above 1kHz, but the lore is that this driver is magic and is good up to forever.

I've been using pretty steep slopes 1.3-1.4k, which works but is a real wrestling match to keep the HF happy, and get reasonable phase alignment, and pull it down enough to get bass. Speaking of which, the acoustic center is quite far forward for a 15". I guess my point is that I would go 3-way or choose a smaller driver if using AE again.

I'm with you. Crossing a 15" above 700Hz would be ill advised, regardless how good the driver is. You'd need a beast of a compression driver to cross that low and a sizable guide to pull it off.

[gstarey66]

Re: Need help with crossover

Hello all,

Would like to ask a question about a Econowave Deluxe style speaker I am trying to build. Having trouble trying to decide on the size of the box to use and could use some suggestions. I did post on another site, but it is quite old, pretty inactive and I doubt will get a response anytime soon.

Drivers: B&C 15TBX100 woofer / DE250-8 tweeter / QSC HiR152 D.I. 90/40 horn / Box - Ported

Option 1: B&C suggests a 4 cubic foot box tuned to 35 hz with this woofer. Problem is when I graph this size box the low bass shows a pretty good positive bump at about 35 hz before response drops off. Also at about 45 hz Xmax is exceeded quite a bit.

Option 2: Now as I would prefer good transient response and accuracy over heavy bass, I have used my box program to look at a box size of 2.3 cubic foot tuned to 40 hz , the curve seems much smoother and does not exceed Xmax as well. Believe this would be more accurate, smoother and likely better transient response design, with a little less bass output.

Guess the question is, am I on the right track leaning towards option 2? I want these speakers to go low enough to work well stand alone with no subs at times.

Also if anyone has already done a crossover design that is working well for this combo of parts, would love to see what someone else is using. Looking at going with a active 24db/ crossover network I already have, but still thinking about it.

Regards, Greg

[NEO Dan]

Re: Need help with crossover

Hi,
If you want something along these lines there are a couple pre-engineered ways to go, DIY Sound Group has a couple kits and there are always the Pi Speakers offerings. Any of them will deliver the goods.

There is something to be said for component selection, not that there is anything wrong with what you've got picked out. However the woofer and the size of the QSC WG that dictate a low crossover point and the DE250 is probably not going to want to go that low at high power. And pushing the woofer to x-max is going to not sound nice in the mid range... Is this strictly an analog stereo setup or is there an AVR with bass management in the mix? That would/should open up some options IMO.

[gstarey66]

Re: Need help with crossover

Hello Dan,

Thanks for the response. I have looked at kits and looked intensely at the econowave deluxe speaker project. I do know that few speakers will crossover properly at 1khz the way this project intends and have selected the speakers accordingly. Also, while I want the capability to go loud, really don't expect to normally go over about twenty watts in my living room with speakers this efficient. While I rarely, if ever, expect to reach Xmax levels, I do want the design to prevent damage to the speakers by someone else cranking on the volume knob. Will probably start with the 4th order electronic crossover network in and work on a passive one after playing with that for a bit.

I do like the idea of kits, I started with heathkits, knight and dynaco kit years ago, have since built my own speakers, amps, pre-amps, headphone amp and a electronic 24db/octave 3-way crossover. Have learned some with every item.

Never really had the software to model while building a speaker before and its been over 15 years since last ones. Just looking to see if there are any pitfalls in what I am considering of using such a small ported box when the manufacturer is suggesting a much larger box.

Anyway, thanks for responding.

Regards,
Greg

[NEO Dan]

Re: Need help with crossover

What you propose is not going to work out well, the passive crossover also EQ's the response "flat", the natural response of the driver+horn/WG is not acceptable with just a high pass. 1 kHz is too low IMO, even the Four Pi is crossed over significantly higher.

I have a setup for the shop that is built to limit excursion to maintain clarity in the midrange, I the AVR to high pass at 100-110 Hz and the box is tuned in the 90's. I wear earplugs when I'm out there working so I tend to play it really LOUD. I run this from an amp that puts out just a bit more than 150v p-p, and I use all of it and then some. Excursion might get to 2-3mm p-p. The woofer will get warm if I run out of amp but the tweeter always stays cool.



If you want to crossover the CD that low and not sound like a Tina Turner cover band you need bigger gear.