Dipoles with a Direct twist

[Skoda]

Hello JBL fans:applaud:

As they say I'am on a misson... I have some desing ideas and were I want to go with this but I feel I need some insight on what to do for some maters (aka the do's and dont's of DIY dipoles with a direct mode;) )

Design Goals:-Have a footprint no bigger then 23''(H)x14''(w)7"(D)
-Meet the requirments for a THX certified dipole speaker
-Timber match my current system
-Amazing performce in not only performence in Ht but in DVD
Audio as well
-Be switchable from cinema mode to music remotely

Current system:-Pioneer VSX84TSX
-JBL HT4H (center)
-JBL HT4V (fronts)
-JBL E10's (to be replaced with this spectacular project
;), SR )
-JBL Tour (to be replaced by HT4V, SRB)

Drivers:-332241-001 (mid)
-336347-001 (tweeter)
-.......?........(woofer)
Horn:-Bi-Raidal 336363-001 (for tweeter)

As you can read its quite the misson:D but I got some snags... I dont have the white paper or datasheet not sure witch you call it:blink: So there for I need some generious member to provide some info, please:applaud: or I'll not be able to work out the tunning box freq and tweeter horn configuration.

For the low frequency driver I'am not sure what to use:blink: I had some Ideas of using some venue or possibly even an extra 332241-001 driver?

I'am also not sure if it would be wise to use 2xHT5 X-over's and wire them out of phase, or DIY it also

any inquiries, thoughts or pms:D are most certainly welcome:bouncy:

Skoda

[Skoda]

been making some progress with the project:)

I have recently ordered the 6 horns to make the image come true. I'am aiming for a 3way dipole speaker and switchable into bipole mode plus direct. the idea came from the S4A from the synthesis line.

The horn can be seen below.

[Skoda]

I have made a rough sketch of what the design goal is but not 100% sure the mid rang drivers should be placed, some what higher then the LF woofer,(still havent found a sutable driver yet but progress is being made;)) the mid range driver is coming from the HT line as well and wil be crossed over at 2.5khz as for as for the LF I was thinking 300hz, but havent seen any dipole speakers x-over at this frequincy, can some one elaborate on this?

woofer below

[Skoda]

I was planing on using the cross overs from the HT5 for the mid and HF and using a saperate passive x-over for the LF basicly Biamping. (block diagram below)

I've been looking at tech sheets for some time now and found that the performance series 8" driver looks well suited for the job along with project array ceneter channel's 8" driver. My last resort would be a GTO 8" from JBL's car audio department;) would any one possibly have the specs for the performance series 8"?

Best Regards :bouncy:
Skoda

[mikebake]

Sounds very ambitious, and expensive. Let us know how it turns out. Good luck.

[Skoda]

Thanks Mike, I'll keep you posted and forum members posted on my progress.

"epensive" well yes, and no. The project's expected cost is going to be around $1100-$1600 dollars CDN depending on which 8" drivers I think can get the job done:). Still will be half of what it would cost for any of the synthesis line dipoles:biting: $3600CDN for a pair of S4A and almost $4000 for the S1A's.

Though i find it defficult getting any information on dipoles or even DIY dipoles...:( There for not many have walked the plank:no:

Best Regards
Skoda

[Robh3606]

I am not sure as to which vintage Synthesis System you are looking at. This is the old version dipole with 2118J's. I thought about doing a switchable Dipole Monopole but never followed through. Just did regular surrounds for discrete DD/SACD and let it go at that.

http://manuals.harman.com/JBL/HOM/Technical%20Sheet/S1A%20SYNTHESIS%201%20ts.pdf


Rob:)

[Skoda]

I am not sure as to which vintage Synthesis System you are looking at. This is the old version dipole with 2118J's. I thought about doing a switchable Dipole Monopole but never followed through. Just did regular surrounds for discrete DD/SACD and let it go at that.

http://manuals.harman.com/JBL/HOM/Technical%20Sheet/S1A%20SYNTHESIS%201%20ts.pdf


Rob:)


:D Rob The S1A was the overral look I was going for sence I dont have to mount them in wall;) but with the S4A's features bipole,direct...etc

http://manuals.harman.com/JBL/HOM/Technical%20Sheet/S4A%20ts.pdf

picked up some wood today well, really hard wood flooring:D A bautiful 1 inch Birch with espresso color finish. Let the glueing begin:applaud:


Best Regards
Skoda:)

[Skoda]

heres A schematic of the polarity switch for tweeter B in monopole mode and shut off of tweeter B/C for direct mode. Took some time to figure it out, lets just say an assignment like this isn't meant for late nights;) :barf:


Best Regards
Skoda:p

[Zilch]

O.K., how about a little tutorial here:

Dipole?
Monopole?
Bipole?
Direct?

I'm clueless what this is about.

Also, what's that horn and tweeter from?

[I don't do HT.... :dont-know ]

[Skoda]

quote=Zilch;135923]O.K., how about a little tutorial here:

Dipole?
Monopole?
Bipole?
Direct?

I'm clueless what this is about.

Also, what's that horn and tweeter from?

[I don't do HT.... :dont-know ][/quote]

I'am sorry Zilch...:) monopole and Bipole are the same, shit...just gave me a complex, maybe?!?! they must be:p ok I'am 99% sure they are. Dipole is alone Dipole (not sure how far I have to go into explaining?)
and direct is of course your convensional speaker, or direct radiating some call it.

heres a link to a site that shows moving images of dipole, direct, bipole/monopole, etc. wave pattern

http://www.kettering.edu/~drussell/Demos/rad2/mdq.html

Best Regards
Skoda:)

[Skoda]

"Also, what's that horn and tweeter from?"

There from the HT series

http://jbl.com/home/products/series.aspx?SerId=HTE&Language=ENG&Country=CA&Region=USA

I beleiever there sound span(don't know the term for it:dont-know ) is 120degrees Width and 60degrees High

Still trying to figure out the quote system here...can't be that hard:blink:

Best Regards
Skoda

[Zilch]

S4S has different crossover frequencies for Dipole, Bipole, and Direct.

Bipole is three-way, apparently.

Dipole has no tweeter, and

Direct has no woofer?

I noticed phase reversals in the cinema layouts shown in the Pro tech references, but didn't understand what was happening there.

[Zilch]

I'am sorry Zilch...:) monopole and Bipole are the same, shit...Well, that sums up my difficulty.

They do that stuff purposely to keep me in the dark.

[I just KNOW it.... :p ]

[Skoda]

"direct has no woofer" correct it doesn't it's 2way from what you see but I've been having problems with finiding driver's with the specs to work out box peramiteurs, and if they did...too big a volume or port(s)

up till now I have not found a 8" driver that can have a 1k cross over, with the specs need to work out the box volumes.

"Dipole has not tweeter" I'am sure there is then why would the design incorperate 2 tweeters in a "dippersion box" (thats what I call it)

"I noticed phase reversals in the cinema layouts shown in the Pro tech references, but didn't understand what was happening there." Not sure what you were looking at:o: but if your referring to the synthesis line S1A, S2A I know what your talking about, personaly I think its a mistake because the spec sheet states the FR:100hz-17Khz

[Skoda]

here's a pic of an S4A to show what I was talking about "dippersion box"

[Skoda]

Here's a schematic of the mid range polarity switch, only mid range driver B is changing polarity for both direct mode and bipole mode sence it does the same thing for both modes I added 2 diodes to prevent undesired switching of the tweeter section.

Not sure if the .65 volts drop is going to be a problem for the 12 volt reallys:blink:

[Skoda]

been some time sence I've visited, but there has been progress :) have recently recieved the horns and the 3/4" birch hard wood is in the wood shop as we speak:applaud: whats left is to:

-pick the 8inch driver/ order it
-waiting for the 5 1/4" drivers
-waiting for the 1"titanium dome tweeters
-order compenets for the x-over's

[Zilch]

O.K., I have a bit of additional knowledge to share, though I forget now where I read it:

Dipole is for use in smaller rooms, where the full-blown THX surround scheme cannot be implemented. The reference was from several years ago, and there was not agreement whether the scheme was adequate.

In dipole mode, the forward and rearward firing pairs are connected out-of-phase with each other, so that sound eminating perpendicular to the side wall is cancelled; there's no direct radiation to the audience. Instead, it's intended to be reflected from the front and rear walls to create the surround "ambience."

Edit: See Figure 4. and related discussion here:

http://www.jblpro.com/pub/technote/tn_v3n03.pdf

[Skoda]

Zilch your right on the money which is why it is a great choice when in my situation given were your sittining the listening position is close(r) to the surround speaker(s) and is noitceable were the sound direction is coming from when using direct radiating speakers. So I plan to solve it with dipole speakers and wish to incoperate A direct radiating mode for when I'am the single person watching a movie in the sweet spot.

[Ian Mackenzie]

Go here for worthwhile infromation on dipoles.

http://www.linkwitzlab.com

[JBL 4645]

The outer-phase fires towards the back of the room while the in-phase fires forwards.

I was going to post a slightly long comment on this issue, but its all politics about direct VS dipolar or bipolar.:)

[Skoda]

JBL 4645 speak your mind, as there is no one stop place for information other then genral operation of this araingment of speakers and some personal thoughts about them couldn't hurt either:D as long as it doesn't to into a flaming argument that is;)