Westlake HR-1's are now home

[Ken Pachkowsky]

Originally posted by MikeM
What you are noticing now will pry end up being better in the long run. those pry sound less thick on the lows which is better. get a Fast High current power amp and trust me the lows will no longer be and issue. $$ Good Luck. Im out of money. In 30 years at this Ive owned about 40 power amps all large 250 and above a side. You know what might be intresting to try on those would be ADCOM 555II for the lows. its lean controlled and dam powerful amp. ive had that amp put mono blocks to shame on lowed control and heck its only around 300. Also the 565 monos Ive had side to side with a 7000.00$ power amp and the lows were very close into 8 ohms.

Hmm, interesting, I have never tried an Adcom. In looking at the specs could be a great choice. 2 of them bridged would tickle the 2235's nicely. Damping factor of 800 would tighten them up very well.

Any other opinions out there?

Thanks Mike

[boputnam]

"Out of the 4350B data sheet the enclosure volumes are:
Low Frequency: 9.5 cubic foot"

I posted on a similar typo on another Thread - but the typo I referred to was the descriptions in the 1982 Pro brochure (page 5), wrt the 4345 and 4355 - the "Enclosure Volumes" are swapped.

JBL note the 4355 as 35-1/2 x 48-1/8 x 20 inches which = 19.2 ft3, NOT the quoted 9.5 ft3!!

9.5 ft3 is the enclosure volume for the 4345, and of this I am certain!

So, in the 4355, those paired 2235H's are given considerably more volume - appropriately so.

From the brochure - doh!

[4313B]

The Engineering Standard for the 4355 states the net effective volume for the dual 2235H's as 9.5 cubic feet.

The Engineering Standard for the 4345 states the net effective volume for the single 2245H as 9.0 cubic feet.

[PSS AUDIO]

Originally posted by boputnam
[I... in the 1982 Pro brochure (page 5), wrt the 4345 and 4355 - the "Enclosure Volumes" are swapped.

JBL note the 4355 as 35-1/2 x 48-1/8 x 20 inches which = 19.2 ft3, NOT the quoted 9.5 ft3!!

So, in the 4355, those paired 2235H's are given considerably more volume - appropriately so.

In a previous post I realized their typo error and I gave the real internal size of the 4350B cabinet and Giskard calculated then that the 4350/55 were tuned at 22 Hz (about)!

[4313B]

The 4350 and 4355 are tuned differently. The 22 Hz figure I came up with was mathematical and should not be used in place of actual measurement.

[boputnam]

The Engineering Standard for the 4355 states the net effective volume for the dual 2235H's as 9.5 cubic feet.

The Engineering Standard for the 4345 states the net effective volume for the single 2245H as 9.0 cubic feet

That may be, but the Brochure still misquotes the two Enclosure Volumes, wrt to the exterior dimensions - see that the 4345 is credited with 19 ft3. So, something got switched there.

Is the Engineering Standard for the 4355 at 9.5 cubic feet intended to be per transducer? If so, that might make some sense (2 x 9.5 = 19 ft3).

[4313B]

Engineering Standard = 9.5 cubic feet.
1976 Pro Catalog = 9.5 cubic feet.
1978 Pro Catalog = 9.5 cubic feet.
1980 Pro Catalog = 9.5 cubic feet.
1982 Pro Catalog = 9.5 cubic feet.

Without actually measuring the inside of the physical enclosure, the volume displacement of all the bracing, drivers, subenclosures, ports/ducts, networks, etc, the physical tuning and the physical port/duct configuration it's all just speculation.

"Is the Engineering Standard for the 4355 at 9.5 cubic feet intended to be per transducer? If so, that might make some sense (2 x 9.5 = 19 ft3)."

I can't imagine JBL ever placing these drivers in such enormous volumes. The actual measured frequency response curve doesn't support such a large volume either.

With the available data from 1981, BassBox 6 Pro speculates that the effective volume is ~ 13 cubic feet tuned to 28 Hz.

[PSS AUDIO]

Originally posted by Giskard
Without actually measuring the inside of the physical enclosure, the volume displacement of all the bracing, drivers, subenclosures, ports/ducts, networks, etc, the physical tuning and the physical port/duct configuration it's all just speculation.

Please read my previous post I gave all the inside measures!

[4313B]

Here:

http://www.danmarx.org/audioinnovation/impanalyzer.html

This is a great little way to measure your tuning frequency.

[MikeM]

Originally posted by Giskard
The Engineering Standard for the 4355 states the net effective volume for the dual 2235H's as 9.5 cubic feet.

The Engineering Standard for the 4345 states the net effective volume for the single 2245H as 9.0 cubic feet.

If you have frequency responce graphs on both the 4350 and 4355 you will see that the 4350 is tuned lower and has more output at and below 30HZ !!

[MikeM]

Originally posted by Ken Pachkowsky
Hmm, interesting, I have never tried an Adcom. In looking at the specs could be a great choice. 2 of them bridged would tickle the 2235's nicely. Damping factor of 800 would tighten them up very well.

Any other opinions out there?

Thanks Mike

I dont think the damping factor is all thats involved because Ive heard amps that are rated high that didnt sound like it. What I do is hunt buy low then use the amp and resell it. ive never taken a loss and have heard many amps. Anyway This amp moved the woofer cones like crazy without the thick mibass #$%^&&** of many. The 555II. The mids and highs are very FORWARD so biamping of whatever is in order. The 5500 is diffrent as the 5802 so dont expect the same from all. Heck im using a crown XLS602 that cranks fine. 244.00$ sounds 80% as good as my last mega buck amp. Im going biamping with tube highs again. Have fun.

[4313B]

Originally posted by MikeM
If you have frequency responce graphs on both the 4350 and 4355 you will see that the 4350 is tuned lower and has more output at and below 30HZ !!

Yes I do, thanks!

[boputnam]

I sent that 5234a away to have the cards custom made and installed. I never took the top off to see what he set them at. I suspect they are set flat. There was no need to check as I was very happy with the bass response.

Hey, Ken...

Just returned from a weekend overwrought with bluegrass / country and Cuervo, and had a chance to open-up that 5234A - as you suspected, the DIP's were in the factory "Flat" position. So, there are no clues there. Sorry, bud...

I'm outa ideas, and outa typo's to post, too!!

[Ian Mackenzie]

The issue would appear to be driving the 4 ohms load or lower presented by the two 2235s.

Why run both in parellel if you can use identical amps to feed each woofer individually? ie 4 x 300 watts

Not many hifi power amps are optimised for 4 ohms, either the output stage or the power supply, hence they can appear subjectively different. Some varieties are specified for peak voltage (on transients ) and may fold under 4 ohms.

Other amps with multiple stages lack stability in return for low distortion from gross negative feedback and can loose control of the woofer under certain conditions.

In the Pro area the Mackie amps and Crown will deliver into 4 ohms like crazy or even 2 ohms!! A good s/hand Crown would be useful with the Westlakes.

I have only used a Phase Linear 700B for a bass amp and it performs very well, the threashold of clipping is 450 watts per channel into 8 ohms and about 550 into 4 ohms. Damping factor is 1000 : 1 and is very stable, but fusing of woofers is recommended.

This model is verteran of the PA scene and is used widely by the most accomplished bass players macka

[Ian Mackenzie]

Heres a close up

macka