What to do with my 4699b

[Val]

I happily now own a pair of 4699b Cabaret Series speakers. They are in good shape. Now I'm trying to figure out what to do with them. I don't really have much opportunity for the "sound production" that these are designed for. I then begin to think about what it would take to convert these to decent home system. The only thing I come up with seems very expensive. I post my idea here as I'd love some feedback.

The problem is that the E155's and E110's are designed for sound production and not reproduction. So they are non-linear and add color by design. Great JBL Tech note explains this well:
http://www.cieri.net/Documenti/JBL/Technical Notes/JBL Technical Note - Vol.1, No.3.pdf

But the E155's and E110's can be reconed (or traded I suppose).

So here's the design goal: make a relatively small foot print DIY project for home listening

Convert/trade the E155's for 2245H's
Convert/trade the E110's for 2122's
Sell/trade the 2370 horn for 2344 butt cheek
Keep the 2426 (yep, it's the only component that would remain as-is)

Then build a small-as-possible cabinet:
2426+2344 on the top
2122 crossover at 1300Hz @ 12db/octave
2245H crossover at 290Hz @ 12db/octave

Sort of a cross between 4345 and 4430 monitor.

Thoughts?

[grumpy]

Thoughts?

Small as possible and 2245 seem to be at odds (8-9ft3 ?)
Seems a shame to pillage working drivers (can you even get 2245/2212 cone kits these days?)

Does seem like a workable group of drivers, once traded/converted... but no clear
template to follow (active bass/mid xover from 4345... mid/high xover from? ... ideas
could come from 4430/5, but an optimal integration would be completely DIY vs. a known
working example). How dirty do you want to get your hands? :)

[Lee in Montreal]

Keep those drivers. Calculate a box as big as possible for the bass driver. Make a smaller box for the mid and high drivers. Purchase a 3-way digital crossover and shape the sound to your liking.

The e155 as an Fs of 30Hz. Not bad. And it is a fast woofer with a low Qts of .20

At least that is what I would do. 10cft bass enclosure and a satellite on top.

You need one sheet of 4'x8' to build a 10cft cab. Plus some spares for bracings.

BTW Trading your e155 for some 2245 would be very positive thinking. Those are not in the same price range. I wouldn't pay more than $100 for an e155 while a 2245 commands $200.00 to $350.00 depending of shape.

[Val]

Small as possible and 2245 seem to be at odds (8-9ft3 ?)

You are right, even a "small" cabinet would probably end up being about 9 cu ft.



Seems a shame to pillage working drivers (can you even get 2245/2212 cone kits these days?)


I know, right? These have not seen heavy use and are in great shape and it would be a shame.


mid/high xover from?
1300 Hz is also from the 4345


How dirty do you want to get your hands? :)
Fairly dirty:blink:

[Val]

Keep those drivers. Calculate a box as big as possible for the bass driver. Make a smaller box for the mid and high drivers. Purchase a 3-way digital crossover and shape the sound to your liking.

The e155 as an Fs of 30Hz. Not bad. And it is a fast woofer with a low Qts of .20

At least that is what I would do. 10cft bass enclosure and a satellite on top.

You need one sheet of 4'x8' to build a 10cft cab. Plus some spares for bracings.

BTW Trading your e155 for some 2245 would be very positive thinking. Those are not in the same price range. I wouldn't pay more than $100 for an e155 while a 2245 commands $200.00 to $350.00 depending of shape.

I like the digital crossover idea, that would allow for experimenting.

[more10]

Keep those drivers. Calculate a box as big as possible for the bass driver. Make a smaller box for the mid and high drivers. Purchase a 3-way digital crossover and shape the sound to your liking.

Good thinking. I am very happy with my miniDSP 4x10 HD (http://www.minidsp.com/products/minidsp-in-a-box/minidsp-4x10-hd)

[Val]

Keep those drivers.

I would like to except for these two things. These speakers, in their current factory condition, do not sound good with recorded music (they do fine with live voice and band). And, after reading the JBL tech note in the first post above, I think I see why, they are not linear by design. I think some eq and different crossover freq might help, but the non-linearity is not addressed by either of those. I'm certainly open to more input on this but I remain unconvinced that the E series would ever be satisfactory home speakers. Anybody running E155/E110 in a home environment?


BTW Trading your e155 for some 2245 would be very positive thinking. Those are not in the same price range. I wouldn't pay more than $100 for an e155 while a 2245 commands $200.00 to $350.00 depending of shape.

I was afraid of that:(

[Val]

So it's been over 4 years since I updated this post...and the 4699B's are still looming in my garage. Lately I've started obsessing about what is the very smallest form factor cabinet I can build for these drivers. I also had the opportunity to hear some of Siegfried Linkwitz speakers which opened my eyes to dipole speakers.

I'm accepting the fact that E155/E110/2425 drivers are not designed for in home fidelity...but I own them and I'm getting the DIY bug!

I've put together a design concept (attached). Feel free to comment.

[turnitdown]

JBL specs the E155 in a 6 cu. ft. box tuned to 40Hz. That should give you great bass in room. Build a small box for the mid and set the horn on top. Use the factory crossover, then tune to taste. Those should sound just fine for hi-fi. They come with the promise of compromise, just like any other speaker OR add a sub and leave as is. The components are decent, the box is too small.

[Lee in Montreal]

Perhaps you can be inspired by Kef's famous 105 serie

Large bass bin and small "satellites" on top. Large box could do 30-80Hz. If you have a WAF factor to respect, then a cab is as big as what can be seen from the front. Therefore, if you make your narrow - let's say 21" wide and 24" deep by 36" tall - then you can end up with some serious volume. Yup. That's almost 10cft internal volume... ;-) But make it "only" 24 inch tall and it's a tad above 6cft. ;-)

https://s-media-cache-ak0.pinimg.com/originals/60/45/0c/60450c1fb960259659626b6f6909bcb5.jpg

[turnitdown]

Purty, and the best use of real estate AND social acceptance factor.

[1audiohack]

Hi Val;

While it’s true that producers are usually not linear like reproducers attempt to be, the E110 is quite linear save for it’s rising response and this is easily leveled with a single pole low pass filter.

While high efficiency drivers can be eq’d level, high efficiency cannot be eq’d into low efficiency drivers.

Thinking about Lee’s suggestion, a 2342 biradial horn is the same size as the E110 and they look great stacked together and are naturally very nearly time aligned.

That stackup E155, E110, 2426/2342 utilizing dsp like a dbx 260 or 360 with proper crossover, alignment and eq, the sound quality would surprize a lot of people. With some sub it would floor them.

The picture you posted could be great for reproducing percussion! I have thought about that style for an ambitious 24 track reproduction system,,, someday.
Barry.

[Earl K]

The E155 & E110 can't be considered as serious music reproducers primarily because of the metal dustcaps and the lighter cones ( the light cone manifesting it's presence in too low an MMS figure for low bass > for the BL figure ).

Both of the above factors are addressable to a great degree.

Dust-caps can be changed out for whatever JBL type goes along with the ( 2123 or 2122 ) & ( 2240 / 2245 ) > or slathered in revoable window caulking goop .

Cone weight can be added in the form of aquaplas ( or even some Hill-Billy Aquaplas by using something likeDuratex cabinet paint (https://www.amazon.com/Acry-Tech-DuraTex-Speaker-Cabinet-Textured/dp/B00M28DUSC) as a substitute ) .

Since your in California, I think it'd just be easier to give all 4 drivers to Ken ( Edgewound > since he has the aquaplas on-hand ) and ask him to make them as HiFi ready as possible .

I don't consider Xmax ( limitations ) as a deal killer here as long as the volume knob is kept in check ( & maybe using a higher overall box tuning on the 18" ) .

Just Saying my 2cents.

:)

[1audiohack]

JBL used the E110’s in the 4680? Line array used as speech reinforcement systems.

It’s funny that about half the audio club meeting I have attended the hosts avoid speech only like crazy. Funny.

I have never asked an audio club host to do this but a very interesting and revealing test of any speaker is an open quality vocal mic and your own voice. I do this as one of many tests with most all of my speaker creations nowdays.

If you band limit E110’s with a bit of signal shaping they are pretty amazing.

I am not saying the E series is intended for hifi but if ya gottem, rockem.

I have a bunch of E110’s. Also some E130’s with felt caps, pretty close to 2220’s.

Anyway I hope you have fun with that stuff.

Barry

[RMC]

Hi Val,

I wouldn't start with the idea of getting rid of everything (except 2426 as you mentioned) and build from scratch, but rather try to SAVE the present boxes with some improvements, considering things are in good condition. Yours must be a more recent edition of 4699B with a 2426, since the initial ones came with a 2425 compression driver (See Cabaret Series brochure 12/86). The more recent 4699B Technical Manual, 09/03, Rev. F I have mentions the 2426.

In practice, your "worst" sound reproduction offender may be the E-110 with its rising response and covering 500-2k hz (the boxe's two x-over freq.). It could be easier and cheaper to just replace the E-110 with another more suitable driver for mid reproduction, not necessarily from JBL because of availability/price. For thinner wallets, you may want to look at some Eminence or Peavey (USA) or Fane (UK) drivers for example. For thicker wallets, you can add B & C, RCF, 18 Sound, Faital Pro, etc.

Try to find a suitable and better behaved 10" first. This may do the trick with less work, hassle and money... Pack the E-110 and keep them for future use or in case you ever sell the boxes.

Don't be fooled by the 4699B's stated 103 db sensitivity rating in the Cabaret Series 12/86 brochure: JBL used the 4 ohms version of the E-155 to raise the sensitivity rating. Watts = voltage squared divided by resistance, or stated differently: W = V^2 / R or impedance. Therefore, the standard 2.83 volts used for sensitivity ratings will produce 2 watts in a 4 ohms load instead of 1 watt in the usual 8 ohms load... Double the power leads to 3 db more sensitivity! The 8 ohms version of the E-155 is rated at 100 db sensitivity according to E-Series Woofers brochure.

Moreover, the sensitivity ratings of JBL's E Series drivers is measured, as mentioned in the above brochure, between 500-2500 hz (leading to higher numbers with rising response), instead of the usual 100- 500 hz they normally use for low frequency drivers (e.g. 2225, 2235 spec sheets). When you cut through the impedance trick and the marketing, in real life you'll probably have an actual woofer sensitivity more around 95-97 db for the real low end below about 250 hz. That gives some hint for the type of sensitivity to look for in a replacement 10" driver. There's already an L-Pad on the compression driver according to the schematic of the x-over in the 4699B (See Technical Manual, 09/03, Rev. F).

This is interesting with regards to the choice of 10" drivers you may find, it opens up more doors to you. "Extreme" driver sensitivity ratings are often the attribute of non-linear or not as well behaved drivers... John Eargle of JBL called that "mid-band sensitivity" ratings in his Loudspeaker Handbook, as well as in his Handbook of Sound System Design. I fully agree with his expression. I'm more interested in real low end.

BTW I tried some quick modeling in Winspeakers software of the E-110 and E-155 to get some indication of the rising response Barry mentioned here for E-110, and have seen about + 2+ db > 200 hz for the E-110 and + 1 db > 250 hz for the E-155. The latter's doesn't appear to be the major concern to me, considering the following.

In my view, the E-155 crossed-over around 250 hz to a suitable more fidelity 10" driver should cure a good part of your reproduction issue and defeats most of the little rising response. Naturally, you'll need to consider baffle hole diameter, sensitivity, frequency response uniformity, acceptable range, power capacity, etc. "It goes without saying, but it goes better by saying it" as sage man Talleyrand said!

If money permits, you may even go the tri-amp way (Cabaret brochure says these are tri-amp ready), with EQ if need be, as other members have mentioned here, since that gives you more flexibility to match driver sensitivities and to decide on x-over frequencies you want/drivers can handle. Depending on the age of your 4699B cabinets, you may have to up-date some on-board x-over components anyway in the future...

Richard

[martin_wu99]

4628B,4698b,4699B are very good sound systems, do some modification on the crossovers,you will find they are very good home HIFI systems:D

[martin_wu99]

some body make it home HIFI system

[martin_wu99]

I happily now own a pair of 4699b Cabaret Series speakers. They are in good shape. Now I'm trying to figure out what to do with them. I don't really have much opportunity for the "sound production" that these are designed for. I then begin to think about what it would take to convert these to decent home system. The only thing I come up with seems very expensive. I post my idea here as I'd love some feedback.

The problem is that the E155's and E110's are designed for sound production and not reproduction. So they are non-linear and add color by design. Great JBL Tech note explains this well:
http://www.cieri.net/Documenti/JBL/Technical Notes/JBL Technical Note - Vol.1, No.3.pdf

But the E155's and E110's can be reconed (or traded I suppose).

So here's the design goal: make a relatively small foot print DIY project for home listening

Convert/trade the E155's for 2245H's
Convert/trade the E110's for 2122's
Sell/trade the 2370 horn for 2344 butt cheek
Keep the 2426 (yep, it's the only component that would remain as-is)

Then build a small-as-possible cabinet:
2426+2344 on the top
2122 crossover at 1300Hz @ 12db/octave
2245H crossover at 290Hz @ 12db/octave

Sort of a cross between 4345 and 4430 monitor.

Thoughts?
You'd better add a UHF(such as 2404/2405) on the top of your 4699B,and do some modification on the crossover,you will be satisfied by.......:D

[Val]

JBL specs the E155 in a 6 cu. ft. box tuned to 40Hz. That should give you great bass in room. Build a small box for the mid and set the horn on top. Use the factory crossover, then tune to taste. Those should sound just fine for hi-fi. They come with the promise of compromise, just like any other speaker OR add a sub and leave as is. The components are decent, the box is too small.

Existing cabs are about 9 cu ft. so 6 cu ft would be an improvement size-wise. Just wondering if anyone has any experience with non-tuned enclosures like H-Frame or W-Frame dipoles. I've built many tuned cabinets but never an open style. My interest is two fold; small size, and different, more open, sound.

79316

[Val]

Hi Val;

Thinking about Lee’s suggestion, a 2342 biradial horn is the same size as the E110 and they look great stacked together and are naturally very nearly time aligned.

That stackup E155, E110, 2426/2342 utilizing dsp like a dbx 260 or 360 with proper crossover, alignment and eq, the sound quality would surprize a lot of people. With some sub it would floor them.


I've always liked the look of the 2342...but I have to say that I've become a little obsessed with the Bella Luna Diamante approach...and I have a friend with a wood lathe I can use. I'm super curious as to how something like this would sound. So who has a Bella Luna Diamante in California?:) Of course the pictured Diamante uses custom designed drivers for this setup...the 2425/E110 would be quite different. Still, might be a fun project.

79317

[Val]

The E155 & E110 can't be considered as serious music reproducers primarily because of the metal dustcaps and the lighter cones ( the light cone manifesting it's presence in too low an MMS figure for low bass > for the BL figure ).

Both of the above factors are addressable to a great degree.

Dust-caps can be changed out for whatever JBL type goes along with the ( 2123 or 2122 ) & ( 2240 / 2245 ) > or slathered in revoable window caulking goop .

Cone weight can be added in the form of aquaplas ( or even some Hill-Billy Aquaplas by using something likeDuratex cabinet paint (https://www.amazon.com/Acry-Tech-DuraTex-Speaker-Cabinet-Textured/dp/B00M28DUSC) as a substitute ) .

Since your in California, I think it'd just be easier to give all 4 drivers to Ken ( Edgewound > since he has the aquaplas on-hand ) and ask him to make them as HiFi ready as possible .

I don't consider Xmax ( limitations ) as a deal killer here as long as the volume knob is kept in check ( & maybe using a higher overall box tuning on the 18" ) .

Just Saying my 2cents.

:)

Ok. I was not considering that I could add mass to these cones. Is low mass the reason for the aluminum dust cover? Interesting. I'm not sure I'm down with the Hill-Billy approach but I did follow that link:bouncy:

[Val]

If you band limit E110’s with a bit of signal shaping they are pretty amazing.


If I build something I will probably go the minidsp 4x10 route with tons of shaping...

[Val]

Yours must be a more recent edition of 4699B with a 2426, since the initial ones came with a 2425 compression driver (See Cabaret Series brochure 12/86).

I hope so, when I get a minute I'll pull the driver and take a look.


It could be easier and cheaper to just replace the E-110 with another more suitable driver for mid reproduction, not necessarily from JBL because of availability/price.

I hear you and agree with you, but, I like the challenge of holding to my design goal of smallest cabinet for these drivers. :)


In my view, the E-155 crossed-over around 250 hz ... If money permits, you may even go the tri-amp way

My 2405/375/LE15/2245 rig in the living room is quad-amped using a minidsp 4x10 so I would design these to connect to that rig for testing. That will allow trying different crossover frequencies.

[Val]

4628B,4698b,4699B are very good sound systems, do some modification on the crossovers,you will find they are very good home HIFI systems:D

I appreciate that! I'm impressed that you have those cabinets in the house. I couldn't swing that around here! :blink:

[turnitdown]

MAN! The speakers that have been sitting in the listening room. I was enamored with the Cabaret series for SR. They sounded nice at venue volumes. At home they were well-behaved at normal listening levels. You might try those just the way they are. With room reinforcement you may find they're just fine for you. When Henry Ford would have a meeting with someone at a restaurant, he would observe whether his guest/interviewee seasoned their food before tasting it and made judgements based on that. IOW - it's either - ready, fire aim or ready, aim, fire.

[martin_wu99]

MAN! The speakers that have been sitting in the listening room. I was enamored with the Cabaret series for SR. They sounded nice at venue volumes. At home they were well-behaved at normal listening levels. You might try those just the way they are. With room reinforcement you may find they're just fine for you. When Henry Ford would have a meeting with someone at a restaurant, he would observe whether his guest/interviewee seasoned their food before tasting it and made judgements based on that. IOW - it's either - ready, fire aim or ready, aim, fire.
The Cabaret series are real good speakers,they are real old-school sound which remind you of those old happy days,thanks to Mark Gander,the designer,please pay special attention to 4628B,because its woofer is just the same as DD55000:D

[martin_wu99]

I appreciate that! I'm impressed that you have those cabinets in the house. I couldn't swing that around here! :blink:
Why?you can,it definitely can be used in the house:D

[RMC]

Hi Val,

You'll be happy to know that JBL's recommended enclosure volumes for the E-155 are 3-8 cu. ft. ( 85-225 litres), according to JBL's E Series Instruction Manual, 2/81, P.5. Naturally, the box size you choose will determine along with tuning frequency how low you can go in the bass range...

I modeled quickly in Winspeakerz the 6 cu. ft./40 hz tuning box mentioned by another member and found in the JBL Enclosure Guide, but the result isn't that good bass wise with an early dropping response below 200 hz and - 3 db @ 50 hz or so. I also tried the same 6/40 box in WIN ISD 2016 Edition (but with a more standard QL 7 box losses number instead of Win Isd's too optimistic default number of QL 10. That way things can be honestly compared with Winspeakers results). Well, the outcome isn't nicer for the same box and tuning. Response is almost - 4 db @ 50 hz. And if tuned a little higher at 45 hz then you get a bit flatter with - 2.5+ db @ 50 hz.

You can get a better curve than these. All depends on how low do you really want to go and box size/tuning you can accept realistically... If I remember correctly, you mentioned before smallest box possible. This ain't a bad idea considering the E-155 very low Qts of 0.20 suitable for "small" boxes. But this is an 18" !

Based on JBL's above-mentioned Manual, 3 cu. ft. would be the minimum acceptable, but that may not be large enough to achieve the low-end response you may have in mind. Do you have an F3 number in mind or box size is the major guiding factor regardless of low frequency cut-off ?

Richard

[Val]

You'll be happy to know that JBL's recommended enclosure volumes for the E-155 are 3-8 cu. ft. ( 85-225 litres), according to JBL's E Series Instruction Manual, 2/81, P.5.

Hi Richard - Thank you for that reference doc. I had not seen it. I think I found my answer regarding an open/dipole configuration:
79342

Sounds like I'd risk damaging the driver.


If I remember correctly, you mentioned before smallest box possible. This ain't a bad idea considering the E-155 very low Qts of 0.20 suitable for "small" boxes. Based on JBL's above-mentioned Manual, 3 cu. ft. would be the minimum acceptable, but that may not be large enough to achieve the low-end response you may have in mind. Do you have an F3 number in mind or box size is the major guiding factor regardless of low frequency cut-off ?

Yes, size is the top design goal. I expect it won't go too low. I'm leaning towards a 3 cu ft reflex box. Thanks!

[RMC]

Hi Val,

I tried a quick modeling in Winspeakerz with a 3.1 cu. ft. net box (the minimum size in the E-series Instruction Manual for E-155) and different tuning frequencies. The best compromise this time seems to be with an Fb of 55 hz. Response would be pretty flat in the bass range and would lead to an F3 of about 58-59 hz, which is not so bad considering such a large driver in such a small box size.

The software tells me the vent would require two 5 in. diameter vents of 6.167 in. long to tune the box at 55 hz. In order to see if such a box size has enough "breathing space" for vent length I checked in the software what 3.1 net meant re internal dimensions and I got: 28.3"H, 17.5" W, 10.8" D. So enough space for vent length. However, on width the cabinet is probably too short for the driver diameter so you may have to adjust cabinet dimensions a little. Which would be done anyway considering the next paragraph below...

According to JBL the volume displaced by an 18" driver is 0.3 cu. ft. (8.5 L) which you'll need to add to box gross volume, as well as bracing and vent volumes and anything else inside the box, in order to get to a 3.1 NET when everything is in place in the box...

BTW with an F3 of about 58-59 hz you may want to add a little EQ around 60 hz and get a little stronger and deeper bass from that small cabinet since you're close to Fb and the vent helps re cone excursion. Bingo!

Richard

[Val]

Hi Val...

Richard - thank you for running those calculations!

[Lee in Montreal]

Sadly, tuning a box so high at 55Hz means that the driver will unload under that frequency. Over excursion at high volume. Considering that the driver has an FS_30, that would be a waste of a good driver for home duty. I'd think that if the max cab volume allowed in the living room by wifey is 3,5cft, perhaps another driver shall be used. Lets not forget that JBL's data are for SR, not necessarily sound reproduction. Tuning to 55hz means lotsa of boomy bass and no bottom end. Fine at the Barmitzvah or basement party, but perhaps not the best sounding. ;-)

[RMC]

Hi Val,

Lee should re-visit his vented-box knowledge. Any vented box will start unloading below tuning frequency, wether its tuned at 30 hz or 55 hz. This is why a high-pass filter somewhere below Fb is always recommended in using a vented vox, to minimize risk of over excursion.

An Fs at 30 hz in itself is almost meaningless if not associated with other relevant parameters such as Qts and Vas numbers which impact box size. And this is a good example with woofer Qts of 0.20 often leading to smaller boxes. The E-155 is not subwoofer class material for sure.

The objective here was to try to save the woofers in the context of Val's requirement of smallest box possible. SR is a form of sound reproduction as opposed to sound production.

Tuning at 55 hz lotsa boomy bass?? Lee should run some curves for himself in Winspeakerz or Win ISD Pro to verify his pretention... Bass does appear pretty flat in the software with that cab size and tuning. And, BTW, Win ISD author in the help files of his software and John Eargle of JBL (see * below) both indicate that modeling of a driver in software using T/S parameters already assumes one boundary (Half-space or 2 Pi) radiation into the room ( ground or wall placement). So no additionnal room reinforcement of the bass for such speaker placement alone, than what predicted by the software. More often than not, a single boundary speaker placement is the usual way its done.

In posts # 16-18 and # 26-27 Martin Wu has an opinion quite contrary to Lee's about the sound of these boxes. As for bottom end, it's knowingly limited by Val's box volume as indicated in post # 29...

Richard

* John Eargle, Loudspeaker Handbook, Chapman & Hall, 1997, P. 58; Handbook of Sound System Design, ELAR, 1989, P. 106.

[RMC]

Hi Val,

I also did a quick modeling of the E-155 in a 3.1 cu. ft. box tuned to 55 hz, using Win ISD Pro 2016 Edition with QL 7 as the usual box loss assumption, and here again there is NO bass bump in the low end. In fact, not only is the response quite reasonably flat, but it drops in the low- end a bit faster than with Winspeakerz.

Instead of the - 3 db @ 58-9 hz in Winspeakerz, WIN ISD gives me -4 db @ about 59 hz. Quite close from one software to another. As long as one compares apples with apples using QL 7 box loss in both programs as I did. So my post # 30 is still valid...

However, with regards to vent length (Winspeakerz: 2 X 5" dia. vents 6.167" long), WIN ISD gives longer vents for 2 X 5" dia. vents: 7.58 inches long. The difference may be explained by the different vent length math formula each software designer used. Therefore, my suggestion is to start with the longer vent lengths and reduce them by cutting- off small portions as need be to reach the target Fb. If you end-up with an Fb of say 57 hz don't lose sleep over that, WIN ISD tells me response will be even a bit flatter in the bass range... (up to Fb around 59 hz).

You can check box Fb by running test tones (e.g. 70 to 50 hz) to the woofer when the speaker is almost finalized and putting a finger lightly on the cone near the surround to feel which test tone frequency leads to least or no cone vibration, that corresponds to box tuning frequency (Fb).

You can seal temporarily around the vent on the inside of the box with modeling clay for example, while doing your Fb tests and when you get the result you want then replace the clay with permanent silicone around the vent on the inside of cabinet. Air- tight boxes (except for vent) are a MUST HAVE here.

BTW there are tons of ready-made Sound Reinforcement boxes on the market from known manufacturers with an F3 around 55-65 hz, including many with 12", 15" or 18" woofer in two or three-way configurations. Yours would certainly not be the odd ones. My previous EQ (with high-pass filter) and/or placement suggestions also remain relevant if need be. Regards,

Richard

[Val]

I appreciate the comments and calculations. For now, I'm planning on working on a cabinet design with no less than 3 cu ft for the E155...hopefully a bit bigger.

I do have a question about the 2342 horn mentioned below. I see they take the screw mount and my 2425 is a 3 bolt mount. Is there an adapter or a different version of the 2342?

Thanks,

g

[RMC]

Hi Val,

Your cabinet size MUST be (not hopefully) larger than 3.1 cu. ft. (net volume needed) to account for box air volume displaced by woofer, bracing, vents, etc (excluding soft fiberglass wool for example lining interior of box) otherwise your NET volume will be too small to deliver the performance the software modeling predicts...

As for your question, I don't have an answer at this point.

Richard

[dezmond]

Have you tried these with any tubes? Mine sound great with 6v6's or el34's.

[Val]

Have you tried these with any tubes? Mine sound great with 6v6's or el34's.

Sadly, no tube amps here