Planning to make a Bud inspired combo – what speaker? 6" or 8"?

[Gabor]

Both Eminence and Celestion offered neo 8” speakers about 15 years ago. I have one of each! I’m sure Eminence would be willing to provide them as EOM products in sufficient quantity. There are some unfavorable opinions about neo speakers in the guitar community which I suspect have more to do with the way early neo speakers were designed rather than an inherent deficiency in the material.

Eminence offers an neo 10” bass guitar speaker that weighs only 3.3 lb, but it’s about $155!
Celestion BN10-200X - Neodymium Bass Speaker

i do not believe 10, 12 inch speakers for jazz guitar amp.

We cut the bass from the signal with different tools, so what we are expecting to "give back" with a bigger speaker? That can not be a "body" because it is no longer in the signal. The only thing what this case a bigger speaker will do is make the signal sluggish.

[Herbie]

Do you have a material cost estimate of your project? I wonder, how it compares to the factory price... I also wonder how many workhours you plan to invest... (I am aware that mainly this is for fun, still...)

Priciest part is the speaker. Used ones go around for 60-80€. The wood is cheap. I have tolex and glue from previous projects. Handles and feet etc are below 20€.

In factory the priciest part is the work. And when I can do the work myself and enjoy it a lot, it is like having paid for my hobby.

(Of course I could use my extra time for rehearsing, but now and then it is nice to create something You can see and touch too!)

[Rograt]

i do not believe 10, 12 inch speakers for jazz guitar amp.

We cut the bass from the signal with different tools, so what we are expecting to "give back" with a bigger speaker? That can not be a "body" because it is no longer in the signal. The only thing what this case a bigger speaker will do is make the signal sluggish.

Something like that. A 12 inch speaker struggles with the upper mids and you end up with a scooped sound. I once had some hifi speakers from Celestion. They made these classic large 3 way speakers, the Ditton 44, employing a 12 inch woofer which were very popular. The ones I had, The Ditton 25, were a similar size but were designed for bass response so they featured a 12 inch woofer, a 12 inch passive radiator, two tweeters and a “super tweeter”. They were great at bringing the house down with Pink Floyd - The Wall but useless at anything else. It didn’t help that the cabinets had almost zero damping and vibrated like hell (not in a good way). Of course guitar speakers are designed to have a wide range but in my opinion a 12 inch speaker can’t replace a 10 inch speaker and vice versa. I play electric through two 4x12s - heaven.

[Herbie]

Oh boy, I started this thread because I was uncertain and a bit confused about the 'secret' of the Bud, but now I am even more confused!

Most players say that Bud 6 is great "for its size – but with 8" or 10" speaker it is even better". But has a Bud or a Bud extension cabinet with an 8" speaker even existed ever? Would the Bud be even more perfect with an 8" speaker?

Maybe I just should give a one more chance for my current 10" combo...

Thanks for everybody for the information and opinions!

[rpjazzguitar]

Long ago, I read a book on loudspeaker design. I don't recall much, but I do recall that speakers have characteristics (free air resonance was one thing mentioned) that interact with the cabinet shape and size, the port, and the tube leading to the port. The book had nomographs to present the relationships. The guitar/amp/EQ also matter. So, it's not just putting a speaker in a box. Others on here will know much more about the engineering aspects.

As it happens, the amps I use have 8" speakers. But, I used to use a 12" speaker and I was perfectly happy with it. I stopped because the amp/cab were too heavy, not because of any problem with the sound.

Many players like the Blu and Bud which have even smaller speakers (6 something inches). Rudy's music used a Bud to demo vintage D'Angelicos. (I did have a ZT Lunchbox with a 6 or so inch speaker which I didn't like, so I'm reluctant to go that small again, but there are pros I respect using the Blu or Bud).

So, I don't have a preference for speaker size. In a blindfold test, after the EQ was adjusted, I don't think I could tell them apart. Maybe not even without EQ adjustment.

I'd guess that the amp manufacturers test various configurations and eventually settle on one. I don't know how a hobbyist can duplicate that effort.

[Herbie]

Long ago, I read a book on loudspeaker design. I don't recall much, but I do recall that speakers have characteristics (free air resonance was one thing mentioned) that interact with the cabinet shape and size, the port, and the tube leading to the port. The book had nomographs to present the relationships. The guitar/amp/EQ also matter. So, it's not just putting a speaker in a box. Others on here will know much more about the engineering aspects.

As it happens, the amps I use have 8" speakers. But, I used to use a 12" speaker and I was perfectly happy with it. I stopped because the amp/cab were too heavy, not because of any problem with the sound.

Many players like the Blu and Bud which have even smaller speakers (6 something inches). Rudy's music used a Bud to demo vintage D'Angelicos. (I did have a ZT Lunchbox with a 6 or so inch speaker which I didn't like, so I'm reluctant to go that small again, but there are pros I respect using the Blu or Bud).

So, I don't have a preference for speaker size. In a blindfold test, after the EQ was adjusted, I don't think I could tell them apart. Maybe not even without EQ adjustment.

I'd guess that the amp manufacturers test various configurations and eventually settle on one. I don't know how a hobbyist can duplicate that effort.

Yeah, but in the end it might be mostly the hi-fi guys who need the calculations for their speaker cabinets. One of the biggest and oldest guitar speaker manufacturers, Celestion has an interesting text on Thiele-parameters in its site:

Thinking of using Thiele/Small parameters to design a guitar speaker cab? Think again... - Celestion

There is more in the text but here is some points:

"Using the Thiele Small parameters of a typical guitar speaker, you will find that halving or doubling the cabinet size makes minimal difference to the response.
The parameters have no relevance to open back cabinets.
Guitar speakers are not recommended for use in ported cabinets (as the increase in cone excursion below the tuning frequency can cause the thin paper edge of the cone to tear)."

I think that the calculations are in a bigger role when people try to make the small cabinets with small speaker to sound bigger and reproducing bass as easily as the larger speakers.

Eminence site tells that they don't give exact dimensions for the closed cabinets because they do not matter, the total volume of the enclosure is most important. The sizes of the vents and ports is where one needs calculations.

[rpjazzguitar]

My DV Mark Little Jazz has a rear port. I don't know if it is a ducted port.

[nevershouldhavesoldit]

"Guitar speakers are not recommended for use in ported cabinets"

Unfortunately, I don't think whoever wrote that understands guitars very well. You missed the most pertinent line in that paragaph - "Vented / tuned / ported boxes are not recommended for lead guitar". Does anyone on this forum ever use the term "lead guitar"?

Here's a more useful quote from Humbucker Music, a Dr Z dealer who says this on their website in reference to Dr Z cabs:

"- Advanced Porting - Porting is basically removing material from the speaker baffle in order to manipulate the way that air and sound travels in and out of the cab while the cab is in use. With porting, you get basically the best attributes of both closed and open back cabs. The benefits are the most apparent in the bass response of the cab. The Z-Best has one of the most powerful bass responses on the market, and even though it is a 2x12 cab, it moves every bit as much air as most 4x12's due to its porting."

The now infamous Ear Candy cabs are ported. The Mesa Boogie Thiele "closed back" 1x12 (the greatest of them all, in my experience) is ported. So are the Little Jazz and the Henriksen Bud and Blu. So are the classic RE jazz cabs. Etc etc etc. Those holes at the bottom are ports:

[Woody Sound]

Way back in the late 70's when I was cutting my teeth, I bought a new JBL K120-12. It came with a booklet with design plans for a cab, with specific cubic vol measurements/dimensions and port sizes. So I built a little closed-back ported single 12 cab accordingly. It was smaller than most open back single 12 cabs you see, barely larger around than the speaker. Well that cab just blew everything else away. I was playing some pretty loud, high energy fusion at the time. Beck, RTF, etc. Well that cab was the best cab I've ever used. Everyone was amazed by its small size and huge output. I used to put it on a restaurant tray stand. I was running a Music Man 130W tube head into it, and it was unbelievable.

I often wonder why all speakers don't come with instructions like that.

[Woody Sound]

So are the classic RE jazz cabs. Etc etc etc. Those holes at the bottom are ports:

And what's interesting is, there is a horizontal plank of plywood inside that divides the baffle and internal area from the narrow port section. It does not go all the way to the back. So, the air goes down and around the back of it to the ported section.

[nevershouldhavesoldit]

And what's interesting is, there is a horizontal plank of plywood inside that divides the baffle and internal area from the narrow port section. It does not go all the way to the back. So, the air goes down and around the back of it to the ported section.

And the internal baffling is part of the tuning process. It defines the circuitous path through which the back radiation from the driver(s) reaches the port(s). The length, taper, and cross-sectional shape and area of that acoustic wave guide determine the frequency response and characteristics of the bottom end.

The admonition in that quoted Celestion page warning against porting guitar speaker cabs is correct that mismatched drivers and ported cabs can cause cone and/or voice coil damage if driven hard down in the range below the tuned frequency of the system. But a well designed ported cab with a well chosen driver will have that point below the range of the instruments being amplified. Remember that the lowest fundamental from a 6 string guitar is 82 Hz. If the driver’s response starts to drop off at 100, the designed resonant point of the cab is 60 Hz, and the cone & voice coil are made of anything stronger than notepaper, it’ll work and sound fine.

You don’t see as many ported bass cabs because it’s harder to design them so that the port-determined peak is well below 41.2 Hz (the frequency of a low E), let alone the low B or C of a 5 or 6 string electric or an upright with a C foot. It takes better drivers in well designed cabs, so the good ones are generally more expensive. And most ported cabs trade sound quality for low end extension. The bottom is not as tight with a port as it is from a closed bass cab.

[Herbie]

Some months have ran under the bridges but I have not been lazy.
I stumbled across a used Eminence Beta 8A speaker for a good price and bought it. It gave me the scale of the amp: 10" x 10" x 10" aka 254 mm x 254 mm x 254 mm. Then I got the woods:



Then a bit thinking how to make the joint. After all I decided to reject the finger joint and determined to make 'lazy man's joints:



Slow progress but at the end I got it up:



Then glueing the tolex around and some development it the grille department. In the end it looks quite neat – at least from distance:







Not bad total weight!



And here it is with a reference point:



Total cost was about one hundred (100) euros, but I had the Quilter, tolex, handle etc already so I had to buy only the speaker and the woods.

But how does it sound? I don't know! I have to study it a bit. I have used to 12" speakers so this is totally something new to me.

I had it in one rehearsal already, tried it in the floor, tilted, lying on its back etc and I was not disappointed – but not overwhelmingly delighted. The bass was boomy when it was in the floor. Best sounds came when raised a bit, for example on a chair. On the other hand I have a tendency of being unsatisfied with my sound all the time.

My bandmates didn't notice the amp until the end of the session. "You sounded the same as usually, so we didn't wonder anything" they said!

Here is a poorly played comparison with a Quilter TB202 (Vintage sound on both) with a) this new one and b) a 12" Celestion Cream Alnico in Tweed cabinet.

I tried to make the adjustments so that they would sound good to me, but in the end they were almost the same: everything 'noonish'. Recorded with a iPhone 7.

Does this Qubic black amp sound like a jazz amp to You?

[ccroft]

First off: Nice work! That looks like a very capable and carry-able amp that makes a good jazz noise. I do like the 12 better, but I could have predicted that. I like 12's. My guitar speaker size journey looks something like:

7 years with a Fender Super - 10"
20 years with Mesa Mark0 - 12"
20 years with Mesa Caliber 22+ - 12"
2 years with Quilter Aviator 8. I wasn't happy until I put in on top of a 12" closed cabinet though.
6 years with TB202 in BlockDock 12 HD

I got a BlockDock 10 a few years ago and switched back & forth with the 12" for a while. The 12 won out, but I keep the 10 for the day that smallness is more important to me than sound/feel. In that case I think I'd prefer to have your little guy!

Along the way there was experience with several other amps owned by others. All plank guitars in the Fender/Boogie days. All archtops for the last 8 or 9. I never played any of these amps on the floor. They're on a chair or tilted (my current preference)

How much for that little guy shipped to Canada :-)

[Herbie]

First off: Nice work! That looks like a very capable and carry-able amp that makes a good jazz noise. I do like the 12 better, but I could have predicted that. I like 12's. My guitar speaker size journey looks something like:

7 years with a Fender Super - 10"
20 years with Mesa Mark0 - 12"
20 years with Mesa Caliber 22+ - 12"
2 years with Quilter Aviator 8. I wasn't happy until I put in on top of a 12" closed cabinet though.
6 years with TB202 in BlockDock 12 HD

I got a BlockDock 10 a few years ago and switched back & forth with the 12" for a while. The 12 won out, but I keep the 10 for the day that smallness is more important to me than sound/feel. In that case I think I'd prefer to have your little guy!

Along the way there was experience with several other amps owned by others. All plank guitars in the Fender/Boogie days. All archtops for the last 8 or 9. I never played any of these amps on the floor. They're on a chair or tilted (my current preference)

How much for that little guy shipped to Canada :-)

Thanks ccroft!

I too have a fixation about 12" speakers, maybe because I have played most of my playing life thru them and most of my favourite bands uses them, starting from AC/DC and Kenny Burrell. They just sound natural. I have tried to like 10"s, but nah. We'll see how long this 8" Gentle Giant stays in the game.

I checked the price of shipping this kinda thing (no, the combo is not for sale... at least yet!) to Canada. It would cost more than I paid for the materials of the cab (the Quilter not included)!

Canada... Your woods are burning, I saw in the news. Terrible. I hope Your place is safe – and out of the smoke!

[ccroft]

Thanks for your concern Herbie! Nothing much out here on the West Coast... yet. Fire season here is generally more like August/Sept. There's one up the Island a ways that's making havoc with one of the highways, but not seeing smoke down at the south end.

It's been fine the last couple of years. We had a serious smoke-out before that. Actually, a lot of it was from Washington and Oregon States. It's a bizarre experience. We had what NYC got. I lived there for a decade but never saw anything close to some of the recent pictures out of there.

As you probably know I already have and love the TB202. I like what you did with the speaker cab and the integration with my fave amp. Please keep us informed on how it works for you, especially if you try a gig with it.

Charles.

[Woody Sound]

Send that 8" combo to ME!

[Herbie]

Thanks for your concern Herbie! Nothing much out here on the West Coast... yet. Fire season here is generally more like August/Sept. There's one up the Island a ways that's making havoc with one of the highways, but not seeing smoke down at the south end.

It's been fine the last couple of years. We had a serious smoke-out before that. Actually, a lot of it was from Washington and Oregon States. It's a bizarre experience. We had what NYC got. I lived there for a decade but never saw anything close to some of the recent pictures out of there.

As you probably know I already have and love the TB202. I like what you did with the speaker cab and the integration with my fave amp. Please keep us informed on how it works for you, especially if you try a gig with it.

Charles.

”Fire season”, oh man. How I miss the Vivaldi’s original seasons!

Good to hear that You are safe. My niece lives in Vancouver and I hear about the local extreme weathers from her.

Today I read that the smoke from eastern Canada fires are already in Norway and in couple days here in Finland. Not as thick in NY, I hope!

I remember that You have found the TB202 too. I am still amazed how versatile amp it is.

The mistake I made with my 10” cab for TB202 was to try to make it all-round combo. In the end I didn’t like it in jazz nor in rock. Now with this 8” combo I can concentrate in jazz sounds only and I expect a lot from it.

[Herbie]

Last saturday I had two gigs with my band with this new combo. First was outdoor garden party and the second was a adult (60 years) birthday coffee party in a large old wooden country clubhouse.

The combo got along just perfectly. In the garden it was miked but in the clubhouse we just played as quietly as possible and I hope that everybody heard everything.

In the garden the eq and volume were about same as I had played home. In the clubhouse the room somehow exaggerated the bass frequencies so that I had to decrease the bass noticeably. But the TB202 has powerful eq knobs so no trouble.

And the traveling was a delight! The bag I found for the amp could take the amp stand, amp and a cooler bag for four 0,5 liter bottles of cold mineral water! Perfect!

[Herbie]

And the pics of the rig. Unfortunately I am not good at taking pics in the gigs. Somehow I just don’t remember.